Zinc-doped coating with photocatalytic potential for antimicrobial effect and osteogenic and immunological modulation: in silico, in vitro, in situ, and in vivo studies

• Grant number: 25/07655-0
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2025
• End date: September 30, 2028
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Valentim Adelino Ricardo Barão
• Grantee: Valentim Adelino Ricardo Barão
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Associated researchers: Bruna Egumi Nagay ; Leonardo Perez Faverani ; Nilson Cristino da Cruz

Abstract

Titanium surfaces treated by plasma electrolytic oxidation (PEO) and doped with zinc (Zn) have shown remarkable bioactivity and antimicrobial properties. Considering that ZnO incorporated into the coating exhibits photocatalytic behavior, this project aims to explore photocatalysis as an innovative strategy to enhance the antimicrobial effect of these surfaces, transforming them into smart, light-responsive biomaterials with on-demand activity. Additionally, the project aims to evaluate the osteogenic and immunomodulatory potential of the Zn coating. For this purpose, commercially pure titanium discs and dental implants will undergo two surface treatments: sandblasting with aluminum oxide followed by acid etching (control group - SLA) and PEO treatment doped with Zn (experimental group - Zn). Subsequently, four complementary studies will be conducted: (1) In silico study to characterize the optical properties of the Zn coating and optimize the visible light activation parameters; (2) In vitro study to evaluate the photocatalytic potential, reactive oxygen species (ROS) generation, long-term surface stability (shelf life), direct antimicrobial activity (with and without light), microbial composition (microcosm model with human saliva), cytocompatibility and osteogenic potential (in pre-osteoblastic cells), and immunomodulatory effects in macrophages; (3) In situ study, in which 12 volunteers will wear palatal devices containing SLA and Zn discs for 7 days to allow biofilm formation. After this period, the samples will be irradiated or not with visible light and analyzed immediately and after 24 hours (recolonization) for viability, morphology, and microbial composition; and (4) In vivo study to assess the osseointegration potential of SLA and Zn implants through histological analysis, micro-computed tomography, and bone-implant contact assessment, in addition to biomechanical and gene expression tests. The in vivo study will also investigate the peri-implant inflammatory response by quantifying pro-inflammatory cytokines (IL-1¿ and TNF-¿), and the antimicrobial effect of the Zn coating, with or without light activation, by counting colony-forming units (CFUs) on discs implanted in the dorsal region of rats. The collected data will be submitted to descriptive statistics and assumption testing to determine the appropriate statistical tests, adopting a significance level of 0.05. (AU)