During the first reporting period, the project focused on designing, assessing, fabricating, and initially validating a novel plasma-assisted multimodal endoscopic system for cancer diagnosis and treatment. Activities included defining the system architecture and integrating multimodal nonlinear imaging (second harmonic generation, nonlinear fluorescence, M-CARS spectroscopy) with cold atmospheric plasma at the fiber tip. An ultrafast laser source was co-designed with an industrial partner and complemented by an in-house mode-locked fiber laser. Advanced hollow-core, multimode, and hybrid optical fibers were designed, fabricated, and characterized for broadband transmission, nonlinear propagation, beam self-cleaning, and plasma compatibility. Supercontinuum generation and nonlinear propagation experiments confirmed feasibility for multiplexed imaging and spectroscopy. A compact endoscopic head with piezoelectric fiber-tip scanning enabled spiral scanning with micrometric resolution over sub-millimetric fields of view. Detection schemes were implemented, and dedicated control and reconstruction software was validated on standard biological samples. Plasma generation at the fiber tip was demonstrated with controllable and reproducible pulses. Biologically, standardized 3D bioprinted spheroids and organoids (healthy and tumoral) were integrated into the workflow. M-CARS hyperspectral microscopy combined with machine-learning analysis successfully discriminated healthy and cancerous organoids. Main achievements include: (i) system-level design and validation of critical components, (ii) fabrication and testing of advanced fibers and plasma endoscopic elements, (iii) demonstration of multimodal imaging and controlled plasma generation, and (iv) proof-of-principle biological validation, establishing a strong foundation for full prototype assembly and advanced testing.
