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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.

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.

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.

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.

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 ...

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.

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.

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.

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.

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.

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.

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.

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.

Collagen is the most abundant protein in humans and animals, comprising of one third of the total proteins that accounts for three quarters of the dry weight skin in humans. Collagen containing a r...

Bioactive glass (BG) with uniform spherical morphology was prepared by EISA (Evaporation Induced Self Assembly) process using non-ionic Pluronic F127 as structure directing agent and phosphoric acid as a source of P2O5 and compared with conventional precursor triethyl phosphate (TEP). EISA method proceeds through ionic interaction mechanism by protonation of surfactant and silicic species. H3PO4 provides H+ and PO43 − ions in reaction medium which play critical role in reaction mechanism. Hydrogen ions increase the protonation of H2O and surfactant, while PO43 − ions act as bridging molecule between different cations, ensuring incorporation of phosphorus in BG network. TEP participates by proton acceptance mechanism, creating competitive environment. Thus H3PO4 facilitates the formation of BG in presence of non-ionic surfactant Pluronic F127. The prepared glasses were characterized by FTIR, SEM-EDX, TGA-DSC and BET surface analyzer. Uniform spherical morphology, improved dispersity, relatively large surface area and better cells focal attachment were observed for BG-H3PO4, prepared by using H3PO4. SiO2–CaO–P2O5 mol% composition of BG-H3PO4 was (66:24:10) close to the theoretical value (65:25:10), while for BG-TEP the actual ratio was (77:20.5:2.5). The surface reactivity, studied by soaking in simulated body fluid, showed rapid growth of hydroxyapatite with Ca/P ratio 1.67 on BG-H3PO4. The proliferation of MC3T3 cells on BG-H3PO4 was remarkably improved as compared to conventional BG. Thus BG-H3PO4 can be considered for biomedical applications in future especially for drug loading and composite application where homogeneous and uniform structure are of utmost importance.

Alveolar bone loss is associated with infections and its augmentation is a pre-requisite for the success of dental implants. In present study, we aim to develop and evaluate novel freeze dried doxycycline loaded chitosan (CS)/hydroxyapatite (HA) spongy scaffolds where hydroxypropylmethyl cellulose (HPMC) was added as a crosslinker. Scaffolds displayed compressive strength of 14MPa/cm3 and 0.34 as elastic response. The interconnected pore diameter was 41-273μm, favorably provided the template supporting cells and transport. An overall 10% degradation was seen after 14day's studies at pH 7.4 in PBS. Doxycycline hyclate, a frequently used drug to counter oral infections, demonstrated an initial burst release (6-8h), followed by a sustain release profile for the remaining 64h. CS/HA/HPMC scaffolds were nontoxic and promoted pre-osteoblast cell viability as seen with live/dead calcein staining after 24h where scaffolds with 10% and 25% HPMC by weight of scaffold had more viable cells. Scaffolds with 10%, 20% and 25% HPMC by weight of scaffold showed efficient cellular adhesion as seen in scanning electron microscopy images (day 8) indicating that pre-osteoblast cells were able to adhere well on the surface and into the porous structure via cytoplasmic extensions. Hoechst 33258 nuclear staining at day 2 and 8 indicated cell proliferation which was further supported byMTT assay at day 2, 4 and 8. Although all scaffolds supported pre-osteoblast cell viability, alkaline phosphatase (ALP) staining demonstrated that upon induction, differentiation was pronounced in case of scaffolds with 10% HMPC scaffolds. Conclusively, these materials having all the required mechanical and biological properties are potential candidates for alveolar bone regeneration.

The aim was to synthesize bioactive electrospun fibers for biomedical and dental application with improved biocompatibility. In situ precipitation of nano-hydroxyapatite (nHA) was performed with various concentrations (0.5%, 1%, 2%, 3%, and 5% wt/wt) of functionalized multi-walled-carbon nanotubes (MWCNTs) by using microwave irradiation technique. The obtained composites were characterized by Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC), and the cylindrical discs were made for mechanical testing. The failure behavior was analyzed by Scanning Electron Microscope (SEM). CNT and HA/CNT were silanized with γ-methacryloxypropyl-trimethoxysilane (MPTS) and mixed with polyvinyl alcohol (10% wt./vol.) and electrospun to fabricate fibers. The biocompatibility of both fibers was accessed by their effects on angiogenesis in a chick chorioallantoic membrane (CAM) assay. The electrospun fibers were analyzed by SEM. FTIR confirmed the structural behavior of pre and post-silanized HA/CNT. XRD showed the phase purity and crystallinity before and after heat treatment. Mechanical properties showed that 3% loaded HA/CNT has higher compressive strength (100.5±5.9MPa) compared to others and the failure behavior exhibited dispersion of CNT in HA matrix. The HA/CNT electrospun fibers showed significantly more blood vessels formation compared to CNT fibers. These HA/CNT electrospun fibers showed promising results in terms of biocompatibility and with improved mechanical properties of CNT reinforced composites, they can be used in load bearing clinical applications.

