Fig. 7

Fig. 7 Summary of our study and potential use of MSN-AVA-TPP loaded with doxycycline for the treatment of M. marinum infection.

a The in vitro studies show that MSN-AVA-TPP@DOX adheres onto mycobacteria in biofilms and planktonic state present in the caseum. The nanosystem reduces the viability of some mycobacteria within the biofilms (1) and is internalized in the Mmar-infected macrophages, reaching the intracellular mycobacteria, and kill them (2). These two abilities of the nanosystem would inhibit the Mmar infection progression from the granuloma to deeper tissue layers. In addition, mycobacteria which interact with the nanosystem would also not be phagocytosed by macrophages and dendritic cells (3), thus limiting the sporotricoid-like lymphatic progression associated with Mmar infection. b Schematic representation the infection course of a zebrafish embryos infected with Mmar. The infection can progress from a first pre-granuloma (dashed square) to other infection foci (embryo on top). Treatment with MSN-AVA-TPP@DOX blocks the infection progression by killing not only extracellular bacteria, but bacteria inside macrophages as well, limiting the spread of the infection and resulting in embryos survival (lower embryo). Created in BioRender. Kremer, L. (2025) https://BioRender.com/48jwn1f.