Study On Degradable Bioactive Nano-composite Scaffold For Tissue Engineering

Tissue engineering as a rising domain has developed rapidly in recently twenty years. Generating new functional tissues requires an inter-disciplinary approach that combines development cell and molecular biology with biochemistry, immunology, engineering, medicine, and the material sciences. Tissue engineering has been applied the principles of engineering and life sciences toward the development biological substitutes as extracorporeal devices that restore, maintain, or improve tissue function ex vivo and in vivo.Bone pathological changes and deformity are common disease in clinical. The treatment, especially for big defects, is a critical question for bone regeneration. The development of tissue engineering has lighted a new way for the therapy of bone disease. In clinical, bone tissue engineering used for treating bone loss has changed the traditional therapy mode and become a hot point of researches. Bone tissue engineering is regenerating new bone tissue cooperated different fields together between material science and biology, repairing or substituting pathological or defective bone tissue and enhancing its function, in order to achieve minimally invasive treatment and function reconstruction in real meaning.Bone tissue is a kind of natural composite making up of nano apatite and collagen. Hydroxyapatite and polymer composite biomaterials have been highlights in hard tissue repair. nano-hydroxyapatite/ polyamide 6 (n-HA/ PA6) composite is similar to natural bone in chemical component with good mechanical properties and bio-degradation. In this paper, n-HA/ PA6 composite is chosen as scaffold material for bone tissue engineering in virtue of these characters. The traditional particle leaching method is improved, and scaffolds with open and interconnected porous structure are prepared. The scaffolds have abundant micro-pores on the walls of macro-pores and the porosity is about 80%.After being characterized, correlative cell and animal experiments are carried through to appraise the biocompatibility in vitro and activated tissue engineered bone is constructed to discuss the feasibility of the scaffolds using in tissue engineering. The cell experiments show that n-HA/PA6 scaffolds have good biocompatibility in vitro and do not influence the differentiation of osteoblasts, and the scaffolds act as template for the adhesion, spreading, migration, differentiation and proliferation of cells at the same time. Animal experiments indicate that n-HA/PA6 scaffolds have good tissue compatibility and the pores of different size are favorable to ingrowth of blood vessels and osteoblasts, and inducing the growth of new bone tissue. The animal implanting experiments of constructed tissue engineered bone show that the tissue engineered bone can shorten the period of bone regeneration therapy. Based on these results, n-HA/PA6 porous scaffolds are excellent materials for bone tissue engineering.