Development of photosensitizing nanoparticles of nanodiamonds and porphyrins

• Grant number: 23/15972-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: April 01, 2024
• End date: March 31, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Dayane Batista Tada
• Grantee: Rafaela Campos Queiroz
• Supervisor: Wilhelm Pfleging
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Federal de São Paulo (UNIFESP). Campus São José dos Campos. São José dos Campos , SP, Brazil
• Institution abroad: Karlsruhe Institute of Technology (KIT), Germany
• Associated to the scholarship: 21/04838-5 - Development of photosensitizer nanoparticles of diamonds and porphyrins, BP.DD

Abstract

The hematogenic infection is one of the main adverse processes in the use of medical implants. In this way, techniques for designing the surface of implants with regards to adjust biocompatibility have been extensively investigated, mainly aiming to avoid bacterial adhesion and proliferation. Considering that the bacteria adhesion depends on the topography and the physical and chemical characteristics of the surfaces, one of the ways to avoid bacterial adhesion on surfaces is to perform laser-assisted surface modification by either laser ablation or laser-induced chemical modification. Additionally, nanotopography provided by either laser exposure close to the ablation threshold or by laser-induced periodical surface structuring (LIPSS) can also improve the tissue regeneration because a rougher implant surface has been shown to display better cell proliferation compared to a smoother surface. The ceramic ²-TCP is a commonly used biomaterial in the field of bone tissue engineering as it promotes osteoconduction, biocompatibility, and suitable pore configuration. In the same field, two biopolymers have also been pointed out as suitable materials for bone regeneration: polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). These biopolymers show several valuable characteristics such as natural origin, biodegradability, biocompatibility, non-toxicity, stereospecificity, piezoelectricity, optical activity, and thermoplasticity that make them suitable for a variety of applications in medicine and industry. The surface roughness can also be reached by the incorporation of nanoparticles on the implant surface. As for example, nanodiamonds (NDs) have been explored for biomedical applications due to their reported ability to create a tunable surface through functionalization processes and excellent biocompatibility. Therefore, the objective of this project is the reliable functionalization of ceramic and polymer surfaces by coupling them to NDs following with the laser texturing. The bacterial adhesion and proliferation on the treated surface will be compared with the untreated surface of PLA, PHBV films, and ceramic scaffolds.