Effects of αCGRP on the Adhesion, Proliferation and Differentiation of Osteoblasts Cultured on Titanium Surfaces

Abstract

αCGRP, a neuropeptide widely distributed in bone tissue, has been demonstrated as a physiological activator of bone formation. However, the regulation of αCGRP on the osseointegration of dental titanium implants is not well understood. In this study, mouse primary calvarial osteoblasts were obtained and cultured on smooth, rough (SLA), and chemically modified (SLActive) titanium discs coated with or without αCGRP (10^-8 M). Scanning electron microscopy and immunofluorescence staining demonstrated that αCGRP promoted cellular adhesion on all three titanium surfaces. MTT colorimetric assay and flow cytometry results displayed an increase in cell growth on all titanium surfaces coated with αCGRP from 3 to 7 days post-seeding. Furthermore, cell growth differed when cultured on different titanium surfaces (smooth> SLA> SLActive). In addition, αCGRP upregulated the mRNA expression of ALP and OCN on SLA and SLActive surfaces from 7 to 14 days. Immunofluorescence results further confirmed that osteoblasts secreted more ALP when cultured on αCGRP-coated surfaces. In addition, αCGRP pre-coated surfaces formed more Alizarin red-positive nodules after culture for 21 days. Taken together, our data indicated that coating titanium discs with αCGRP enhanced the adhesion, proliferation, differentiation, and mineralization of osteoblasts, particularly on SLActive surfaces.