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Sheyda Akhshabi,1 Esmaeil Biazar,2 Vivek Singh,3 Saeed Heidari Keshel,4 Nagaraja Geetha1 1Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysuru, Karnataka, India; 2Department of Biomaterials Engineering, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran; 3Prof Brien Holden Eye Research Center, Sudhakar and Sreekanth Ravi Stem Cell Biology Laboratory, L. V. Prasad Eye Institute, Hyderabad, Telangana, India; 4Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Background: Collagen and chondroitin sulfate (CS) are an essential component of the natural extracellular matrix (ECM) of most tissues. They provide the mechanical stability to cone the compressive forces in ECM. In tissue engineering, electrospun nanofibrous scaffolds prepared by electrospinning technique have emerged as a suitable candidate to imitate natural ECM functions. Cross-linking with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxy succinimide can overcome the weak mechanical integrity of the engineered scaffolds in addition to the increased degradation stability under physiological conditions. Materials and methods: This study has synthesized nanofibrous collagen–CS scaffolds by using the electrospinning method. Results: The results have shown that incorporation of CS in higher concentration, along with 1-ethyl-3-(3-dimethyl-aminopropyl)-1-carbodiimide hydrochloride/N-hydroxy succinimide, enhanced mechanical stability. Scaffolds showed more resistance to collagenase digestion. Fabricated scaffolds showed biocompatibility in corneal epithelial cell attachment. Conclusion: These results demonstrate that cross-linked electrospun CO–CS mats exhibited a uniform nanofibrous and porous structure, especially for lower concentration of the cross-linker and may be utilized as an alternative effective substrate in tissue engineering. Keywords: collagen, chondroitin sulfate, CS, extracellular matrix, ECM, cross linker, electrospinning, nanofiber

Jafar Ai1, Esmaeil Biazar2, Mostafa Jafarpour3, Mohamad Montazeri4, Ali Majdi5, Saba Aminifard5, Mandana Zafari5, Hanie Akbari R6, Hadi Rad Gh71Department of Tissue Engineering, Faculty of Advanced Technologies, Tehran University of Medical Sciences, Tehran; 2Department of Chemistry, Islamic Azad University – Tonekabon Branch, Mazandaran; 3Department of Microbiology, Faculty of Science, Islamic Azad University – Tonekabon Branch, Mazandaran; 4Faculty of Medical Sciences, Babol University of Medical Sciences; 5Young Researchers Club – Islamic Azad University, Tonekabon Branch, Mazandaran; 6Faculty of Medical Sciences, Islamic Azad University – North branch, Tehran; 7Faculty of Medical Sciences, Islamic Azad University – Tonekabon Branch, Mazandaran, IranAbstract: Nanotechnology has wide applications in many fields, especially in the biological sciences and medicine. Nanomaterials are applied as coating materials or in treatment and diagnosis. Nanoparticles such as titania, zirconia, silver, diamonds, iron oxides, carbon nanotubes, and biodegradable polymers have been studied in diagnosis and treatment. Many of these nanoparticles may have toxic effects on cells. Many factors such as size, inherent properties, and surface chemistry may cause nanoparticle toxicity. There are methods for improving the performance and reducing toxicity of nanoparticles in medical design, such as biocompatible coating materials or biodegradable/biocompatible nanoparticles. Most metal oxide nanoparticles show toxic effects, but no toxic effects have been observed with biocompatible coatings. Biodegradable nanoparticles are also used in the efficient design of medical materials, which will be reviewed in this article.Keywords: nanotechnology, nanotoxicology, nanomaterials, nanobiomaterials