The development of new biomaterials with tailored properties is highly desired in tissue engineering field. The neovascularization is essential part of tissue regeneration which provides food and nutrients to cells. There is a real need for proangiogenic biomaterials to assist wound healing. The ideal dressing should be inexpensive and achieve rapid healing with minimal inconvenience to the patient. In this paper, new porous thyroxin containing pro-angiogenic hydrogels were generated via freeze gelation protocol. The chemical structural analysis of the synthesized hydrogels was investigated by Fourier Transform Infrared (FTIR) spectroscopy. The morphology and pore dimensions were studied by scanning electron microscopy (SEM). In swelling studies, 10 μg thyroxine loaded hydrogel (TLH-10) showed greater degree of swelling as compared to 1 μg loaded thyroxine material (TLH-1) and control. The degradation studies were tested in three different media, i.e. phosphate buffer saline (PBS), lysozyme and hydrogen peroxide and relatively higher degradation was seen in hydrogen peroxide. The synthesized materials were implanted on the chick chorioallantoic membrane to investigate their angiogenic potential. The TLH-1 hydrogel stimulated angiogenesis greater than the TLH-10; in this case blood vessels were attached and very much grown into the scaffold. Keywords: Thyroxine, CAM-assay, Chitosan, Collagen, Biodegradable, Tissue engineering, Angiogenesis

Ionic liquid due to its green nature as well as having the ability to dissolve biopolymer, was used in the preparation of collagen and alginate hydrogels. The collagen and alginate hydrogels were prepared in different ratios of collagen and alginate, labeled CA5040, CA6030 and CA7020. The prepared hydrogels were characterized with Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Thermogravimetric analysis (TGA) analysis. The samples were evaluated for water uptake behavior and mechanical properties using electrodynamic fatigue testing system. The biocompatibility was assessed through hemolysis and MTT assay on rat mesenchymal stem cells (rMSC) which showed satisfactory results. The drug loading and subsequent antibacterial properties were also performed. The prepared collagen and alginate hydrogels are suggested to be used for skin dressing.

Angiogenesis is a process of formation of new small blood vessels from existing vessels and is very critical for proper and rapid tissue healing. As reactive oxygen species (ROS) are known for their ability to promote angiogenesis, in this study zinc oxide (ZnO) and zinc peroxide (ZnO2) nano-particles (NP's) encapsulated chitosan (CS) and cellulose based hydrogels were synthesized. ZnO2 is comparatively stronger oxidizing agent as compared to ZnO, therefore, in this study it was hypothesized that ZnO2 would deliver better angiogenic potential than ZnO. Three types of hydrogels were prepared; control hydrogel (without nano-particles), hydrogel having ZnO NP's and hydrogel having ZnO2 NP's. The hydrogels were characterized by scanning electron microscopy (SEM) for structural morphology, Fourier transform infrared spectroscopy (FTIR) for chemical functional groups analyses and X-ray Diffraction (XRD) to investigate the crystalline or amorphous structure of NP's. The solution absorption capacity was tested in PBS and degradation was investigated in PBS, PBS/H2O2 and PBS/lysozyme solutions. The angiogenic behavior of these materials was studied in chorioallantoic membrane (CAM) assay and ZnO2 based material showed significant higher angiogenesis. Keywords: Angiogenesis, Chorioallantoic membrane assay, Zinc oxide nanoparticles, Zinc peroxide nanoparticles, Reactive oxygen species

Raman spectroscopy is an advanced chemical analytical technique that has gained significant interest in cancer research, in particular early detection and monitoring of cancer, with added advantage...

