Search

Poor angiogenesis at injury site is a major problem in chronic wounds, which could lead to limbs amputation in adverse cases. To overcome this issue, several efforts have made in literature and by our group as well to develop pro-angiogenic agents. For this purpose, metal oxides due to their oxidative potential have been studied and found very attractive agents. Cerium oxides are proven to be non-toxic and their biological studies have already proved their importance in preventing chronic inflammation, and neurological diseases among several others by modulating the intracellular reactive oxygen species. In current study, we report the synthesis and neovascularization activity of cerium oxide and cerium peroxide nanoparticles when loaded into chitosan and collagen hydrogel. The hydrogels were characterized by FTIR, SEM and XRD. The pro-angiogenic behavior of these hydrogels was studied by in-vivo CAM assay. It was found that cerium peroxide loaded material showed significantly increase in angiogenesis as compared to cerium oxide loaded materials. It was demonstrated that cerium peroxide hydrogels enhanced the angiogenic capability in CAM assay as compared to cerium oxide and hence holds good potential for chronic ulcer and burn wounds healing.

This research on a thyroxine/heparin-based cotton wound dressing tests angiogenic and wound healing ability of thyroxine/heparin in a chick chorionic allantoic membrane bioassay and in skin wounds in healthy rats. Commercially available cotton dressings were simply loaded with thyroxine/heparin solutions and coated with wax. Prior to undertaking the animal study, we assessed in vitro release of thyroxine/heparin from coated and uncoated cotton dressings. Both showed more than 85% release of drug over 14 days, though the lesser release was observed in wax-coated thyroxine/heparin dressing as compared to uncoated thyroxine/heparin dressing. Testing of angiogenesis through CAM assay proved good angiogenic potential of heparin and thyroxin, but the thyroxine found more angiogenic than heparin. In animal study, full-thickness skin wounds of 20 mm diameter showed good healing in both heparin and thyroxine-treated groups. But the most striking result was seen in the thyroxine-treated group where thyroxine showed significant difference with heparin-treated group and completely healed the wounds in 23 days. Thus, the study suggest that thyroxine possesses greater angiogenic and wound healing potential than heparin, and the use of thyroxine/heparin-loaded wax-coated cotton dressing could be a cost-effective option for the management of chronic wounds.

We report fabrication of reduced graphene oxides (RGO) papers using thermal reduction by vacuum-assisted for thermal exfoliation and in situ reduction of graphene oxide (GO) at temperatures as low as 180 °C. The conjugated sp2-carbon structure of GO was restored throughout the reduction process, and the thermal stability of the RGO papers was substantially better than that of the GO paper, according to Raman analysis and thermogravimetry analysis (TGA). The RGO paper that was reduced for 24 h exhibited the highest electrical conductivity of (29.3 ± 0.4) × 103 S m−1 at 180 °C. As the reduction degree of the RGO paper deepens, the thickness of the sample gradually decreases, indicating that the conduction type of RGO paper can be controlled by regulating the reduction degree. Thus, we demonstrate a simplified fabrication way for flexible conducting RGO paper of significant application potential as electrodes in a variety of devices.

The way to analyze data in spectroscopy has changed substantially. At the same time, data science has evolved to the point where spectroscopy can find space to be housed, adapted and be functional. The integration of the two sciences has introduced a knowledge gap between data scientists who know about advanced machine learning techniques and spectroscopists who have a solid background in chemometrics. To reach a symbiosis, the knowledge gap requires bridging. This review article focuses on introducing data science subjects to non-specialist spectroscopists, or those unfamiliar with the subject. The article will explain concepts that are covered in machine learning, such as supervised learning, unsupervised learning, deep learning, and most importantly, the difference between machine learning and artificial intelligence. This article also includes examples of published spectroscopy research, in which some of the concepts explained here are applied. Machine learning together with spectroscopy can provide a useful, fast, and efficient tool to analyze samples of interest both for industrial and research purposes. © 2020 Taylor & Francis Group, LLC.

