Preparation and characterization of inducible bone repair composite scaffold with genipin-crosslinked bionic bone structure / 中国组织工程研究

ABSTRACT

BACKGROUND:Although there is a certain progress in the preparation of tissue-engineered bone tissue using a variety of materials, some deficiencies have appeared such as mismatching between scaffold degradation rate and new bone formation rate, slow tissue growth, toxic metabolites. OBJECTIVE:To build a new type of inducible bone repair composite scaffold with bionic bone structurematerials and to evaluate its physicochemical and biological properties. METHODS: Icarin encapsulated by chitosan was used to prepare drug-loaded microspheres, and the drug release rate of the microspheres was detected. Chitosan microspheres were mixed with colagen to build the core part of scaffold materials. Hydroxyapatite (HA), polycaprolactone (PCL) and colagen were mixed in hexafluoride isopropanol (HFIP) to prepare the HA/PCL/colagen outer part of composite scaffold material at the rate of 033, 133, 233, 333. Each proportional electrospinning was used for one layer, and finaly the 4-layer outer tube of the scaffold was produced. The tube core and outer tube were crosslinked by 1% genipin. Universal material testing machine, surface contact angle meter, infrared spectroscopy, scanning electron microscope, water absorption, permeability, porosity,in vitro degradation tests for cross-linked and uncross-linked were used to observe the structure and characteristics of tubular materials. Bone marrow mesenchymal stem cels were seeded on the surface of cross-linked and uncross-linked bone repair materials to evaluate the biocompatibility of the scaffolds. Cross-linked and uncross-linked bone repair materials were implanted subcutaneously into Wistar rats to evaluate the histocompatibility of the scaffolds. RESULTS AND CONCLUSION:The drug in the scaffold had a suitable release; the bone scaffold material had good uniformity, and cross-linked scaffolds materials had better mechanical properties, water absorption and permeability than the uncross-linked(P < 0.05). The degradation rate of the cross-linked group was significantly lower than that of the uncross-linked group (P< 0.05). Hematoxylin-eosin staining showed that the bone marrow mesenchymal stem cels could adhere wel to the cross-linked and uncross-linked materials. No inflammatory reactions occurred after subcutaneous implantation of cross-linked and uncross-linked materials. These findings indicate that the cross-linked scaffold for inducible bone tissue engineering has good biocompatibility and mechanical properties.