Elastin and collagen enhances electrospun aligned polyurethane as scaffolds for vascular graft

Mismatch in mechanical properties between synthetic vascular graft and arteries contribute to graft failure. The viscoelastic properties of arteries are conferred by elastin and collagen. In this study, the mechanical properties and cellular interactions of aligned nanofibrous polyurethane (PU) scaffolds blended with elastin, collagen or a mixture of both proteins were examined. Elastin softened PU to a peak stress and strain of 7.86&nbsp;MPa and 112.28&nbsp;% respectively, which are similar to those observed in blood vessels. Collagen-blended PU increased in peak stress to 28.14&nbsp;MPa. The growth of smooth muscle cells (SMCs) on both collagen-blended and elastin/collagen-blended scaffold increased by 283 and 224&nbsp;% respectively when compared to PU. Smooth muscle myosin staining indicated that the cells are contractile SMCs which are favored in vascular tissue engineering. Elastin and collagen are beneficial for creating compliant synthetic vascular grafts as elastin provided the necessary viscoelastic properties while collagen enhanced the cellular interactions. <br /

Biocompatibility evaluation of protein-incorporated electrospun polyurethane-based scaffolds with smooth muscle cells for vascular tissue engineering

10.1007/s10853-013-7359-9Journal of Materials Science48155113-5124JMTS

The surface nanostructures of titanium alloy regulate the proliferation of endothelial cells

To investigate the effect of surface nanostructures on the behaviors of human umbilical vein endothelial cells (HUVECs), surface nanostructured titanium alloy (Ti-3Zr2Sn-3Mo-25Nb, TLM) was fabricated by surface mechanical attrition treatment (SMAT) technique. Field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed to characterize the surface nanostructures of the TLM, respectively. The results demonstrated that nano-crystalline structures with several tens of nanometers were formed on the surface of TLM substrates. The HUVECs grown onto the surface nanostructured TLM spread well and expressed more vinculin around the edges of cells. More importantly, HUVECs grown onto the surface nanostructured TLM displayed significantly higher (p &lt; 0.01 or p &lt; 0.05) cell adhesion and viabilities than those of native titanium alloy. HUVECs cultured on the surface nanostructured titanium alloy displayed significantly higher (p &lt; 0.01 or p &lt; 0.05) productions of nitric oxide (NO) and prostacyclin (PGI2) than those of native titanium alloy, respectively. This study provides an alternative for the development of titanium alloy based vascular stents

Elastin in vascular grafts

The clinical demand for a superior vascular graft is rising due to the increase in cardiovascular disease with an aging population. Despite decades of research, clinically translatable solutions remain limited. Recent progress in vascular graft engineering has highlighted the significance of biological integration for the success of implanted grafts. Thus there has been an increase in the usage of biological materials in vascular graft manufacture. Elastin, a natural protein that makes up a significant portion of the natural vascular extracellular matrix, has been demonstrated to be particularly important with both mechanical and biological modulatory roles. Progress in understanding elastogenesis, the process by which elastin is naturally synthesized, and increased access to synthetic elastin-based materials, has increased the usage of elastin in vascular graft engineering. In this chapter, we explore recent advances in the utilization of elastin as a material for vascular graft engineering. In particular, we focus on the myriad of methods which incorporate elastin into vascular grafts which demonstrate superior biological functionality and closer resemblance to native blood vessels