A critical factor to favor a good prognosis in breast cancer (BC) patients is early detection. Offering prompt diagnosis, treatment, and delaying or stopping the progression of the disease are the key aspects of breast cancer management. The use of FTIR spectroscopy on ex vivo breast samples can elucidate important biochemical information associated with the presence and progression of breast cancer. In this study, tissue microarrays of breast cancer biopsy samples (n = 378), and normal breast (n = 134) were analyzed using FTIR spectroscopy, principal component analysis (PCA) for feature extraction, and validation employing linear discriminant analysis (LDA). The differentiation between normal breast and breast cancer was successfully achieved with a sensitivity of 92% and specificity of 86%. Lipids and proteins spectral bands were identified as the main differentiators between normal and breast cancer. FTIR results also highlighted that chemical structural changes formed an important part of breast cancer evolution. Regardless of the heterogeneity of breast cancer, the use of multivariate analysis and FTIR spectroscopy offers a suitable and reliable tool for BC monitoring and diagnosis. The integration of spectroscopic techniques such as FTIR in cancer diagnosis and monitoring could add useful information enabling the diagnosis and management of breast cancer patients.

In December 2019, the coronavirus 2019 (COVID-19) outbreak, initiated in Wuhan, China, from where it subsequently spread globally, thereby posing serious threats to public health around the world.[...

Introduction: Diabetic wounds are challenging to treat due to a wide range of pathophysiological changes. Hypoxia is one of the predominant contributing factors of poor vascularization and chronicity in diabetic wounds. This study was designed to develop polycaprolactone (PCL)-based oxygen-releasing electrospun wound dressings and evaluate their efficacy for improved full thickness wound healing in diabetic rats. Methods: PCL-based oxygen releasing wound dressings were made using electrospinning technology. The developed dressings were characterized in terms of physical as well as biological properties both in vitro and in vivo. E-spun nanofibrous dressings were physically characterized with scanning electron microscopy, Fourier-transform infrared spectroscopy, and Energy-dispersive X-ray spectroscopy. To study the likely impact of the fabricated wound dressings in hypoxic conditions, HIF-1α expression analysis was carried out both at gene and protein levels. Wound dressings were further evaluated for their healing potential for extensive wounds in diabetic rat models. Results: The experimental results showed that the developed dressings were capable of continuously generating oxygen for up to 10 days. Cell studies further confirmed pronounced expression of HIF-1α at gene and protein levels in cells seeded on PCL-sodium percarbonate (SPC) and PCL scaffolds compared with the cells cultured on a tissue culture plate. Chorioallantoic membrane assay revealed the supportive role of oxygen releasing dressings on angiogenesis compared to the control group. Histological assessment of the regenerated skin tissues proved that full thickness wounds covered with SPC loaded PCL dressings had a comparatively better vascularized and compact extracellular matrix with completely covered thick epithelium. Discussion: The developed oxygen generating polymeric nanofibrous wound dressings could potentially be used as an envisioned approach for the efficient recovery of chronic diabetic wounds. © 2020 Zehra et al.

Osteochondral defects are relatively common in weight-bearing joints of the lower extremities and require multiple approaches of treatment. This work is focused on designing three-dimensional (3D) bilayered scaffolds fully integrating a top chitosan/hydroxypropylmethyl cellulose layer (CS/HPMC) mimicking cartilage and a bottom chitosan/hydroxypropylmethyl cellulose/nano-hydroxyapatite layer (CS/HPMC/nHAp) imitating bone for the treatment of osteochondral defects prepared by freeze drying. Additionally, an anti-inflammatory drug (in the bottom layer) and an antibiotic drug (in the top layer) are incorporated in the form of microspheres and nanofibers, respectively, into these scaffolds to diminish/prevent post-surgical inflammation/infection through sustained release of the drugs. The scaffolds were characterized by a variety of techniques. FT-IR analysis confirmed that there is no/weak interactions between the components, SEM images showed that both layers of the scaffolds have homogenous pore distribution, and scaffolds exhibited reproducible swelling and degradation behavior. Drug release was shown to take place over a period of 14 days in PBS. The scaffolds supported the growth and proliferation of MC3T3 pre-osteoblast cells in vitro and have potential for use in vivo application in the future.

