title: Optimizing the osteogenicity of nanotopography using block co-polymer phase separation fabrication techniques.
abstract: Both temporary and permanent orthopedic implants have, by default or design, surface chemistry, and topography. There is increasing evidence that controlling nanodisorder can result in increased osteogenesis. Block co-polymer phase separation can be used to fabricate a nanotopography exhibiting a controlled level of disorder, both reproducibly and cost-effectively. Two different topographies, produced through the use of block co-polymer phase separation, were embossed onto the biodegradable thermoplastic, polycaprolactone (PCL). Analysis of the topography itself was undertaken with atomic force microscopy, and the topography's effect on human osteoblasts studied through the use of immunocytochemistry and fluorescence microscopy. Planar controls had a surface roughness 0.93 nm, and the substrates a high fidelity transfer of a disordered pattern of 14 and 18 nm. Cytoskeletal organization and adhesion, and increased expression of Runx2 were significantly greater on the smallest nanotopography. Expression of osteopontin and osteocalcin protein, and alizarin red staining of bone nodules were greatest on the smallest feature nanopatterns. Highly osteogenic, disordered nanotopographies can be manufactured into thermoplastics in a rapid and cost-effective way through the use of block co-polymer phase separation. Osteogenic topographies reproducibly and cost-effectively produced have a potentially useful application to the fields of implant technology and regenerative orthopedics.
authors.affiliation: Centre for Cell Engineering, Institute of Molecular, Cell & Systems Biology, College of Medical, Veterinary & Life Sciences, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK. sarahmaclaine@fsmail.net
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Maclaine
authors.forename: Neha
authors.initials: N
authors.lastname: Gadhari
authors.forename: Raphael
authors.initials: R
authors.lastname: Pugin
authors.forename: Robert M Dominic
authors.initials: RM
authors.lastname: Meek
authors.forename: Martha
authors.initials: M
authors.lastname: Liley
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Dalby
mesh_terms: D002448:Cell Adhesion; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis; D006801:Humans; D018625:Microscopy, Atomic Force; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*; D015675:Osteocalcin / Q000096:biosynthesis; D010012:Osteogenesis / Q000502:physiology*; D053495:Osteopontin / Q000096:biosynthesis; D013499:Surface Properties
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D015675:Osteocalcin; D053495:Osteopontin