© 2011 The Authors - ISSN 0391-3988 Int J Artif Organs ( 2011; : 9) 929-946 34 929 TITANIUM OXIDE AND ANTIBACTERIAL SURFACES IN BIOMEDICAL DEVICES Device-related infections: a clinical demand driving material science research An increasing number of clinical procedures requires the use of biomedical devices, whose widespread presence in modern therapeutic treatments is driving the demand for better performances and longer reliability. One of the major issues of both short-term devices and implantable pros- theses is represented by device-related infections (DRIs) Titanium oxide antibacterial surfaces in biomedical devices Livia Visai 1,2 , Luigi De Nardo 3,4 , Carlo Punta 3,4 , Lucio Melone 3 , Alberto Cigada 3,4 , Marcello Imbriani 5 , Carla Renata Arciola 6 1 Department of Molecular Medicine and Center for Tissue Engineering (C.I.T), University of Pavia, Pavia - Italy 2 Salvatore Maugeri Foundation IRCCS, Pavia - Italy; and International Center for Studies and Research in Biomedicine (ICB) - Luxembourg 3 Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Milan - Italy 4 INSTM (National Consortium for Materials Science and Technology) Local Unit, Politecnico di Milano, Milan - Italy 5 Department of Public Health and Neuroscience and Maugeri Foundation IRCCS, Pavia - Italy 6 Research Unit on Implant Infections, Rizzoli Orthopaedic Institute and Department of Experimental Pathology of the University of Bologna, Bologna - Italy ABSTRACT Titanium oxide is a heterogeneous catalyst whose efficient photoinduced activity, related to some of its allotropic forms, paved the way for its widespread technological use. Here, we offer a comparative analysis of the use of titanium oxide as coating for materials in biomedical devices. First, we introduce the photoinduced catalytic mechanisms of TiO 2 and their action on biological environment and bac- teria. Second, we overview the main physical and chemical technologies for structuring suitable TiO 2 coatings on biomedical devices. We then present the approaches for in vitro characterization of these surfaces. Finally, we discuss the main aspects of TiO 2 photoactivated antimicrobial activity on medical devices and limitations for these types of applications. KEY WORDS: Biomaterial surface modifications, Titanium oxide, Antibacterial properties, Infection- resistant materials Accepted: August 31, 2011 REVIEW due to bacterial colonization and proliferation (1). About half of the 2 million cases of nosocomial infections that occur each year in the United States are associated with indwelling devices (2): these infections generally require a longer period of antibiotic therapy and repeated surgical procedures, resulting in potential risks for the patient and increased costs for the healthcare system. The planktonic bacteria that colonize a device surface tend to form a biofilm and the sessile bacterial cells, en- closed in a self-produced polymeric matrix of this kind, can withstand host immune responses and generally show extraordinary antibiotic resistance (3). Eventually, bacteria rapid multiply and disperse in planktonic form, giving rise DOI: 10.5301/ijao.5000050