Chitosan/collagen-based hydrogels were studied for their promising role in skin tissue engineering applications due to their unique biocompatibility and biodegradation properties. Amino acids are not only the mean of protein building units but also support endothelial cells proliferation and trigger angiogenesis during wound healing. The purpose of this study was to prepare amino acid based pro-angiogenic materials. Three structurally closed amino acids (AA) (arginine, alanine and phenylalanine) were loaded into chitosan/collagen hydrogels (ACC hydrogels) to study their effect on angiogenesis. In this study the ACC hydrogels were prepared through freeze drying procedure and their angiogenic potential was studied by chorioallantoic membrane assay (CAM assay). FTIR analysis was performed to confirm that there was no chemical change took place in polymeric materials during synthesis procedures. Results revealed that, arginine-loaded hydrogels were the most porous, with more interconnected pores and also the maximum growth of blood vessels were found around and inside the arginine loaded scaffold. The qualitative analysis for blood vessels showed the significant difference between control, chitosan/collagen alanine loaded hydrogel (CH-Ala), chitosan/collagen phenylalanine loaded hydrogel (CH-Phe) and chitosan/collagen arginine loaded hydrogel (CH-Arg) materials. Among these studied materials the CH-Arg was found more capable for angiogenesis.

Herein we report on the preparation of a bioactive glass (BAG)-based photocurable resin for the additive manufacturing of BAG scaffolds with high filler loadings. The preparation of glass/ceramics resins for stereolithography with high filler loading is always a challenge, especially for fillers with a high refractive index variance. Various photocurable resin compositions with and without bioactive glass fillers have been investigated to see the influence of bioactive glass on physical properties of the resin and resulting green body. The effect of concentration of monomers, reactive diluent, light absorber (Sudan orange G dye), photoinitiator (PI), non-reactive diluent, and fillers (BAG) on rheology and photocuring behavior of the resin and tomography of the resulting 3D structures have been investigated. The BAG contents affect the rheology of resin and influence the rate of the polymerization reaction. The resin compositions with 55-60% BAG, 10% PEG-200 (diluent), 1% of PI and 0.015% of the dye were found to be suitable compositions for the stereolithographic fabrication. A higher percentage of PI caused over-curing, while a higher amount of dye decreased the cure depth of the resin. The micro-computed tomography (µ-CT) and scanning electron microscopic (SEM) images of the resulting green bodies display a relatively dense glass scaffold without any visible cracks and good interlayer connection and surface finishing. These properties play an important role in the mechanical behavior of 3D scaffolds. This study will be helpful to prepare high density glass/ceramic slurries and optimize their printing properties.

For many years, calcium phosphate coatings to tailor the degradation behavior of magnesium and magnesium-based alloys for orthopaedic applications have received lots of research attention. However, prolong degradation behavior, its effect on biological and mechanical properties as well as osteoblastic response to single-step hydrothermally deposited calcium phosphate coatings remain poorly documented. In this study, Alamar blue assay, cell attachment, live/dead assay, and qRT-PCR were done to study the biological response of the coatings. Furthermore, immersion testing in SBF for 28 days and compression testing of the degraded samples were carried out to examine the degradation behavior and its effect on mechanical properties. The results indicated that coatings have a significant influence on both the substrate performance and structural integrity of coated AZ91-3Ca alloy. Immersion test revealed that coating deposited at pH 7, 100°C (CP7100) improves the hydrogen evolution rate by 65% and the degradation rate by 60%. As the degradation performance of coated samples improves so does the mechanical strength. CP7100 samples successfully retained 90% of their compressive strength after 14 days of immersion while bare AZ91-3Ca alloy lost its mechanical integrity. Furthermore, biological studies show that cells are happily proliferating, differentiating, and adhering to the coating surfaces, which indicates, improved osteointegration and osteogenesis with no sign of alkaline poisoning. qRT-PCR results showed that calcium phosphate coatings enhanced the mRNA levels for RUNX2, Col1A, and ALP that may exhibit a speedy bone recovery. Thus, calcium phosphate coatings produced via a single-step hydrothermal method improve the degradation behavior, mechanical integrity and stimulate the differentiation of osteoblast lining. This leads toward faster bone regeneration, which shows a great potential of these coatings to be used on degradable implants as a bioactive protective layer.

In the current study, boric acid loaded chitosan (CS) and collagen-based hydrogels were prepared. Hydrogels with four different boric acid concentrations were prepared; control hydrogel (wi...

