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

alpha CGRP, a neuropeptide widely distributed in bone tissue, has been demonstrated as a physiological activator of bone formation. However, the regulation of alpha CGRP 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 alpha CGRP (10(-8) M). Scanning electron microscopy and immunofluorescence staining demonstrated that alpha CGRP 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 alpha CGRP from 3 to 7 days post-seeding. Furthermore, cell growth diffbred when cultured on different titanium surfaces (smooth> SLA> SLActive). In addition, alpha CGRP 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 alpha CGRP-coated surfaces. In addition, alpha CGRP pre-coated surfaces formed more Alizarin red-positive nodules after culture for 21 days. Taken together, our data indicated that coating titanium discs with alpha CGRP enhanced the adhesion, proliferation, differentiation, and mineralization of osteoblasts, particularly on SLActive surfaces.