Preparation And Characterization Of Sustained-released Composite Scaffold With The Antituberculosis Drug Inh And Hydroxyapatite

Biodegradable polymers play important roles in drug delivery and tissue engineering. As carriers for drug delivery, biodegradable polymers can realize the control of drug delivery while won’t long-term stay in the body. As scaffolds for tissue engineering, they can provide environment similar to natural extracellular matrix for cell attachment, proliferation and differentiation. On the other hand, various Ca-P minerals are also often used in drug delivery and tissue engineering field. Those Ca-P minerals can provide the essential ions like Ca and P for the bone regeneration, and neutralize the acidic degraded products from biodegradable polymers. Therefore, targeting for controlled drug release and bone regeneration, this thesis carried out two parts of study, the first part "Preparation and characterization of sustained-released scaffold with the antituberculosis drug" and the second part "The preparation of hydroxyapatite by calcining of biomimeralized PLLA-gelatin composite fibers". In the first part, β-tricalcium phosphate (β-TCP) and isoniazid (INH) were added into polylactide (PLLA)/dioxane solution to prepare PLLA/β-TCP/INH composite scaffold with uniform pore structure and porosity as high as96%. The drug release study showed that a sustain at least80days. Since crustalline PLLA is a polymer with low degradation rate, there was minor change in Mw of PLLA, mechananical properties of PLLA/β-TCP/INH composite scaffold during the80days’experimental period. By in vitro co-culture with osteoblasts, the compersite scaffolds demonstrated good cell attachment. And the animal test proved it was able to guide the bone regeneration. These results suggested that the PLLA/β-TCP/INH composite scaffold might realize the drug control release for the treatment of tuberculosis and guided bone regeneration simultaneously.The second part of the thesis focused on the preparation of hydroxyapatite by calcining of biomimeralized PLLA-gelatin composite fibrous scaffold. PLLA-gelatin composite fibrous scaffold were prepared by electrospinning, and then were mineralized and calcined to prepare hydroxyapatite. The effects of the mineralized time, the calcining temperature and the calcining time on final products were studied. These factors played important roles on the morphology and structure of calcinized hydroxyapatite. To obtain hexagon-shaped hydroxyapatite, which were similar to the calcinized products from antler and human tibia, parameters were set as:biomineralization in5times simulated body fluid for24hrs and calcinized at1000℃for1hr.