Development of economical bone repair materials that can avoid bone infections is a necessity. Hydroxyapatite (HA) and grafted hydroxyapatite (g-HA) were prepared by the in situ co-precipitation method and explored for controlled delivery of moxifloxacin. It was revealed that high surface area, surface charge, and low degree of crystallinity of g-HA enhanced its electrostatic interaction with an antibiotic moxifloxacin and improved in vitro release of the drug as compared to pure HA. In vitro antibacterial activity showed that drug release from HA and g-HA was effective against Staphylococcus aureus and Escherichia coli. The biocompatibility of HA and g-HA was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

In graphene oxide (GO) reinforced composite materials, the uniform dispersion of GO and its interaction with matrix is highly desired for better mechanical properties. In order to achieve better interlocking and uniform microstructure, ion interaction approach has been used for the synthesis of GO and bioactive glass ceramics (BGC) composites. Oxygenated functional groups of GO played a decisive role in GO and BGC interlocking and towards the uniform homogeneity of the composite. GO-BGC composites with different GO to BGC weight ratios (0.5 to 2.0 wt.-%) were synthesized via the base-catalyzed sol-gel method and characterized by FTIR, RAMAN, SEM, TGA-DSC, and X-Ray diffraction techniques. An increase in micro-hardness was observed with the addition of GO up to 1 wt.-%, however, further loading led to a decrease in hardness. Moreover, GO-BGC composites were thermally more stable as compared to pristine GO. Bio-mineralization studies showed that composites were bioactive and GO supported the formation of the apatite layer. Furthermore, the composites were cytocompatible as was demonstrated by MTT assay using rat mesenchymal stem cells. This study can provide interesting insights into the synthesis and applications of novel composite biomedical materials.

Injectable, self-setting calcium phosphate cements (CPCs) are synthetic bone substitutes considered favorable for the repair and regeneration of bone due to their osteocompatibility and unique handling properties. However, their clinical applicability can be compromised due to insufficient cohesion upon injection into the body coupled with poor degradation rates that restricts new bone formation. Consequently, carboxymethyl cellulose (CMC) was incorporated into CPC formulations to improve their cohesion and injectability while poly (D,L -lactic-co-glycolic acid) (PLGA) porogens were added to introduce macroporosity and improve their biodegradation rate. Like most biomaterials, CPCs are gamma irradiated before clinical use to ensure sufficient sterilization. However, it is well known that gamma irradiation also reduces the molecular weight of CMC and PLGA via chain scission, which affects their material properties. Therefore, the aim of this study is to measure the effect that gamma irradiation has on the molecular weight of CMC at varying doses of 15, 40, or 80 kGy and investigate how this affects the handling (i.e., injectability, cohesion, washout, and setting times) and in vitro degradation behavior of CPC formulations. Results reveal that the molecular weight of CMC decreases with increasing gamma irradiation dose, thereby reducing the viscosifying capabilities of CMC, which causes CPCs to deteriorate more readily. Further, the addition of CMC seems to inhibit the degree of phase transformation during cement setting while the subsequent reduction in molecular weight of PLGA after gamma irradiation improves the in vitro degradation rate of CPCs due to the faster degradation rate of low molecular weight PLGA. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2216-2228, 2019.

Skin has a highly regulated pH environment of around pH 7.2 but with an acid barrier mantle of around pH 5.5. Trauma, inflammation, and infection are all thought to disrupt this pH environment but ...

Raman spectroscopy can detect conformational changes in collagen structures and these findings are reviewed in this article. More specifically, some progressive diseases are mainly caused by altera...