Objective The regeneration of periodontal tissues lost as a consequence of destructive periodontal disease remains a challenge for clinicians. Guided tissue regeneration (GTR) has emerged as the most widely practiced regenerative procedure. Aim of this study was to electrospin chitosan (CH) membranes with a low or high degree of fiber orientation and examines their suitability for use as a surface layer in GTR membranes, which can ease integration with the periodontal tissue by controlling the direction of cell growth. Methods A solution of CH-doped with polyethylene oxide (PEO) (ratio 95:5) was prepared for electrospinning. Characterization was performed for biophysiochemical and mechanical properties by means of scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, swelling ratio, tensile testing and monitoring degradation using pH analysis, weight profile, ultraviolet–visible (UV–vis) spectroscopy and FTIR analysis. Obtained fibers were also assessed for viability and matrix deposition using human osteosarcoma (MG63) and human embryonic stem cell-derived mesenchymal progenitor (hES-MP) cells. Results Random and aligned CH fibers were obtained. FTIR analysis showed neat CH spectral profile before and after electrospinning. Electropsun mats were conducive to cellular attachment and viability increased with time. The fibers supported matrix deposition by hES-MPs. Histological sections showed cellular infiltration as well. Significance The surface layer would act as seal to prevent junctional epithelium from falling into the defect site and hence maintain space for bone regeneration.

A new low-temperature continuous approach for the surface modification of hydroxyapatite (HA) is described. In this method, the HA particle surfaces were modified using methacrylic acid, vinylphosphonic acid, adipic acid, citric acid, or polyvinyalcohol, respectively, using a continuous plastic flow synthesis (CPFS) system at a reaction temperature of 70 °C for 5 min. The materials were investigated using a range of analytical techniques, including TEM (transmission electron microscopy), zeta potential, XRD (X-ray diffraction), BET (Brunauer–Emmett–Teller) surface area analysis, FTIR (Fourier transform infrared) spectroscopy, and XPS (X-ray photoelectron spectroscopy). The presence of organic agents in the reagents, resulted in a significant reduction in particle size of the nano-HA rods; TEM studies confirmed the formation of highly dispersed nanorods of HA with average lengths and diameters in the ranges 20–60 nm and 4–10 nm, respectively. XPS analyses suggested that the Ca:P molar ratio decreased from ...

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.

An oronasal fistula is a passage between the oral and nasal cavity. Currently, surgical procedures use mucosal flaps or collagen grafts to make a barrier between oral and nasal cavities. Our aim was to develop a cell-free synthetic repair material for closure of nasal fistulas. We surface functionalized electrospun polyurethane (PU) and poly-L-lactic acid (PLLA) and composite polymer (PU-PLLA) membranes with acrylic acid through plasma polymerization. Membranes were treated in a layer-by-layer approach to develop highly charged electrostatic layer that could bind heparin as a pro-angiogenic glycosaminoglycan. The properties were evaluated through physical, chemical, and mechanical characterization techniques. Cytotoxicity was tested with MC3T3 pre-osteoblast cell lines for 3, 7, and 14 days, and vasculogenesis was assessed by implantation into the chorio-allantoic membrane in chick embryos for 7 days. In vivo biocompatibility was assessed by subcutaneous implantation in rats for 1, 3, and 6 weeks. The membranes consisted of random fibers of PLLA-PU with fiber diameters of 0.47 and 0.12 μm, respectively. Significantly higher cell proliferation and migration of MC3T3 cells at 3, 7, and 14 days were shown on plasma-coated membranes compared with uncoated membranes. Further, it was found that plasma-coated membranes were more angiogenic than controls. In vivo implantation of membranes in rats did not reveal any gross toxicity to the materials, and wound healing was comparable with the native tissue repair (sham group). We therefore present a plasma-functionalized electrospun composite polymer membrane for use in the treatment of fistulas. These membranes are flexible, non-cytotoxic, and angiogenic, and we hope it should lead to permanent closure of oronasal fistula.

