Tunable and processable shape memory composites based on degradable polymers

Abstract

Biodegradable shape memory polymers are attractive materials for the design of biomedical scaffolds as they allow deploying implants remotely with minimal intervention, whilst allowing degradation and tissue repair. However, shape memory properties are difficult to design from common degradable polymers, without chemical modifications. Here were developed readily tunable processable shape memory polymer composites (SMPCs) based on established degradable polymers in the biomedical field (poly(trimethylene carbonate) (PTMC) and poly(lactic acid) (PLA) fibres). These SMPCs rely on the glass-rubber transition of the PLA network to trigger shape recovery, whilst the elastic PTMC matrix optimises the full recovery of the scaffold to permanent shape. We demonstrate the performance of SMPCs can be readily designed by adjusting the loading and processing of the fibre network, or through the addition of plasticizing poly(ethylene glycol) chains. Importantly, we demonstrate that the use of cut fibres allows the solution processing of SMPCs, which should enable the design of potentially degradable shape memory 3D scaffolds with complex shapes.