Surface modification of bulk titanium substrates for biomedical applications via low-temperature microwave hydrothermal oxidation

• Type of Material: Article
• Authors: Alice Cheng, Georgia Institute of Technology; W. Brandon Goodwin, Georgia Institute of Technology; Ben M. Deglee, Georgia Institute of Technology; Rolando A. Gittens, Institute for Scientific Research and High Technology Services (INDICASAT); Jonathan P. Vernon, Air Force Research Laboratory; Sharon L. Hyzy, Virginia Commonwealth University; Zvi Schwartz, Virginia Commonwealth University; Kenneth H. Sandhage, Georgia Institute of Technology; Barbara Boyan, Emory University
• Language: English
• Date: 2018-03-01
• Publisher: Wiley
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018 John Wiley & Sons, Inc. All rights reserved.
• Final Published Version (URL): http://dx.doi.org/10.1002/jbm.a.36280
• Title of Journal or Parent Work: Journal of Biomedical Materials Research Part A
• Volume: 106
• Issue: 3
• Start Page: 782
• End Page: 796
• Grant/Funding Information: A.C. was supported by a National Science Foundation Graduate Research Fellowship.
• Keywords: Nanoparticles; Engineering, Biomedical; Energy; wetting; Nanosize rutile; Implant surfaces; Materials Science, Biomaterials; H2O2; Materials Science; surface modification; Pure titanium; Technology; oxidation; Hydrogen Peroxide; Science & Technology; nanostructured materials; Transformation; Engineering; biomaterials; Photocatalytic activity
• Research Categories: Engineering, Biomedical; Chemistry, Biochemistry; Engineering, Materials Science

Abstract

Micro-to-nanoscale surface topographies of orthopaedic and dental implants can affect fluid wetting and biological response. Nanoscale features can be superimposed on microscale roughness of titanium (Ti) surfaces at high temperatures, resulting in increased osteoblast differentiation. However, high temperatures can compromise mechanical properties of the bulk material. Here, we have developed a novel low-temperature microwave hydrothermal (MWHT) oxidation process for nanomodification of microrough (SLA) Ti surfaces. Nanoscale protuberances (20 –100 nm average diameter) were generated on SLA surfaces via MWHT treatment at 200°C in H2O, or in aqueous solutions of H2O2 or NH4OH, for times ranging from 1 to 40 h. The size, shape, and crystalline content of the nanoprotuberances varied with the solution used and treatment time. The hydrophilicity of all MWHT-modified surfaces was dramatically enhanced. MG63 and normal human osteoblasts (NHOsts) were cultured on MWHT-treated SLA surfaces. While most responses to MWHT-modified surfaces were comparable to those seen on SLA controls, the MWHT-generated nanotopography reduced osteocalcin production by NHOst cells, suggesting that specific nanotopographic characteristics differentially mediate osteoblast phenotypic expression. MWHT processing provides a scalable, low-temperature route for tailoring nanoscale topographies on microroughened titanium implant surfaces with significantly enhanced wetting by water, without degrading the microscale surface structure of such implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 782–796, 2018.