Polylactic Acid Hydrophilic Modified And Modified Objects Outside The Drug Release Study

Polylactic acid (PLA) is a kind of medical macromolecule material with good biodegradability and biocompatibility. It has been extensively applied in bone repairing and fixing, drug releasing system, and systematization project. But PLA is polyester, lacking of hydrophilic group in its structure, material's surface forms strong hydrophobe, this will badly influence its appetency with cells, at the same time under its degradation, there will form acidity accumulation, which will lead inflammation in part of material embedded, To some extent, all these shortcomings could restrict PLA's application in medical field.Maleic anhydride (MAH) and diamine modified PLA, by introducing active anhydride group on PLA, and then react to diamine to introduce active amino group. In this paper, diamine modified PLA was prepared for the first time ; synthesization technologies was optimized ; The performance and structure of PLA, MPLA and EMPLA were test, We studied their external-degradation, including determination of weight loss, pH, moisture absorption rate, and so on. At the same time, three kinds of scaffolds co-cultured with osteoblasts have been studied, too.All those results show that after modification, the degradation of material has been improved obviously. The introduction of ethylenediamine neutralize the acidity which was result in by lactic acid(LA) produced by PLA in its process of self-degradation, so the acidity accelerative self-degradation was controlled effectively, pH change of EMPLA solution and its molecular weight decrease were slow ; Simultaneity, the hydrophilicity and biocompatibility of material were improved obviously. The results of scaffolds co-cultured with osteoblasts show that cell adherency on MPLA and EMPLA was tighter than on DL-PLA, extracelluarmatrix (ECM) inosculated well with the edge of material, cell amount was much more, too. In three materials, EMPLA was the best one, cells on EMPLA were...