Nano-structure TiO2 film coating on 316L stainless steel via sol-gel technique for blood compatibility improvement


1 Department of Materials Science and Engineering, Iran University of Science and Technology, Narmak, Tehran, Iran

2 Iranian Blood Transfusion Research Centre, Tehran, Iran


Titanium oxides are known to be appropriate hemocompatible materials which are suggested as coatings for blood-contacting devices. Little is known about the influence of nanometric crystal structure, layer thickness, and semiconducting characteristics of TiO2
on blood hemostasis.
Materials and Methods:
Having used sol-gel dip coating method in this study, TiO2 thin films were deposited on nano-scale electro-polished stainless steel 316L with 1 to 5 nano-sized layers. Surface morphology and structure of the film were studied with X-ray diffraction and atomic force microscopy. Blood compatibility was also determined by measuring the platelet activation (CD62P expression), platelet adhesion (Scanning Electron Microscopy), and the blood clotting time on these samples.  
The films were compact and smooth and existed mainly in the form of anatase. By increasing the number of TiO2 thin layer, clotting time greatly extended, and the population of activated platelet and P-selectine expression changed according to the surface characteristics of each layer.  
The findings revealed that stainless steel 316L coated with nano-structured TiO2 layer improved blood compatibility, in terms of both blood platelet activity and coagulation cascade, which can decrease the thrombogenicity of blood contacting devices which were made from stainless steel.


1. Syganov I, Maitz MF, Wieser E. Blood compatibility of titanium based coatings prepared by metal plasma immersion ion implantation and deposition. Appl Surf Sci. 2004; 235: 156-163.
2. Zhang F, Liu X, Mao Y, Huang N, Chen Y, Zheng Z, et al. Artificial heart valves: improved hemocompatibility by titanium oxide coatings prepared by ion beam assisted deposition. J Surf Coat Tech. 1998; 103: 146-150
3. Stoeckel D, Bonsignore C, Dud S. Minimally invasive therapy & allied technology, a survey of stent designs. 2002; 11(4): 137-147.
4. Serruys P, Strauss BH, Beatt KJ. Angiographic follow-up after placement of a self-expanding coronary-artery stent. New Engl J Med. 1991; 324: 13-17
5. Cannan CR. Curr Cardiol Rep. 2001; 3(1): 78-84.
6. Huang N, Yang P, chen X. Blood compatibility of amorphous titanium oxide films synthesized by ion beam enhanced deposition. J Biomaterials. 1998; 19: 771-776.
7. Kastrati A, Shomig A, Dirchinger J. Increased risk of restenosis after placement of gold-coated stents. J Circulation. 2000; 101(21): 2478-2483.
8. Bolz A, Schaldach M. Artificial Heart Valves: Improved blood compatibility by PECVD a-SiC:H coating. J Artificial organs.1990; 14(4): 260-269.
9. Mitamura Y, Hosooka K, Matumoto T. Development of a ceramic heart valve. J Biomater Appl. 1989; 4: 33-55.
10. Dion I, Roques X, Baquey C, Baudet E, Basse Cathalinat B, More N. Hemocompatibility of diamond-Like carbon coating. Biomed Mater Eng. 1993; 3:51-55.
11. Ebert R, Schaldach M. The applicability of rutile ceramics for cardiovascular devices. Physics in Medicine and Biology. 1980; 25: 1185-1190.
12. Huang N. In vitro Investigation of Blood Compatibility of Ti with Oxide Layers of Rutile Structure. J Biomaterial Applications. 1994; 8(4): 404-412.
13. Maitz MF, Pham MT, Wieser E, Tsyganov I. Blood compatibility of titanium oxides with various crystal structure and element doping. J Biomater Appl. 2003; 17: 303-.
14. Jing-Xio Liu. Da- Zhi Yang, Fei Shi, Ying-Ji Cai. Sol–gel deposited TiO2 film on NiTi surgical alloy for biocompatibility improvement. J Thin Solid Films. 2003; 429: 225-230.
15. Motlagh D, Yang J, Lui KY, Webb AR, Ameer GA. Hemocompatibility evaluation of poly(glycerol-sebacate) in vitro for vascular tissue engineering. J Biomaterials. 2006; 27: 4315-4325.
16. Imai Y, Nose Y. A new method for evalution of antithrombogenicity of materials. J Biomed Mater Res. 1972; 6: 165-172.
17. Grunkemeir JM, Tsai WB, Horbett TA. Hemocompatibility of treated polystyrene substrates: Contact activation, platelet adhesion, and procoagulant activity of adherent platelets. J Biomed Mater Res. 1998; 41: 657-670.
18. Sunny MC, Sharma CP. Titanium-protein interaction: changes with oxide layer thickness. J Biomaterial Applications. 1991; 5: 89-98.
19. Trepanier C, Tabrizian M, Yahia L’H. Effect of modification of oxide layer on NiTi stent corrosion resistance. J Biomed Mater Res. 1998; 43: 433-440.
20. cacciafesta P. Visualisation of human plasma fibrinogen adsorbed on titanium implant surfaces with different roughness. J Sur Sci. 2001; 491: 405-420.
21. Shirkhanzadeh M. Nanoporous alkoxy-derived titanium oxide coating: a reactive overlayer for functionalizing titanium surface. J Mater Sci Med. 1998; 9: 355-362.