Kun Liu,Shengyue Tang,Ling Zhu,Wei Wen,Mingxian Liu,Hong Li,Changren Zhou,Binghong Luo
Poly( D, l -lactide) (PDLLA) as a kind of bone repair material has been widely concerned, however, the development of PDLLA material with remarkable cell affinity and osteogenic activity is still a big challenge. Inspired by the unique liquid crystal property and viscoelasticity of bone extracellular matrix (ECM), here, a new kind of chitin whisker gel (nCG) with the bone ECM-like liquid crystal phase and viscoelasticity was developed, which was further stably adhered to PDLLA membrane to obtain the nCG-coated composite membrane (PP@nCG) taking advantage of polydopamine. The design of bone ECM-like liquid crystal gel surface on the PDLLA membrane could not only improve cell adhesion and proliferation, but also highly enhance calcium phosphate mineralization . Creatively, the modulus of surface coated nCG can be easily adjusted by changing the degree of deacetylation of chitin whiskers to simulate the viscoelasticity of bone ECM and regulate cell behaviors and fate. Interestingly, the PP@nCG membrane with high-modulus nCG coating shows a stronger effect on promoting cell affinity and osteogenic activity compared with that with low-modulus nCG coating. This study opens a new window to bionic designing novel composite materials with bone ECM-like liquid crystal characteristic and viscoelasticity for bone repair.
Chengjin Wang,Yang Yang,Jingyuan Ji,Yongcong Fang,Liliang Ouyang,Lei Zhang,Wei Sun
Intimal hyperplasia and restenosis caused by excessive proliferation of smooth muscle cells (SMC) are the main factors for the failure of stent implantation. Drug-eluting stents carried with antiproliferative drugs have emerged as a successful approach to alleviate early neointimal development. However, these agents have been reported to have an undesirable effect on re-endothelialization. In this study, we proposed an integrated bioresorbable stent coated with dipyridamole (DP)-loaded poly(D,L-lactide) (PDLLA) nanofibers. Three-dimensional (3D) bioresorbable stents were fabricated by printing on a rotation mandrel using polycaprolactone (PCL), and the stents were further coated with PDLLA/DP nanofibers. The in vitro degradation and drug release evaluation illustrated the potential for long-term release of DP. Stents coated with PDLLA/DP nanofibers showed excellent hemocompatibility. The cell viability, proliferation, and morphology analysis results revealed that stents coated with PDLLA/DP nanofibers could prevent the proliferation of SMC and have no adverse effects on endothelial cells. The in vivo implantation of stents coated with PDLLA/DP nanofibers showed initial patency and continuous endothelialization and alleviated neointimal formation. The attractive in vitro and in vivo performance indicated its potential for restenosis prevention and endothelialization.
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