Fighting Bacteria with ultrafast LAser fabrication of sharp nanoSTructured surfaces

Antibiotic resistance is a major global health threat that could cause over 10 million deaths within the next two decades. To address this challenge, non-pharmacological strategies are needed to limit bacterial colonization on medical devices. The BLAST project focuses on engineering antibacterial surfaces for titanium implants in order to prevent bacterial colonization. Its main objective is to combine strong antibacterial properties with excellent biocompatibility.

In nature, some insect wings exhibit nanoscale spikes capable of mechanically destroying bacteria. While bactericidal nanotopographies have been demonstrated in air-exposed systems (rupture of bacterial membranes), their efficiency in physiological liquid environments remains poorly understood. Inspired by both terrestrial bactericidal nanostructures and aquatic antifouling interfaces, this project seeks to design surfaces with controlled interactions in biological fluids.

This PhD project aims to bridge this gap by investigating mechanically active biointerfaces under hydrated conditions, where protein adsorption, fluid dynamics, and cell mechanics critically modulate surface/bacteria interactions.

Nanostructures can be fabricated on metallic surfaces using femtosecond laser processing. This technique enables the generation of highly controlled nanostructures with precise shapes and dimensions.

The project will investigate whether these surfaces are effective against a wide range of bacteria, including antibiotic-resistant and highly virulent strains. At the same time, the interaction between these nanostructures and human cells will be carefully studied. A key challenge is achieving a balance between antibacterial activity and tissue integration, particularly for permanent implants such as dental or orthopedic devices.

The PhD project will involve: (i) contributing to nanotexture generation, (ii) conducting surface topography characterization for correlations (SEM, confocal microscopy, AFM), (iii) analyzing bactericidal and bacteriostatic effects, and (iv) assessing in vitro biocompatibility.

The PhD student will work in a multidisciplinary environment, interacting with the Hubert Curien laboratory (engineering of nanotextures), the Laboratory of Tribology and System Dynamics (LTDS) (surface topography characterization) and SAINBIOSE (bone and vascular teams) (microbiology and cellular in-vitro tests).

La symbolique de son acronyme,SAINBIOSE, indique la volonté des chercheurs de disciplines différentes (médecins, ingénieurs, biologistes) de travailler ensemble pour améliorer la prise en charge des patients. SAINBIOSE étudie les pathologies chroniques et du vieillissement des systèmes vasculaire et ostéo-articulaire par des approches transversales combinant recherches fondamentales, technologiques et cliniques.

Sur ce sujet de thèse, le Laboratoire SAINBIOSE collaborera avec :

-Le laboratoire LTDS spécialiste de la caractérisation des surfaces

-Le laboratoire Hubert Curien et la plateforme Manutech USD spécialistes des texturations par laser

- Master Degree (or equivalent) in biology, biomedical engineering or materials science

- The candidate must have a good background in microbiology and cellular biology

- Be someone able to and enjoy to solve problems and pushing research to achieve results

- High degree of responsibility and independence, while collaborating with your team and lab mates, and other laboratory staff.

- Good management skills, good presentation skills, excellent written and oral English level.