Micro/nano-structured TiO2 surface with dual-functional antibacterial effects for biomedical applications

Xiang Ge; Chengzu Ren; Yonghui Ding; Guang Chen; Xiong Lu; Kefeng Wang; Fuzeng Ren; Meng Yang; Zhuochen Wang; Junlan Li; Xinxin An; Bao Qian; Yang Leng

doi:10.1016/j.bioactmat.2019.10.006

Micro/nano-structured TiO₂ surface with dual-functional antibacterial effects for biomedical applications

Bioact Mater. 2019 Nov 1:4:346-357. doi: 10.1016/j.bioactmat.2019.10.006. eCollection 2019 Dec.

Authors

Xiang Ge^{1

2}, Chengzu Ren¹, Yonghui Ding^{3

4}, Guang Chen¹, Xiong Lu⁵, Kefeng Wang⁶, Fuzeng Ren⁷, Meng Yang², Zhuochen Wang⁸, Junlan Li¹, Xinxin An⁹, Bao Qian¹⁰, Yang Leng²

Affiliations

¹ Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, Tianjin, 300354, China.
² Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
³ Center for Advanced Regenerative Engineering, Northwestern University, Evanston, IL, 60208, USA.
⁴ Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
⁵ Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
⁶ National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, 610064, China.
⁷ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China.
⁸ State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, 300072, China.
⁹ School of Humanities, Tianjin Agricultural University, Tianjin, 300384, China.
¹⁰ Department of Machine Elements and Engineering Design, University of Kassel, Kassel, 34125, Germany.

Abstract

Implant-associated infections are generally difficult to cure owing to the bacterial antibiotic resistance which is attributed to the widespread usage of antibiotics. Given the global threat and increasing influence of antibiotic resistance, there is an urgent demand to explore novel antibacterial strategies other than using antibiotics. Recently, using a certain surface topography to provide a more persistent antibacterial solution attracts more and more attention. However, the clinical application of biomimetic nano-pillar array is not satisfactory, mainly because its antibacterial ability against Gram-positive strain is not good enough. Thus, the pillar array should be equipped with other antibacterial agents to fulfill the bacteriostatic and bactericidal requirements of clinical application. Here, we designed a novel model substrate which was a combination of periodic micro/nano-pillar array and TiO₂ for basically understanding the topographical bacteriostatic effects of periodic micro/nano-pillar array and the photocatalytic bactericidal activity of TiO₂. Such innovation may potentially exert the synergistic effects by integrating the persistent topographical antibacterial activity and the non-invasive X-ray induced photocatalytic antibacterial property of TiO₂ to combat against antibiotic-resistant implant-associated infections. First, to separately verify the topographical antibacterial activity of TiO₂ periodic micro/nano-pillar array, we systematically investigated its effects on bacterial adhesion, growth, proliferation, and viability in the dark without involving the photocatalysis of TiO₂. The pillar array with sub-micron motif size can significantly inhibit the adhesion, growth, and proliferation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Such antibacterial ability is mainly attributed to a spatial confinement size-effect and limited contact area availability generated by the special topography of pillar array. Moreover, the pillar array is not lethal to S. aureus and E. coli in 24 h. Then, the X-ray induced photocatalytic antibacterial property of TiO₂ periodic micro/nano-pillar array in vitro and in vivo will be systematically studied in a future work. This study could shed light on the direction of surface topography design for future medical implants to combat against antibiotic-resistant implant-associated infections without using antibiotics.

Keywords: Micro/nano-structured surface; Non-invasive treatment; Photocatalytic bactericidal property; Titanium dioxide; Topographical bacteriostatic activity.

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