297 results on '"Mohan Edirisinghe"'
Search Results
2. Biomedical Efficacy of Garlic‐Extract‐Loaded Core‐Sheath Plasters for Natural Antimicrobial Wound Care
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Hamta Majd, Merve Gultekinoglu, Cem Bayram, Beren Karaosmanoğlu, Ekim Z. Taşkıran, Didem Kart, Özgür Doğuş Erol, Anthony Harker, and Mohan Edirisinghe
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antibacterial ,cell‐compatible ,garlic plasters ,naturopathic healthcare ,wound healing ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Abstract This work explores the application of Allium sativum (Garlic) extract, in the creation of novel polymeric core‐sheath fibers for wound therapy applications. The core‐sheath pressurized gyration (CS PG) technology is utilized to mass‐produce fibers with a polycaprolactone (PCL) core and a polyethylene oxide (PEO) sheath, loaded with garlic extract. The produced fibers maintain structural integrity, long‐term stability and provide a cell‐friendly surface with rapid antibacterial activity. The physical properties, morphology, therapeutic delivery, cytotoxicity, thermal and chemical stability of PCL, PEO, PEO/Garlic, Core‐Sheath (CS) PEO/PCL and PEO/Garlic/PCL fibers are analyzed. Findings show that the addition of garlic extract greatly increases the fibers’ thermal durability, while decreasing their diameter, thus improving cell adhesion and proliferation. In‐vitro release tests reveal a rapid release of garlic extract, which has significant antibacterial action against both Gram‐negative Escherichia coli (E. coli) and Gram‐positive Staphylococcus aureus (S. aureus) bacteria species. Cell viability experiments validate the fiber samples' biocompatibility and nontoxicity, making them appropriate for integrative medicine applications. These core‐sheath structures emphasize the potential of combining natural therapeutic agents with advanced material technologies to develop cost‐effective, sustainable and highly effective wound dressings, offering a promising solution to the growing concerns associated with conventional synthetic antibacterial agents.
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- 2024
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3. Tackling Data Scarcity Challenge through Active Learning in Materials Processing with Electrospray
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Fanjin Wang, Anthony Harker, Mohan Edirisinghe, and Maryam Parhizkar
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active learning ,machine learning ,materials development ,materials discovery ,small data ,Computer engineering. Computer hardware ,TK7885-7895 ,Control engineering systems. Automatic machinery (General) ,TJ212-225 - Abstract
Machine learning (ML) has been harnessed as a promising modelling tool for materials research. However, small data, or data scarcity, is a bottleneck when incorporating ML in studies involving experimentation. Current experiment planning methods show several disadvantages: one‐factor‐at‐a‐time (OFAT) experimentation became impractical due to limited laboratory resources; conventional design of experiments (DoE) failed to incorporate high‐dimensional features in ML; Surrogate‐based or Bayesian optimization (BO) shifted the goal to optimize material properties rather than guiding training data accumulation. The present research proposes leveraging active learning (AL) to strategically select critical data for experimentation. Two AL strategies, query‐by‐Committee (QBC) algorithm and Greedy method, are benchmarked against random query baseline on various materials datasets. AL is shown to efficiently reduce model prediction errors with minimal additional experiment data. Investigation of hyperparameters revealed benefits of applying AL at an early stage of experimental dataset construction. Moreover, AL is implemented and validated for an in‐house materials development task ‐ electrospray modelling. AL exploration as a paradigm is highlighted to guide experiment design for efficient data accumulation purposes, and its potential for further ML modelling. In doing so, the power of ML is expected to be fully unleashed to experimental researchers.
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- 2024
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4. Design and Fabrication of Sustained Bacterial Release Scaffolds to Support the Microbiome
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Anne Marie Klein, Nanang Qosim, Gareth Williams, Mohan Edirisinghe, and Rupy Kaur Matharu
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probiotics ,drug delivery ,microfibres ,bioactive fibres ,sustained release ,Pharmacy and materia medica ,RS1-441 - Abstract
Fibres in the micro- and nanometre scale are suited to a broad range of applications, including drug delivery and tissue engineering. Electrospinning is the manufacturing method of choice, but it has some limitations. Novel pressure-driven fibre-forming techniques, like pressurised gyration (PG), overcome these limitations; however, the compatibility of PG with biological materials has not yet been evaluated in detail. For the first time, this limitation of PG was investigated by optimising PG for microbial cell processing and incorporating bacterial cultures into fibrous polymeric scaffolds for sustained release. Multiple polymer–solvent systems were trialled, including polyvinylpyrrolidone (PVP)/phosphate-buffered saline (PBS) 25% w/v, polyethylene oxide (PEO)/PBS 20% w/v, and PVP/ethanol 20% w/v. Rheological studies revealed the surface tension of the PVP/PBS, PEO/PBS, and PVP/ethanol polymer–solvent systems to be 73.2, 73.9, and 22.6 mN/m, respectively. Scanning electron microscopy showed the median fibre diameters to be between 9.8 μm and 26.1 μm, with PVP producing larger fibres. Overnight Bacillus subtilis cultures were then incorporated into the chosen polymeric solutions and processed into fibres using PG. The produced cell-loaded fibres were incubated in LB broth to assess the cell viability of the encapsulated cells. Colony counts post-incubation showed the PVP/PBS 25% fibres resulted in 60% bacterial growth, and PEO/PBS 20% fibres led to 47% bacterial growth, whereas PVP/ethanol 20% fibres did not lead to any bacterial growth. Based on the results gathered during this study, it can be concluded that PG offers a promising way of encapsulating cells and other sensitive biological products while having many notable advantages compared to electrospinning. This research demonstrates proof of concept research-based evidence and showcases the potential of pressurised gyration as a key disruptive innovation in probiotic delivery system design and manufacturing.
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- 2024
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5. High Dose Progesterone Loaded PCL‐Polysorbate 80 Transdermal Fibers for Potential Application in Gynecological Oncology
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Omar Shafi, Saurabh Phadnis, Un Hou Chan, Mohan Edirisinghe, and Francis Brako
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drug release ,electrospinning ,functional biomaterials ,gynecology ,oncology ,palliative care ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Abstract Progesterone (P4), commonly administered in high doses for endometrial cancer palliative management, has limitations in current delivery systems. This preliminary in vitro drug release study introduces electrospun patches to offer a new perspective on P4 delivery. The study aimed to assess the influence of the surfactant polysorbate 80 (PS80) on the release of P4 from polycaprolactone (PCL) fibers. The PS80 effects are examined to inform the fine‐tuning of the fibre generation process. Patches developed, PCL wet (with PS80) and PCL dry (without PS80), showed encapsulation efficiencies of 76% and 42%, respectively. The dose levels studied are 6.1 mg for PCL wet and 4.4 mg for PCL dry samples. Molecular studies show that higher surfactant levels improved P4‐polymer mixing, enhancing dissolution and release rates. Patches with PS80 released 66% of the drug in 17 h, while those without released only 51%. Release data best fit the Weibull model, showcasing promise for these patches in transdermal P4 delivery. This study offers a non‐invasive option compared to traditional methods and underscores the need for further research to confirm the patches' clinical effectiveness for potential use in gynecological oncology.
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- 2024
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6. Micro‐ and Nanomanufacturing for Biomedical Applications and Nanomedicine: A Perspective
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Fanjin Wang, Anthony Harker, Mohan Edirisinghe, and Maryam Parhizkar
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healthcare ,micromanufacturing ,microparticles ,nanomanufacturing ,nanomedicine ,nanoparticles ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Almost a century's dedicated research into micro‐ and nanomaterials has yielded fruitful development of preparation methods, achieving fine control over product properties among a broad spectrum of materials. One critical application of these materials lies within the healthcare sector for diagnostic, prophylactic, and therapeutic purposes. However, bench‐to‐bedside translations are still hindered by some unmet demands, especially the scaling‐up from lab‐scale preparation to industry‐level production. The current review recapitulates the strategies of micro‐ and nanomaterial preparation from a holistic viewpoint. The similarities in synthesis and processing methods for various types of materials are highlighted. Furthermore, patents of commercialized nanomedicines are revisited to reveal a solid progress of micro‐ and nanomanufacturing in the last decade. In conclusion, further interdisciplinary research between fields in materials manufacturing is beneficial for the clinical translation and eventually unleashing the power of materials at small dimensions.
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- 2023
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7. A Global Challenge: Sustainability of Submicrometer PEO and PVP Fiber Production
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Manul Amarakoon, Shervanthi Homer‐Vanniasinkam, and Mohan Edirisinghe
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energy consumption ,green engineering ,manufacture ,polymeric fiber ,sustainability ,Technology ,Environmental sciences ,GE1-350 - Abstract
Abstract The field of submicrometer polymeric production currently has a predominant research focus on morphology and application. In comparison, the sustainability of the manufacture of submicrometer polymeric fibers, specifically the energy efficiency, is less explored. The principles of Green Chemistry and Green Engineering outline frameworks for the manufacture of “greener” products, where the most significant principles in the two frameworks are shown to be centered on energy efficiency, material wastage, and the use of non‐hazardous materials. This study examines the power consumption during the production of Polyethylene oxide (PEO) and Polyvinylpyrrolidone (PVP) submicrometer fibers under magnitudes of the key forming parameters to generate fibers via pressure spinning. The energy consumption, along with the fiber diameter, and production rate during the manufacture of fibers is predominantly attributed to the characteristics of polymeric solutions utilized.