Angiogenesis is one of the most important processes in repair and regeneration of many tissues and organs. Blood vessel formation also play a major role in repair of dental tissue(s) after ailments like periodontitis. Here we report the preparation of chitosan/carboxymethyl cellulose/hydroxyapatite based hydrogels, loaded with variable concentrations of thyroxin i.e., 0.1 μg/ml, 0.5 μg/ml and 1 μg/ml. Scanning electron microcopy images (SEM) showed all hydrogels were found to be porous and solution absorption study exhibited high swelling potential in aqueous media. FTIR spectra confirmed that the used materials did not change their chemical identity in synthesized hydrogels. The synthesized hydrogels demonstrated good bending, folding, rolling and stretching abilities. The hydrogels were tested in chick chorioallantoic membrane (CAM) assay to investigate their angiogenic potential. Hydrogel containing 0.1 μg/ml of thyroxine showed maximum neovascularization. For cytotoxicity analyses, preosteoblast cells (MC3T3-E1) were seeded on these hydrogels and materials were found to be non-toxic. These hydrogels with pro-angiogenic activity possess great potential to be used for periodontal regeneration.

A novel tri-layered, functionally-graded chitosan membrane (FGM) with bioactive glass gradient (50%, 25%, and 0% wt.) was developed by lyophilization. A step-wise grading of chitosan, bioactive glass (BG), and Pluronic F127 was introduced into the membrane in which each layer has separate surface functions that play a role of guided tissue regeneration (GTR) membranes. The lower layer was designed to replicate alveolar bone and contains 50%wt. BG, the middle layer contains 25%wt. BG, while the upper layer was non-porous without BG and it did not support cell growth. Scanning Electron Microscopy (SEM) revealed that the lower FGM surface possessed a porous structure with embedded BG particles, while the upper surface was non-porous with interconnected architecture. The contact angle measurement confirmed that the surface with BG was hydrophilic (≈00), while the opposite surface was hydrophobic (910 ± 3.840). Both osteoblast and fibroblast cells have maximum adhesion at contact angle

With an increase in the demand for skin regeneration products, there is a noticeable increase in developing materials that encourage, wound healing and skin regeneration. It has been reported that antioxidants play an important role in anti-inflammatory reactions, cellular proliferation and remodeling phase of wound healing. While consideration all these factors, a novel α-tocopherol acetate (vitamin E) (VE) loaded bi-layered electrospun membrane, based on lower polycaprolactone (PCL) layer and upper polylactic acid (PLA) layer, was fabricated through electrospinning. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), in-vitro degradation studies, swelling studies and VE release studies were performed to evaluate structural, physical and in-vitro behavior of membranes. Biological properties of membranes were evaluated through cell proliferation assay, cell adhesion studies, live/dead cell assay and CAM assay. SEM images showed that the average diameter of nanofibers ranged from 1 to 6 μm, while addition of VE changed the diameter and morphology of fibers. Bi-layered membranes showed significant swelling behavior through water uptake, membranes loaded with 30% VE showed 8.7% and 6.8% degradation in lysozyme and H2O2 respectively. 20% and 30% VE loaded membranes followed Korsmeyer-Peppas and first order drug release kinetics followed by non-fickian drug release kinetics. Membranes showed non-toxic behavior and supported cell proliferation via alamar blue assay, cell adhesion via SEM, cell viability via live/dead assay and wound healing by scratch assay. CAM assay showed that membranes having VE supported angiogenesis and showed significant formation of blood vessels making it suitable for skin regeneration and wound healing. Results showed that large surface area of nanofibers, porous structure and biocompatible nature are suitable for targeted clinical applications.

Head and neck cancer (HNC) is the sixth most common malignancy worldwide. Squamous cell carcinoma, the primary cause of HNC, evolves from normal epithelium through dysplasia before invading the connective tissue to form a carcinoma. However, less than 18% of suspicious oral lesions progress to cancer, with diagnosis currently relying on histopathological evaluation, which is invasive and time consuming. A non-invasive, real-time, point-of-care method could overcome these problems and facilitate regular screening. Raman spectroscopy is a non-invasive optical technique with the ability to extract molecular level information to help determine the functional groups present in a tissue and the molecular conformations of tissue constituents. In the present study, Raman spectroscopy was assessed for its ability to discriminate between normal, dysplastic and HNC. Tissue engineered models of normal, dysplastic and HNC were constructed using normal oral keratinocytes, dysplastic and HNC cell lines, and their biochemical content predicted by interpretation of spectral characteristics. Spectral differences were evident in both the fingerprint (600/cm to 1800/cm) and high wave-number compartments (2800/cm to 3400/cm). Visible differences were seen in peaks relating to lipid content (2881/cm), protein structure (amide I, amide III), several amino acids and nucleic acids (600/cm to 1003/cm). Multivariate data analysis algorithms successfully identified subtypes of dysplasia and cancer, suggesting that Raman spectroscopy not only has the potential to differentiate between normal, pre-malignant and cancerous tissue models but could also be sensitive enough to detect subtypes of dysplasia or cancer on the basis of their subcellular differences. Copyright © 2016 John Wiley & Sons, Ltd.

