Different Organization of Type I Collagen Immobilized on Silanized and Nonsilanized Titanium Surfaces Affects Fibroblast Adhesion and Fibronectin Secretion

Abstract

ABSTRACT:Silanization has emerged in recent years as a way to obtain a stronger and more stable attachment of biomolecules to metallic substrates. However, its impact on protein conformation, a key aspect that influences cell response, has hardly been studied. In this work we analyzed by AFM the distribution and conformation of type I collagen on plasma treated surfaces before and after silanization. Subsequently, we investigated the effect of the different collagen conformations on fibroblasts adhesion and fibronectin secretion by immunofluorescence analyses. Two different organosilanes were used on plasma-treated titanium surfaces, either 3-chloropropyl-triethoxy-silane (CPTES), or 3-Glycidyloxypropyl-triethoxy-silane (GPTES). The properties and amount of the adsorbed collagen was assessed by contact angle, XPS, OWLS and AFM.AFM studies revealed different conformations of type I collagen depending on the silane employed. Collagen was organized in fibrillar networks over very hydrophilic (plasma treated titanium) or hydrophobic (silanized with CPTES) surfaces, the latter forming little globules with a beads-on-a-string appearance, whereas over surfaces presenting an intermediate hydrophobic character (silanized with GPTES), collagen was organized into clusters with a size increasing at higher protein concentration in solution.Cell response was strongly affected by collagen conformation, especially at low collagen density. The samples exhibiting collagen organized in globular clusters (GPTES-functionalized samples) favored a faster and better fibroblast adhesion, as well as better cell spreading, focal adhesions formation and more pronounced fibronectin fibrillogenesis. In contrast, when a certain protein concentration was reached at the material surface the effect of collagen conformation was masked, and similar fibroblast response was observed in all samples.

αv-Class integrin binding to fibronectin is solely mediated by RGD and unaffected by an RGE mutation

“…The diverse functions of FN are indispensable for mammalian development ( George et al, 1993 ; Georges-Labouesse et al, 1996 ) and affect diseases such as inflammation, fibrosis, and metastasis ( Erdogan et al, 2017 ). The properties of FN are also used in regenerative medicine, where full-length FN, FN fragments, or FN peptidomimetica serve as substrates for bio-inspired materials ( Salmerón-Sánchez et al, 2011 ; Marín-Pareja et al, 2015 ). FN is a modular protein composed of three types of folding units (type I, II, and III), which contain interaction motifs for cell adhesion molecules, including integrins and syndecans.…”

Biofunctionalization of Dental Abutment Surfaces by Crosslinked ECM Proteins Strongly Enhances Adhesion and Proliferation of Gingival Fibroblasts

“…In addition to the osseointegration of the implant material's surface, the adhesion of the abutment to the gingival tissue is crucial in order to ensure a biological seal against deleterious stimuli in the oral cavity. [2] However, the mucosa around the implant abutment displays numerous differences from that surrounding natural teeth: The collagen fibers run parallel to the implant surface, [3] blood supply is reduced due to the lack of a periodontal ligament, [1] and fewer fibroblasts are present. [4,5] Taken together, these factors result in a reduced sealing capacity of the gingiva against bacterial invasion and compromise the longevity of the implant.…”

Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layer physical properties

“…The chosen protein layers consist of collagen and fibrinogen, selected as references both for their interest in engineering biocompatible surfaces [40,41] but most significantly for their strong solvent content and hence acoustic properties challenging to analyze. Collagen is a fibrillar protein of the extracellular matrix possessing self-assembly properties, involved in biorecognition processes.…”