Electrospun hydroxyethyl cellulose nanofibrous scaffolds functionalized with hydroxyapatite for bone tissue engineering

Bone tissue engineering focuses on using scaffolds as vital substitute to regenerate the bone structure and therefore recover the function of bone tissue. Selection of the suitable material is an important step towards the construction of bioactive engineered scaffolds with appropriate surface architecture, biocompatibility, biodegradability and biomechanical properties that can mimic the natural bone extracellular matrix (ECM). The main aim of this research is to prepare bio-compatible and biodegradable scaffolds based on hydroxyethyl cellulose (HEC) using water as the only solvent. The biochemically and functionally designed nanofibrous scaffolds of HEC polymer with polyvinyl alcohol (PVA) were prepared by electrospinning technique. HEC was blended with PVA in various weight concentrations to get a suitable viscosity for electrospinning. For functionalization of HEC/PVA nanofibers, the nanohydroxyapatite (nHA) particles were synthesized and then reinforced in HEC/PVA scaffolds through electrospinning. Furthermore, bio-mineralization of HEC/PVA scaffolds was performed using simulated body fluid (SBF) and alternate calcium phosphate (ACP) soaking process to mimic ECM. The cytocompatibility of unmineralized and mineralized scaffolds was evaluated by in-vitro cell culture studies. Scanning electron microscopy and Field emission scanning electron microscopy were used for structural analysis. Mechanical properties were investigated by Universal testing machine. Energy dispersive X-ray, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Thermo-gravimetric analysis, Differential scanning calorimetery and Dynamic mechanical analysis were used to analyse chemical, and thermal properties of scaffolds. The prepared nanofibrous scaffolds exhibit excellent morphology with interconnected porous structure. Changing HEC concentration had great influence on the structure and properties of the scaffolds. With increasing HEC concentration, the fiber diameter decreased and pore size increased. The diameters of electrospun nanofibrous scaffolds varied in the range of 379 nm to 524 nm and the pore sizes varied from 9 μm to 6 μm.The results revealed that the biocompatible HEC/PVA scaffolds possess good mechanical and chemical properties. The rod like nHA particles with chemical composition of natural bone minerals was successfully prepared by wet chemichal method. The results confirmed the reinforcement of nHA patricles in HEC/PVA electrospun nanofibers. Coating of mineral cystals was found on the surface of scaffolds after bio-mineralization. The deposition of biomimetic minerals increased with time of immersion in SBF and nHA deposition was found to increase with high content of HEC during ACP soaking process. The influence of biomineralization was observed with improved bioactivity and mechanical properties of the scaffolds. The enhancement in properties after mineralization could be due to the presence of mineral particles on nanofibrous scaffolds which allows the penetration and migration of cells and provides good mechanical strength with strong chemical interaction. These results suggest that the HEC/PVA scaffolds are promising biomaterials for bone tissue engineering

Characterization of Modified Cellulose (MC)/Poly (vinyl alcohol) Electrospun Nanofibers for Bone Tissue Engineering

In bone tissue engineering a variety of polymers were used to develop a suitable artificial bioactive scaffold for bone tissue regeneration. In this present study, we were using modified cellulose. Randomly oriented nanofibrous scaffolds of MC and poly (vinyl alcohol) (PVA) were synthesized by electrospinning technique. The blend solutions of MC/PVA with different weight ratio of MC to PVA were prepared using water as solvent to fabricate nanofibers. The morphology, diameter of electrospun nanofibers was studied using SEM. The crystalline and thermal properties of nanofibers were investigated by DSC and chemical characterization by FTIR analysis. These results showed that MC/PVA nanofibrous scaffold provides a beneficial frame for bone tissue engineering

Scaffolds from Chemically Modified Cellulose Nanofibers for Skin Tissue Engineering

The objective of this research is to develop a three-dimensional porous scaffold to support cell adhesion and proliferation and to guide cells moving into the repair area in the wound healing process by using electrospinning technique. A series of modified cellulose/PVA nanofibers scaffolds in different concentrations were prepared and blended to evaluate the optimal tissue engineering scaffold. The cross-linking nanofibers scaffolds were characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). SEM images revealed that with decreasing cellulose content the average diameters of blend nanofibers were increased from 241±17.03 to 320±27.17 nm. Biocompatibility assay showed cells attached and spread actively on all modified cellulose nanofibers scaffolds with globular morphology after 7 days culturing which exhibit excellent biocompatibility and enhancement of cell penetration and growth within nanofibers mats. Results indicate that the modified cellulose have potential application in skin tissue engineering

Development of biomimetic electrospun polymeric biomaterials for bone tissue engineering. A Review

201

Development of biomimetic electrospun polymeric biomaterials for bone tissue engineering. A review

Electrospinning is a promising and versatile technique that is used to fabricate polymeric nanofibrous scaffolds for bone tissue engineering. Ideal scaffolds should be biocompatible and bioactive with appropriate surface chemistry, good mechanical properties and should mimic the natural extracellular matrix (ECM) of bone. Selection of the most appropriate material to produce a scaffold is an important step towards the construction of a tissue engineered product. Bone tissue engineering is an interdisciplinary field, where the principles of engineering are applied on bone-related biochemical reactions. Scaffolds, cells, growth factors, and their interrelation in microenvironment are the major concerns in bone tissue engineering. This review covers the latest development of biomimetic electrospun polymeric biomaterials for bone tissue engineering. It includes the brief details to bone tissue engineering along with bone structure and ideal bone scaffolds requirements. Details about various engineered materials and methodologies used for bone scaffolds development were discussed. Description of electrospinning technique and its parameters relating their fabrication, advantages, and applications in bone tissue engineering were also presented. The use of synthetic and natural polymers based electrospun nanofibrous scaffolds for bone tissue engineering and their biomineralization processes were discussed and reviewed comprehensively. Finally, we give conclusion along with perspectives and challenges of biomimetic scaffolds for bone tissue engineering based on electrospun nanofibers

