The optimization and production of stable homogeneous amine enriched surfaces with characterized nanotopographical properties for enhanced osteoinduction of mesenchymal stem cells.

Abstract

Silane modification has been proposed as a powerful biomaterial surface modification tool. This is the first comprehensive investigation into the effect of silane chain length on the resultant properties of -NH2 silane monolayers and the associated osteoinductive properties of the surface. A range of -NH2 presenting silanes, chain length 3-11, were introduced to glass coverslips and characterized using water contact angles, atomic force microscopy, X-ray photoelectron spectroscopy, and Ninhydrin assays. The ability of the variation in chain length to form a homogenous layer across the entirety of the surfaces was also assessed. The osteoinductive potential of the resultant surfaces was evaluated by real-time polymerase chain reaction, immunocytochemistry, and von Kossa staining. Control of surface chemistry and topography was directly associated with changes in chain length. This resulted in the identification of a specific, chain length 11 (CL11) which significantly increased the osteoinductive properties of the modified materials. Only CL11 surfaces had a highly regular nano-topography/roughness which resulted in the formation of an appetite-like layer on the surface that induced a significantly enhanced osteoinductive response (increased expression of osteocalcin, CBFA1, sclerostin, and the production of a calcified matrix) across the entirety of the surface. © 2018 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1862-1877, 2018.