Magnesium and Mg-alloys are suitable replacement to metallic implants (Titanium, stainless steel, Co-Cr alloys) in terms of stress shielding effect and repeated surgery requirement. However, the only hindrance in their successful use as biodegradable orthopedic implants is their high corrosion rates in physiological environment. Thus, in present study, we developed the single step hydrothermal process to deposit bioactive coatings that may lower the corrosion rate. Highly crystalline, cytocompatible, bioresorbable and high strength monetite (CaHPO4) coating successfully produced on Ca-containing Mg-alloy via hydrothermal process. Deposition parameters have significant influence on coatings morphology and degree of crystallinity. XRD pattern indicates sharp, intense and well-defined peaks of monetite along with minor peaks of brucite and spinel phases. SEM study reveals that compact and defects free coatings were deposited at 100 °C. FTIR analysis showed all characteristic peaks that confirms the presence of monetite. Corrosion behavior of coated and uncoated specimen were analyzed using potentiodynamic polarization scan in simulated body fluid (SBF) at 37 °C. Calcium phosphate (CaP) coating significantly improve the degradation rate of Mg-alloy. Corrosion rate was 80% lower in CaP coated Mg-alloy specimens than bare Mg-alloy. Adhesion strength of coatings was determined using lap shear test demonstrating a cohesive failure at 21.89 MPa stress. Furthermore, cytotoxicity of coated and uncoated alloy was assessed by using Alamar Blue (AB) assay on NIH3T3 mouse fibroblast cell line for 9 days indicate no significant difference in proliferation of cells for CaP coated Mg-alloy and positive control. These results suggest that hydrothermal method reported here can potentially be used to deposit compact, highly crystalline, bioresorbable, cytocompatible and protective coatings with high adhesion strength on intricate geometries for degradable implant applications.

Use of spectroscopic techniques for clinical applications is increasing rapidly, especially the use of Infrared (IR) and Raman (RS) spectroscopy for the diagnosis of human diseases including infect...

This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively., Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich., Development of a guided occlusive biodegradable membrane with controlled morphology in order to restrict the ingrowth of epithelial cells is still a challenge in dental tissue engineering. A bilayer membrane with a non-porous upper layer (polyurethane) and porous lower layer (polycaprolactone and bioactive glass composite) with thermoelastic properties to sustain surgery treatment was developed by lyophilization. Morphology, porosity, and layers attachment were controlled by using the multi-solvent system. In vitro and in vivo biocompatibility, cell attachment, and cell proliferation were analyzed by immunohistochemistry and histology. The cell proliferation rate and cell attachment results showed good biocompatibility of both surfaces, though cell metabolic activity was better on the polycaprolactone-bioactive glass surface. Furthermore, the cells were viable, adhered, and proliferated well on the lower porous bioactive surface, while non-porous polyurethane surface demonstrated low cell attachment, which was deliberately designed and a pre-requisite for guided tissue regeneration/guided bone regeneration membranes. In addition, in vivo studies performed in a rat model for six weeks revealed good compatibility of membranes. Histological analysis (staining with hematoxylin and eosin) indicated no signs of inflammation or accumulation of host immune cells. These results suggested that the fabricated biocompatible bilayer membrane has the potential for use in periodontal tissue regeneration.

Mucin-1 (MUC-1) is associated with a broad range of human epithelia including gastric, lung and colorectal. In this work, a direct competitive electrochemical immunosensor based on gelatin modified transduction platform was designed. Dopamine (DA)/mucin-1 functionalized electro-active carbon nanotubes were employed as signal generating probes in the construction of electrochemical immunosensor for early stage diagnosis of breast cancer. The gelatin modified electrode served as a support to immobilize antibody (anti-MUC-1), while electrochemical response of functionalized electro-active carbon nano probes was used for quantitative measurement of MUC-1. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out to characterize the transduction surface at different fabrication steps. The developed immunosensor permitted the detection of MUC-1 in the linear range of 0.05−940 U/mL, with a detection limit (LOD) of 0.01 U/mL. The immunosensor showed recovery values in the range of 96% for human serum sample analysis, demonstrating its practical applicability.

Formation of blood vessels during bone regeneration represents a major challenge for tissue engineered constructs. Poor revascularization can lead to scaffold failure and consequently, leads to non-healing fracture. Heparin is known to bind with angiogenic growth factors influencing the process of new blood vessels formation. There are several problems associated with the use of growth factors in clinic such as low stability, uncontrolled delivery to the site, and high price. The aim of the present study was to explore the potential of heparin to produce pro-angiogenic bone regeneration materials. Chitosan/hydroxyapatite freeze-gelled scaffolds were prepared and loaded with heparin. Different concentrations of heparin were successfully loaded onto the scaffolds, its release from the scaffold was analysed by toluidine blue assay and their angiogenic effect was evaluated by chorioallantoic membrane (CAM) assay to determine the optimal concentration of heparin to induce a proangiogenic effect. It was noted that low heparin concentrations exhibited a positive effect, with approximately 28 μg per scaffold indicating a significant increment in blood vessels. The synthesized materials showed no cytotoxic effects when evaluated by using U2OS cell line.

