Effect of surface topography on in vitro osteoblast function and mechanical performance of 3D printed titanium

Abstract

Critical‐sized defects remain a significant challenge in orthopaedics. 3D printed scaffolds are a promising treatment but are still limited due to inconsistent osseous integration. The goal of the study is to understand how changing the surface roughness of 3D printed titanium either by surface treatment or artificially printing rough topography impacts the mechanical and biological properties of 3D printed titanium. Titanium tensile samples and discs were printed via laser powder bed fusion. Roughness was manipulated by post‐processing printed samples or by directly printing rough features. Experimental groups in order of increasing surface roughness were Polished, Blasted, As Built, Sprouts, and Rough Sprouts. Tensile behavior of samples showed reduced strength with increasing surface roughness. MC3T3 pre‐osteoblasts were seeded on discs and analyzed for cellular proliferation, differentiation, and matrix deposition at 0, 2, and 4 weeks. Printing roughness diminished mechanical properties such as tensile strength and ductility without clear benefit to cell growth. Roughness features were printed on mesoscale, unlike samples in literature in which roughness on microscale demonstrated an increase in cell activity. The data suggest that printing artificial roughness on titanium scaffold is not an effective strategy to promote osseous integration.

Effect of micro-arc oxidation surface modification of 3D-printed porous titanium alloys on biological properties

“…The complex and interconnected pore structures constructed using 3D printing technology can help ingrowth of bone and blood vessels (9)(10)(11). However, changing the macro structure of 3D-printed porous scaffolds simply cannot promote the proliferation and differentiation of osteoblasts, and filament diameter less than 100 μm can affect the mechanical properties of scaffolds (12).…”

Improvement in osteogenesis, vascularization, and corrosion resistance of titanium with silicon-nitride doped micro-arc oxidation coatings

“…In addition, as shown in Figures 2B,C , the MAO treatment significantly enhanced the surface roughness and hydrophilicity, which might also promote cell adhesion/proliferation. Increased surface roughness reportedly promoted osteoblast spread and migration ( Jiang et al, 2013 ; Abar et al, 2021 ). In the cell viability tests, as an inorganic nanomaterial with excellent biocompatibility, Si 3 N 4 did not show significant cytotoxicity, consistent with previous reports ( Bock et al, 2015 ; Fiani et al, 2021 ; Lee et al, 2021 ).…”

Use of 3D-Printed Implants in Complex Foot and Ankle Reconstruction

“…Many studies have shown increased osteoblast proliferation on scaffolds with roughened surfaces 20,21 ; however, other work refutes this, showing no increased activity of preosteoblasts on titanium cages with printed roughness with roughness features of .100 mm. 22 For current practice, the authors rely on the natural surface roughness from the fabrication process without performing any secondary treatment such as laser or acid etching.…”