Saeed Heidari Keshel1, S Neda Kh Azhdadi2, Azadeh Asefnezhad2, Mohammad Sadraeian3, Mohamad Montazeri4, Esmaeil Biazar51Stem Cell Preparation Unit, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch - Islamic Azad University; 3Young Researchers Club, Islamic Azad University, North Tehran Branch, Tehran; 4Faculty of Medical Sciences, Babol University of Medical Sciences, Babol; 5Department of Chemistry, Islamic Azad University, Tonekabon, IranAbstract: Surface modification of medical polymers is carried out to improve biocompatibility. In this study, conventional polyurethane was exposed to microwave plasma treatment with oxygen and argon gases for 30 seconds and 60 seconds. Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated the presence of functional groups. Atomic force microscope images of samples irradiated with inert and active gases indicated the nanometric topography of the sample surfaces. Samples irradiated by oxygen plasma indicated high roughness compared with those irradiated by inert plasma for the different lengths of time. In addition, surface roughness increased with time, which can be due to a reduction of contact angle of samples irradiated by oxygen plasma. Contact angle analysis indicated a reduction in samples irradiated with both types of plasma. However, samples irradiated with oxygen plasma indicated lower contact angle compared with those irradiated by argon plasma. Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation among samples radiated by oxygen plasma for longer than for normal samples.Keywords: surface topography, polyurethane, plasma treatment, cellular investigation

Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm) compared with those irradiated with inert plasma (16 nm) at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

Biazar E, Heidari M, Asefnezhad A, Montazeri N. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation. International Journal of Nanomedicine. 2011;6:631-639.The correct spelling of the third author's name is "Asefnejad."Original article

Heidari S, Azhdadi SN, Asefnezhad A, Sadraeian M, Montazeri M, Biazar EThe relationship between cellular adhesion and surface roughness for polyurethane modified by microwave plasma radiation. International Journal of Nanomedicine. 2011;6:641-647.The correct spelling of the third author's name is "Asefnejad."Original Article

Decellularized marine tissues have been regarded as a desirable biomaterial because of their biological risk reduction, less religious constraints, and resemblance to mammalian tissues. The properties of these matrices can be improved by adding cross-linkers. In this study, after decellularization of the of Tilapia and Grass carp fish skin, a comparative study was conducted between them. Due to the higher abundance of collagen and glycosaminoglycans (GAGs) in Tilapia skin, it was selected for further study. In the next step, the cross-linking process was performed with three concentrations of 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/ N-Hydroxysuccinimide (EDC/NHS) and tannic acid cross-linkers. The MTT results showed that the cross-linked samples with low concentrations of EDC/NHS had higher biocompatibility compared to the cross-linked sample with high concentration of EDC/NHS, as well as all samples cross-linked with tannic acid. Mechanical and physical studies conducted on the skin of Tilapia fish showed that the 15 mM/7.5 mM concentration of EDC/NHS increased the mechanical and temperature strength and decreased the degradability and it did not influence cell attachment. In general, it was shown that different fish skins differ in terms of collagen and GAGs, and the optimal concentration of EDC cross-linker improves the mechanical and physical properties of the matrix derived from fish skin., Competing Interests: Conflict of Interest Statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: To address the limitations of Cultivated Limbal Epithelial Transplantation (CLET) and the use of amniotic membrane (AM) in treating Limbal Stem Cell Deficiency (LSCD), we aimed to develop a Collagen/Silk Fibroin (Co/SF) scaffold enriched with Platelet-Rich Growth Factor (PRGF) to support the proliferation, maintenance, and differentiation of Wharton's jelly-derived mesenchymal stem cells (WJMSCs) into corneal epithelial cells (CECs)., Method: Scaffolds loaded with PRGF were evaluated through release studies, cytotoxicity assays, and cell differentiation. The proliferation and differentiation of WJMSCs and Limbal Epithelial Stem Cells (LESCs) were investigated using MTT assays, real-time PCR and immunostaining., Results: The PRGF-loaded Co/SF scaffold significantly promoted the proliferation of both WJMSCs and LESCs in a concentration-dependent manner. Real-time PCR and immune staining revealed a significant increase in the expression of P63, ABCG2, and cytokeratin 3/12 markers in WJMSCs, a significant decrease in the expression of P63 and ABCG2, and a significant increase in the expression of cytokeratin 3/12 markers indicating successful differentiation into CECs., Conclusion: The WJMSC cultured on PRGF-enriched Co/SF scaffold demonstrates potential as a viable alternative to conventional CLET, offering a promising strategy for corneal tissue regeneration.