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- 2023
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8. Pressurized Gyration: Fundamentals, Advancements, and Future
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Yanqi Dai, Jubair Ahmed, and Mohan Edirisinghe
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fibers ,mass production ,polymers ,pressure ,rotation ,Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Abstract As a facile, efficient, and low‐cost fiber manufacturing strategy, pressurized gyration/rotation (PG) is attracting tremendous attention. This review provides a comprehensive introduction to the working setups, fundamental principles, processing parameters, and material feed properties of this technology. The characterizations of products prepared by this technology and their wide application fields are summarized. The development potentials and broader application prospects of PG are discussed. PG holds significant promise for the scale‐up of ultrafine fiber manufacturing.
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- 2023
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9. Antiviral properties of porous graphene, graphene oxide and graphene foam ultrafine fibers against Phi6 bacteriophage
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Seda Gungordu Er, Tanveer A. Tabish, Mohan Edirisinghe, and Rupy Kaur Matharu
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graphene oxide ,porous graphene ,graphene foam ,antiviral ,nanofiber ,electrospinning ,Medicine (General) ,R5-920 - Abstract
As the world has experienced in the Coronavirus Disease 2019 pandemic, viral infections have devastating effects on public health. Personal protective equipment with high antiviral features has become popular among healthcare staff, researchers, immunocompromised people and more to minimize this effect. Graphene and its derivatives have been included in many antimicrobial studies due to their exceptional physicochemical properties. However, scientific studies on antiviral graphene are much more limited than antibacterial and antifungal studies. The aim of this study was to produce nanocomposite fibers with high antiviral properties that can be used for personal protective equipment and biomedical devices. In this work, 10 wt% polycaprolactone-based fibers were prepared with different concentrations (0.1, 0.5, 1, 2, 4 w/w%) of porous graphene, graphene oxide and graphene foam in acetone by using electrospinning. SEM, FTIR and XRD characterizations were applied to understand the structure of fibers and the presence of materials. According to SEM results, the mean diameters of the porous graphene, graphene oxide and graphene foam nanofibers formed were around 390, 470, and 520 nm, respectively. FTIR and XRD characterization results for 2 w/w% concentration nanofibers demonstrated the presence of graphene oxide, porous graphene and graphene foam nanomaterials in the fiber. The antiviral properties of the formed fibers were tested against Pseudomonas phage Phi6. According to the results, concentration-dependent antiviral activity was observed, and the strongest viral inhibition graphene oxide-loaded nanofibers were 33.08 ± 1.21% at the end of 24 h.
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- 2022
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10. Alleviating the toxicity concerns of antibacterial cinnamon‐polycaprolactone biomaterials for healthcare‐related biomedical applications
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Jubair Ahmed, Merve Gultekinoglu, Cem Bayram, Didem Kart, Kezban Ulubayram, and Mohan Edirisinghe
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antibacterial ,biomaterial ,cinnamon ,cytotoxicity ,fiber ,Medicine - Abstract
Abstract Fibrous constructs with incorporated cinnamon‐extract have previously been shown to have potent antifungal abilities. The question remains to whether these constructs are useful in the prevention of bacterial infections in fiber form and what the antimicrobial effects means in terms of toxicity to the native physiological cells. In this work, cinnamon extract containing poly (ε‐caprolactone) (PCL) fibers were successfully manufactured by pressurized gyration and had an average size of ∼2 μm. Cinnamon extract containing PCL fibers were tested against Escherichia coli, Staphylococcus aureus, Methicillin resistant staphylococcus aureus, and Enterococcus faecalis bacterial species to assess their antibacterial capacity; it was found that these fibers were able to reduce viable cell numbers of the bacterial species up to two orders of magnitude lower than the control group. The results of the antibacterial tests were assessed by scanning electron microscopy (SEM). The constructs were also tested under indirect MTT tests where they showed little to no toxicity, similar to the control groups. Additionally, cell viability fluorescent imaging displayed no significant toxicity issues with the fibers, even at their highest tested concentration. Here we present a viable method for the production the non‐toxic and naturally abundant cinnamon extracted fibers for numerous biomedical applications.
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- 2021
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11. MedComm ‐ Biomaterials and Applications announcement
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Mohan Edirisinghe and Zhiyong Qian
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Materials of engineering and construction. Mechanics of materials ,TA401-492 ,Medical technology ,R855-855.5 - Published
- 2022
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12. Severe Acute Respiratory Syndrome Type 2‐Causing Coronavirus: Variants and Preventive Strategies
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Mehmet Onur Aydogdu, Jennifer L. Rohn, Nazila V. Jafari, Francis Brako, Shervanthi Homer‐Vanniasinkam, and Mohan Edirisinghe
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COVID‐19 ,prevention ,severe acute respiratory syndrome type 2‐causing coronavirus ,spike protein mutations ,variant of concern ,Science - Abstract
Abstract COVID‐19 vaccines have constituted a substantial scientific leap in countering severe acute respiratory syndrome type 2‐causing coronavirus (SARS‐CoV‐2), and worldwide implementation of vaccination programs has significantly contributed to the global pandemic effort by saving many lives. However, the continuous evolution of the SARS‐CoV‐2 viral genome has resulted in different variants with a diverse range of mutations, some with enhanced virulence compared with previous lineages. Such variants are still a great concern as they have the potential to reduce vaccine efficacy and increase the viral transmission rate. This review summarizes the significant variants of SARS‐CoV‐2 encountered to date (December 2021) and discusses a spectrum of possible preventive strategies, with an emphasis on physical and materials science.
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- 2022
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13. Antimicrobial Fibrous Bandage-like Scaffolds Using Clove Bud Oil
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Carlota von Thadden, Esra Altun, Mehmet Aydogdu, Mohan Edirisinghe, and Jubair Ahmed
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clove bud ,anti-microbial ,bandages ,natural remedies ,commercial production ,Biotechnology ,TP248.13-248.65 ,Medicine (General) ,R5-920 - Abstract
Wounds are characterised by an anatomical disruption of the skin; this leaves the body exposed to opportunistic pathogens which contribute to infections. Current wound healing bandages do little to protect against this and when they do, they can often utilise harmful additions. Historically, plant-based constituents have been extensively used for wound treatment and are proven beneficial in such environments. In this work, the essential oil of clove bud (Syzygium aromaticum) was incorporated in a polycaprolactone (PCL) solution, and 44.4% (v/v) oil-containing fibres were produced through pressurised gyration. The antimicrobial activity of these bandage-like fibres was analysed using in vitro disk diffusion and the physical fibre properties were also assessed. The work showed that advantageous fibre morphologies were achieved with diameters of 10.90 ± 4.99 μm. The clove bud oil fibres demonstrated good antimicrobial properties. They exhibited inhibition zone diameters of 30, 18, 11, and 20 mm against microbial colonies of C. albicans, E. coli, S. aureus, and S. pyogenes, respectively. These microbial species are commonly problematic in environments where the skin barrier is compromised. The outcomes of this study are thus very promising and suggest that clove bud oil is highly suitable to be applied as a natural sustainable alternative to modern medicine.
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- 2022
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14. Videographic Analysis of Blink Dynamics following Upper Eyelid Blepharoplasty and Its Association with Dry Eye
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Felix H. W. Mak, PhD, Michelle Ting, FRCOphth, Matthew R. Edmunds, FRCOphth, Anthony Harker, MA, DPhil, Mohan Edirisinghe, FREng, Sirisha Duggineni, MBBS, Fabiola Murta, FRCOphth, and Daniel G. Ezra, MA, MD, FRCOphth
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Surgery ,RD1-811 - Abstract
Background:. This study was undertaken to characterize the effects of upper eyelid blepharoplasty on blink dynamics and to evaluate the hypothesis that changes in blink dynamics following blepharoplasty are associated with postoperative dry eye. Methods:. The voluntary blink of 14 eyes of 7 patients with dermatochalasis undergoing upper eyelid blepharoplasty was recorded with a high-speed camera preoperatively and 6–8 months postoperatively, alongside a group of 11 controls. The images were analyzed for palpebral aperture, blink duration, and maximum velocity during opening and closing phases. Patients undergoing blepharoplasty were assessed for dry eye symptoms pre- and postoperatively at 6–8 months using the ocular surface disease index score. Results:. Despite intraoperative orbicularis oculi resection, there was no significant compromise of blink duration or maximum velocity of eyelid opening or closure post-blepharoplasty. Postoperatively, patients had an increase in palpebral aperture compared with both preoperatively (8.71 versus 7.85 mm; P = 0.013) and control groups (8.71 versus 7.87 mm; P = 0.04). Postoperatively at 6–8 months, there was an increase in dry eye symptoms in 6 of 7 patients compared with preoperatively (ocular surface disease index, 16.6 versus 12.5; P < 0.05). There was no positive correlation between the increase in palpebral aperture and the increase in dry eye symptoms (r = –0.4; P = 0.30). Conclusions:. Using modern videographic technology, this study demonstrates that upper eyelid blepharoplasty results in an increase in resting palpebral aperture but has no effect on dynamic blink parameters. Changes in palpebral aperture or blink dynamics are unlikely to be the cause of dry eye syndrome following blepharoplasty.
