Composite chitosan 3D scaffold structure for tissue engineering :materials, fabrication method and characterisation

Current methods reporting preparation of chitosan and chitosan blend scaffolds are ambiguous, contradictory of one another and not conclusive of scaffold mechanical and chemical characteristics. One possibility is the lack of understanding of chitosan properties and the variety of chitosan grades available commercially, used to produce scaffolds. There is an evident gap in literature with regards scaffold preparation or a concise look at the methodical sequence from material selection and characterisation to the preparation and analysis of a scaffold for specific tissue engineering application. Commercially available chitosan was purified and refined; blended with a compatible biopolymer and processed to form a suitable scaffold structure for tissue engineering application. TPP was incorporated into the composite blend to broaden the application of chitosan and the resulting scaffold structures within the field of tissue engineering. Analysis of the effect of blend composition and processing method on the chemical and mechanical properties of the scaffolds was performed using tensile testing, DSC, DMTA, contact angle analysis, protein adsorption, SEM and determination of enzymatic degradation rates. A systematic approach was used to determine the suitability for scaffolds produced from each of the three processing methods in tissue engineering application. Results show that the processing methods of dry blending with leaching, freezedrying and electrospinning produce scaffold structures suitable for specific applications and that each have individual advantages over the other two. Dry blended structures have excellent mechanical strength but lack the pore architecture evident in freeze dried structures. Freeze dried structures lack mechanical strength but have a promising controlled porous structure with good interconnectivity and uniform pore diameter with chitosan content greater than 50% by weight in a chitosanlPCL blend. Regarding electrospinning the optimum solution is 6%w/v chitosan in 60%v/v acetic acid at 20kV, distance of Scm and feed-rate of SOJlLlmin. The addition of TPP in the blend altered the surface hydrophilicity, crystallinity,flexibility and enzymatic degradation rates of the chitosanlPCL/TPP blends.EThOS - Electronic Theses Online ServiceGBUnited Kingdo