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.

Platelet-functionalized three-dimensional poly-ε-caprolactone fibrous scaffold prepared using centrifugal spinning for delivery of growth factors

“…These cells are frequently used in tissue engineering studies to study scaffold biocompatibility and bone tissue formation. [51][52][53][54][55] On the other hand, differences between osteosarcoma lines and primary osteoblast cells have been published. 56,57 Main differences have been found in proliferation kinetics, cell morphology and synthesis of ECM proteins.…”

Additive manufacturing of Ti6Al4V alloy via electron beam melting for the development of implants for the biomedical industry

“… Osteoblasts Manufactured structures provide a way to initiate cell migration and impregnation of cells and tissues into the manufactured structure, thus leading to a regeneration of the mineralized extracellular matrix by differentiation of pre-osteoblasts [ 187 ], [ 188 ]. Regarding their potential use in orthopedic applications, osteoblast organization, as well as adhesion, spreading, and alignment to the geometries of the biomaterial struts, has been observed on the surfaces of EBM-manufactured samples [ 189 ]. There is a significant difference in cellular response depending on the pore size of manufactured structures [ 190 ].…”

“…Also, the presence of an oxide layer on the surface of samples enables the absorption of fibronectin, a protein that favors osteoblast adhesion and osseointegration [ 192 ]. Osteoblast organization, as well as adhesion, spreading, and alignment to the geometries of the biomaterial struts, has been identified within complex titanium surface geometries [ 189 ]. Bioactivity The bioactivity of manufactured and modified samples has been improved via micro-arc oxidation/anodizing, which provides a multimodal surface roughness (nano-, micro-, and macro-scale roughness) [ 193 ].…”

“…Osteoblast organization, as well as adhesion, spreading, and alignment to the geometries of the biomaterial struts, has been identified within complex titanium surface geometries [189].…”

X-ray Tomography Characterisation of Lattice Structures Processed by Selective Electron Beam Melting

“…Selective Electron Beam Melting (SEBM) is one AM route that is becoming increasingly popular. This method may be employed to process light-weight structures [2], bio-compatible materials [3] and heat transfer media [4], among other things. There are advantages to all of these applications from the production of porous lattices, and, as this additive process uses an electron beam capable of being deflected magnetically, (unlike other beams such as lasers, which are driven by mirrors) the manufacture of these structures can be carried out relatively quickly by SEBM.…”