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- 2020
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15. Generating Antibacterial Microporous Structures Using Microfluidic Processing
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Christina Katsakouli, Xinyue Jiang, Wai Keith Lau, Jennifer L. Rohn, and Mohan Edirisinghe
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Chemistry ,QD1-999 - Published
- 2019
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16. Effect of copolymer composition on particle morphology and release behavior in vitro using progesterone
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Yue Zhang, Talayeh Shams, Anthony Henry Harker, Maryam Parhizkar, and Mohan Edirisinghe
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Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
This study was aimed at improving dissolution rate and sustained release of progesterone by varying copolymer composition and polymer: drug ratio of PLGA. Drug-loaded particles were prepared using electrohydrodynamic atomization. The effects of polymer: drug ratio and copolymer composition on particle properties and in vitro drug-release profile were investigated. The physical form of the generated particles was determined via X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR). Drug release in vitro was found to be dependent on copolymer composition, where the release rate increased with decreased lactide content of PLGA. Particles produced with solutions of copolymer (75:25) had elongated shapes. In general, the obtained results indicated that the prepared microparticles were ideal carriers for oral administration of progesterone offering great potential to improve the dissolution rate of drugs that suffer from low aqueous solubility. Keywords: Electrohydrodynamic, Progesterone, Mathematical modelling, Drug delivery system
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- 2018
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17. Process Modeling for the Fiber Diameter of Polymer, Spun by Pressure-Coupled Infusion Gyration
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Xianze Hong, Anthony Harker, and Mohan Edirisinghe
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Chemistry ,QD1-999 - Published
- 2018
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18. Utilising Co-Axial Electrospinning as a Taste-Masking Technology for Paediatric Drug Delivery
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Hend E. Abdelhakim, Alastair Coupe, Catherine Tuleu, Mohan Edirisinghe, and Duncan Q. M. Craig
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co-axial electrospinning ,taste-masking ,Eudragit E PO ,Kollicoat Smartseal ,E-tongue ,chlorpheniramine maleate ,Pharmacy and materia medica ,RS1-441 - Abstract
The present study describes the use of two taste-masking polymers to fabricate a formulation of chlorpheniramine maleate for paediatric administration. Co-axial electrospinning was utilized to create layered nanofibres; the two polymers, Eudragit® E PO and Kollicoat® Smartseal, were alternated between the core and the shell of the system in order to identify the optimum taste-masked formulation. The drug was loaded in the core on all occasions. It was found that the formulation with Kollicoat® Smartseal in the core with the drug, and Eudragit® E PO in the shell showed the most effective taste-masking compared to the other formulations. These fibres were in the nano-range and had smooth morphology as verified by scanning electron microscopy. Solid-state characterization and thermal analysis confirmed that amorphous solid dispersions were formed upon electrospinning. The Insent E-tongue was used to assess the taste-masking efficiency of the samples, and it was found that this formulation was undetectable by the bitter sensor, indicating successful taste-masking compared to the raw version of the drug. The E-tongue also confirmed the drug’s bitterness threshold as compared to quinine HCl dihydrate, a parameter that is useful for formulation design and taste-masking planning.
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- 2021
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19. Evolution of self-generating porous microstructures in polyacrylonitrile-cellulose acetate blend fibres
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Suntharavathanan Mahalingam, Xiaowen Wu, and Mohan Edirisinghe
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Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Polyacrylonitrile (PAN), cellulose acetate (CA) and polyacrylonitrile - cellulose acetate (PAN-CA) fibres were formed in single and binary solvents which were subjected to gyration under pressure. Fibres in the diameter range 200–2000 nm were generated using a rotating speed of 36,000 rpm and a working pressure of 3 × 105 Pa. Long fibre morphologies with isotropic distribution of fibre orientation were obtained from PAN polymer solutions with a concentration of 5–15 wt%. Short fibre morphologies with anisotropic distribution of fibre orientation were produced for CA polymer solutions with a concentration of 25 wt% and below this concentration polygonal beads were generated. PAN-CA fibre bundles were generated and these showed remarkable self-generating porous characteristics when the working pressure was changed from 1 to 3 × 105 Pa. For comparison, porous PAN-CA fibres were also generated by solvent etching and porogen leaching techniques and in these the etching time and porogen concentration influenced the pore size of the generated fibres. Fourier transform infrared and Raman spectroscopies were performed to elucidate the bonding characteristics in the fibres. Release characteristics of the porous fibrous structures were studied using vanillin as the active ingredient. A mathematical model which allows the evaluation of the fibre diameter as a function of rotating speed and working pressure is presented and this helps to understand the solvent mass transfer taking place during fibre forming. Keywords: Polymer, Fibre, Composite, Porous, Self-generating, Pressure, Gyration
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- 2017
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20. Novel Preparation, Microstructure, and Properties of Polyacrylonitrile-Based Carbon Nanofiber–Graphene Nanoplatelet Materials
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Xiaowen Wu, Suntharavathanan Mahalingam, Amalina Amir, Harshit Porwal, Mike J. Reece, Valentina Naglieri, Paolo Colombo, and Mohan Edirisinghe
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Chemistry ,QD1-999 - Published
- 2016
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21. Comparative Study of the Antimicrobial Effects of Tungsten Nanoparticles and Tungsten Nanocomposite Fibres on Hospital Acquired Bacterial and Viral Pathogens
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Rupy Kaur Matharu, Lena Ciric, Guogang Ren, and Mohan Edirisinghe
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tungsten ,nanoparticles ,nosocomial infection ,antimicrobial ,tungsten oxide ,bacteria ,Chemistry ,QD1-999 - Abstract
A significant proportion of patients acquire hospital associated infections as a result of care within the NHS each year. Numerous antimicrobial strategies, such as antibiotics and surface modifications to medical facilities and instruments, have been devised in an attempt to reduce the incidence of nosocomial infections, but most have been proven unsuccessful and unsustainable due to antibiotic resistance. Therefore, the need to discover novel materials that can combat pathogenic microorganisms is ongoing. Novel technologies, such as the potential use of nanomaterials and nanocomposites, hold promise for reducing these infections in the fight against antimicrobial resistance. In this study, the antimicrobial activity of tungsten, tungsten carbide and tungsten oxide nanoparticles were tested against Escherichia coli, Staphylococcus aureus and bacteriophage T4 (DNA virus). The most potent nanoparticles, tungsten oxide, were incorporated into polymeric fibres using pressurised gyration and characterised using scanning electron microscopy and energy dispersive X-ray spectroscopy. The antimicrobial activity of tungsten oxide/polymer nanocomposite fibres was also studied. The results suggest the materials in this study promote mediation of the inhibition of microbial growth in suspension.
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- 2020
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22. A Portable Device for the Generation of Drug-Loaded Three-Compartmental Fibers Containing Metronidazole and Iodine for Topical Application
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Francis Brako, Chaojie Luo, Rupy Kaur Matharu, Lena Ciric, Anthony Harker, Mohan Edirisinghe, and Duncan Q. M. Craig
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trilayered fibers ,portable electrospinning ,wound dressing ,combination therapy ,compartmental drug delivery ,Pharmacy and materia medica ,RS1-441 - Abstract
The use of combination therapies for the treatment of a range of conditions is now well established, with the component drugs usually being delivered either as distinct medicaments or combination products that contain physical mixes of the two active ingredients. There is, however, a compelling argument for the development of compartmentalised systems whereby the release, stability and incorporation environment of the different drugs may be tailored. Here we outline the development of polymeric fine fiber systems whereby two drugs used for the treatment of wounds may be separately incorporated. Fibers were delivered using a newly developed handheld electrospinning device that allows treatment at the site of need. Crucially, the delivery system is portable and may be used for the administration of drug-loaded fibers directly into the wound in situ, thereby potentially allowing domiciliary or site-of-trauma administration. The three-layered fiber developed in this study has polyethylene glycol as the outermost layer, serving as a structural support for the inner layers. The inner layers comprised iodine complexed with polyvinylpyrrolidone (PVP) and metronidazole dispersed in polycaprolactone (PCL) as a slow release core. The systems were characterized in terms of structure and architecture using scanning electron microscopy, transmission electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy and diffractometry. As antibacterial creams are still used for managing infected wounds, the performance of our trilayered fiber was studied in comparison with creams containing similar active drugs. Drug release was measured by UV analysis, while antimicrobial efficiency was measured using agar diffusion and suspension methods. It was found that the trilayered systems, averaging 3.16 µm in diameter, released more drug over the study period and were confirmed by the microbacterial studies to be more effective against P. aeruginosa, a bacterium commonly implicated in infected wounds. Overall, the portable system has been shown to be capable of not only incorporating the two drugs in distinct layers but also of delivering adequate amounts of drugs for a more effective antibacterial activity. The portability of the device and its ability to generate distinct layers of multiple active ingredients make it promising for further development for wound healing applications in terms of both practical applicability and antimicrobial efficacy.
