Effects on Interfacial Properties and Cell Adhesion of Surface Modification by Pectic Hairy Regions

Abstract

Polystyrene Petri dishes, aminated by a plasma deposition process, were surface modified by the covalent linking of two different enzymatically modified hairy regions (HRs) from pectin containing, for example, rhamnogalacturonan-I and xylogalacturonan structural elements. The two polysaccharide preparations share the same structural elements of apple pectin, but the relative amounts and lengths of the neutral side chains present differ. Surface analysis by X-ray photoelectron spectroscopy, contact angle measurement, and atomic force microscope (AFM) force-separation curves was used to characterize the effects on surface chemistry and interfacial forces of the surface modification process. Cell adhesion experiments using continuous L-929 fibroblasts and primary aortic smooth muscle cells were performed to evaluate the effect of the polysaccharide nature on cell adhesion. Results show that immobilization of the HR affects the interfacial field of forces and the cell behavior: "equilibrium" contact angles, obtained by a recently introduced vibrational approach, decrease after HR immobilization reaching a value close to 20 degrees . AFM force-separation curves show a more extended (or softer) interface in the case of the HR bearing longer side chains. Accordingly, depending on the HR preparation, cells shifted from spread morphology and adhesion behavior quantitatively comparable to that observed on conventional tissue culture polystyrene to rounded morphology and significantly lower adhesion. These data show that engineering of plant pectins can be a valuable tool to prepare novel and finely tuned polysaccharides having different chemico-physical and biological properties, to be used in the surface modification of medical devices and materials.

Plant Products for Innovative Biomaterials in Dentistry

“…Pectins may also contain a complex RG-II component attached to the homogalacturonan region [29,30]. In addition to these natural variations, pectin structures can be further modified in vitro by pectinolytic exo-or endoenzymes, consisting of commercial, micro-organism-derived enzyme mixtures designed for degrading pectin gels [31,32]. Pectin fragments formed by enzymatic treatments consist of modified hairy regions (MHR), which may be used in the coating of biomedical devices, according to their chemical, physical and biological properties.…”

“…Thus, pectins are nowadays under enthusiastic investigation in the biomaterial field as novel candidates for soft and hard tissue engineering and dental titanium coating [32,33,35,36,44]. Promising in vitro and in vivo results indicate the possibility of using enzymatically modified apple pectin fragments as dental implant nano-coatings [13,45].…”

“…As described by a previous work, the surface-functionalization was obtained by means of aminating plasma deposition process, then coated with MHR using carbodiimide-mediated condensation between deposited amino groups and carboxyl groups of MHR [32]. MHR-B coating, in…”

“…Modified pectic nano-coating in vitro appears to be a promising direction to enhance the biocompatibility of bone and dental implants [45]. In particular, the authors explained the higher activity of MHRs-B by considering the relationship between cellular preference and surface wettability [32,47]: more hydrophobic MHRs-B were markedly more biocompatible than the more wettable MHRs-A [48].…”

Plant-derived pectin nanocoatings to prevent inflammatory cellular response of osteoblasts following <em>Porphyromonas gingivalis</em> infection

“…Recently, it was reported that plant-derived polysaccharides, mainly Rhamnogalacturonan-I (RG-I) pectins, have potential to improve bone regeneration, [11][12][13] prevent inflammation, 14,15 and act as a delivery mechanism for therapeutic agents. 15 RG-I is the first molecule derived from plants that has been introduced and tested as a potential nanocoating to be applied to biomaterial surfaces, for example, titanium, to improve bone healing and osseointegration.…”