Three Dimensional Nanofibrous Scaffold of Chitosan/Strontium-Substituted Calcium Phosphate for Bone Tissue Engineering

Abstract

Because of the biocompatibility biodegradability and better mechanical properties chitosan is a good choice for tissue engineering materials In the applications of tissue engineering chitosan has been used for cell cultures For example bone cartilage skin nerve and so on Among the above bone and cartilage cells are the most used in the cell culture Chitosan has many attractive properties to be good culture template owing to the promoting wound healing and antibiotic Hydroxyapatite (HA) is one of the major compositions in human bone Due to its good biocompatibility osteoconductivity non-toxic and non-irritating hydroxyapatite is a good material of implants Strontium (Sr) is a trace element in human body and 98% of the total content exists in the skeleton It can enhance the number and activity of osteoblasts as well as reduce the number and activity of osteoclasts Therefore Sr-substituted hydroxyapatite (SrHA) also can improve bone formation and inhibit bone resorption In this study HA and SrHA are synthesized under chemical precipitation method and hydrothermal method Microstructure was observed with transmission electron microscopy (TEM) Through the analyses of energy dispersive x-ray spectroscopy (EDS) X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FTIR) the calcium phosphate with syntheses was mainly hydroxyapatite and combined with strontium Bioceramics and polymers have some defects Consequently chitosan HA and SrHA are used to be bone repair materials in this study Besides the popular and novel technique "Electrospinning" was used to fabricate chitosan nanofibrous scaffolds containing calcium phosphate Electrospining provided porous structures which are quite similar to the extracellular matrix (ECM) With field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) the images showed the calcium phosphate particles were well-dispersed in the nanofibers With the spectrums of energy dispersive x-ray (EDS) X-ray diffraction (XRD) and Fourier transform infrared (FTIR) the existence of calcium phosphate was proved After 14-day immersion in SBF SEM images showed the deposition of apatite on the surface and the release of strontium ion in SBF was observed through inductively coupled plasma-mass (ICP) analysis In vitro test by Alamar blue and ALP assay cells (MC3T3-E1) proliferate and differentiate the most at the scaffolds containing SrHA and the scaffolds are suitable for bone tissue repair

Date of Award	2015 Feb 13
Original language	English
Supervisor	Tzer-Min Lee (Supervisor)