title: Shape Memory Performance of Thermoplastic Amphiphilic Triblock Copolymer poly(D,L-lactic acid-co-ethylene glycol-co-D,L-lactic acid) (PELA)/Hydroxyapatite Composites.
abstract: Biodegradable polymer/hydroxyapatite (HA) composites are desired for skeletal tissue engineering. When engineered with thermal-responsive shape memory properties, they may be delivered in a minimally invasive temporary shape and subsequently triggered to conform to a tissue defect. Here we report the shape memory properties of thermoplastic amphiphilic poly(D,L-lactic acid-co-ethylene glycol-co-D,L-lactic acid) (PELA, 120 kDa) and HA-PELA composites. These materials can be cold-deformed and stably fixed into temporary shapes at room temperature and undergo rapid shape recovery (< 3 s) at 50 °C. Stable fixation (>99% fixing ratio) of large deformations is achieved at -20 °C. While the shape recovery from tensile deformations slows with higher HA contents, all composites (up to 20 wt% HA) achieve high shape recovery (>90%) upon 10-min equilibration at 50 °C. The permanent shapes of HA-PELA can be reprogramed at 50 °C, and macroporous shape memory scaffolds can be fabricated by rapid prototyping.
authors.affiliation: Dept. of Orthopedics & Physical Rehabilitation, Dept. of Cell & Developmental Biology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655, USA.
authors.forename: Artem B
authors.initials: AB
authors.lastname: Kutikov
authors.affiliation: Dept. of Orthopedics & Physical Rehabilitation, Dept. of Cell & Developmental Biology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655, USA.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Reyer
authors.affiliation: Dept. of Orthopedics & Physical Rehabilitation, Dept. of Cell & Developmental Biology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Song
keywords: biodegradable; hydroxyapatite; rapid prototyping; shape memory polymer; tissue engineering