3D-printed poly(L-lactic acid) Haversian bone scaffold with microspherulitic surface and biocompatibilities

This work proposes a facile fabrication strategy of poly(_L-lactic acid) haversian bone scaffold with micro-spherulitic surface, designed by combination of the fused deposition modeling (FDM) 3D printing and homo-epithelial crystallization (EC). Further long chain branched modification of PLLA scaffold was carried out by a two-step ring-opening reaction of pyromellitic dianhydride (PMDA) and 1,3-phenylene-bis-oxazoline (1,3-PBO) to control the deformation stability and crystallization of PLLA. The influence of concentric circular gaps and the extrusion rate on the morphology of PLLA haversian bone scaffold was investigated and optimized. Furthermore, the micro-spherulitic surface increased the number of nanoscale cell attachment sites, which modified the biocompatibilities of the scaffold and significantly improved the adhesion and proliferation of mouse bone marrow macrophages (iBMDM) and embryonic fibroblasts (NIH-3T3) cells. This work offers a strategy for designing and manufacturing polymer bone-engineering scaffold with micro-spherulitic structure and good biocompatibilities.