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- 2020
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23. Preparation, characterization and release kinetics of ethylcellulose nanoparticles encapsulating ethylvanillin as a model functional component
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Megdi Eltayeb, Eleanor Stride, and Mohan Edirisinghe
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Electrohydrodynamic processing ,Polymer ,Nanoparticles ,Functional component ,Controlled release ,Encapsulation efficiency ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Food grade polymeric nanoparticles have the potential to play a key role in the future of active component delivery which is an essential characteristic of functional foods. For this potential to be realized, it is important to study both the loading and release characteristics of the encapsulated material from the particle matrix as a function of particle size, material properties and processing conditions. In this study, ethylcellulose nanoparticles encapsulating ethylvanillin as a model active component were prepared by electrohydrodynamic processing. The mean particle size varied between 45 and 85 nm and the polydispersity index between 16 and 34%. The loading capacity and encapsulation efficiency ranged between 67 and 81% and 71 and 84%, respectively. It was found that the release rate was a function of both the nanoparticle size and structure, and hence of the composition and processing conditions. FT-IR analysis demonstrated that there was no degradation of the encapsulated material during processing or whilst encapsulated within the particle. It was therefore concluded that electrohydrodynamic processing was a suitable method for producing nanoparticles that can be readily tailored for the encapsulation and controlled release of specific active components to engineer the functional characteristics of food products.
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- 2015
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24. A comparison of methods to assess the antimicrobial activity of nanoparticle combinations on bacterial cells.
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Claire Bankier, Yuen Cheong, Suntharavathanan Mahalingam, Mohan Edirisinghe, Guogang Ren, Elaine Cloutman-Green, and Lena Ciric
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Medicine ,Science - Abstract
Bacterial cell quantification after exposure to antimicrobial compounds varies widely throughout industry and healthcare. Numerous methods are employed to quantify these antimicrobial effects. With increasing demand for new preventative methods for disease control, we aimed to compare and assess common analytical methods used to determine antimicrobial effects of novel nanoparticle combinations on two different pathogens.Plate counts of total viable cells, flow cytometry (LIVE/DEAD BacLight viability assay) and qPCR (viability qPCR) were used to assess the antimicrobial activity of engineered nanoparticle combinations (NPCs) on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria at different concentrations (0.05, 0.10 and 0.25 w/v%). Results were analysed using linear models to assess the effectiveness of different treatments.Strong antimicrobial effects of the three NPCs (AMNP0-2) on both pathogens could be quantified using the plate count method and flow cytometry. The plate count method showed a high log reduction (>8-log) for bacteria exposed to high NPC concentrations. We found similar antimicrobial results using the flow cytometry live/dead assay. Viability qPCR analysis of antimicrobial activity could not be quantified due to interference of NPCs with qPCR amplification.Flow cytometry was determined to be the best method to measure antimicrobial activity of the novel NPCs due to high-throughput, rapid and quantifiable results.
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- 2018
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25. Novel Preparation of Monodisperse Microbubbles by Integrating Oscillating Electric Fields with Microfluidics
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Anjana Kothandaraman, Anthony Harker, Yiannis Ventikos, and Mohan Edirisinghe
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microfluidics ,superimposed electric fields ,microbubbles ,CFD ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Microbubbles generated by microfluidic techniques have gained substantial interest in various industries such as cosmetics, food engineering, and the biomedical field. The microfluidic T-junction provides exquisite control over processing parameters, however, it relies on pressure driven flows only; therefore, bubble size variation is limited especially for viscous solutions. A novel set-up to superimpose an alternating current (AC) oscillation onto a direct current (DC) field is invented in this work, capitalising on the possibility to excite bubble resonance phenomenon and properties, and introducing relevant parameters such as frequency, AC voltage, and waveform to further control bubble size. A capillary embedded T-junction microfluidic device fitted with a stainless-steel capillary was utilised for microbubble formation. Furthermore, a numerical model of the T-junction was developed by integrating the volume of fluid (VOF) method with the electric module; simulation results were attained for the formation of the microbubbles with a particular focus on the flow fields along the detachment of the emerging bubble. Two main types of experiments were conducted in this framework: the first was to test the effect of applied AC voltage magnitude and the second was to vary the applied frequency. Experimental results indicated that higher frequencies have a pronounced effect on the bubble diameter within the 100 Hz and 2.2 kHz range, whereas elevated AC voltages tend to promote bubble elongation and growth. Computational results suggest there is a uniform velocity field distribution along the bubble upon application of a superimposed field and that microbubble detachment is facilitated by the recirculation of the dispersed phase. Furthermore, an ideal range of parameters exists to tailor monodisperse bubble size for specific applications.
- Published
- 2018
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26. Binary polymer systems for biomedical applications
- Author
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Ayda Afshar, Merve Gultekinoglu, and Mohan Edirisinghe
- Subjects
Mechanics of Materials ,Mechanical Engineering ,Materials Chemistry ,Metals and Alloys - Published
- 2022
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27. Nanofiber Based on Electrically Conductive Materials for Biosensor Applications
- Author
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Seda Gungordu Er, Alesha Kelly, Sumudith Bhanuka Warnarathna Jayasuriya, and Mohan Edirisinghe
- Abstract
Biosensors are analytical tools that enable the transmission of different signals produced from the target analyte to a transducer for the production of real-time clinical diagnostic devices by obtaining meaningful results. Recent research demonstrates that the production of structured nanofiber through various methods has come to light as a potential platform for enhancing the functionality of biosensing devices. The general trend is towards the use of nanofibers for electrochemical biosensors. However, optical and mechanical biosensors are being developed by functionalization of nanofibers. Such nanofibers exhibit a high surface area to volume ratio, surface porosity, electroconductivity and variable morphology. In addition, nanosized structures have shown to be effective as membranes for immobilizing bioanalytes, offering physiologically active molecules a favorable microenvironment that improves the efficiency of biosensing. Cost effective, wearable biosensors are crucial for point of care diagnostics. This review aims to examine the electrically conductive materials, potential forming methods, and wide-ranging applications of nanofiber-based biosensing platforms, with an emphasis on transducers incorporating mechanical, electrochemical and optical and bioreceptors involving cancer biomarker, urea, DNA, microorganisms, primarily in the last decade. The appealing properties of nanofibers mats and the attributes of the biorecognition components are also stated and explored. Finally, consideration is given to the difficulties now affecting the design of nanofiber-based biosensing platforms as well as their future potential.
- Published
- 2022
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28. Generating Lifetime-Enhanced Microbubbles by Decorating Shells with Silicon Quantum Nano-Dots Using a 3-Series T-Junction Microfluidic Device
- Author
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Bingjie Wu, C. J. Luo, Ashwin Palaniappan, Xinyue Jiang, Merve Gultekinoglu, Kezban Ulubayram, Cem Bayram, Anthony Harker, Naoto Shirahata, Aaqib H. Khan, Sameer V. Dalvi, and Mohan Edirisinghe
- Subjects
Silicon ,Microbubbles ,Lab-On-A-Chip Devices ,Microfluidics ,Quantum Dots ,Electrochemistry ,General Materials Science ,Serum Albumin, Bovine ,Surfaces and Interfaces ,Condensed Matter Physics ,Spectroscopy - Abstract
Long-term stability of microbubbles is crucial to their effectiveness. Using a new microfluidic device connecting three T-junction channels of 100 μm in series, stable monodisperse SiQD-loaded bovine serum albumin (BSA) protein microbubbles down to 22.8 ± 1.4 μm in diameter were generated. Fluorescence microscopy confirmed the integration of SiQD on the microbubble surface, which retained the same morphology as those without SiQD. The microbubble diameter and stability in air were manipulated through appropriate selection of T-junction numbers, capillary diameter, liquid flow rate, and BSA and SiQD concentrations. A predictive computational model was developed from the experimental data, and the number of T-junctions was incorporated into this model as one of the variables. It was illustrated that the diameter of the monodisperse microbubbles generated can be tailored by combining up to three T-junctions in series, while the operating parameters were kept constant. Computational modeling of microbubble diameter and stability agreed with experimental data. The lifetime of microbubbles increased with increasing T-junction number and higher concentrations of BSA and SiQD. The present research sheds light on a potential new route employing SiQD and triple T-junctions to form stable, monodisperse, multi-layered, and well-characterized protein and quantum dot-loaded protein microbubbles with enhanced stability for the first time.
