Immobilization of fibronectin in chitosan substrates improves cell adhesion and proliferation

Abstract

Covalent grafting of biomolecules is a strategy to improve the biocompatibility and bioactivity of materials. However, it is critical to maintain the biological activity of the biomolecule upon its attachment to the surface. In the present study we compared the biological properties of chitosan, in which the surface was enriched with fibronectin (Fn), using two methodologies: chemical immobilization, using a water-soluble carbodiimide; and simple adsorption. X-ray photoelectron spectroscopy studies confirmed the successful immobilization of Fn onto modified membranes. SaOs-2 cells were seeded onto these surfaces to assess the biological consequences of such modifications. The presence of Fn stimulated cell adhesion on chitosan. It was found that after 7 days of culture in the presence of covalently attached Fn, the cells are confluent; significantly fewer cells were detected in unmodified film and in film with adsorbed Fn. This result is consistent with the fact that considerable desorption of Fn from chitosan takes place within 24 h in culture medium. This study showed that Fn may be easily covalently attached onto chitosan substrates, improving the biological performance of the material. The technique could find applications in tissue-engineering strategies, as the surface modification of chitosan-based substrates could be carried out in more complex geometries, such as in scaffolds or particles.

Immobilization of chitosan film containing semaphorin 3A onto a microarc oxidized titanium implant surface via silane reaction to improve MG63 osteogenic differentiation

“…The release rate in lysozyme was much faster, which should be attributed to the degradation caused by lysozyme. 26 Although many reports hold the idea that chitosan film could improve cell adhesion and proliferation, 16,27 there are also conflicts that there is no significant cell growth improvement. 26,28 Our result is in agreement with the latter that no significant difference of attachment and viability has been observed between CS-MAO and MAO, and because Sema3A has no dramatic influence on cellular viability and proliferation, 13 CS/Sema-MAO has not shown enhancement of cell growth either.…”

Improved fibronectin-immobilized fibrinogen microthreads for the attachment and proliferation of fibroblasts

“…These data indicate that increased cell proliferation with increasing FN grafting is consistent with the findings of a recently published work on natural carbohydrate polymers grafted with FN. 33 Although the assay results revealed that both Fbg and FN/Fbg were biocompatible, the microfibers containing nanostructures could enhance much higher cell proliferation compared to highly porous and less porous microfibers. It is well known that FN is a large ECM protein that has been extensively studied because of its significant role in numerous physiological processes, such as cell adhesion, migration, proliferation, survival, and wound healing.…”

“…32,33 Briefly, with some modification, Fbg microfibers were covalently cross-linked with FN, using EDC as a cross-linking agent. The cross-linking reaction consisted of two steps.…”

“…33 After 6 hours of FN cross-linking, the solution was measured by a colorimetric method to quantify un-cross-linked FN using the Bradford protein assay. The measured value was subtracted from the initial measurement, which corresponded to the FN crosslinked on the Fbg fiber surface.…”

Selective Cell Recruitment and Spatially Controlled Cell Attachment on Instructive Chitosan Surfaces Functionalized with Antibodies

“…Published works report the coating or tailoring of biomaterials with bioactive molecules, such as fibronectin [3], laminin [4], growth factors [5,6] or their integrin-binding epitopes including RGD [7,8] and GFOGER [9]. These studies report the influence of such biomolecules in cell adhesion, differentiation or proliferation.…”