Biomimetic Growth of Bone-Like Apatite Via Simulated Body Fluid on Hydroxyethyl Cellulose/Polyvinyl Alcohol Electrospun Nanofibers

In this study, randomly oriented hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibers were fabricated by electrospinning. The blend solutions of HEC/PVA with different weight ratio of HEC to PVA were prepared using water as solvent to fabricate nanofibers. These nanofibrous scaffolds were coated with bone-like apatite by immersing into 10x simulated body fluid (SBF) for different time periods. The morphology and structure of the nanofibers were characterized by SEM, FTIR and DSC. FESEM-EDS and FTIR analysis were used to confirm the deposition of apatite on the surface of nanofibers. The results of this study suggest that this apatite coated nanofibrous scaffolds could be a suitable biomaterial for bone tissue engineering

Cross-Linking Effect on Electrospun Hydroxyethyl Cellulose/Poly(Vinyl Alcohol) Nanofibrous Scaffolds

The electrospinning of hydroxyethyl cellulose/poly(vinyl alcohol) (HEC/PVA) was carried out with glutaraldehyde as a cross li nker to fabricate water insoluble nanofibers. The concentration of HEC (5wt%) and PVA (15wt%) was prepared and blended in different weight ratios of HEC to PVA (50:50, 40:60 and 70:30) were electrospun to get nanofibers. The microstructure of the obtained nanofibers were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) before and after crosslinking. SEM images showed that there was no swelling or remarkable changes in the surface morphology after treated with glutaraldehyde. XRD analysis il lustrated the effect of crosslinking on the crystallinity of the nanofibers. The results showed that these crosslinked HEC/PVA fibers were suitable for variety of applications such as tissue engineering scaffolds, drug delivery and medical prostheses

Fabrication, Characterization and In Vitro Biocompatibility of Electrospun Hydroxyethyl Cellulose/poly (vinyl) Alcohol Nanofibrous Composite Biomaterial for Bone Tissue Engineering

Development ofnovel scaffold materials that mimic the extracellular matrix, architecturally and func- tionally, is becoming highly important to meet the demands of the advances in bone tissue engineering. This paper reports, the fabrication of natural polymer cellulose derived hydroxyethyl cellulose(HEC) based nanostructured scaffolds with uniform fiber morphology through electrospinning. Poly(vinyl alcohol) (PVA) was used as anionic solvent for supporting the electrospinning of HEC. Scanning electron microscopy and ImageJ analysis revealed the formation of non-woven nanofibers with well-defined porous architecture. The interactions between HECandPVA in the electrospun nanofibers were studied by differential scanning calorimetry, X-raydiffraction, dynamic mechanical analysis thermo-gravimetric analysis; Fourier transform-infrared spectroscopy,X-ray photoelectronspectroscopy and tensiletest. The mechanical properties of scaffolds were significantly altered with different ratios of HEC/PVA. Further, the biocompatibility of HEC/PVAscaffolds was evaluated using human osteosarcomacells. TheSEM images revealed favorable cellsattachment and spreading on the nanofibrous scaffolds and MTS assay showed increased cell proliferation afterdifferent time periods. Thus, these results indicate that HEC based nanofibrous scaffolds will be a promising candidate for bone tissue engineering

Fabrication, characterization and in vitro biocompatibility of electrospun hydroxyethyl cellulose/poly (vinyl) alcohol nanofibrous composite biomaterial for bone tissue engineering

Development of novel scaffold materials that mimic the extracellular matrix, architecturally and functionally, is becoming highly important to meet the demands of the advances in bone tissue engineering. This paper reports, the fabrication of natural polymer cellulose derived hydroxyethyl cellulose (HEC) based nanostructured scaffolds with uniform fiber morphology through electrospinning. Poly (vinyl alcohol) (PVA) was used as an ionic solvent for supporting the electrospinning of HEC. Scanning electron microscopy and ImageJ analysis revealed the formation of non-woven nanofibers with well-defined porous architecture. The interactions between HEC and PVA in the electrospun nanofibers were studied by differential scanning calorimetry, X-ray diffraction, dynamic mechanical analysis thermo-gravimetric analysis; Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy and tensile test. The mechanical properties of scaffolds were significantly altered with different ratios of HEC/PVA. Further, the biocompatibility of HEC/PVA scaffolds was evaluated using human osteosarcoma cells. The SEM images revealed favorable cells attachment and spreading on the nanofibrous scaffolds and MTS assay showed increased cell proliferation after different time periods. Thus, these results indicate that HEC based nanofibrous scaffolds will be a promising candidate for bone tissue engineering

Nanohydroxyapatite-coated hydroxyethyl cellulose/poly (vinyl) alcohol electrospun scaffolds and their cellular response

The present study focused on the preparation of nanohydroxyapatite (nHA)-coated hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibrous scaffolds for bone tissue engineering application. The electrospun HEC/PVA scaffolds were mineralized via alternate soaking process. FESEM revealed that the nHA was formed uniformly over the nanofibers. The nHA mineralization enhanced the tensile strength and reduced the elongation at breakage of scaffolds. The wettability of the nanofibrous scaffolds was significantly improved. The in vitro biocompatibility of scaffolds was evaluated with human osteosarcoma cells. nHA-coated scaffolds had a favorable effect on the proliferation and differentiation of osteosarcoma cell and could be a potential candidate for bone regeneration