Study On Injectable Chitosan Hydrochloride Based Scaffold In Bone Tissue Engineering

To engineer living tissue in vitro, selected cells are coaxed to grow on bioactivedegradable scaffolds that provide three-dimensional space in favor of cell metabolismand assembly into three-dimensional tissues. The scaffold in tissue engineering can bemodulated between flexibility and rigidity according to polymer properties. Thepreformed scaffolds are implanted via surgery and the injectable ones form in situ toavoid surgical hurt. Bone is a biocomposite composed of bone cells, i.e. osteoblastand osteoclast and extracellular matrixes made up of collagen protein fibers, abundled array of crosslinked helical polypeptide strands, threading throughhydroxyapatite(HA). From the biomimetic point of view, the injectable biocompositewas fabricated in combination with chitosan hydrochloride(CH) based hydrogel and β－tricalcium phosphate(TCP), which is similar to natural bone in components The water soluble CH was synthesized and characterized by FT-IR, XRD, XPSand element analysis. The cytocompatibility of CH was estimated with 2T3 cell lines.The injectable CH scaffold in tissue engineering was fabricated through mixing CHand β-glycerol phosphate disodium(GP) solution with β-TCP powder, whose pHresponsibility, temperature dependence and composite effect were evaluated as well.The biocompatibility of CH based composites was determined through injecting intoWistar rats subcutaneously. The primary amine groups were turned into quaternary ammonium ones whilechitosan was changed into CH, which turned the dense chitosan molecular packagesinto loose ones. CH exhibited the good compatibility to cells and improvement in celladhesion and viability. Sol-gel phase transitions and gel ratios of the injectable CHbased biocomposite were modulated via optimization of supramolecular interactionsof CH, GP and β-TCP, i.e. hydrogen bonding, electrostatic and hydrophobicinteraction, which provided the advantages in delivery and encapsulation of osteoblastetc, and exhibited good biocompatibility. The injectable chitosan based biocompositeis a potential scaffold in tissue engineering.