Natural-derived biomaterials can be used as substrates for the growth, proliferation, and differentiation of cells. In this study, bovine vitreous humor as a biological material was cross-linked to silk fibroin with different concentration ratios to design a suitable substrate for corneal tissue regeneration. The cross-linked samples were evaluated with different analyses such as structural, physical (optical, swelling, and degradation), mechanical, and biological (viability, cell adhesion) assays. The results showed that all samples had excellent transparency, especially those with higher silk fibroin content. Increasing the ratio of vitreous humor to silk fibroin decreased mechanical strength and increased swelling and degradation, respectively. There was no significant difference in the toxicity of the samples, and with the increase in vitreous humor ratio, adhesion and cell proliferation increased. Generally, silk fibroin with vitreous humor can provide desirable characteristics as a transparent film for corneal wound healing., (© 2024 Wiley Periodicals LLC.)

While significant progress has been made in creating polymeric structures for tissue engineering, the therapeutic application of these scaffolds remains challenging owing to the intricate nature of replicating the conditions of native organs and tissues. The use of human-derived biomaterials for therapeutic purposes closely imitates the properties of natural tissue, thereby assisting in tissue regeneration. Decellularized extracellular matrix (dECM) scaffolds derived from natural tissues have become popular because of their unique biomimetic properties. These dECM scaffolds can enhance the body's ability to heal itself or be used to generate new tissues for restoration, expanding beyond traditional tissue transfers and transplants. Enhanced knowledge of how ECM scaffold materials affect the microenvironment at the injury site is expected to improve clinical outcomes. In this review, recent advancements in dECM scaffolds are explored and relevant perspectives are offered, highlighting the development and application of these scaffolds in tissue engineering for various organs, such as the skin, nerve, bone, heart, liver, lung, and kidney., (© 2024 Wiley‐VCH GmbH.)

