| Preparation of a kind of abresorbable reservoir targeted control-released drug carrier was investigated for resolution to the problem remained in effective drug administration which is either toxic or ready to result in adverse influence to liver and kidney for the treatment of human's bone disease such as osteocarcinoma or bone tuberculosis, the drug-incorporated carrier must only consistently release drug to the defective parts, and is also in vivo degradable as well as advantageous to formation and repairing of bone tissue for avoidance of second surgery.In this study, type- I collagen was preliminarily isolated from rat-tail tendon by acetic acid digestion followed by alkaline purification. Biomimetic bone-like HAp/Col composite was prepared by co-precipitation or modulated mineralization method etc. through in vitro simulating biomineralization or self- organization process of nature bone and the adopted methods were comparatively investigated. Based on these experiments the synthesis mechanism of biomimetic bone-like composite was initially probed. XRD, SEM, TEM, TGA/DSC and FT-IR to analyze its crystalline structure, morphology and components characterized the material specimen. The characterization results of the specimen indicated a promising similarity of both composition and nanometric configuration to nature bone, formation of intimate bonding between hydroxyapaptite and collagen as well as a composition of a.22% organics and 78% non-organics.The following work in this study includes the fabrication of 3-D porous reservoir control-released drug carrier which was further synthesized with nolylactide by thermal-induced phase separation /non-solvent extraction pore leaching technique and characterization of pore morphology, density, porosity and mechanical properties of the specimens. In vitro release test of model compound BTB was carried out to study the control-releasing behavior, based on experimental data the releasing kinetics in line with an established model was tentatively proposed. Results show that inter-connective pores distributed evenly in hydroxyapaptite/collagen/polylactide drug carrier with connective mini-channels through the buxom pore walls, the pore size range, porosity and mechanical strength of the carrier are suitable for drug control release. Model compound release test with an approximate zero-order release prior to its 80% release rate meet the requirements of drug control -release, therefore the prepared drug carrier is expected to be used in the treatment of bone disease for control release. |
