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

• Main Author: Chahal, Sugandha
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: Q Science (General)
• Online Access: http://umpir.ump.edu.my/id/eprint/18217/19/Electrospun%20hydroxyethyl%20cellulose%20nanofibrous%20scaffolds%20functionalized%20with%20hydroxyapatite%20for%20bone%20tissue%20engineering.pdf; http://umpir.ump.edu.my/id/eprint/18217/
• Institution: Universiti Malaysia Pahang

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.