Experimental Studies On Compound Artificial Bone Constructed By Using Tissue-engineering Methods

Experimental studies on compound artificial bone constructed by using tissue-engineering methodsAbstractTissue engineering, a new field, takes the principles of biology and engineering toward the development of biological substitutes that restore, maintain, or improve tissue function. The core of tissue engineering consists of seed cell, scaffold matrial and the fabrication of function tissue.Materials: In this study, marrow stromal cells (MSC) were used as seed cells of bone tissue engineering. To investigate the growth and the biological characteristics of MSC, common culture and perfusion culture system was adapted. By means of tissue engineering technique, the compound artifical bone was fabricated by using poly-beta-hydroxybutyrate (PHB) and MSC. To investigate the feasibility of using MSC as bone-derived cell and PHB as scaffold material, the MSC/PHB complexs were implanted ectopic in immununodeficiency animals (nude mice) and also were implanted into autogenenous skull critical defects.Method: MSCs from New Zealand rabbits were harvested and culutured in vitro. After multiplied, dexamethasone was used to promote the osteoblastic phenotype of the cells. The growth and the biological characteristics of marrow stromal osteoblast (MSO) was observed through cell morphological survey, cell growth curve, division rate, adhenivve rate counting, von-kossa staining, scanning electronic microscope (SEM), electronic microscope survey (EMS), alkaline phosphatase (ALP) and osteocalcin (OC) test. The efectiveness of bone formation was assessed by means of roentgenographic analysis, gross inspection and histological observation.Results: MSC can be cultured in vitro and induced into MSO. Under the condition of perfusion culuture system, MSO showed stable biological characteristic and can contiune proliferation and differentiation. In immununodeficiency animals (nude mice) the ectopic osteogenesis of the MSC/PHB complexs was obvious. In the control, only fibrous tissue had been found. The autogenenous skull defects can be repaired by MSC/PHB complexs effectively, but can not in the control group.Conclusion: Since MSC can be induced into MSO and proliferate rapidly in vitro, it can be a kind of ideal seeded cell for bone tissue engineering. Seed cells can be cultured and multiplied in the perfusion culture system in which their biological characteristics maintained stable. PHB possesses good biocompatibility and can be ideal scaffold material for bone tissue engineering.