- Published
- 2022
29. Alleviating the toxicity concerns of antibacterial cinnamon‐polycaprolactone biomaterials for healthcare‐related biomedical applications
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Kezban Ulubayram, Didem Kart, Merve Gultekinoglu, Jubair Ahmed, Cem Bayram, and Mohan Edirisinghe
- Subjects
biology ,Chemistry ,biomaterial ,Biomaterial ,Original Articles ,medicine.disease_cause ,biology.organism_classification ,Antimicrobial ,Enterococcus faecalis ,antibacterial ,Staphylococcus aureus ,Toxicity ,medicine ,cytotoxicity ,Medicine ,Original Article ,Food science ,Viability assay ,Fiber ,Escherichia coli ,cinnamon ,fiber - Abstract
Fibrous constructs with incorporated cinnamon‐extract have previously been shown to have potent antifungal abilities. The question remains to whether these constructs are useful in the prevention of bacterial infections in fiber form and what the antimicrobial effects means in terms of toxicity to the native physiological cells. In this work, cinnamon extract containing poly (ε‐caprolactone) (PCL) fibers were successfully manufactured by pressurized gyration and had an average size of ∼2 μm. Cinnamon extract containing PCL fibers were tested against Escherichia coli, Staphylococcus aureus, Methicillin resistant staphylococcus aureus, and Enterococcus faecalis bacterial species to assess their antibacterial capacity; it was found that these fibers were able to reduce viable cell numbers of the bacterial species up to two orders of magnitude lower than the control group. The results of the antibacterial tests were assessed by scanning electron microscopy (SEM). The constructs were also tested under indirect MTT tests where they showed little to no toxicity, similar to the control groups. Additionally, cell viability fluorescent imaging displayed no significant toxicity issues with the fibers, even at their highest tested concentration. Here we present a viable method for the production the non‐toxic and naturally abundant cinnamon extracted fibers for numerous biomedical applications., Cinnamon directly extracted into a polycaprolactone polymer base was spun with pressurized gyration to produce a high yield of cinnamon‐extracted bandage‐like fibers. These fibers where then characterized and tested for cytotoxity and antibacterial activity against Escherichia coli, Staphylococcus aureus, Methicillin Resistant Staphylococcus aureus and Enterococcus faecalis.
- Published
- 2021
30. Perspective: Covid-19; emerging strategies and material technologies
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Ursula Edirisinghe, Mohan Edirisinghe, Jubair Ahmed, and Hussain Alenezi
- Subjects
Coronavirus disease 2019 (COVID-19) ,Renewable Energy, Sustainability and the Environment ,business.industry ,Perspective (graphical) ,Human factors and ergonomics ,02 engineering and technology ,Public relations ,021001 nanoscience & nanotechnology ,01 natural sciences ,010305 fluids & plasmas ,Biomaterials ,Work (electrical) ,0103 physical sciences ,Health care ,Pandemic ,Ceramics and Composites ,Global health ,Original Article ,0210 nano-technology ,business ,Waste Management and Disposal ,Personal protective equipment - Abstract
It will be remembered in history as the event that brought the world together with science and technology; the COVID-19 pandemic has allowed for decades worth of progression in both healthcare policies and technology development. It has been a show of unprecedented global health policies ranging from the legal requirement for public facemask use to the use of tough movement restrictions that has bought the world’s economy to its knees. Here, we observe the impact of national lockdowns, facemask usage, and their effect on infection rates. It is clear that healthcare policies alone cannot tackle a pandemic. There is a huge pressure to develop personal protective equipment that not only has the capacity to prevent transmission but also has the ergonomics to be worn for long durations. In this work, we reveal our views and thoughts on the healthcare policies and developing materials and technology strategies that have contributed to reduce the damage of the pandemic, coming from the perspectives of materials scientists and a UK National Health Service consultant doctor.
- Published
- 2021
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31. Wholly Biobased, Highly Stretchable, Hydrophobic, and Self-healing Thermoplastic Elastomer
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Yeyen Nurhamiyah, Marie Finnegan, Amalina Amir, Biqiong Chen, Mohan Edirisinghe, and Efrosyni Themistou
- Subjects
chemistry.chemical_classification ,Condensation polymer ,Materials science ,Dimer acid ,02 engineering and technology ,Polymer ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Elastomer ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Polymerization ,chemistry ,Coating ,Polyamide ,engineering ,General Materials Science ,Thermoplastic elastomer ,Composite material ,0210 nano-technology - Abstract
Renewable polymers with excellent stretchability and self-healing ability are interesting for a wide range of applications. A novel type of wholly biobased, self-healing, polyamide-based thermoplastic elastomer was synthesized using a fatty dimer acid and a fatty dimer amine, both containing multiple alkyl chains, through facile one-pot condensation polymerization under different polymerization times. The resulting elastomer shows superior stretchability (up to 2286%), high toughness, and excellent shape recovery after being stretched to different strains. This elastomer also displays high room-temperature autonomous self-healing efficiency after fracture and zero water uptake during water immersion. The highly entangled main chain, the multiple dangling chains, the abundant reversible physical bonds, the intermolecular diffusion, and the low ratio of amide to methylene group within the elastomer are responsible for these extraordinary properties. The polymerization time influences the properties of the elastomer. The use of the optimal self-healing thermoplastic elastomer in anticorrosion coating, piezoresistive sensing, and highly stretchable fibers is also demonstrated. The elastomer coating prevents stainless-steel products from corrosion in a salty environment due to its superhydrophobicity. The elastomer serves as a robust flexible substrate for creating self-healing piezoresistive sensors with excellent repeatability and self-healing efficiency. The elastomer fiber yarn can be stretched to 950% of its original length confirming its outstanding stretchability.
- Published
- 2021
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32. Copolymer Composition and Nanoparticle Configuration Enhance in vitro Drug Release Behavior of Poorly Water-soluble Progesterone for Oral Formulations
- Author
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Upulitha Eranka Illangakoon, Mohan Edirisinghe, Christopher Thrasivoulou, Maryam Parhizkar, A. H. Harker, Rui Zhang, Yue Zhang, and C. J. Luo
- Subjects
Pharmaceutical Science ,Nanoparticle ,02 engineering and technology ,01 natural sciences ,Crystallinity ,chemistry.chemical_compound ,Drug Delivery Systems ,poly ,Polylactic Acid-Polyglycolic Acid Copolymer ,X-Ray Diffraction ,International Journal of Nanomedicine ,Spectroscopy, Fourier Transform Infrared ,Drug Discovery ,Copolymer ,poorly water-soluble drugs ,Original Research ,Drug Carriers ,Chemistry ,PLGA ,General Medicine ,lactide-co-glycolide ,oral formulations ,021001 nanoscience & nanotechnology ,Drug delivery ,0210 nano-technology ,coaxial electrospray ,Drug Compounding ,Biophysics ,Biological Availability ,Bioengineering ,progesterone ,010402 general chemistry ,Biomaterials ,Particle Size ,Fourier transform infrared spectroscopy ,copolymer ,Organic Chemistry ,Water ,core-shell nanoparticles ,0104 chemical sciences ,Bioavailability ,Drug Liberation ,Solubility ,Chemical engineering ,drug delivery ,Microscopy, Electron, Scanning ,Nanoparticles ,Pharmaceutics ,Spectrophotometry, Ultraviolet ,bioavailability - Abstract
Yue Zhang,1 Rui Zhang,1 Upulitha Eranka Illangakoon,1,2 Anthony Henry Harker,3 Christopher Thrasivoulou,4 Maryam Parhizkar,1,2 Mohan Edirisinghe,1 CJ Luo1 1Department of Mechanical Engineering, University College London, London WC1E 7JE, UK; 2UCL School of Pharmacy, University College London, London WC1N 1AX, UK; 3Department of Physics & Astronomy, University College London, London WC1E 6BT, UK; 4Cell & Developmental Biology, Division of Biosciences, University College London, London WC1E 6BT, UKCorrespondence: CJ Luo Tel +44 20 7679 3942Email chaojie.luo@ucl.ac.ukHypothesis: Developing oral formulations to enable effective release of poorly water-soluble drugs like progesterone is a major challenge in pharmaceutics. Coaxial electrospray can generate drug-loaded nanoparticles of strategic compositions and configurations to enhance physiological dissolution and bioavailability of poorly water-soluble drug progesterone.Experiments: Six formulations comprising nanoparticles encapsulating progesterone in different poly(lactide-co-glycolide) (PLGA) matrix configurations and compositions were fabricated and characterized in terms of morphology, molecular crystallinity, drug encapsulation efficiency and release behavior.Findings: A protocol of fabrication conditions to achieve 100% drug encapsulation efficiency in nanoparticles was developed. Scanning electron microscopy shows smooth and spherical morphology of 472.1± 54.8 to 588.0± 92.1 nm in diameter. Multiphoton Airyscan super-resolution confocal microscopy revealed core-shell nanoparticle configuration. Fourier transform infrared spectroscopy confirmed presence of PLGA and progesterone in all formulations. Diffractometry indicated amorphous state of the encapsulated drug. UV-vis spectroscopy showed drug release increased with hydrophilic copolymer glycolide ratio while core-shell formulations with progesterone co-dissolved in PLGA core exhibited enhanced release over five hours at 79.9± 1.4% and 70.7± 3.5% for LA:GA 50:50 and 75:25 in comparison with pure progesterone without polymer matrix in the core at 67.0± 1.7% and 57.5± 2.8%, respectively. Computational modeling showed good agreement with the experimental drug release behavior in vitro.Keywords: core-shell nanoparticles, oral formulations, bioavailability, drug delivery, poorly water-soluble drugs, progesterone, poly, lactide-co-glycolide, PLGA, copolymer, coaxial electrospray
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- 2020
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33. Self-assembled micro-stripe patterning of sessile polymeric nanofluid droplets
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Cem Bayram, Han Wu, Merve Gultekinoglu, Xinyue Jiang, Mohan Edirisinghe, and Kezban Ulubayram
- Subjects
Materials science ,Internal flow ,Drop (liquid) ,technology, industry, and agriculture ,Evaporation ,Coffee ring effect ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Volumetric flow rate ,Biomaterials ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Nanofluid ,chemistry ,Chemical engineering ,0210 nano-technology ,Ethylene glycol - Abstract
When sessile nanofluid droplets evaporate, solid nanoparticles can be organized in a wide variety of patterns on the substrate. The composition of the nanofluid, internal flow type of droplet and the rate of drying affect drop geometry, and the final pattern. Using poly(lactic-co-glycolic acid)-block-poly(ethylene glycol)(PLGA-b-PEG) as the example, we produced micro-stripe patterning from nanoparticles by drying of sessile fluid droplets. We investigated the nanoparticle properties and flow dynamics to clarify their effects on the patterning. Nanoparticles were prepared by hydrodynamic flow focusing using a T-junction microfluidic device with high production efficiency and the ability to generate an extremely narrow size distribution. PLGA-b-PEG was prepared as oil phase in acetonitrile and water/oil flow rate was changed from 1 to 3 at constant oil phase flow rate (50 μL/min). Then, nanofluid was collected on the surface as sessile droplets within acetonitrile/water binary dispersed phase. Depending on size, charge and size-distribution, the nanoparticles deposited on the surface exhibited various patterns. Dynamic Light and X-ray Scattering measurements showed that, approximately 100 nm particles with relatively low PDI (0.04) were produced for the first time in surfactant free conditions in a microfluidic device and they generated self-assembled ordered patterns, which are regulated by the type of internal flow in the sessile nanofluid droplet during sequential evaporation of acetonitrile and water.
