Institut des Biomolécules Max Mousseron (IBMM), UMR CNRS 5247, University of Montpellier 1, University of Montpellier 2-Faculty of Pharmacy, 15 Av. C. Flahault, Montpellier, 34093, France.
Mater Sci Eng C Mater Biol Appl. 2013 Oct;33(7):4133-9. doi: 10.1016/j.msec.2013.06.001. Epub 2013 Jun 7.
The objective of this work was to develop and study new biodegradable thermoplastics with improved mechanical properties for potential use as temporary implantable biomaterials. Linear poloxamer and star-shaped poloxamine have been used as macroinitiators for the ring-opening polymerization (ROP) of lactide to yield high molecular weight PLA-based thermoplastic block copolymers. The influence of the nature of the macroinitiator, PLA crystallinity and initial molecular weight on the copolymers properties was investigated by performing a 7-week degradation test in PBS. The evaluation of water uptakes and molecular weights during the degradation pointed out an early hydrolytic degradation of the 100-kg∙mol(-1) copolymers compared to the 200-kg∙mol(-1) ones (molecular weight decrease of ca. 40% and 20%, respectively). A dramatic loss of tensile mechanical properties was also observed for the 100-kg∙mol(-1) copolymers, whereas the 200-kg∙mol(-1) copolymers showed stable or even slightly improved properties with Young's moduli around 500 MPa and yield strains around 3% to 4%. Finally, the cytocompatibility of the more stable 200 kg∙mol(-1) copolymers was confirmed by murine mesenchymal stem cells (MSCs) culture.
这项工作的目的是开发和研究具有改进的机械性能的新型可生物降解热塑性塑料，以潜在用作临时可植入生物材料。线性泊洛沙姆和星形聚氧乙烯胺已被用作丙交酯开环聚合（ROP）的大分子引发剂，以得到高分子量的基于 PLA 的热塑性嵌段共聚物。通过在 PBS 中进行 7 周的降解试验，研究了大分子引发剂的性质、PLA 的结晶度和初始分子量对共聚物性能的影响。在降解过程中对水吸收和分子量的评估指出，与 200-kg·mol(-1)共聚物相比，100-kg·mol(-1)共聚物的早期水解降解更快（分子量分别约降低 40%和 20%）。还观察到 100-kg·mol(-1)共聚物的拉伸力学性能急剧下降，而 200-kg·mol(-1)共聚物的性能稳定甚至略有提高，杨氏模量约为 500 MPa，屈服应变约为 3%至 4%。最后，通过鼠间充质干细胞（MSCs）培养证实了更稳定的 200 kg·mol(-1)共聚物的细胞相容性。