Platelet-rich fibrin (PRF), which is the rich source of growth factors, has been used as an efficient scaffold in tissue engineering and wound healing. In this study, tannic acid as a green cross-linker with different concentrations (0.5%, 1%, 5% and 10%) was used to improve the properties of PRF. The cross-linked gel scaffolds were evaluated by analyses such as scanning electron microscopy, Fourier transform infrared spectroscopy, swelling and degradation, mechanical strength, cell toxicity, cell adhesion and antibacterial test. The results showed that the scaffold structure changes by increasing cross-linker concentration. The swelling rate decreased from 49% to 5% for the samples without the cross-linker and with tannic acid (10%), respectively. The degradation percentage for the cross-linked samples was 8%, which showed a lower degradation rate than the non-cross-linked samples (63%). The mechanical strength of the scaffold with the cross-linker increased up to three times (Young's modulus for the non-cross linked and the cross-linked samples: 0.01 and 0.6 MPa, respectively). Cytotoxicity was not observed up to 10% cross-linker concentration. The cells proliferated well on the cross-linked scaffolds and also showed a good antibacterial effect. In general, tannic acid can improve the physical and mechanical properties of PRF without negatively affecting its biological properties., (© 2023 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Cold atmospheric plasma (CAP) is an ionized matter with potential applications in various medical fields, ranging from wound healing and disinfection to cancer treatment. CAP's clinical usefulness stems from its ability to act as an adjustable source of reactive oxygen and nitrogen species (RONS), which are known to function as pleiotropic signaling agents within cells. Plasma-activated species, such as RONS, have the potential to be consistently and precisely released by carriers, enabling their utilization in a wide array of biomedical applications. Furthermore, understanding the behavior of CAP in different environments, including water, salt solutions, culture medium, hydrogels, and nanoparticles, may lead to new opportunities for maximizing its therapeutic potential. This review article sought to provide a comprehensive and critical analysis of current biomaterial approaches for the targeted delivery of plasma-activated species in the hope to boost therapeutic response and clinical applicability., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Fish skin grafting as a new skin substitute is currently being used in clinical applications. Acceleration of the wound healing, lack of disease transmission, and low cost of the production process can introduce fish skin as a potential alternative to other grafts. An appropriate decellularization process allows the design of 3D acellular scaffolds for skin regeneration without damaging the morphology and extracellular matrix content. Therefore, the role of decellularization processes is very important to maintain the properties of fish skin. In this review article, recent studies on various decellularization processes as well as biological, physical, and mechanical properties of fish skin and its applications with therapeutic effects in wound healing were investigated., (© 2023 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Biological matrices can be modified with cross-linkers to improve some of their characteristics as scaffolds for tissue engineering. In this study, chemical cross-linker 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) was used with different ratios (5, 10, 20, 30, and 40 mM) to improve properties such as mechanical strength, denaturation temperature, and degradability of the acellular fish skin as a biological scaffold for tissue engineering applications. Morphological analysis showed that the use of cross-linker at low concentrations had no effect on the structure and textiles of the scaffold, while increasing mechanical strength, denaturation temperature, and degradation time. Cytotoxicity and cellular studies showed that the optimal cross-linker concentration did not significantly affect cell viability as well as cell adhesion. In general, utilising the carbodiimide cross-linker with the optimal ratio can improve the characteristics and function of the biological tissues such as acellular fish skin., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Hemorrhage control is vital for clinical outcomes after surgical treatment and pre-hospital trauma injuries. Numerous biomaterials have been investigated to control surgical and traumatic bleeding. In this study, for the first time, perlite was introduced as an aluminosilicate biomaterial and compared with other ceramics such as kaolin and bentonite in terms of morphology, cytotoxicity, mutagenicity, and hemostatic evaluations. Cellular studies showed that perlite has excellent viability, good cell adhesion, and high anti-mutagenicity. Coagulation results demonstrated that the shortest clotting time (140 seconds with a concentration of 50 mg mL -1 ) was obtained for perlite samples compared to other samples. Therefore, perlite seems most efficient as a biocompatible ceramic for hemorrhage control and other biomaterial designs., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Natural biomaterials are crucial in ocular tissue engineering because they allow cells to proliferate, differentiate, and stratify while maintaining the typical epithelial phenotype. In this study, membranes as dressings were formed from silk fibroin and collagen (Co) extracted from fish skin and then modified with carbodiimide chemical cross linker in different concentrations. The samples were evaluated by different analyses such as structural, physical (optical, swelling, denaturation temperature, degradation), mechanical, and biological (viability, cell adhesion, immunocytochemistry) assays. The results showed that all membranes have excellent transparency, especially with higher silk fibroin content. Increasing the cross linker concentration and the ratio of silk fibroin to Co increased the denaturation temperature and mechanical strength and, conversely, reduced the degradation rate and cell adhesion. The samples did not show a significant difference in toxicity with increasing cross linker and silk fibroin ratio. In general, samples with a low silk fibroin ratio combined with cross linker can provide desirable properties as a membrane for corneal wound healing., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Plant-derived tannic acid as a green material can play an important role in improving the mechanical and physical properties of biomaterials. Tannic acid can be used as an antioxidant, antimicrobial, and cross-linking agent in biomaterial products due to its unique functional groups. Its active phenolic groups can react with biomaterial functional groups to form bonds that improve performance. In this review, the mechanism of effectiveness of tannic acid as a natural crosslinker in improving the properties of biomaterials for various applications, such as tissue engineering, tissue adhesives, drug delivery, wound healing, and toxicity studies, has been investigated. In general, tannic acid can be a suitable alternative to synthetic crosslinkers in biomaterial applications., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Acellular skin as a scaffold has a good potential to regenerate or repair damaged tissues. Growth factors such as Plasma Rich in Growth Factor (PRGF) as a rich source of active proteins can accelerate tissue regeneration. In this study, an acellular scaffold derived from fish skin with growth factors was used to repair full-thickness skin defects in a rat model. Cellular results demonstrated that epithelial cells adhere well to acellular scaffolds. The results of animal studies showed that the groups treated with acellular scaffold and growth factor have a high ability to close and heal wounds on the 28th day after surgery. Histological and staining results showed that in the treated groups with scaffold and growth factor, an epidermal layer was formed with some skin appendages similar to normal skin. Overall, such scaffolds with biological agents can cause an acceptable synergistic effect on skin regeneration and wound healing., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Platelet-rich fibrin (PRF) as a rich source of effective growth factors has been used as a scaffold in tissue regeneration. It is known that PRF exhibits rapid degradability against enzymes, which should be decreased using crosslinking agents to reduce the release rate of growth factors and increase the effectiveness of tissue regeneration. In this study, a carbodiimide crosslinker with different concentrations (0.01%, 0.05%, 1%, and 2%) was used to modify and improve the properties of PRF gel. The crosslinked gels were evaluated with analyses such as SEM, swelling, degradability, mechanical strength, release test, cytotoxicity, and cell adhesion. The results showed that with increasing crosslinker concentration, the morphology of the fiber structure changes drastically, the swelling rate decreases from 300% (control) to 160% for the crosslinked gel, the degradation time for the control sample increases from 8 days to more than two weeks for the crosslinked gel, and the Young's modulus increases from 0.15 MPa (control) to 0.61 MPa for the crosslinked samples. Growth factors also showed lower release with increasing crosslinking ratio. Cytotoxicity assays demonstrated that by increasing the crosslinker concentration to 1% w/v, no cytotoxicity was observed. Cellular studies with DAPI staining showed that the cells penetrated well into the gels and were well distributed, especially in gels with lower crosslinker concentrations. In addition, the modified PRF gel can be used as a scaffold for tissue regeneration., Competing Interests: The authors state no conflict of interest and have received no payment in the preparation of this manuscript., (This journal is © The Royal Society of Chemistry.)

