Abstract
It is well established that cell behaviour is responsive to the surrounding environment. Chemistry, material stiffness and topography allow control of cell adhesion, proliferation, growth and differentiation. Biomimicry is playing a role in the next generation of biomaterials, surface engineering on orthopaedic implants may promote improved skeletal integration.
Human osteoblasts were cultured on engineered micro-topographical features with nanoscale depths, similar in scale to an osteoclast resorption pit. Three different micro-topographies were used (in addition to planar controls.) created on a hot moulded polymer. The cells were cultured in basal media on surfaces with 20, 30 and 40 micrometer circular pits, each with a depth of 400 nanometers. The cells were fixed at time points 3 days, 21 days and 28 days to allow assessment of cytoskeletal development, production of protein markers of bone production (osteopontin) and mineral deposition respectively.
At each time point greater indicators of cell activity and bone production were evident on the 30 and 40 micrometer structures as compared with the 20 micrometer structures and the planar controls. These positive results include increased focal adhesions, stronger expression of intracellular and extracellular osteopontin and more mature nodules of calcium formation.
This in vitro study demonstrates that micro and nanotopographies influence cell activity. Osteoblast response can be induced on the surface of a future generation of orthopaedic implants, lasting long after the effects chemical application have expired. Further research is required to assess the potential application to implant grade materials.
