Preparation And Properties Of Polylactic Acid Based Targeting Polymer Antitumor Drugs

The goal of this research is to use polylactic acid as a polymer drug carrier and combine with small molecule antitumor drugs to prepare polymer drugs through certain ways.This can achieve the purpose of improving the efficacy of small molecule drugs,reducing toxic side effects,achieving long-term relief controlled release and targeting.Sulfadiazine has enrichment at the tumor site.In this experiment,stannous octoate was used as a catalyst to initiate the ring-opening polymerization of lactide to prepare a drug carrier.SF-K with a yield of 80%can be prepared under the optimum process conditions.SF-PLA can be obtained by initiating ring-opening polymerization of lactide at an oil bath temperature of 170 0 C.The structure and performance of SF-PLA can be analyzed by FT-IR,NMR,XRD,DSC and other methods.Since HA can inhibit the acid-catalyzed degradation of PLA,the HA/PLA complex is prepared by physical mixing as a drug carrier.The FT-IR and SEM analysis confirmed that the composition of SF-PLA.The particle size of SF-PLA is a bit large,and the particles are polygon.The optimal ratio of HA:PLA is 1:4.5-Fu is a common antitumor drug.5-Fu/PLA composite microspheres,5-Fu/HA/PLA composite microspheres and 5-Fu/SF-PLA composite microspheres were prepared by solvent evaporation method.The structure,properties and drug release properties were characterized by UV,FT-IR,SEM and NMR.So we can draw some conclusions.The optimum drug loading of 5-Fu/PLA composite microspheres was 35.40%,and the optimal encapsulation efficiency was 72.32%.The optimal drug loading of 5-Fu/HA/PLA composite microspheres was 35.40%,and the optimal encapsulation efficiency was 79.21%.The release rate of microspheres in alkaline solution is lower than that in acidic and neutral solutions.Moreover,during the sustained release of the 5-Fu/HA/PLA composite microspheres,there will be a sudden release in the first 40 hours,and then a gentle release will occur.The final release rate of microspheres can reach up to 92%.The optimum drug loading of 5-Fu/SF-PLA composite microspheres was 35.77%,and the optimal encapsulation efficiency was 78.33%.The release rate of microspheres in alkaline solution is lower than that in acidic and neutral solutions.Moreover,during the sustained release of the 5-Fu/SF-PLA composite microspheres,there will be a sudden release in the first 30 hours,and then a gentle release will occur.The final release rate of microspheres can reach up to 95%.Moreover,in the process of preparing the microspheres,the quality of 5-fluorouracil is changed within a certain range,and the drug loading of the microspheres is not affected.But the encapsulation efficiency of the microspheres increases with the decrease of 5-fluorouracil in the microspheres.