Shape memory PLLA-TMC/CSH-dPA microsphere scaffolds with mechanical and bioactive enhancement for bone tissue engineering

Abstract

Porous biodegradable bone scaffold is a remarkable strategy for bone-tissue engineering. It is well known that some basic requirements such as the biodegradabilty, biocompatibility, porous structure, surface properties, mechanical properties and plasticity of the scaffolds are vital for new bone formation. In this article, we adopted a low temperature method and poly (dopamine) coating strategy to fabricate porous shape-memory poly (L-lactide-co-trimethlyene carbonate)/calcium sulfate hemihydrate-poly (dopamine) microsphere scaffolds with uniform microstructure. Compared with PLLA-TMC microspheres, PLLA-TMC/CSH and PLLA-TMC/CSH-dPA microspheres have rougher surface and increased Tg. The mechanical properties and biodegradability of scaffolds were also tested in vitro, and the biocompatibility and osteoconductivity were monitored by CCK-8 and ALP activity assay using MC3T3-E1 cells. Strikingly, compared with PLLA-TMC scaffolds, PLLA-TMC/20CSH scaffolds possessed an enhanced initial compression modulus and higher degradation rate. Meanwhile, the compression modulus of all P/CSH scaffolds matched the cancellous bone during degradation period (103.04–623.75 MPa). Moreover, the PLLA-TMC/CSH-dPA microsphere scaffolds were non-toxic and contributed to cell adhesion. In summary, the prepared PLLA-TMC/CSH-dPA microsphere scaffold in this work is a promising approach for bone-tissue engineering.