Synthesis and Application of Medical Grade Polylactic Acid Materials
Polylactic acid(PLA)is widely used in the medical field,including as packaging materials,medical sutures,tissue engineering scaffolds and drug-controlled release systems,due to its excellent biocompatibility and biodegradability.The ring-opening polymerization of lactide is an ideal method for the synthesis of PLA,with metal catalysts being the predominant catalytic system.However,the trace amounts of metal ions remaining in the polymer and their cytotoxicity limit the biomedical applications of PLA.In this study,a two-step improved method was employed to synthesize medical-grade degrad-able PLA with controlled molecular weight.The structure of the PLA material was characterized by 1H NMR,IR,GPC and HPLC.The influence of the amount of dodecanol and the polymerization time on the molecular weight and properties of the synthesized PLA was investigated.PLA bone nails were designed and fabricated using 3D printing technology,and their degradation behavior,hemolysis rate,and cytotoxicity were studied.The results showed that at a polymerization temperature of 130℃,a re-action time of 24 hours,the addition of 0.05％(mass fraction,same below)tin octoate,and 0.03％mass ratio dodecanol,the number-average molecular weight of PLA was over 350,000,with a purity exceeding 99.0％and dispersity index was 2.031.The nails degraded by ten weeks in PBS buffer so-lution,with a residue of 23.4％,demonstrating good degradation performance.The hemolysis rate was less than 5％,and no cytotoxicity was observed because the cell survival rate of 100％test solution was 75％,which was higher than the reference value of 70％.
medical grade polylactic acidbone naildegradation behaviormolecular weightcytotoxicity
万方数据
维普
