Preparation and Characterisation of High Aspect Ratio Materials for Bone Tissue Engineering

Abstract

This research work aims to give an overview of the synthesis of high aspect ratio materials for bone tissue engineering. The work was carried out using high aspect materials of both natural (micro fibrillated cellulose from jute, spider silk, cocoon silk) and synthetic grade (MgO and ZnO nanorods). Micro fibrillated cellulose was extracted from jute by washing it thoroughly with sodium hydroxide and bleaching it with hydrogen peroxide followed by acid hydrolysis with sulphuric acid. Spidroin was extracted from spider silk using different benign solvents and fibroin was extracted from Bombyx mori following the lithium bromide standard protocol. Hydrothermal method was followed for synthesis of magnesium oxide and zinc oxide nanorods. Micro fibrillated cellulose was characterized by SEM, XRD, FTIR, DSC, TGA, dispersion studies, and phytochemical tests. Spidroin and fibroin was analyzed using Fluorescence microscopy, FTIR, and CD. Magnesium oxide and zinc oxide nanorods were characterized using SEM, and XRD. Also, a comparative in-vitro cytotoxicity of all these materials was checked using adipose derived stem cells (ADSCs). From the SEM results it was found that the cellulose extracted from jute were micro fibrillated. The FTIR and XRD data showed that cellulose type II was extracted. Also the degradation of cellulose at 270 °C was confirmed from TGA results. Both spidroin and fibroin was successfully extracted using simple benign solvents. FTIR and CD data showed the presence of good amount of ß-sheets. FESEM of both MgO and ZnO showed that the nanoparticles agglomerated together to form nanorod like structure. The MTT study revealed that spider silk was more compatible followed by cocoon silk, cellulose, MgO and ZnO. This concludes that while both the high aspect ratio as well as the biocompatibility of the materials is an important factor designing materials for load bearing application.