Mesenchymal stem cell adhesion and spreading on microwave plasma-nitrided titanium alloy.
Improved methods to increase surface hardness of metallic biomedical implants are being developed in an effort to minimize the formation of wear debris particles that cause local pain and inflammation. However, for many implant surface treatments, there is a risk of film delamination due to the mismatch of mechanical properties between the hard surface and the softer underlying metal. In this article, we describe the surface modification of titanium alloy (Ti-6Al-4V), using microwave plasma chemical vapor deposition to induce titanium nitride formation by nitrogen diffusion. The result is a gradual transition from a titanium nitride surface to the bulk titanium alloy, without a sharp interface that could otherwise lead to delamination. We demonstrate that vitronectin adsorption, as well as the adhesion and spreading of human mesenchymal stem cells to plasma-nitrided titanium is equivalent to that of Ti-6Al-4V, while hardness is improved 3- to 4-fold. These in vitro results suggest that the plasma nitriding technique has the potential to reduce wear, and the resulting debris particle release, of biomedical implants without compromising osseointegration; thus, minimizing the possibility of implant loosening over time.
Clem
William C
WC
Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294-4440, USA.
Konovalov
Valery V
VV
Chowdhury
S
S
Vohra
Yogesh K
YK
Catledge
Shane A
SA
Bellis
Susan L
SL
D002448:Cell Adhesion; D048430:Cell Shape; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D008872:Microwaves; D011475:Prosthesis Failure; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D019096:Vitronectin / Q000494:pharmacology
D020099:Coated Materials, Biocompatible; D019096:Vitronectin; C041500:titanium nitride; D014025:Titanium