The competitive adsorption of human proteins onto natural-based biomaterials

Abstract

This study aims to further the understanding of nanoscale structures relevant for cellular recognition on contact and interaction with natural-based materials. The correlation between surface characteristics and protein adsorption from unitary and complex protein systems was investigated with respect to altering the bulk chemistry of the substrate material. Polymeric blends of starch and cellulose acetate, polycaprolactone (SPCL) and ethylene vinyl alcohol (SEVA-C) were used. Different proteins, bovine serum albumin, human serum albumin (HSA) and human fibronectin (HFN), were selected for this study. The construction of adsorption isotherms is an important starting point towards characterizing the interactions between surfaces and proteins. In this study, albumin adsorption isotherms fit the Freundlich model and were correlated with the chemistry and morphology of surfaces. In addition, protein distribution, quantification and competition were measured using fluorimetry and visualized by confocal microscopy. The analysis of unitary systems demonstrated that the adsorption of HSA was generally lower than that of HFN. In the latter case, SPCL and SEVA-C blends reached adsorption values of 97 and 89 per cent, respectively. In studying the co-adsorption of proteins, an increase in both HSA and HFN on SEVA-C surfaces was observed. SPCL showed no substantial increase in the adsorption of the proteins in competitive conditions. The similarity of these materials with other polysaccharide-based materials increases the relevance of the presented results. This study provides valuable information for the development of strategies towards the control of protein orientation and functionality as the availability of cell signalling epitopes for a broader family of materials that continue to be a significant component of this field of research.

Anin vivomethod for measuring the adsorption of plasma proteins to titanium in humans

“…The in vitro methods used to study the adsorption of protein to biomaterials are inherently limited. Studies using a single-protein solution, or even a combination of several stock proteins, do not accurately reflect the amount of protein adsorbed in vivo or the competition between different proteins (Alves et al 2010;Pegueroles et al 2012). The exposure of the biomaterials to human plasma ex vivo presents difficulties because of the need for heparinization, which may interfere with the readings of the concentration of protein.…”

Influence of excipients on characteristics and release profiles of poly(ε-caprolactone) microspheres containing immunoglobulin G

“…When the microspheres formulated with carbohydrates were compared, the highest IgG loading and encapsulation efficiency was observed in starch group (Group S), probably due to the electrostatic interaction between protein and starch. The potential to physically adsorb proteins on starch-based biomaterials has been shown in previous studies [41,42]. .…”

BSA adsorption onto nanospheres: Influence of surface curvature as probed by electrophoretic light scattering and UV/vis spectroscopy

“…Moreover, it is well known that the simplest theoretical model that can be used to describe the adsorption of a monolayer is the Langmuir model [23][24][25][26]. This model is based on a kinetic approach, assumes an energetically uniform surface and disregards the interaction between adsorbed molecules.…”

“…The Langmuir model assumes a dynamic adsorption process with reciprocation between adsorbed and unadsorbed protein molecules and disregards the interaction between adsorbed molecules [23][24][25][26]. The Freundlich isotherm, empirical in origin, is suitable for heterogeneous surfaces and allows interactions between adsorbed molecules and between these and the surface being involved in the dynamic adsorption process [25][26][27][28]. The Langmuir-Freundlich isotherm, also known as Sip's equation, is a combination of the Langmuir and Freundlich adsorption behaviors, found to better describe the adsorption process of several molecular systems [19,29,30].…”

“…the Langmuir, Freundlich and Langmuir-Freundlich adsorption isotherm models, were used to fit and describe the experimental data. The Langmuir model assumes a dynamic adsorption process with reciprocation between adsorbed and unadsorbed protein molecules and disregards the interaction between adsorbed molecules [23][24][25][26]. The Freundlich isotherm, empirical in origin, is suitable for heterogeneous surfaces and allows interactions between adsorbed molecules and between these and the surface being involved in the dynamic adsorption process [25][26][27][28].…”