Effects of Chemical Composition on the Shape Memory Property of Poly(DL-lactide-co-trimethylene carbonate) as Self-Morphing Small- Diameter Vascular Scaffolds

Smart materials have great potential in many biomedical applications, in which biodegradable shape memory polymers (SMPs) can be used as surgical sutures, implants, and stents. Poly(DL-lactide-co-trimethylene carbonate) (PDLLTC) represents one of the promising SMPs and is widely used in biomedical applications. However, the relationship between its shape memory property and chemical structure has not been fully studied and needs further elaboration. In this work, PDLLTC copolymers in different compositions have been synthesized, and their shape memory properties have been investigated. It has been found that the shape memory property is related to the chemical composition and polymeric chain segments. The copolymer with a DLLA/TMC ratio of 75:25 (PDLLTC7525) has been demonstrated with great shape fixation and recovery ratio at human body temperature. Furthermore, PDLLTC7525-based self-morphing small-diameter vascular scaffolds adhered with inner electrospun aligned gelatin/hyaluronic acid (Gel/HA) nanofibers have been constructed, as a merit of its shape memory property. The scaffolds have been demonstrated to facilitate the proliferation and adhesion of endothelial cells on the inner layer. Therefore, PDLLTC with tailorable shape memory properties represents a promising candidate for the development of SMPs, as well as for small-diameter vascular scaffolds construction.

Automated summary

Smart materials, specifically biodegradable shape memory polymers (SMPs), have significant potential in various biomedical applications such as surgical sutures, implants, and stents. Poly(DL-lactide-co-trimethylene carbonate) (PDLLTC) is a promising SMP widely used in the field, but the relationship between its shape memory property and chemical structure requires further investigation. In this study, different compositions of PDLLTC copolymers were synthesized and their shape memory properties were studied. The results showed that the shape memory property is influenced by the chemical composition and polymeric chain segments. PDLLTC copolymer with a DLLA/TMC ratio of 75:25 (PDLLTC7525) exhibited excellent shape fixation and recovery ratio at human body temperature. Furthermore, PDLLTC7525-based self-morphing small-diameter vascular scaffolds, incorporating electrospun aligned gelatin/hyaluronic acid (Gel/HA) nanofibers on the inner layer, showed great potential for facilitating endothelial cell proliferation and adhesion. Thus, PDLLTC with customizable shape memory properties holds promise for SMP development and small-diameter vascular scaffold construction.