title: Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications.
abstract: In this study, we report on a group of complementary human osteoblast in vitro test methods for the preclinical evaluation of 3D porous titanium surfaces. The surfaces were prepared by additive manufacturing (electron beam melting [EBM]) and plasma spraying, allowing the creation of complex lattice surface geometries. Physical properties of the surfaces were characterized by SEM and profilometry and 3D in vitro cell culture using human osteoblasts. Primary human osteoblast cells were found to elicit greater differences between titanium sample surfaces than an MG63 osteoblast-like cell line, particularly in terms of cell survival. Surface morphology was associated with higher osteoblast metabolic activity and mineralization on rougher titanium plasma spray coated surfaces than smoother surfaces. Differences in osteoblast survival and metabolic activity on titanium lattice structures were also found, despite analogous surface morphology at the cellular level. 3D confocal microscopy identified osteoblast organization within complex titanium surface geometries, adhesion, spreading, and alignment to the biomaterial strut geometries. Mineralized nodule formation throughout the lattice structures was also observed, and indicative of early markers of bone in-growth on such materials. Testing methods such as those presented are not traditionally considered by medical device manufacturers, but we suggest have value as an increasingly vital tool in efficiently translating pre-clinical studies, especially in balance with current regulatory practice, commercial demands, the 3Rs, and the relative merits of in vitro and in vivo studies. Biotechnol. Bioeng. 2016;113: 1586-1599. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.
authors.affiliation: JRI Orthopaedics Ltd., Sheffield, United Kingdom.
authors.forename: G
authors.initials: G
authors.lastname: Stevenson
authors.affiliation: JRI Orthopaedics Ltd., Sheffield, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Rehman
authors.affiliation: JRI Orthopaedics Ltd., Sheffield, United Kingdom.
authors.forename: E
authors.initials: E
authors.lastname: Draper
authors.affiliation: Mercury Centre, University of Sheffield, Sheffield, United Kingdom.
authors.forename: E
authors.initials: E
authors.lastname: Hernández-Nava
authors.affiliation: Mercury Centre, University of Sheffield, Sheffield, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Hunt
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, Sheffield, S3 7HQ, United Kingdom. j.w.haycock@sheffield.ac.uk.
authors.forename: J W
authors.initials: JW
authors.lastname: Haycock
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry / Q000633:toxicity; D045744:Cell Line, Tumor; D006801:Humans; D007595:Joint Prosthesis; D009985:Orthopedics; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D013499:Surface Properties; D014025:Titanium / Q000633:toxicity
chemical_list: D001672:Biocompatible Materials; D014025:Titanium
keywords: additive manufacturing; in vitro test; osteoblast; plasma spraying; surface topography; titanium alloy