- Published
- 2020
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34. Antibacterial Properties of Honey Nanocomposite Fibrous Meshes
- Author
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Rupy Kaur Matharu, Jubair Ahmed, Jegak Seo, Kersti Karu, Mitra Ashrafi Golshan, Mohan Edirisinghe, and Lena Ciric
- Subjects
Polymers and Plastics ,General Chemistry ,antibacterial ,fibres ,honey ,manuka ,nanocomposite ,composite polymer - Abstract
Natural substances are increasingly being developed for use in health-related applications. Honey has attracted significant interest, not only for its physical and chemical properties, but also for its antibacterial activity. For the first time, suspensions of Black Forest honeydew honey and manuka honey UMF 20+ were examined for their antibacterial properties against Escherichia coli and Staphylococcus epidermidis using flow cytometry. The inhibitory effect of honey on bacterial growth was evident at concentrations of 10, 20 and 30 v/v%. The minimum inhibitory effects of both honey types against each bacterium were also investigated and reported. Electrospray ionisation (ESI) mass spectrometry was performed on both Black Forest honeydew honey and manuka honey UMF 20+. Manuka honey had a gluconic concentration of 2519 mg/kg, whilst Black Forest honeydew honey had a concentration of 2195 mg/kg. Manuka honey demonstrated the strongest potency when compared to Black Forest honeydew honey; therefore, it was incorporated into nanofiber scaffolds using pressurised gyration and 10, 20 and 30 v/v% manuka honey-polycaprolactone solutions. Composite fibres were analysed for their morphology and topography using scanning electron microscopy. The average fibre diameter of the manuka honey-polycaprolactone scaffolds was found to range from 437 to 815 nm. The antibacterial activity of the 30 v/v% scaffolds was studied using S. epidermidis. Strong antibacterial activity was observed with a bacterial reduction rate of over 90%. The results show that honey composite fibres formed using pressurised gyration can be considered a natural therapeutic agent for various medicinal purposes, including wound-healing applications.
- Published
- 2022
35. Facile One-Pot Method for All Aqueous Green Formation of Biocompatible Silk Fibroin-Poly(Ethylene Oxide) Fibers for Use in Tissue Engineering
- Author
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Phoebe Louiseanne Heseltine, Cem Bayram, Merve Gultekinoglu, Shervanthi Homer-Vanniasinkam, Kezban Ulubayram, and Mohan Edirisinghe
- Subjects
Biomaterials ,Ethylene Oxide ,Tissue Engineering ,Biomedical Engineering ,Solvents ,Humans ,Water ,Fibroins ,Amides ,Polyethylene Glycols - Abstract
Silk fibroin (SF) fibers are highly regarded in tissue engineering because of their outstanding biocompatibility and tunable properties. A challenge remains in overcoming the trade-off between functioning and biocompatible fibers and the use of cytotoxic, environmentally harmful organic solvents in their processing and formation. The aim of this research was to produce biocompatible SF fibers without the use of cytotoxic solvents, via pressurized gyration (PG). Aqueous SF was blended with poly(ethylene oxide) (PEO) in ratios of 80:20 (labeled SF-PEO 80:20) and 90:10 (labeled SF-PEO 90:10) and spun into fibers using PG, assisted by a range of applied pressures and heat. Pure PEO (labeled PEO-Aq) and SF solubilized in hexafluoro-isopropanol (HFIP) (labeled SF-HFIP) and aqueous SF (labeled SF-Aq) were also prepared for comparison. The resulting fibers were characterized using SEM, TGA, and FTIR. Their in vitro cell behavior was analyzed using a Live/Dead assay and cell proliferation studies with the SaOS-2 human bone osteosarcoma cell line (ATCC, HTB-85) and human fetal osteoblast cells (hFob) (ATCC, CRL-11372) in 2D culture conditions. Fibers in the micrometer range were successfully produced using SF-PEO blends, SF-HFIP, and PEO-Aq. The fiber thickness ranged from 0.71 ± 0.17 μm for fibers produced using SF-PEO 90:10 with no applied pressure to 2.10 ± 0.78 μm for fibers produced using SF-PEO 80:10 with 0.3 MPa applied pressure. FTIR confirmed the presence of SF via amide I and amide II bands in the blend fibers because of a change in structural conformation. No difference was observed in thermogravimetric properties among varying pressures and no significant difference in fiber diameters for pressures. SaOS-2 cells and hFOb cell studies demonstrated higher cell densities and greater live cells on SF-PEO blends when compared to SF-HFIP. This research demonstrates a scalable and green method of producing SF-based constructs for use in bone-tissue engineering applications.
- Published
- 2022
36. Optimised Release of Tetracycline Hydrochloride from Core-Sheath Fibres Produced by Pressurised Gyration
- Author
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Hamta Majd, Anthony Harker, Mohan Edirisinghe, and Maryam Parhizkar
- Subjects
Pharmaceutical Science - Published
- 2022
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37. Core-sheath polymer nanofiber formation by the simultaneous application of rotation and pressure in a novel purpose-designed vessel
- Author
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Muhammet Emin Cam, Mohan Edirisinghe, Hussain Alenezi, Alenezi, Hussain, Cam, Muhammet Emin, and Edirisinghe, Mohan
- Subjects
chemistry.chemical_classification ,DAMAGE ,Materials science ,Scanning electron microscope ,General Physics and Astronomy ,THERMAL-PROPERTIES ,Polymer ,Confocal scanning microscopy ,Focused ion beam ,Polyvinyl alcohol ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Nanofiber ,ELECTROSPUN ,Composite material ,Spinning - Abstract
Forming polymeric core–sheath nanofibers is gaining prominence owing to their numerous potential applications, most notably in functional scenarios such as antiviral filtration, which is attracting significant attention due to the current COVID pandemic. This study has successfully designed and constructed a novel pressurized gyration vessel to fabricate core–sheath polymer nanofibers. Several water-soluble and water-insoluble polymer combinations are investigated. Both polyethylene oxide and polyvinyl alcohol were used as the core while both poly(lactic acid) (PLA) and poly(caprolactone) (PCL) were used as the sheath; PLA and PCL were used as core and sheath, in different instances; respectively. The fluid behavior of the core–sheath within the vessel was studied with and without applied pressure using computational fluid dynamics to simulate the core–sheath flow within the chamber. A high-speed camera was used to observe the behavior of jetted solutions at core–sheath openings, and the best scenario was achieved using 6000 rpm spinning speed with 0.2 MPa (twice atmospheric) applied pressure. The surface morphology of core–sheath fibers was studied using a scanning electron microscope, and focused ion beam milling assisted scanning electron microscopy was used to investigate the cross-sectional features of the produced fibers. Laser confocal scanning microscopy was also used to verify the core–sheath structure of the fibers, which were further characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. Thus, using a variety of polymer combinations, we show, both theoretically and experimentally, how core–sheath fibers evolve in a vessel that can serve as a scalable manufacturing pressurized gyration production process.
- Published
- 2021
38. Graphene‐Based Nanocomposites as Antibacterial, Antiviral and Antifungal Agents
- Author
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Seda Gungordu Er, Mohan Edirisinghe, and Tanveer A. Tabish
- Subjects
Biomaterials ,Biomedical Engineering ,Pharmaceutical Science - Abstract
Over the past decade, there have been many interesting studies in the scientific literature about the interaction of graphene-based polymeric nanocomposites with microorganisms to tackle antimicrobial resistance. These studies have reported variable intensities of biocompatibility and selectivity for the nanocomposites towards a specific strain, but it is widely believed that graphene nanocomposites have antibacterial, antiviral, and antifungal activities. Such antibacterial activity is due to several mechanisms by which graphene nanocomposites can act on cells including stimulating oxidative stress; disrupting membranes due to sharp edges; greatly changing core structure mechanical strength and coarseness. However, the underlying mechanisms of graphene nanocomposites as antiviral and antifungal agents remain relatively scarce. In this review, we summarize recent advances in the synthesis, functional tailoring, and antibacterial, antiviral, and antifungal applications of graphene nanocomposites. We first introduce the synthesis of graphene materials and graphene-based polymeric nanocomposites with techniques such as pressurized gyration, electrospinning, chemical vapor deposition, and layer-by-layer self-assembly. Then, we present the antimicrobial mechanisms of graphene membranes and demonstrate typical in vitro and in vivo studies on the use of graphene nanocomposites for antibacterial, antiviral, and antifungal applications. Finally, the review describes the biosafety, current limitations and potential of antimicrobial graphene-based nanocomposites. This article is protected by copyright. All rights reserved.
