In vitro evaluation of collagen immobilization on polytetrafluoroethylene through NH3 plasma treatment to enhance endothelial cell adhesion and growth.

Background: Polytetrafluoroethylene (PTFE) is poorly biocompatible due to its low surface energy and hydrophobicity, which cause weak cell attachment and proliferation and complicate its use in implants.
Objective: NH3 plasma was used for surface modification and binding of amine groups on the PTFE surface. Collagen was immobilized on the plasma-treated PTFE in order to enable it to support enhanced cell adhesion and growth.
Methods: PTFE was exposed to NH3 plasma and collagen was immobilized on the NH3 plasma-treated surface. ATR-IR, SEM, EDXA and contact angle were conducted to determine the composition, microstructure and wettability of samples. The cytocompatibility of the samples was assessed via the growth HUVEC cells using MTT assay.
Results: Plasma treatment resulted in an incorporation of functional groups, containing N2 and O2 that caused the PTFE surface to become hydrophilic with contact angle 68°. Also, a reduction in F/C ratio was observed after collagen immobilization that indicates the presence of collagen. Cells proliferated in greater numbers on the collagen immobilized-PTFE as compared to the plasma-treated one.
Conclusions: Plasma treatment incorporates functional polar moieties on the PTFE surface, causing enhanced wettability, collagen immobilization and cell viability. Collagen-immobilized PTFE may offer a valuable solution in biomedical applications such as vessel grafts.