Characterization of collagen II fibrils containing biglycan and their effect as a coating on osteoblast adhesion and proliferation

Abstract

Collagen has been used as a coating material for titanium-based implants for bone contact and as a component of scaffolds for bone tissue engineering. In general collagen type I has been used, however very little attention has been focussed on collagen type II. Collagen-based coatings and scaffolds have been enhanced by the incorporation of the glycosaminoglycan chondroitin sulphate (CS), however the proteglycan biglycan, which is found in bone and contains glycosaminoglycan chains consisting of CS, has not been used as a biomaterial component. The study had the following aims: firstly, five different collagen II preparations were compared with regard to their ability to bind CS and biglycan and the changes in fibril morphology thereby induced. Secondly, the effects of biglycan on the adhesion of primary rat osteoblasts (rO) as well as the proliferation of rO, primary human osteoblasts (hO) and the osteoblast-like cell line 7F2 were studied by culturing the cells on surfaces coated with collagen II fibrils containing biglycan. Fibrils of the collagen II preparation which bound the most biglycan were used to coat titanium surfaces. Bare titanium, titanium coated with collagen II fibrils and titanium coated with collagen II fibrils containing biglycan were compared. It was found that different collagen II preparations showed different affinities for CS and biglycan. In four of the five preparations tested, biglycan reduced fibril diameter, however the ability of a preparation to bind more biglycan did not appear to lead to a greater reduction in fibril diameter. Fibrils containing biglycan promoted the formation of focal adhesions by rO and significantly enhanced the proliferation of hO but not of rO or 7F2 cells. These results should encourage further investigation of biglycan as a component of collagen-based scaffolds and/or coatings.

Regenerative potential of glycosaminoglycans for skin and bone

“…Immobilized monosulfated HA facilitated the proliferation and TNAP activity of human osteoblasts in the same manner as a coating with collagen [97]. Implant coating with collagen fibrils and CS or CS-PGs promotes adhesion and differentiation of osteoblasts and osseointegration [87,[107][108][109][110][111][112].…”

Nanocoating of Titanium Implant Surfaces with Organic Molecules. Polysaccharides Including Glycosaminoglycans

“…1 Polysaccharides, including glycosaminoglycans have been used for implant surface coating, based on both the direct and indirect adhesion mechanism. [12][13][14][15][16][17][18][19][20][21] The advantage of polysaccharides compared to proteins as nanocoating material is that they stay longer at the coated surface and therefore have a cell attracting effect for a longer time. 14 22 23 Thus, the properties enable polysaccharides to carry signal molecules and support biologically active substances.…”

Screening for novel cell adhesive regions in bovine Achilles tendon collagen peptides

“…Historically, collagen isolated from diverse sources has been used successfully as an effective coating material (Jokinen et al 2004;Douglas et al 2008). In the present study, the number of cells adhering to coated bovine tendon collagen has been used as a positive control against that of the peptides.…”

“…Ligand recognition occurs through an independently folding domain, the inserted or I-domain located in ␣ subunit, in juxtaposition to the N-terminal blades of the ␤ propeller, also in the ␣ subunit. The domain adopts a Rossman fold and harbours a metal ion-dependent adhesion site or MIDAS Douglas et al 2008). Although the metal is held by oxygen atoms, one empty coordination site remains available for bond formation by a ligand carboxylate anion; which is why E or D residues present in ligand play a crucial role in ligand recognition and signal transfer.…”