For many years, discovering the appropriate methods for the treatment of skin irritation has been challenging for specialists and researchers. Bio-printing can be extensively applied to address the demand for proper skin substitutes to improve skin damage. Nowadays, to make more effective biomimicry of natural skin, many research teams have developed cell-seeded bio-inks for bioprinting of skin substitutes. These loaded cells can be single or co-cultured in these structures. The present review gives a comprehensive overview of the methods, substantial parameters of skin bioprinting, examples of in vitro and in vivo studies, and current advances and challenges in skin tissue engineering., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Light can act as an effective and strong agent for the cross-linking of biomaterials and tissues and is recognized as a safe substitute for chemical cross-linkers to modify mechanical and physical properties and promote biocompatibility. This review focuses on the research about crosslinked biomaterials with different radiation sources such as Laser or ultraviolet (UV) that can be applied as scaffolds, controlled release systems,and tissue adhesives for cornea healing and tissue regeneration., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Nowadays, viral infections are one of the greatest challenges for medical sciences and human society. While antiviral compounds and chemical inactivation remain inadequate, physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections, without the risk of drug resistance and other unwanted side effects. Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations. This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation, including high energy ultraviolet, gamma ray, X-ray, and neutron, and non-ionizing photo-inactivation, including lasers and blue light., Competing Interests: Competing interests Dayong Jin is an Editor for the journal, no other author has reported any competing interest., (© The Author(s) 2022.)

