Effect of Modified Pectin Molecules on the Growth of Bone Cells

Abstract

The aim of this study was to investigate molecular candidates for bone implant nanocoatings, which could improve biocompatibility of implant materials. Primary rat bone cells and murine preosteoblastic MC3T3-E1 cells were cultured on enzymatically modified hairy regions (MHR-A and MHR-B) of apple pectins. MHRs were covalently attached to tissue culture polystyrene (TCPS) or glass. Uncoated substrata or bone slices were used as controls. Cell attachment, proliferation, and differentiation were investigated with fluorescence and confocal microscopy. Bone cells seem to prefer MHR-B coating to MHR-A coating. On MHR-A samples, the overall numbers as well as proportions of active osteoclasts were diminished compared to those on MHR-B, TCPS, or bone. Focal adhesions indicating attachment of the osteoblastic cells were detected on MHR-B and uncoated controls but not on MHR-A. These results demonstrate the possibility to modify surfaces with pectin nanocoatings.

Plant Products for Innovative Biomaterials in Dentistry

“…Promising in vitro and in vivo results indicate the possibility of using enzymatically modified apple pectin fragments as dental implant nano-coatings [13,45]. Biocompatibility of titanium implant materials appeared to be improved when coated with two apple-derived MHR molecules (MHR-A and MHR-B).…”

“…Biocompatibility of titanium implant materials appeared to be improved when coated with two apple-derived MHR molecules (MHR-A and MHR-B). MHR were obtained by treating homogenized apple tissues in vitro with commercial pectinolytic enzyme mixtures, which allowed to separate the rhamnogalacturonan and homogalacturonan regions of a pectin molecule into suspension [45]. A 6-10 nm thick MHR pectin nanocoating on the titanium surface was produced by grafting MHRs onto titanium samples by carbodiimide condensation: indeed, amino groups, present onto titanium and obtained via allylamine plasma deposition, were covalently linked to the carboxyl groups of MHR [45].…”

“…Then, the possibility to modify dental titanium surfaces with pectin nanocoatings was further investigated in order to enhance osteoblast differentiation. MC3T3-E1 cell line, primary murine cells and human mesenchymal cells (hMC) were cultured on titanium disks, coated with the above reported rhamnogalacturonan-rich modified hairy regions (MHR-A and MHR-B) of apple pectins [45]. Consistently with their previous paper, Kokkonen et al reported as MHRs-B and pure titanium (but not MHRs-A) seem to be the most favorable for osteoblast cell spreading, as well related to the highest abundance of cellular focal adhesions and to an increasing amount of calcium deposition.…”

“…Moreover, after ten day of differentiation, when hMC morphology was fully osteoblastic, cells cultured on MHRs-B showed the highest alkaline phosphatase activity, supporting an increased osteoblast differentiation. 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].…”

Evaluation of apatite-forming ability and mechanical property of pectin hydrogels

“…Pectin is a natural polysaccharide included in most plants as a component of extracellular matrix and has high biological compatibility. 19) Its chemical structure is shown in Fig. 1.…”