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Updated: Oct 21, 2025
Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion
Published on: August 15, 2016
Surface modification of polytetrafluoroethylene (PTFE) with a heparin-immobilized extracellular matrix (ECM) coating
Chenglong Yu1, Huaguang Yang2, Lu Wang3
1Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, College of Textiles, Donghua University, Shanghai 201620, China; Engineering Research Center of Technical Textiles of Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, United States; Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, United States.
Abstract:
Intimal hyperplasia, thrombosis formation, and delayed endothelium regeneration are the main causes that restrict the clinical applications of PTFE small-diameter vascular grafts (inner diameter < 6 mm). An ideal strategy to solve such problems is to facilitate in situ endothelialization. Since the natural vascular endothelium adheres onto the basement membrane, which is a specialized form of extracellular matrix (ECM) secreted by endothelial cells (ECs) and smooth muscle cells (SMCs), functionalizing PTFE with an ECM coating was proposed. However, besides ECs, the ECM-modified PTFE improved SMC growth as well, thereby increasing the risk of intimal hyperplasia. In the present study, heparin was immobilized on the ECM coating at different densities (4.89 ± 1.02 μg/cm2, 7.24 ± 1.56 μg/cm2, 15.63 ± 2.45 μg/cm2, and 26.59 ± 3.48 μg/cm2), aiming to develop a bio-favorable environment that possessed excellent hemocompatibility and selectively inhibited SMC growth while promoting endothelialization. The results indicated that a low heparin density (4.89 ± 1.02 μg/cm2) was not enough to restrict platelet adhesion, whereas a high heparin density (26.59 ± 3.48 μg/cm2) resulted in decreased EC growth and enhanced SMC proliferation. Therefore, a heparin density at 7.24 ± 1.56 μg/cm2 was the optimal level in terms of antithrombogenicity, endothelialization, and SMC inhibition. Collectively, this study proposed a heparin-immobilized ECM coating to modify PTFE, offering a promising means to functionalize biomaterials for developing small-diameter vascular grafts.