The use of decellularized natural skin as an extracellular matrix (ECM) may be a great candidate to regenerate damaged tissues. In this study, decellularized scaffolds from fish skin were designed by different techniques (physical, chemical, and enzymatic methods) and investigated by analyses such as Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Tensile strength, Degradability, Histological studies, Toxicity test, and Determination of DNA content. Results showed that the best sample is related to the decellularized skin by hypertonic & hypotonic technique and Triton X100 solutions. Structural and mechanical results were demonstrated that samples have similar properties to human skin to regenerate it. The cytotoxicity results showed that decellularized skin by hypertonic & hypotonic method and Triton solution is non-toxic with minimal amount of genetic materials. Cellular results with epithelial cells indicated good adhesion on decellularized matrix, so it can be a suitable candidate for skin tissue regeneration., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Microorganisms such as bacteria and their derived biopolymers can be used in biomaterials and tissue regeneration. Various methods have been applied to regenerate damaged tissues, but using probiotics and biomaterials derived from bacteria with improved economic-production efficiency and highly applicable properties can be a new solution in tissue regeneration. Bacteria can synthesize numerous types of biopolymers. These biopolymers possess many desirable properties such as biocompatibility and biodegradability, making them good candidates for tissue regeneration. Here, we reviewed different types of bacterial-derived biopolymers and highlight their applications for tissue regeneration.

Abstract: Alternative treatment approaches to improve the regeneration ability of damaged peripheral nerves are currently under investigation. The aim of the current study was to evaluate the effects of leucocyte/platelet-rich fibrin (L-PRF) with or without a collagen membrane as a supporter on crushed sciatic nerve healing in a rat model. Recovery of motor function and electrophysiologic measurements were evaluated at 4 weeks postoperatively. The whole number of myelinated axons, peripheral nerve axon density, average nerve fiber diameter (μm), and G-ratio were analyzed and compered among the groups. Functional, electrophysiological, and histological evaluations showed no significant difference among the groups with the exception of the L-PRF with collagen membrane groups that showed relatively positive effects on the functional and histological nerve recovery. In addition, the collagen membrane with L-PRF can be effect in nerve regeneration., Competing Interests: The authors report no conflicts of interest., (Copyright © 2020 by Mutaz B. Habal, MD.)

The current study deals with the preparation and characterization of polysaccharide-based biocomposite films acquired by the incorporation of cellulose nanofiber within glycerol plasticized matrix formed by starch. The application of starch-based films is limited due to highly hydrophilic nature and poor mechanical properties. These problems are solved by forming a nanocomposite of thermoplastic starch (TPS) as matrix and cellulose nanofiber (CNF) as reinforcement. CNF is successfully prepared from short henequen fibers which consist of almost 60% cellulose by a chemo-mechanical process. TPS/CNF composite films are prepared by the polymer solution casting method, and their characterizations are obtained by water vapor transmission rate (WVTR), atomic force microscopy (AFM), oxygen transmission rate (OTR), X-ray diffraction, light transmittance and tensile test. The 0.4 wt% CNF loaded TPS films showed approximately the maximum improvement in tensile strength. Tensile strength and elastic modulus increased by up to 80% and 170% respectively. Above 0.5 wt% CNF, tensile strength starts to deteriorate. WVTR and OTR results show improvement in water vapor barrier properties of TPS matrix. The AFM analysis shows the topography of the surface of the nanocomposite. The morphology of nanofibers is studied by using the scanning electron microscopy (SEM) and the transmission electron microscopy (TEM)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In the last decade, the use of new technologies in the reconstruction of body tissues has greatly developed. Utilising stem cell technology, nanotechnology and scaffolding design has created new opportunities in tissue regeneration. The use of accurate engineering design in the creation of scaffolds, including 3D printers, has been widely considered. Three-dimensional printers, especially high precision bio-printers, have opened up a new way in the design of 3D tissue engineering scaffolds. In this article, a review of the latest applications of this technology in this promising area has been addressed.

A nanofibrous silk nerve conduit has been evaluated for its efficiency based on the promotion of peripheral nerve regeneration in rats. The designed tubes with or without Schwann cells were implanted into a 10 mm gap in the sciatic nerves of the rats. Four months after the surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology. The results demonstrated that the nanofibrous grafts, especially in the presence of Schwann cells, enabled reconstruction of the rat sciatic nerve trunk with a restoration of nerve continuity and formation of nerve fibres with myelination. Histological data demonstrated the presence of Schwann and glial cells in regenerated nerves. This study strongly supports the feasibility of using artificial nerve grafts for peripheral nerve regeneration by bridging large defects in a rat model.

