Department of Chemistry "G. Ciamician" and INSTM UdR of Bologna, University of Bologna , via Selmi 2, 40126 Bologna, Italy.
Department of Civil, Chemical, Environmental and Materials Engineering, University of Bologna , via Terracini 28, 40131 Bologna, Italy.
Biomacromolecules. 2017 Aug 14;18(8):2499-2508. doi: 10.1021/acs.biomac.7b00644. Epub 2017 Jul 5.
A biodegradable and biocompatible electrospun scaffold with shape memory behavior in the physiological temperature range is here presented. It was obtained starting from a specifically designed, biobased PLLA-based triblock copolymer, where the central block is poly(propylene azelate-co-propylene sebacate) (P(PAz60PSeb40)) random copolymer. Shape memory properties are determined by the contemporary presence of the low melting crystals of the P(PAz60PSeb40) block, acting as switching segment, and of the high melting crystal phase of PLLA blocks, acting as physical network. It is demonstrated that a straightforward annealing process applied to the crystal phase of the switching element gives the possibility to tune the shape recovery temperature from about 25 to 50 °C, without the need of varying the copolymer's chemical structure. The thermal annealing approach here presented can be thus considered a powerful strategy for "ad hoc" programming the same material for applications requiring different recovery temperatures. Fibroblast culture experiments demonstrated scaffold biocompatibility.
本文介绍了一种在生理温度范围内具有形状记忆行为的可生物降解和生物相容的电纺支架。它是由一种专门设计的基于生物基 PLLA 的嵌段共聚物制备的，其中中间嵌段是聚（丙烯三亚甲基碳酸酯-co-丙烯己二酸酯）（P(PAz60PSeb40)）无规共聚物。形状记忆性能取决于作为切换段的 P(PAz60PSeb40) 嵌段的低熔点晶体的同时存在，以及作为物理网络的 PLLA 嵌段的高熔点晶体相。结果表明，直接对切换元件的晶体相进行退火处理，可以在不改变共聚物化学结构的情况下，将形状回复温度从约 25°C 调节到 50°C。本文提出的热退火方法因此可以被认为是一种用于“定制”相同材料以适应需要不同回复温度的应用的强大策略。成纤维细胞培养实验证明了支架的生物相容性。
