Collagen-lactoferrin fibrillar coatings enhance osteoblast proliferation and differentiation.

Lactoferrin is a milk-derived glycoprotein with anabolic effects on the bone tissue. In this study, artificial extracellular matrices (aECM) consisting of collagen type I fibrils formed in the presence of lactoferrin at two different concentrations (0.5 and 1 mg mL(-1) ) were prepared on the surface of poly(lactic-co-glycolic acid) (PLGA) foils. The aim of the study was to investigate the effects of aECM on the adhesion, growth and osteogenic differentiation of human osteoblast-like Saos-2 cells. On days 1 and 3 after seeding, higher numbers of cells were found on samples with collagen and collagen-lactoferrin coatings (particularly on those formed at the higher concentration of lacroferrin) than on control microscopic glass coverslips. Cells on coatings formed in the presence of lactoferrin had more numerous and better developed vinculin-containing focal adhesion plaques. On day 7, cells on coatings with and without lactoferrin produced significantly higher levels of osteocalcin than cells on control polystyrene cell culture dishes, the highest average values being found on samples with the lower concentration of lactoferrin. Expression of collagen I and alkaline phosphatase was on a similar level in cells on all tested samples and control polystyrene. Thus, lactoferrin promotes adhesion, growth and osteogenic differentiation of Saos-2 cells and is promising as a bone implant coating component.