Surface modification of medical polymers is carried out to improve biocompatibility. In this study, conventional polymers (chitosan and polypropylene) were modified to laser at different features (oriented and non-oriented) to create a vast range of physicochemical characteristics on the surface of polymers and investigate their effects on biocompatibility of treated surfaces. Atomic force microscope (AFM) was applied to study the morphology of treated samples in comparison with those of the untreated PS. Contact angle analyses were used to evaluate the wettability and surface energy of the treated films. AFM studies showed that after laser treatment, some distinctive nanostructures are created on the surface of polymers. The data from contact angle measurements demonstrated that laser irradiation created surfaces with a vast range of properties in the wettability point of view. The cellular results revealed that after surface modification by laser irradiation, biocompatibility of polymeric films, especially oriented films was enhanced.

The aim of this study was to develop nanofibrous gelatin substrates for eyelid fat stem cell (EFSC) expansion that can serve as a potential alternative substrate to replace human amniotic membrane. Biocompatibility results indicated that all substrates were highly biocompatible, as EFSCs could favorably attach and proliferate on the nanofibrous surfaces. Microscopic figures showed that the EFSC were firmly anchored to the substrates and were able to retain a normal stem cell phenotype. Immunocytochemistry (ICC) and real time-PCR results revealed change in the expression profile of EFSCs grown on nanofibrous substrates when compared to those grown on control in epithelial induction condition. In addition, electrospun gelatin mats especially oriented scaffold provides not only a milieu supporting EFSCs expansion, but also serves as a useful alternative carrier for ocular surface tissue engineering and could be used as an alternative substrate to amniotic membrane.

Unrestricted somatic stem cells (USSCs) loaded in nanofibrous polycaprolactone (PCL) scaffolds can be used for skin regeneration when grafted onto full-thickness skin defects of rats. Nanofibrous PCL scaffolds were designed by the electrospinning method and crosslinked with laminin protein. Afterwards, the scaffolds were evaluated by scanning electron microscopy, and physical and mechanical assays. In this study, nanofibrous PCL scaffolds loaded with USSCs were grafted onto the skin defects. The wounds were subsequently investigated 21 days after grafting. Results of mechanical and physical analyses showed good resilience and compliance to movement as a skin graft. In animal models; study samples exhibited the most pronounced effect on wound closure, with statistically significant improvement in wound healing being seen at 21 days post-operatively. Histological examinations of healed wounds from all samples showed a thin epidermis plus recovered skin appendages in the dermal layer for samples with cell. Thus, the graft of nanofibrous PCL scaffolds loaded with USSC showed better results during the healing process of skin defects in rat models.

Single-wall carbon nanotubes (SWCNT) represent a novel nanomaterial applied in various nanotechnology fields because of their surface chemistry properties and high drug cargo capacity. In this study, SWCNT are pre-functionalized covalently with paclitaxel (PTX) - an anticancer drug, and folic acid (FA), as a targeting agent for many tumors. The samples are investigated and evaluated by different analyses such as Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), absorption spectroscopic measurements (UV-Visible), elemental analysis, and cell analyses with cancer cell line cultures. The results show good conjugation of the targeting molecule and the anticancer drug on the surface of the carbon nanotubes (CNT). This work demonstrates that the SWCNT-PTX-FA system is a potentially useful system for the targeted delivery of anticancer drugs.

Magnetic separation has numerous advantages in isolating cancerous and normal cells used in the diagnosis and treatment sectors. Here, we produced magnetic nanocomposite films made of polyhydroxybutyrate (PHB)/magnetite nanoparticles (γ-Fe2O3), and the properties of the films by SEM, TEM, FTIR, DMTA, contact angle, and cellular analyses were investigated. The microscopic images showed uniform distribution of γ-Fe2O3 magnetic nanoparticles in polymeric matrix. The chemical bounds between magnetic nanoparticles and polymeric matrix demonstrated using the FTIR spectrophotometer. The DMTA and contact angle results indicated an increase in the glass transition temperature and hydrophilic properties of nanocomposites is achieved by increasing the magnetic nanoparticles amount in polymer matrix. The cellular results were showed that adhesion of cancer cells compared to normal cells was significantly enhanced by the induction of a magnetic field. These nanocomposite films can be used as a substrate for cellular adhesion and separation processes.