Hydroxyapatite (HA) is a synthetic bio-ceramic very much like biological apatite which is the mineral constituent of bone. Biological apatite, however, varies in chemical composition with the presence of several additional ions such as Mg+2, Zn+2, Mn+2, Na+, K+, Sr+2, CO3−2, HPO4−2, F−1 and SiO4−4. These ions are responsible for specific biological functions; therefore, their substitution into the HA lattice is of interest. Zinc (Zn+2) is of interest due to its presence in all biological tissues and role in various biological functions. Traditional methods for synthesis of phase pure or substituted HA are either time consuming or require expensive methodologies. Traditional co-precipitation method often requires ageing time up to 24 h or more, in order to ensure that the precipitated amorphous apatitic phase attains stoichiometry ratio (i.e. Ca:P molar ratio of 1.67). Stochiometric ratio also plays an important role in thermal stability. It was envisaged that microwave irradiation of pre-precipitated suspensions can be used as a quick route for synthesis of zinc substituted calcium phosphates. This study, therefore, explores the possibility of incorporating zinc into the apatitic structure, the effect of zinc concentration and temperature on phase-purity and morphology. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Fourier Transform Infra-Red Spectroscopy were used to characterize the materials. Increasing zinc content influenced phase-purity and thermal stability of the resulting material.

Formation of blood vessels during bone regeneration represents a major challenge for tissue engineered constructs. Poor revascularization can lead to scaffold failure and consequently, leads to non-healing fracture. Heparin is known to bind with angiogenic growth factors influencing the process of new blood vessels formation. There are several problems associated with the use of growth factors in clinic such as low stability, controlled delivery to the site, and price. The aim of the present study was to explore the potential of heparin to produce pro-angiogenic bone regeneration materials. Chitosan/hydroxyapatite freeze-gelled scaffolds were prepared and loaded with heparin. Different concentrations of heparin were successfully loaded onto the scaffolds, its release from the scaffold was analysed by toluidine blue assay and their angiogenic effect was evaluated by chorioallantoic membrane (CAM) assay to determine the optimal concentration of heparin to induce a proangiogenic effect. It was noted that low heparin concentrations exhibited a positive effect, with approximately 28 µg per scaffold indicating a significant increment in blood vessels. The synthesized materials showed no cytotoxic effects when evaluated by using U2OS cell line.

Introduction: Raman and Infrared spectroscopic techniques are being used for the analysis of different types of cancers and other biological molecules. It is possible to identify cancers from normal tissues both in fresh and fixed tissues. These techniques can be used not only for the early diagnosis of cancer but also for monitoring the progression of the disease. Furthermore, chemical pathways to the progression of the disease process can be understood and followed. Areas covered: More recently, Artificial Intelligence (AI), Neural Network (NN), and Machine Learning are being combined with spectroscopy, which is making it easier to understand the chemical structural details of cancers and biological molecules more precisely and accurately. In this report, these aspects are being outlined by using breast cancer as a specific example. Expert opinion: A pathway showing to combine vibrational spectroscopy with AI and ML has immense potential in predicting various stages of different disease processes, in particular, in cancer diagnosis, staging, and designing treatment. This will result in improved patient care pathways.

The aim of this study was anin-situsynthesis of hydroxyapatite (HA) on cellulose fibers to be used as a new reinforcing agent for dental restorations. The microwave irradiation method was used for synthesis and the materials were characterized with analytical techniques. The prepared dental resin composites were mechanically tested by a universal testing machine and electrodynamic fatigue testing system. FTIR, XRD, SEM/EDS analysis confirmed the successful synthesis of HA on cellulose fibers. The Alamar blue biocompatibility assay showed more than 90% cell viability for the prepared cellulose/HA. The mechanical properties of resin composites improved with cellulose content from 30 wt.% to 50 wt.% in the polymer matrix. Substantially, increasing the cellulose/HA content from 40% to 50% improved the mechanical properties. The results suggested that HA could be successfully synthesized on cellulose fibers using microwave irradiation and contributed to improving the mechanical properties of dental resin composites.

Coronavirus was for the first time identified in 1960 as a cause of common cold. It is an enveloped RNA virus, single-stranded with a pleomorphic or spherical shape having projections of glycoprote...

