Fibrinogen adsorption and host tissue responses to plasma functionalized surfaces

Abstract

The physical and chemical characteristics of material surfaces are thought to play important roles in biomaterial-mediated tissue responses. To understand the importance of discrete biomaterial chemical characteristics in modifying host tissue responses, we constructed surfaces bearing different functional groups using radio frequency glow discharge plasma polymerization. Surfaces evaluated included those having high concentrations of −OH, −NH 2 , −CF 3 , and siloxyl groups. These surfaces and polyethylene terephthalate controls were used to assess the importance of particular physicochemical characteristics in surface:protein:cell interactions both in vitro and in vivo. The results obtained show that surface functionalities do significantly affect both the adsorption and ''denaturation'' of adsorbed fibrinogen (which is an important mediator of inflammatory responses to biomaterial implants). In addition, these sur-faces provoke different degrees of acute inflammatory responses. Interestingly, the amounts of ''denatured'' fibrinogen that spontaneously accumulate on the individual surfaces correlate closely with the extent of biomaterialmediated inflammation. These results suggest that surfaces that tend to ''irreversibly'' bind fibrinogen prompt greater acute inflammatory responses. Unexpectedly, all test surfaces except those bearing a siloxyl group engender relatively similar biomaterial-mediated fibrotic responses. Thus surface functionalities alone may not be sufficient to affect subsequent fibrotic responses.

Nanopatterning effects on astrocyte reactivity

“…26,[37][38][39] Surface topography has been shown to either directly influence the cell response, or indirectly affect the cell responses through the affects they have on the adsorption of proteins. 10,[40][41][42] Cell adhesion results comparing substrates coated with fibronectin, collagen, or no protein revealed that on all protein-coated substrates, there was significantly more cell adhesion on both of the protein-coated substrates compared with the substrates without any protein coating. The results demonstrate that the adsorption of both fibronectin and collagen decreased the contact angle of the substrates, therefore making them more hydrophilic, which is consequently desirable for cell attachment.…”

“…Keller et al 44 observed ultrahigh-molecular-weight polyethylene surface nanotopography alters the protein orientation and partially aligns single human plasma fibrinogen molecules. Tang et al [40][41][42] have done numerous studies analyzing the cell response to various coating of functional groups on material surfaces. They found subsequent cellular responses were partially mediated by the surface chemistries of the materials due to the functional group coatings.…”

“…They found subsequent cellular responses were partially mediated by the surface chemistries of the materials due to the functional group coatings. [40][41][42] Activated astrocytes are characterized by hypertrophy, hyperplasia, upregulation of GFAP, increased formation of filaments, irregularly shaped nuclei. 2,[45][46][47][48] Nanotopography has been shown to affect the cells' adhesion, morphology, alignment, proliferation, gene expression profiles, and even prevent biofouling and contamination on the material's surface.…”

Macrophage and dendritic cell phenotypic diversity in the context of biomaterials

“…Although these materials also induced different numbers of total adherent phagocytes depending on the functionality (ANH 2 > ACF 3 > AOH) after short-term implantation, the chronic fibrotic outcome was similar among these different chemistries. 177 In another study, tetrafluoroethylene-hexafluoropropylenecopolymer films were plasma polymerized with tetraglyme to minimize fibrinogen adsorption on the surfaces. However, in vivo studies showed that tetrafluoroethylene-hexafluoropropylene-copolymer films with or without polymerized tetraglyme provoked similar levels of fibrous encapsulation.…”

Surface chemistry and polymer film thickness effects on endothelial cell adhesion and proliferation

“…19 A variety of innovative approaches have been employed to modify solid surfaces in these studies of cell-surface interactions. Examples of techniques employed for this purpose include self-assembled monolayers (SAM's), [14][15][16][17][18][19] photoinitiated grafting, 20 grafting, 11 radio frequency glow discharge (RFGD), also identified as plasma enhanced chemical vapor deposition (PECVD) or plasma polymerization, 3,6,7,12,13,21 and Ar plasma treatment. 22 The present study utilized the RFGD approach to deposit polymeric films containing ACOOH groups, as obtained by the plasma polymerization of vinylacetic acid.…”