ECM-mimetic heparin glycosamioglycan-functionalized surface favors constructing functional vascular smooth muscle tissue in vitro.

Contractile vascular smooth muscle accounts for the normal physiological function of artery. Heparin, as a native glycosaminoglycan, has been well known for its important function in promoting or maintaining the contractile phenotype of vascular smooth muscle cells (VSMCs). In this study, heparin-functionalized non-woven poly(ε-caprolactone) (PCL) mat was fabricated by a facile and efficient surface modification protocol, which enables the control of surface heparin density within a broad range. Surface heparization remarkably increased the hydrophilicity of PCL, and reduced platelet adhesion. MTT assay showed that VSMC proliferation was evidently inhibited on the heparin-functionalized PCL surface in a dose-dependent manner. Gene analysis confirmed that surface heparization also promoted the transition of VSMCs from synthetic phenotype to contractile one. Furthermore, with a proper surface density of heparin, it allowed VSMCs to grow in a certain rate, while exhibiting contractile phenotype. Culture of VSMCs on a modified PCL mat with moderate heparin density (PCL-Hep-20) for 2 days resulted in a confluent layer of contractile smooth muscle cells. These data suggest that the heparin-modified PCL scaffolds may be a promising candidate to generate functional vascular tissues in vitro.