Derivatization of Plasma Polymerized Thin Films and Attachment of Biomolecules to Influence HUVEC‐Cell Adhesion

Abstract

Plasma polymerized films of allylamine were surface derivatized in subsequent wet chemical processes using a diepoxy‐PEG linker to covalently bind different biomolecules that are known to influence cell adhesion. The initial attachment of human umbilical vein endothelial cells (HUVECs) was studied on (i) unmodified PTFE, (ii) PTFE modified with a layer of plasma polymerized allylamine (pp‐AA), and (iii) PTFE modified with a layer pp‐AA which was further modified using known adhesion molecules coupled to the functional surface via a linker molecule. Statistical analysis of the data initially show significant adhesion improvement of HUVECs on pp‐AA and on pp‐AA modified with either L‐RGD or C‐RGD in comparison to the bare PTFE. The statistical significances between the pp‐AA surface and the modified pp‐AA/RGD surface were however found to be negligible. A significant further improvement was observed for the modified surfaces derivatized with the very much larger fibronectin.

The effect of extracellular matrix proteins on the cellular response of HUVECS and HOBS after covalent immobilization onto titanium

“…Although attempts to quantify the primary amines within the plasma‐polymerized allylamine film failed, the infrared spectra showed the presence of primary amines that were later used for the covalent coupling procedure. In agreement with literature, the primary amines of pp‐AA films can be used for covalent immobilization of biomolecules . With the described plasma polymerization parameters, we deposited ultrathin plasma polymer films of a mean thickness of 160 nm.…”

“…The pp‐AA was conducted in a custom‐made plasma reactor . The basic setup consists of a 30‐cm long, cylindrical Pyrex glass tube with a diameter of about 10 cm.…”

“…Therefore, common wet chemical techniques are limited to the functional groups available on the material surfaces. To overcome these limitations, plasma polymerization of allylamine (pp‐AA) was shown to be a suitable technique to generate ultrathin primary amine‐rich films on various materials that can be used for covalent or non‐covalent immobilization of different biomolecules …”

An important step towards a prevascularized islet macroencapsulation device—effect of micropatterned membranes on development of endothelial cell network

“…Indeed, with the fibronectin coating, we achieved an increased attachment of NHDFs and HUVECs on coated membranes in comparison to no-coated ones, similar to coverslip positive controls. The positive effect of fibronectin coating on cell attachment to various materials (e.g., poly (tetrafluoroethylene, PES) was also observed by other researchers [ 42 – 44 ]. Cells are able to attach to ECM molecules such as fibronectin through integrins, activating intracellular signaling pathways directing cell viability, proliferation and differentiation [ 45 ].…”

“…Besides an increase in initial cell attachment, the fibronectin coating also improved the proliferation of both NHDFs and HUVECs. Our findings are consistent with the results obtained by Lotz et al and Pendegrass et.al., who used fibronectin to improve attachment of HUVECs and NHDFs on hydroxyapatite discs and poli(tetrafluoroetylen) films respectively [ 42 , 44 ]. We also applied a 200 µg/ml fibronectin coating on our micropatterned PES/PVP membranes.…”