Osteoblast proliferation and differentiation on a barrier membrane in combination with BMP2 and TGFβ1

Bioresorbable collagen membranes are routinely utilized in guided bone regeneration to selectively direct the growth and repopulation of bone cells in areas of insufficient volume. However, the exact nature by which alveolar osteoblasts react to barrier membranes as well as the effects following the addition of growth factors to the membranes are still poorly understood. The objective of the present study was therefore to investigate the effect of a bioresorbable collagen membrane soak-loaded in growth factors bone morphogenetic protein 2 (BMP2) or transforming growth factor beta 1 (TGF beta 1) on osteoblast adhesion, proliferation, and differentiation. Prior to experimental seeding, membranes were soaked in either BMP2 or TGF beta 1 at a concentration of 10 ng/ml for 5 min. Human osteoblasts adhered to all soak-loaded membranes as assessed by scanning electron microscopy. Growth factors BMP2 and TGF beta 1 increased osteoblast proliferation at 3 or 5 days post-seeding when compared to control collagen membranes. Analysis of real-time PCR revealed that administration of BMP2 increased osteoblast differentiation markers such as osterix, collagen I, and osteocalcin. BMP2 also increased mineralization of primary osteoblasts as demonstrated by alizarin red staining when compared to control and TGF beta 1 soak-loaded membranes. The combination of a collagen barrier membrane with growth factors TGF beta 1 and BMP2 significantly influenced adhesion, proliferation, and differentiation of primary human osteoblasts. The described in vitro effects following the combination of collagen barrier membranes with growth factors TGF beta 1 and BMP2 provide further biologic support for the clinical application of this treatment strategy in guided bone regeneration procedures.