Enhanced vascularization in hybrid PCL/gelatin fibrous scaffolds with sustained release of VEGF.

Kai Wang,Qiang Zhao,Yiwa Pan,Yun Cui,Xin Zhou,Deling Kong,Xuejiao Chen

doi:10.1155/2015/865076

Abstract

Creating a long-lasting and functional vasculature represents one of the most fundamental challenges in tissue engineering. VEGF has been widely accepted as a potent angiogenic factor involved in the early stages of blood vessel formation. In this study, fibrous scaffolds that consist of PCL and gelatin fibers were fabricated. The gelatin fibers were further functionalized by heparin immobilization, which provides binding sites for VEGF and thus enables the sustained release of VEGF. In vitro release test confirms the sustained releasing profile of VEGF, and stable release was observed over a time period of 25 days. In vitro cell assay indicates that VEGF release significantly promoted the proliferation of endothelial cells. More importantly, in vivo subcutaneous implantation reflects that vascularization has been effectively enhanced in the PCL/gelatin scaffolds compared with the PCL counterpart due to the sustained release of VEGF. Therefore, the heparinized PCL/gelatin scaffolds developed in this study may be a promising candidate for regeneration of complex tissues with sufficient vascularization.

Highlights

Blood vessels can provide necessary oxygen and nutrients to cell by diffusion processes, but the effective distance of diffusion is 100–200 μm around a capillary [1]
For the regeneration of blood vessels, immature and regressed capillaries within the wall of blood vessel led to calcification after a long period of implantation, which resulted in the restenosis failure [4]
Of the two fiber components, synthetic polymer PCL provides mechanical support, while native polymer gelatin contributes the functional groups for further heparization and vascular endothelial growth factor (VEGF) loading

Summary

Introduction

Blood vessels can provide necessary oxygen and nutrients to cell by diffusion processes, but the effective distance of diffusion is 100–200 μm around a capillary [1]. Sufficient vascularization has a decisive effect on maintaining the survival of regenerated tissue in the field of tissue engineering. Only a few thin tissues, such as skin, cartilage, or cornea, can successfully survive after implantation [2]. For the regeneration of blood vessels, immature and regressed capillaries within the wall of blood vessel led to calcification after a long period of implantation, which resulted in the restenosis failure [4]. Until now none of them have been proven fully successful in development of long-lasting vasculature (blood vessels)

Methods

Results

Conclusion