This article reviews some of the recent advances on FTIR spectroscopy in areas related to natural tissues and cell biology. It is an update on our previously published review on the applications of...

Periodontal disease is associated with the destruction of periodontal tissues, along with other disorders/problems including inflammation of tissues and severe pain. This paper reports the synthesis of meloxicam (MX) immobilized biodegradable chitosan (CS)/poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) based electrospun (e-spun) fibers and films. Electrospinning was employed to produce drug loaded fibrous mats, whereas films were generated by solvent casting method. In-vitro drug release from materials containing varying concentrations of MX revealed that the scaffolds containing higher amount of drug showed comparatively faster release. During initial first few hours fast release was noted from membranes and films; however after around 5h sustained release was achieved. The hydrogels showed good swelling property, which is highly desired for soft tissue engineered implants. To investigate the biocompatibility of our synthesized materials, VERO cells (epithelial cells) were selected and cell culture results showed that these all materials were non-cytotoxic and also these cells were very well proliferated on these synthesized scaffolds. These properties along with the anti-inflammatory potential of our fabricated materials suggest their effective utilization in periodontital treatments.

Raman spectroscopy is rapidly moving from an experimental technique for the analysis of biological molecules to a tool for the real-time clinical diagnosis and in situ evaluation of the oral tissue in medical and dental research. The purpose of this study is to identify various applications of Raman spectroscopy, to evaluate the contemporary status, and to explore future directions in the field of dentistry. Several in-depth applications are presented to illustrate Raman spectroscopy in early diagnosis of soft tissue abnormalities. Raman spectroscopy allows researchers to analyze histological and biochemical composition of biological tissues. The technique not only demonstrates its role in the disclosure of dysplasia and malignancy, but also in performing guided biopsies, diagnosing sialoliths, and assessment of surgical margins. Raman spectroscopy is used to identify the molecular structures and their components to give substantial information about the chemical structure properties of these mole...

New blood vessel formation is an essential part of wound healing to provide cells with the nutrients and oxygen for their survival. Many nonhealing ulcers fail to heal because of poor blood supply and skin grafts will also fail to take on poorly vascularized wound beds. There is a real need for proangiogenic biomaterials to assist wound healing. In vivo heparin binds proangiogenic growth factors and helps regulate new blood vessel formation, hence heparin containing biomaterials are attractive. To achieve a hydrogel with high heparin binding capacity a composite of chitosan, poly(vinyl alcohol) (PVA) and polycaprolactone (PCL) was produced. Chitosan is a biodegradable natural polymer with great potential for biomedical applications due to its biocompatibility, high charge density and nontoxicity. PVA is biocompatible and nontoxic with good chemical stability, film-forming ability, and high hydrophilicity. PCL has physicochemical and mechanical properties comparable to those of the biological tissu...

A limited blood flow to skeletal tissues results in minimal therapeutic effect of drugs being administered to a patient using conventional ways. To obtain sufficient amount of drug at an effected site, implanted drug delivery systems based on biomaterials can be used. In this study, surface modified hydroxyapatites (m-HA) were prepared and evaluated as drug delivery systems. The effect of modifiers on surface properties of HA and their in vitro drug delivery efficiency were investigated. For synthesis of m-HA, a simple in situ co-precipitation method was used. Hydroxyapatite was subjected to surface modification by various carboxylic acids such as adipic acid, malonic acid, succinic acid and stearic acid. This surface modification affected its surface properties such as surface area, pore size, pore volume, particle size and crystallinity. The m-HA were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Brunauer–Emmett–Teller (BET) technique was used to compute surface properties of m-HA. The highest BET surface area of 143 m2 g−1 has been found for HA modified with malonic acid and the lowest surface area of 37 m2 g−1 was calculated for stearic acid modified HA. The BET adsorption average pore size (17–20 nm) of m-HA confirmed its mesoporous nature. The biocompatible nature of the prepared m-HA was assessed by 3-(4,5)-dimethylthiahiazo(-z-yl)-3,5-di-phenytetrazoliumromide (MTT) assay. To evaluate the influence of functional groups and surface properties of m-HA on drug delivery efficiency, ibuprofen was used as a model drug. In vitro drug delivery experimental results indicated that drug loading and release efficiency relied on functional groups, surface area, and porosity of m-HA. The percentage loading of ibuprofen was good for samples containing free –COOH groups and high surface area. A drug loading of 22 mg g−1 has been found for malonic acid modified HA (ma-HA) having high surface area, pore volume, whereas a poor loading of 2.03 mg g−1 has been observed for stearic acid modified HA (st-HA) sample having low surface area and pore volume. A sustained drug release profile showed that 61% drug had been released from malonic acid modified HA (ma-HA) in 24 hours. A 100% drug release was observed for st-HA in 8 hours. Succinic acid modified HA and adipic acid modified HA exhibited intermediate drug release profiles. The drug release behavior of m-HA followed Fick's laws of diffusion.

