Biomaterials surface properties such as topography and roughness impact adherent cell behavior, particularly on osteoblasts in bone tissue engineering research. 1 Their effects on osteoblasts are well characterized, however, anisotropic nature of bone surface patterns can result in distinctive behavior. Herein, we report the feasibility and effectiveness of transferring native bone surface topography from a bovine femur onto chitosan (CH), chitosan/graphene oxide (CH/GO), and poly (dimethyl siloxane) (PDMS) for the investigation of osteoblast behavior on these bone surface mimicked (BSM) biomaterials. CH composites were modified with hydroxyapatite (HA) and BSM PDMS membranes were modified with fibronectin (FN) for enhanced biocompatibility. 2,3

Human fetal osteoblast (hFOB) cells adherence on BSM chitosan composites have shown statistically significant increases in viability compared to plain chitosan membranes as shown by MTT viability assay. Presence of HA further increased the viability of cells on BSM CH/HA and BSM CH/GO/HA membranes, in comparison with their controls. Scanning Electron Microscopy (SEM) imaging has also shown native-like osteoblastic cell morphology and Extracellular Matrix (ECM) deposition is present on BSM CH/GO/HA membranes at day 7. BSM PDMS membranes were used to further investigate osteoblastic behavior. A surface transfer quality quantification approach by SEM image processing was introduced. BSM PDMS membranes and their controls were functionalized with FN, a native ECM protein, for biocompatibility and they have later seeded with hFOB cells. Cell viabilities on BSM PDMS membranes were shown to be significantly enhanced on both short- and long-term culture (days 1-21) using alamarBlue cell proliferation assay, along with increased mineralization and intracellular alkaline phosphatase compared to their plain PDMS control groups until day 14 and day 7, respectively. Maturation and differentiation markers for osteoblast cells were significantly increased over the course of 7 days, compared to both TCPS and plain PDMS. Alignment of osteoblast cells on BSM PDMS membranes was observed. Our approach for utilizing soft lithography for transferring bone surface topography on different polymers can be extended to various other tissues and fabrication of such platforms can result in a better understanding of native tissue biology in vitro.

(1)    Bacakova, L.; Filova, E.; Parizek, M.; Ruml, T.; Svorcik, V., Biotechnology Advances, 2011, 29 (6), 739–767.
(2)    Puza, F.; Rostami, S.; Özçolak-Aslan, B.; Odabaş, S.; Jandt, K.D.; Garipcan, B., Advanced Engineering Materials, 2022, 2200777.
(3)    Erenay, B.; Sağlam, A.S.Y.; Garipcan B.; Jandt, K.D.; Odabaş, S., Biomaterial Advances, 2022, 142, 213170.