- Published
- 2023
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39. Polysorbate enhanced progesterone loaded drug diffusion from macromolecular fibrous patches for applications in obstetrics and gynaecology
- Author
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Omar Shafi, Mohan Edirisinghe, and Francis Brako
- Subjects
Pharmaceutical Science - Published
- 2023
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40. Enhanced efficacy in drug-resistant cancer cells through synergistic nanoparticle mediated delivery of cisplatin and decitabine
- Author
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RB Pedley, Maryam Parhizkar, Richard Browning, Jonathan C. Knowles, Eleanor Stride, Philip James Thomas Reardon, A. H. Harker, and Mohan Edirisinghe
- Subjects
Drug ,Combination therapy ,media_common.quotation_subject ,Decitabine ,Bioengineering ,02 engineering and technology ,Drug resistance ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Pharmacokinetics ,medicine ,General Materials Science ,media_common ,Cisplatin ,Chemistry ,General Engineering ,General Chemistry ,021001 nanoscience & nanotechnology ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,PLGA ,Cancer cell ,Cancer research ,0210 nano-technology ,medicine.drug - Abstract
There are several limitations with monodrug cancer therapy, including poor bioavailability, rapid clearance and drug resistance. Combination therapy addresses these by exploiting synergism between different drugs against cancer cells. In particular, the combination of epigenetic therapies with conventional chemotherapeutic agents can improve the initial tumour response and overcome acquired drug resistance. Co-encapsulation of multiple therapeutic agents into a single polymeric nanoparticle is one of the many approaches taken to enhance therapeutic effect and improve the pharmacokinetic profile. In this study, different types of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), matrix and core–shell (CS), were investigated for simultaneous encapsulation of a demethylating drug, decitabine, and a potent anticancer agent, cisplatin. It was shown that by altering the configuration of the CS structure, the release profile could be tuned. In order to investigate whether this could enhance the anticancer effect compared to cisplatin, human ovarian carcinoma cell line (A2780) and its cisplatin resistant variant (A2780cis) were exposed to free cisplatin and the CS–NPs. A better response was obtained in both cell lines (11% and 51% viability of A2780 and A2780cis, respectively) using CS–NPs than cisplatin alone (27%, 82% viability of A2780 and A2780cis, respectively) or in combination with decitabine (22%, 96% viability of A2780 and A2780cis, respectively) at equivalent doses (10 μM).
- Published
- 2020
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41. Environmental Impact of Polymer Fiber Manufacture
- Author
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Manul Amarakoon, Hussain Alenezi, Shervanthi Homer‐Vanniasinkam, and Mohan Edirisinghe
- Subjects
Polymers and Plastics ,General Chemical Engineering ,Organic Chemistry ,Materials Chemistry - Published
- 2022
- Full Text
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42. Facile One-Step Synthesis of PVDF Bead-on-String Fibers by Pressurized Gyration for Reusable Face Masks
- Author
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Ruiran Huang, Yanqi Dai, Jubair Ahmed, and Mohan Edirisinghe
- Subjects
Polymers and Plastics ,pressurized gyration ,polyvinylidene fluoride (PVDF) ,bead-on-string fiber ,fiber morphology ,β-phase ,hydrophobicity ,General Chemistry - Abstract
Single-use face masks pose a threat to the environment and are not cost-effective, which prompts the need for developing reusable masks. In this study, pressurized gyration (PG) successfully produced bead-on-string polyvinylidene fluoride (PVDF) fibers with fiber diameters ranging from 2.3 μm to 26.1 μm, and bead diameters ranging from 60.9 μm to 88.5 μm by changing the solution parameters. The effect of the solution parameters on the crystalline phase was studied by Fourier-transform infrared spectroscopy (FT-IR), where the β-phase contents of PG PVDF fibers reached over 75%. The fiber morphology and β-phase contents of PG PVDF fibers indicated the potential mechanical and electrostatic filtration efficiency of PG PVDF fibers, respectively. Additionally, the hydrophobicity was investigated by static water contact angle tests, and the PVDF fibers showed superior hydrophobicity properties (all samples above 125°) over commercial polypropylene (PP) single-use masks (approximately 107°). This study supports the notion that the PG PVDF fiber mats are a promising candidate for future reusable face masks.
- Published
- 2022
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- View/download PDF
43. Nozzle‐Pressurized Gyration: A Novel Fiber Manufacturing Process
- Author
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Yanqi Dai, Jubair Ahmed, Angelo Delbusso, and Mohan Edirisinghe
- Subjects
Polymers and Plastics ,General Chemical Engineering ,Organic Chemistry ,Materials Chemistry - Published
- 2022
- Full Text
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44. Exploiting the antiviral potential of intermetallic nanoparticles
- Author
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Lena Ciric, Mohan Edirisinghe, Rupy Kaur Matharu, Yuen-Ki Cheong, and Guogang Ren
- Subjects
Silver ,viruses ,Intermetallic ,medicine.disease_cause ,Biomaterials ,Bacteriophage ,chemistry.chemical_compound ,Bacteriophage MS2 ,medicine ,Alloys ,Antiviral ,Waste Management and Disposal ,Escherichia coli ,Composites ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,RNA ,RNA virus ,DNA virus ,biology.organism_classification ,Virology ,Zinc ,Ceramics and Composites ,Nanoparticles ,Original Article ,DNA ,Copper - Abstract
Abstract Viral pandemic outbreaks cause a significant burden on global health as well as healthcare expenditure. The use of antiviral agents not only reduces the spread of viral pathogens but also diminishes the likelihood of them causing infection. The antiviral properties of novel copper-silver and copper-zinc intermetallic nanoparticles against Escherichia coli bacteriophage MS2 (RNA virus) and Escherichia coli bacteriophage T4 (DNA virus) are presented. The intermetallic nanoparticles were spherical in shape and were between 90 and 120 nm. Antiviral activity was assessed at concentrations ranging from 0.05 to 2.0 wt/v% for 3 and 24 h using DNA and RNA virus model organisms. Both types of nanoparticles demonstrated strong potency towards RNA viruses (> 89% viral reduction), whilst copper-silver nanoparticles were slightly more toxic towards DNA viruses when compared to copper-zinc nanoparticles. Both nanoparticles were then incorporated into polymeric fibres (carrier) to investigate their antiviral effectiveness when composited into polymeric matrices. Fibres containing copper-silver nanoparticles exhibited favourable antiviral properties, with a viral reduction of 75% after 3 h of exposure. The excellent antiviral properties of the intermetallic nanoparticles reported in this study against both types of viruses together with their unique material properties can make them significant alternatives to conventional antiviral therapies and decontamination agents.
- Published
- 2021
45. Accelerated diabetic wound healing by topical application of combination oral antidiabetic agents-loaded nanofibrous scaffolds: An in vitro and in vivo evaluation study
- Author
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Sumeyye Cesur, Levent Kabasakal, Büşra Ertaş, Oguzhan Gunduz, Zehra Demirbas, Christina Katsakouli, Ceyda Ekentok, Ece Guler, Ayse Nur Hazar-Yavuz, Hussain Alenezi, Gul Sinemcan Ozcan, Muhammet Emin Cam, Mehmet S. Eroglu, Dilek Akakin, Mohan Edirisinghe, Cam, Muhammet Emin, Ertas, Busra, Alenezi, Hussain, Hazar-Yavuz, Ayse Nur, Cesur, Sumeyye, Ozcan, Gul Sinemcan, Ekentok, Ceyda, Guler, Ece, Katsakouli, Christina, Demirbas, Zehra, Akakin, Dilek, Eroglu, Mehmet Sayip, Kabasakal, Levent, Gunduz, Oguzhan, and Edirisinghe, Mohan
- Subjects
Materials science ,food.ingredient ,Combination therapy ,METFORMIN ,Diabetic wound healing ,Nanofibers ,FABRICATION ,Bioengineering ,02 engineering and technology ,Pharmacology ,010402 general chemistry ,01 natural sciences ,Gelatin ,PPAR ,Diabetes Mellitus, Experimental ,Biomaterials ,Chitosan ,Glibenclamide ,chemistry.chemical_compound ,Mice ,DELIVERY ,food ,Dermis ,Pressurized gyration ,In vivo ,HYPERGLYCEMIA ,medicine ,Animals ,Hypoglycemic Agents ,Fibroblast ,CHITOSAN ,Wound Healing ,Tissue Scaffolds ,Pioglitazone ,Electrospinning ,RECEPTOR ,GELATIN ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Rats ,medicine.anatomical_structure ,chemistry ,Mechanics of Materials ,Drug delivery ,0210 nano-technology ,medicine.drug - Abstract
The combination of oral antidiabetic drugs, pioglitazone, metformin, and glibenclamide, which also exhibit the strongest anti-inflammatory action among oral antidiabetic drugs, were loaded into chitosan/gelatin/polycaprolactone (PCL) by electrospinning and polyvinyl pyrrolidone (PVP)/PCL composite nanofibrous scaffolds by pressurized gyration to compare the diabetic wound healing effect. The combination therapies significantly accelerated diabetic wound healing in type-1 diabetic rats and organized densely packed collagen fibers in the dermis, it also showed better regeneration of the dermis and epidermis than single drug-loaded scaffolds with less inflammatory cell infiltration and edema. The formation of the hair follicles started in 14 days only in the combination therapy and lower proinflammatory cytokine levels were observed compared to single drug-loaded treatment groups. The combination therapy increased the wettability and hydrophilicity of scaffolds, demonstrated sustained drug release over 14 days, has high tensile strength and suitable cytocompatibility on L929 (mouse fibroblast) cell and created a suitable area for the proliferation of fibroblast cells. Consequently, the application of metformin and pioglitazone-loaded chitosan/gelatin/PCL nanofibrous scaffolds to a diabetic wound area offer high bioavailability, fewer systemic side effects, and reduced frequency of dosage and amount of drug.
