Drug-Releasing Performance Of 5-Fluorouracil-Load PLA Scaffold

In recent years, polylactic acid is widely used in the controlled release of drugs and in the tissue engineer scaffold materials, due to its excellent biocompatibility and mechanical properties. In this paper, 5-fluorouracil was used as model drug and organic phase separation method was used to prepare 5-fluorouracil-loaded PLA scaffold. The surface and section morphology, the connectivity of channels and the pore size were analyzed by SEM; the combination between the drug with the carrier and the structure of the scaffold was measured by FTIR and XRD. The results show that the porosity of the scaffold was very high and the connectivity of channels was preferably. The drug dispersed uniformLy in the polymer and the polymer has strong adsorption with drug because of the presence of hydrogen bonds.In vitro drug release study we confirmed the best in vitro drug release environment is PH=7.2, temperature of 37℃, the volume of 200mL; and by increasing the drug dosage, the concentration of PLA, the particle size of the drug, the high molecular, we obtained 5-fluorouracil-loaded PLA scaffold with better quality; the same quantity of drug and the volume of coagulant didn’t cause significant impact on the drug release.We used chitosan and 5-fluorouracil to prepared drug-loaded microspheres, and then loaded on PLA to form a composite scaffold, the initial burst release was reduced to 30% or less, due to the dual role of controlled release; by blending hydroxyapatite with 5-fluorouracil and PLA, we prepared composite scaffold, because of the interaction between hydroxyapatite and 5-fluorouracil, the drug release time was extended and the highest drug loading ratio was 92.31%; we also prepared another composite scaffold by coating with gelatin shell, the drug diffusion was prevented, making the drug release has not yet reached a plateau after 12d, extended the drug release time.Using a variety of kinetic model (Zero order kinetic model, First order kinetic model, Higuchi model, Korsemeyar Peppas model and Hixson-Crowell model) to simulate in vitro drug release profile of drug-loading scaffold and composite scaffold, analyzing its drug release mechanism. The Korsemeyar Peppas model was more in line, followed diffusion mechanism of drug release, correlation coefficient was above 0.9900.