Vinculin focal adhesion of osteoblast‐like cells on PEEK coated with ultra‐thin polymer nano films

Abstract

PEEK is the polymer of choice to replace metal encapsulants and other parts in active medical implants fixated into bone. The current challenge is to improve its biocompatibility with bone tissue to ultimately achieve osseointegration. PEEK sheets surfaces coated with plasma deposited nano thin polymer films using CH 4 , (CH 4 1 O 2 ) and (CH 4 1 N 2 ) gases. PEEK samples plasma treated with nonpolymerizing gases (O 2 ) were also used for comparison. The adhesion performance of osteoblast like cells on the plasmatreated PEEK surfaces and the presence of Vinculin in these cells were evaluated after long culturing period (12 days). X-ray photoelectron spectroscopy and Auger spectroscopy were used to provide surface molecular information, surface hardness and molecular density. All plasma-treated surfaces retained functionality after the sterilization process. PEEK surfaces with high number of oxygen functional groups and particularly oxygen rich thin polymer coating (plasma deposition using CH 4 1O 2 gas mixture) resulted in strong cellular adhesion strength and large Vinculin amount. Further, osteoblast-like cells responded better to surfaces with lower molecular density acting like another signal for cell adhesion. The osteoblast-like cells response was weaker for surfaces with both thin films with nitrogen functional groups and nonfunctional (nonpolar) films. Furthermore, thin films rich in nitrogen functional groups repelled the cells, showed abnormal cells shape, smaller Vinculin amount and induced thicker cellular clusters with poor spread.

Antibacterial titanium nano-patterned arrays inspired by dragonfly wings

“…7b , these focal adhesion points were able to be detected by the application of anti-vinculin, an antibody that is used for the detection of viniculin. Vinculin is a cytoskeletal protein believed to be one of several interacting proteins that are involved in anchoring F-actin, a cellular protein that forms microfilaments, to the membrane 49 . The adhesion plaque of fibroblasts on any surface is formed by proteins such as vinculin, talin, alpha-actinin and paxillin.…”

Behaviour of Vascular Smooth Muscle Cells on Amine Plasma-Coated Materials with Various Chemical Structures and Morphologies

“…No specific relation between the concentration of O and N functional groups and the cell proliferation has been reported [ 20 , 22 , 24 ]. Several studies have even revealed better cell adhesion or better cell proliferation on surfaces containing oxygen functionalities than on surfaces with nitrogen functional groups [ 18 , 21 , 23 , 29 ]. The discrepancies among the findings presented by different research groups strongly suggest a complexity of the problem, in which the overall chemical structure comprising nitrogen and oxygen-containing groups can be more important than the exact concentration of certain groups.…”

“…Similarly, the proliferation rate of adipose-derived stem cells cultured on pyrrole-modified PS dishes increased in correlation with the increasing concentration of nitrogen and nitrogen-related functional groups [ 38 ]. However, other publications have revealed quite opposite findings that show reduced proliferation of various cell types cultured on amine-PP coatings prepared from AA, a methane/nitrogen mixture or from CPA [ 29 , 32 , 48 ]. Similarly ambiguous results were observed in the present study.…”

“…Coating with thin plasma polymer (PP) films via plasma-enhanced chemical vapor deposition (PECVD) is considered as the most stable modification method for introducing nitrogenated species to the surface. PECVD has already been applied in many studies to improve the biocompatibility of artificial polymers for various cell types, e.g., osteosarcoma cells [ 29 , 30 , 31 ], endothelial cells [ 32 ], fibroblasts [ 33 , 34 , 35 ], myoblasts [ 36 , 37 ], or adipose-derived stem cells [ 38 ]. Although PPs are characterized by a complex chemical structure, PECVD can be easily tuned by choosing suitable reactive gases or monomers and by appropriate conditions of the plasma deposition process (e.g., pressure, discharge power or the monomer flow rate).…”

RxpsG a new open project for Photoelectron and Electron Spectroscopy data processing

“…RxpsG has been used for spectral analysis since some years during which it was tested and gradually improved and contributed to several publications [3][4][5][6][7][8]. This article describes the main features of RxpsG and its application in the analysis of real XPS spectra.…”