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- 2021
46. The effect of solvent and pressure on polycaprolactone solutions for particle and fibre formation
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Esra Altun, Jubair Ahmed, Mehmet Onur Aydogdu, Anthony Harker, and Mohan Edirisinghe
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Polymers and Plastics ,Organic Chemistry ,Materials Chemistry ,General Physics and Astronomy - Published
- 2022
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47. Advanced Manufacturing Research for Healthcare
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Mohan Edirisinghe
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Engineering ,business.industry ,Manufacturing ,Scale (chemistry) ,Ultrasound imaging ,Advanced manufacturing ,Structure generation ,Health systems engineering ,business ,Combined method ,Manufacturing engineering ,Great Pace - Abstract
Inventing novel methods for making fine bubbles, particles, capsules and fibres of the micro-nano scale is an essential part of modern advanced science and engineering. These structures play an important part in key areas like healthcare engineering which is of a very high utilitarian value and public demand. Microbubbles are crucial contrast agents in ultrasound imaging, and also very effective in drug delivery. Particles and capsules are extensively used in modern therapeutics. Fibres are used in advanced applications such as tissue engineering, microbial screening and chronic wound healing strategies. However, the quest to make these structures in a reproducible manner with high productivity and process control is still elusive and is a hot topic where scale-up possibilities and actual industrial manufacturing are crucial factors. The Biomaterials Processing & Forming Laboratory (www.edirisinghelab.com) has been at the forefront of this research and this talk will illustrate how these novel making developments are currently taking place at great pace. This work has led to many inventions and has won over 20 high impact factor international journal front covers. For example, microbubble generation using microfluidics and electrohydrodynamics and their combination has led to a new medical frontier (1), we are the inventors of the combined method. We have also invented new electrohydodynamic devices which can make 4-layered particles (2) and these are paving the way to a new generation of therapeutics, for example to combat urinary tract infections in a new way. We have invented a new fibre manufacturing method called pressurised gyration (3) which has allowed doped-manufacturing of polymeric fibres with a high yield and this has revolutionized fibre-mesh generation for making antimicrobial filtration mats, tissue engineering constructs and wound healing and drug delivery patches. Our work has also paved new ways of utilising graphene and its derivatives in biomedical engineering (4). More exciting developments are in progress in collaboration with USA, China and Europe to further harness these manufacturing technologies especially in biotechnology (5) and core-sheath structure generation to enhance biomedical applications (6) and this talk will briefly indicate the exciting progress we are making in these areas. References M.Edirisinghe and S.Dalvi, Langmuir, 2019, Volume 35, Issue 31 (special issue), pages 9995-10222 S.Labbaf, H.Ghanbar, E.Stride and M.Edirisinghe, Macromol Rapid Commun. 2014; 35(6), 618–623. P.Heseltine, J.Ahmed and M.Edirisinghe, Macromol Mater. & Eng., 2018, Vol. 303((9), 1800218. M.Edirisinghe, The Royal Society Interface Focus, Special Issue, April 2018, Vol. 8, issue 3. J.Ahmed, M.Gultekinoglu and M.Edirisinghe, Biotech. Adv., 2020, Volume 41, July-August issue, 107549. S.Mahalingam, R.Matharu, S.Homer-Vanniasinkam and M.Edirisinghe, Appl. Phys. Rev., 2020, 7, 041302 .
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- 2020
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48. Next‐generation Antimicrobial Peptides (AMPs) incorporated nanofibre wound dressings
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Jubair Ahmed, Ayda Afshar, Candan Tamerler, Hussain Alenezi, Mohan Edirisinghe, Cate Wisdom, and Esra Yuca
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biology ,Staphylococcus epidermidis ,Chemistry ,Antimicrobial peptides ,Wound healing ,biology.organism_classification ,Microbiology - Published
- 2020
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49. Novel antibiotic-loaded particles conferring eradication of deep tissue bacterial reservoirs for the treatment of chronic urinary tract infection
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Jennifer L. Rohn, James Malone-Lee, Eleanor Stride, Nazila V. Jafari, Harry Horsley, Mohan Edirisinghe, Dhanuson Dharmasena, and Wai K. Lau
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medicine.drug_class ,Urinary system ,Urinary Bladder ,Antibiotics ,Pharmaceutical Science ,Video microscopy ,02 engineering and technology ,urologic and male genital diseases ,Microbiology ,03 medical and health sciences ,Humans ,Medicine ,Progenitor cell ,030304 developmental biology ,0303 health sciences ,Bacteria ,business.industry ,Intracellular parasite ,Biofilm ,021001 nanoscience & nanotechnology ,Anti-Bacterial Agents ,Nitrofurantoin ,Biofilms ,Urinary Tract Infections ,0210 nano-technology ,business ,Intracellular ,medicine.drug - Abstract
A significant proportion of urinary tract infection (UTI) patients experience recurrent episodes, due to deep tissue infection and treatment-resistant bacterial reservoirs. Direct bladder instillation of antibiotics has proved disappointing in treating UTI, likely due to the failure of infused antibiotics to penetrate the bladder epithelium and accumulate to high enough levels to kill intracellular bacteria. This work investigates the use of nitrofurantoin loaded poly(lactic-co-glycolic acid) (PLGA) particles to improve delivery to intracellular targets for the treatment of chronic UTI. Using electrohydrodynamic atomisation, we produced particles with an average diameter of 2.8 μm. In broth culture experiments, the biodegradable particles were effective against a number of UTI-relevant bacterial strains. Dye-loaded particles demonstrated that intracellular delivery was achieved in all cells in 2D cultures of a human bladder epithelial progenitor cell line in a dose-dependent manner, achieving far higher efficiency and concentration than equivalent quantities of free drug. Time-lapse video microscopy confirmed that delivery occurred within 30 min of administration, to 100% of cells. Moreover, the particles were able to deliver the drug to cells through multiple layers of a 3D human bladder organoid model causing minimal cell toxicity, displaying superior killing of bacterial reservoirs harboured within bladder cells compared with unencapsulated drug. The particles were also able to kill bacterial biofilms more effectively than the free drug. These results illustrate the potential for using antibiotic-loaded microparticles to effectively treat chronic UTIs. Such a delivery method could be extrapolated to other clinical indications where robust intracellular delivery is required, such as oncology and gene therapy.
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- 2020
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50. COVID‐19: Facemasks, healthcare policies and risk factors in the crucial initial months of a global pandemic
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Mohan Edirisinghe, A. H. Harker, and Jubair Ahmed
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medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Public health ,Environmental health ,Pandemic ,Health care ,medicine ,Outbreak ,Mandate ,Disease ,business ,Scientific evidence - Abstract
Previous pandemics have shown that facemask use becomes highly popular in public settings due to fear of the disease spreading. There is, however, a lack of strong scientific evidence that facemasks can significantly reduce the spread of respiratory diseases and as such, most governing policies do not mandate these coverings. There is a stark contrast between the policies and acceptance of facemasks across different geographies. In this work, several data sources have been thoroughly analysed to elucidate how viral diseases are transmitted and spread with particular emphasis on the novel SARS‐CoV‐2 virus which is causing an outbreak of COVID‐19. The different types of facemasks and respirators are also explained, the nature of their design and their efficacy is also examined. Several key factors which have been hypothesised to contribute to the spread of viral infections are elaborated in detail including the effect of temperature and humidity, public transportation systems, population density, socio‐economics and sociology. In this work, data are analysed to explain how the disease is spread, how facemasks function and the differences in the number of initial cases based on several contributing factors to the spread of disease. There are also some dangers in automatically recommending community facemask wearing, such as a reduction in the immune system functionality from the reduced exposure to microbes and the disposal issues which result from the large‐scale use of such materials. The questions of whether facemasks are useful in a community setting or if they divert valuable material away from critical healthcare providers are discussed.
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- 2020
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