Aim: The aim of this study was to design multi-walled carbon nanotubes (MWCNTs) loaded with paclitaxel (PTX) anti-cancer drug and investigate its anti-cancerous efficacy of human gastric cancer., Background: Carbon nanotubes (CNTs) represent a novel nano-materials applied in various fields such as drug delivery due to their unique chemical properties and high drug loading., Patients and Methods: In this study, multi-walled carbon nanotubes (MWCNTs) pre-functionalized covalently with a paclitaxel (PTX) as an anti-cancer drug and evaluated by different analyses including, scanning electron microscope (SEM), particle size analyzer and cellular analyses., Results: A well conjugated of anti-cancer drug on the carbon nanotube surfaces was shown. This study demonstrates that the MWCN-PTX complex is a potentially useful system for delivery of anti-cancer drugs. The flow cytometry, CFU and MTT assay results have disclosed that MWCNT/PTXs might promote apoptosis in MKN-45 gastric adenocarcinoma cell line., Conclusion: According to results, our simple method can be designed a candidate material for chemotherapy. It has presented a few bio-related applications including, their successful use as a nano-carriers for drug transport.

Injectable hydrogel is one of the great interests for tissue engineering and cell encapsulation. In the study, the thermosensitive chitosan/gelatin/β-glycerol phosphate (C/G/GP) disodium salt hydrogels were designed and investigated by different analyses. The eye fat-derived stem cells were used to evaluate the biocompatibility of hydrogels based on their phenotypic profile, viability, proliferation, and attachment ability. The results show that the sol/gel transition temperature of the C/G/GP hydrogel was in the range of 31.1-33.8 °C at neutral pH value, the gelation time was shortened, and the gel strength also improved at body temperature when compared with the C/GP hydrogel. In vitro cell culture experiments with eyelid fat-derived stem cells in hydrogel showed beneficial effects on the cell phenotypic morphology, proliferation, and differentiation. Microscopic figures showed that the eyelid fat stem cell were firmly anchored to the substrates and were able to retain a normal stem cell phenotype. Immunocytochemistry (ICC) and real-time-PCR results revealed change in the expression profile of eyelid fat stem cells grown with hydrogels when compared to those grown on control in epithelial induction condition. This study indicates that using chitosan/gelatin/β-glycerol phosphate hydrogel for cell culture is feasible and may apply in minimal invasive surgery in the future.

Purpose: The aim of this study was to develop nanofibrous polycaprolactone (PCL) substrate for limbal stem cell (LSC) expansion that can serve as a potential alternative substrate to replace human amniotic membrane (AM)., Materials and Methods: The human limbus stem cell was used to evaluate the biocompatibility of substrates (nanofibrous scaffold and, human AM) based on their phenotypic profile, viability, proliferation and attachment ability., Results: Biocompatibility results indicated that the all substrates were highly biocompatible, as LSCs could favorably attach and proliferate on the nanofibrous surface. Microscopic figures showed that the human LSCs were firmly anchored to the substrates and were able to retain a normal corneal stem cell phenotype. Microscopic analyses illustrated that cells infiltrated the nanofibers and successfully formed a three-dimensional corneal epithelium, which was viable for two weeks. Immunocytochemistry (ICC) and real time-PCR results revealed no change in the expression profile of LECs grown on nanofibrous substrate when compared to those grown on human AM., Conclusion: In addition, electrospun nanofibrous PCL substrate provides not only a milieu supporting LSCs expansion, but also serve as a useful alternative carrier for ocular surface tissue engineering and could be used as an alternative substrate to AM.