Bioactive glasses (BGs) as third generation biomaterials have the ability to form an interfacial bonding more rapidly than other bioceramics between implant and host tissues in defect treatment. Therefore, BGs have shown great applications in the field of bone tissue engineering, dental materials, skin and other tissue regeneration. This review is based on inorganic and organic BG composites being used in bone tissue engineering and summarizes current developments in improving the biological behavior of BGs and their composites. A main focus was given to highlight the role of BGs and their composites in osteogenic differentiation and angiogenesis, followed by their cytotoxicity, protein adsorption ability and antibacterial properties. BGs were found to enhance the cell proliferation and cell attachment without any toxic effects with a significant increase in metabolic activity and possess osteogenic properties. Organic and inorganic dopants have been used to improve their cytocompatibility, osteoconductivity and promote stem cell differentiation towards the osteogenic lineage. BGs have also been used as graft materials because of their significant role in angiogenesis, as they stimulate relevant cells (i.e. fibroblasts, osteoblasts and endothelial cells) to release angiogenic growth factors. They show good protein adsorption because they act as templates for the adsorption of proteins which in turn depends upon surface properties. Antibacterial effects were also observed in BGs as a result of the high aqueous pH value in body fluids due to the presence of alkaline ions. There has been significant research work performed on silica-based bioactive glasses but not much literature can be found on phosphate- and borate-based bioactive glasses, which have good solubility and degradation, respectively.

In the present study, cuttlefish bones are used to prepare highly porous hydroxyapatite (HA) scaffolds via hydrothermal treatment at 200 °C. Raw cuttlefish bones (CB) and the hydrothermal products have been analyzed and compared for their composition and microstructure, using X-ray powder diffraction (XRD), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), porosity estimation and compressive strength measuring techniques. Characterization reveals that cuttlebone has high porosity approaching above 70%, and possesses the laminar structure of aragonite mixed with some organic materials. The compressive strength of the CB-HA is improved after coating with both polyvinyl alcohol (PVA) and polycaprolactone (PCL). Furthermore, our in vitro biocompatibility studies revealed that CB-HA and PVA coated CB-HA scaffolds are non-cytotoxic and support the adherence and proliferation of rMSCs, comparable to pure HA scaffolds. Altogether, our results suggest that naturally derived CB-HA, PVA and PCL coated CB-HA scaffolds are potential cheap candidates for bone tissue engineering applications, and also that PVA and PCL coatings provide better mechanical strength.

Nanoparticles are well recognized for their biological applications including tissue-regeneration due to large surface area and chemical properties. In this study, K-doped zinc oxide (ZnO) nanoparticles containing porous hydrogels were synthesized via freeze gelation. The morphology and pore dimensions were studied by scanning electron microscopy (SEM). The chemical structural analysis of the synthesized hydrogels was investigated by Fourier Transform Infrared (FTIR) spectroscopy. In swelling studies, material containing ZnO nanoparticles with 2% potassium dopant concentration CLH-K2.0) showed greater degree of swelling as compared to all other materials. The degradation studied was tested in three different degradation media, i.e. phosphate buffer saline (PBS), lysozyme and hydrogen peroxide and relatively higher degradation was seen in hydrogen peroxide. The synthesized hydrogels were implanted on the chick chorioallantoic membrane (CAM) to investigate their angiogenic potential. The CLH-K2.0 hydrogel stimulated angiogenesis greater than all other materials; blood vessels were attached and grown inside this scaffold, showing its strong angiogenic potential.