An RGD-restricted substrate interface is sufficient for the adhesion, growth and cartilage forming capacity of human chondrocytes

Abstract

This study aimed at testing whether an RGD-restricted substrate interface is sufficient for adhesion and growth of human articular chondrocytes (HAC), and whether it enhances their post expansion chondrogenic capacity. HAC/ substrate interaction was restricted to RGD by modifying tissue culture polystyrene (TCPS) with a poly(ethylene glycol) (PEG) based copolymer system that renders the surface resistant to protein adsorption while at the same time presenting the bioactive RGD-containing peptide GCRGYGRGDSPG (RGD). As compared to TCPS, HAC cultured on RGD spread faster (1.9-fold), maintained higher type II collagen mRNA expression (4.9-fold) and displayed a 19% lower spreading area. On RGD, HAC attachment efficiency (66±10%) and proliferation rate (0.56±0.04 doublings/day), as well as type II collagen mRNA expression in the subsequent chondrogenic differentiation phase, were similar to those of cells cultured on TCPS. In contrast, cartilaginous matrix deposition by HAC expanded on RGD was slightly but consistently higher (15% higher glycosaminoglycan-to-DNA ratio). RDG (bioinactive peptide) and PEG (no peptide ligand) controls yielded drastically reduced attachment efficiency (lower than 11%) and proliferation (lower than 0.20 doublings/day). Collectively, these data indicate that restriction of HAC interaction with a substrate through RGD peptides is sufficient to support their adhesion, growth and maintenance of cartilage forming capacity. The concept could thus be implemented in materials for cartilage repair, whereby in situ recruited/infiltrated chondroprogenitor cells would proliferate while maintaining their ability to differentiate and generate cartilage tissue.

Extracellular-Matrix-Based and Arg-Gly-Asp–Modified Photopolymerizing Hydrogels for Cartilage Tissue Engineering

“…31 Similarly, chondrocyte spreading due to high RGD concentration has shown to decrease cell size and reduce ECM synthesis overtime in polyethylene glycol dimethacrylate (PEGDM) hydrogel. 32,33 Accordingly, in our study, slight decrease in GAG and collagen accumulation was observed in PEG-RGD hydrogel compared with that in PEG-RDG hydrogels. Conversely, ECM-based hydrogels exhibited biodegradation properties upon exposure to their respective degradable enzymes.…”

Maximizing phenotype constraint and extracellular matrix production in primary human chondrocytes using arginine–glycine–aspartate concentration gradient hydrogels

“…4C) are similar to a previous 2-D study. It found that higher RGD concentrations led to an initial increase in chondrocyte spreading followed by a decrease in the chondrocyte foot-print over time and an increase of initial spreading over the control but leads to decreased cell size over time [27]. The organization of actin within chondrocytes is also thought to contribute to cellular phenotype, pericellular matrix synthesis and retention of the proteoglycans in the tissue [62,72].…”

A survey of state-of-the-art surface chemistries to minimize fouling from human and animal biofluids

“…Rather, the following are combinations thereof (i.e. [142][143][144][145][146][147][148][149][150][151][152][153][154][155] At pH 7.4 (HEPES 156 or PBS buffer), these PLL-g-PEG macromolecules were shown to display the ability to spontaneously self-assemble onto a variety of metal oxide substrates made of niobium, [142][143][144]151,152,154,155 titanium, 142,143,[145][146][147][148]150,153 silicon/titanium, 142 or tantalum. Nonetheless, these 'outliers' are no less important and form, as a matter of fact, some of the best antifouling coatings known against blood plasma/serum (see Table 1 in upcoming subsection IV.A.).…”