Biomaterials that promote angiogenesis are required for repair and regeneration of bone. In-situ formed injectable hydrogels functionalised with bioactive agents, facilitating angiogenesis have high demand for bone regeneration. In this study, pH and thermosensitive hydrogels based on chitosan (CS) and hydroxyapatite (HA) composite materials loaded with heparin (Hep) were investigated for their pro-angiogenic potential. Hydrogel formulations with varying Hep concentrations were prepared by sol&ndash, gel technique for these homogeneous solutions were neutralised with sodium bicarbonate (NaHCO3) at 4 &deg, C. Solutions (CS/HA/Hep) constituted hydrogels setting at 37 &deg, C which was initiated from surface in 5&ndash, 10 minutes. Hydrogels were characterised by performing injectability, gelation, rheology, morphology, chemical and biological analyses. Hydrogel solutions facilitated manual dropwise injection from 21 Gauge which is highly used for orthopaedic and dental administrations, and the maximum injection force measured through 19 G needle (17.191 &plusmn, 2.296N) was convenient for manual injections. Angiogenesis tests were performed by an ex-ovo chick chorioallantoic membrane (CAM) assay by applying injectable solutions on CAM, which produced in situ hydrogels. Hydrogels induced microvascularity in CAM assay this was confirmed by histology analyses. Hydrogels with lower concentration of Hep showed more efficiency in pro-angiogenic response. Thereof, novel injectable hydrogels inducing angiogenesis (CS/HA/Hep) are potential candidates for bone regeneration and drug delivery applications.

Introduction Diabetic wounds are challenging to treat due to a wide range of pathophysiological changes. Hypoxia is one of the predominant contributing factors of poor vascularization and chronicity in diabetic wounds. This study was designed to develop polycaprolactone (PCL) -based oxygen-releasing electrospun wound dressings and evaluate their efficacy for improved full thickness wound healing in diabetic rats. Methods PCL-based oxygen releasing wound dressings were made using electrospinning technology. The developed dressings were characterized in terms of physical as well as biological properties both in vitro and in vivo. E-spun nanofibrous dressings were physically characterized with scanning electron microscopy, Fourier-transform infrared spectroscopy , and Energy-dispersive X-ray spectroscopy. To study the likely impact of the fabricated wound dressings in hypoxic conditions, HIF-1α expression analysis was carried out both at gene and protein levels. Wound dressings were further evaluated for their healing potential for extensive wounds in diabetic rat models. Results The experimental results showed that the developed dressings were capable of continuously generating oxygen for up to 10 days. Cell studies further confirmed pronounced expression of HIF-1α at gene and protein levels in cells seeded on PCL-sodium percarbonate (SPC) and PCL scaffolds compared with the cells cultured on a tissue culture plate. Chorioallantoic membrane assay revealed the supportive role of oxygen releasing dressings on angiogenesis compared to the control group. Histological assessment of the regenerated skin tissues proved that full thickness wounds covered with SPC loaded PCL dressings had a comparatively better vascularized and compact extracellular matrix with completely covered thick epithelium. Discussion The developed oxygen generating polymeric nanofibrous wound dressings could potentially be used as an envisioned approach for the efficient recovery of chronic diabetic wounds.

The success of a dental implant relies on the presence of an optimal alveolar ridge. The aim of this study was to fabricate HPMC crosslinked chitosan based scaffolds for alveolar bone repair. Our results indicated that HPMC crosslinked CH/BG foams presented better morphological structure (132-90.5 μm) and mechanical responses (0.451 MPa with 100 mg BG) as confirmed by SEM analysis and fatigue testing respectively. Cytotoxicity analysis at day 2, 4 and 8 demonstrated that all composites were non-toxic and supported cellular viability. Calcein AM/propidium iodide staining, Hoechst nuclear staining and cell adhesion assay reiterated that scaffolds supported pre-osteoblast cell growth, adhesion and proliferation. Differentiation potential of pre-osteoblast cells was enhanced as confirmed by alkaline phosphate assay. Furthermore, loss of S. aureus viability as low as 35% was attributed to synergistic effects of components. Overall, our results suggest that HPMC crosslinked scaffolds are potential candidates for alveolar bone repair.

