聚乳酸/聚乙二醇-聚乳酸新型亲水支架的制备与研究

利用热致相分离/粒子沥滤结合法,制备了聚乳酸(PDLLA)以及聚乳酸与聚乙二醇-聚乳酸共聚物(PELA)复合的PDLLA/PELA组织工程支架。讨论了聚乙二醇(PEG)分子量、PELA含量及组成比对于支架内部结构、力学性能、降解行为和细胞毒性的影响。结果表明,热致相分离/粒子沥滤结合法制备的支架,具有100~250μm大孔与5~40μm小孔兼备的特殊内部结构,PEG含量愈高、PEG分子量愈小,支架的孔隙率愈大。PDLLA/PELA比率的减小,PEG/PLA比率的增大会引起支架力学性能的下降和降解的加速。材料无细胞毒性。当支架中PDLLA/PELA为3∶1,PEG 5000/PLA为25∶75时,其内部孔形态最为理想。

Preparation and In Vitro Characterization of Novel Hydrophilic Poly(D,L-lactide)/Poly(ethylene glycol)-poly(lactide) Composite Scaffolds

A new technique was developed to fabricate PDLLA and PDLLA/PELA composite scaffolds by thermally induced phase separation in combination, with particulate-leaching. Effects of PDLLA/PELA ratio, PEG/PLA ratio and PEG molecular weight on properties of mechanics, degradation behavior and cell toxicity as well as morphological properties were investigated. As the result showed, by thermally induced phase separation/ particulate-leaching, a unique morphology that macropores (100-250 microm) and micropores (5-40 microm)coexisted in the scaffold was obtained. An increase of PEG content or a decrease of PEG molecular weight raised the porosity of the scaffold. A decrease of PDLLA/PELA ratio or an increase of PEG/PLA ratio weakened mechanical properties and accelerated the degradation of the scaffold. PDLLA and PDLLA/PELA scaffolds didn't show cell toxicity. When PDLLA/PELA ratio was 3:1 and PEG5000/PLA ratio was 25:75, the scaffold got a regular, highly interconnected, macro-co-micro porous structure.