This research paper demonstrates efficacy of chitosan and thyroxine loaded chitosan (CS) dressings for their angiogenic and wound healing potential. The dressings were prepared by freeze gelation method. Thyroxine was loaded by physical adsorption into chitosan membranes. The porosity was analyzed by scanning electron microscopy (SEM) and chemical structures were investigated by Fourier transform infra-red spectroscopy (FTIR). Cell culture studies showed materials were non-toxic and chorioallantoic membranes assay (CAM) confirmed that the thyroxine loaded chitosan stimulated angiogenesis much higher than simple chitosan dressings. In addition, thyroxine loaded dressings showed excellent wound healing potential when tested on full thickness rats wounds. A good epithelialization was obtained along with robust wound closure. Overall, as compared to chitosan, thyroxine containing membranes showed high level of angiogenesis and fast wound healing.

Preterm birth (PTB) is the single-most important determinant of infant adverse outcome worldwide, accounting for over 1 million neonatal deaths a year. Given its complex pathophysiology, prediction and prevention of PTB remain elusive. Current screening methods lack accuracy and reliability, and have failed to reduce the incidence and consequences of PTB. Hence, there remains a real need to develop noninvasive and more cost-effective screening tests, which can facilitate earlier identification of women at greatest risk, more timely prevention, and better risk stratification and management of PTB. Spectroscopic techniques have shown great promise to meet this demand. Therefore, in this article, the literature is reviewed to assess current evidence regarding the potential application of spectroscopic techniques to predict PTB via in vitro analysis of biofluids as well as in vivo study of cervical remodeling. In addition, preliminary data exploring the use of Raman spectroscopy (RS) to analyze cervicovaginal fluid (CVF) in pregnancy as a predictive tool for PTB is detailed for the first time with the aim to inform future avenues of research.

Osteochondral defects are still a big challenge for the surgeons because of good biocompatibility and higher mechanical strength requiring issues of the implants. In this study, different concentra...

Degradable implant membranes designed to separate hard and soft tissues and to trigger the growth of underlying bone and with antimicrobial properties are needed for the management of bone defects, ridge augmentation and to facilitate dental implants. In this study, the composite scaffolds of poly(lactic acid) (PLA), poly(caprolactone) (PCL) blended with nano hydroxyapatite and cefixime‐β cyclodextrin (Cfx‐βCD) inclusion complexes were synthesized by electrospinning. The prepared electrospun fibrous membranes were characterized by scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. Membranes were microporous with random fibers in the range of 0.2–0.37 µm. The data from FTIR spectral analysis helped to characterize the presence of PCL, PLA, Cfx, and βCD in the electrospun membranes. In addition, the mechanical properties (i.e., elastic modulus and tensile strength) of the scaffolds were investigated. The mechanical strength and suture retention ability of the membranes was comparable to that of skin grafts. Drug release assays confirmed the slow release of Cfx from the membranes in the presence of βCD and antimicrobial studies showed that the membranes possessed antibacterial properties. The interaction of cells with membranes was evaluated by culturing them with the mouse pre‐osteoblast cell line MC3T3 and assessment of bone formation was done using Alizarin Red Assay. Culturing MC3T3 cells on the scaffolds showed that cells attached and entered the membranes and increased in number over time. In summary, these membranes are flexible, strong, bactericidal and osteogenic, which are the ideal implant properties for dental and maxillofacial surgery.

Tissue engineering and regenerative medicine are emerging as future approaches for the treatment of acute and chronic diseases. Numerous clinical conditions exist today and include congenital disorders, trauma, infection, inflammation, and cancer, in which hard and soft tissue damage, organ failure and loss are still not treated effectively. Researchers are constantly developing new biomaterials and tissue-engineered technologies to stimulate tissue regeneration. Various emerging approaches according to organ, tissue, disease and disorder are identified. Irrespective, engineered biomaterials are required to regenerate and ultimately reproduce the original physiological, biological, chemical, and mechanical properties. Biodegradable materials have been used extensively as regenerative therapies. The selection, design, biological and physicochemical properties of these materials are important and must be considered for stimulating tissue growth. In this review, we critique recently developed biodegradable materials for tissue regeneration of some targeted organs e.g., skin, nerves, blood vessels, heart, cornea, trachea, dental/oral structure and bones.