Development of a Fast Large Area Multiphoton Exoscope (FLAME)

Summary. Our long-term goal is to develop a powerful tool based on multiphoton microscopy (MPM) for non- invasive human skin imaging in order to improve clinical diagnosis, guide effective treatment and advance clinical and cosmetic/pharmaceutical research by providing access to dynamic cellular and molecular processes during therapy. MPM is a nonlinear optical imaging technique that provides unique structural and molecular contrast based on endogenous signals such as second harmonic generation from collagen and two- photon excited fluorescence from NADH/FAD+, keratin, melanin and elastin fibers. This contrast allows MPM to provide multi-color, rich molecular information content images that can enhance diagnostic accuracy. MPM overcomes fundamental limitations of existing optical imaging technologies for sub-surface skin imaging and extends the area of applicability beyond skin lesions that can be diagnosed through morphological assessment alone. Validation of the clinical potential of this technology has been facilitated over the past 10 years by a device developed by Jenlab in Germany, currently the only clinical MPM system on the market. This device has technical limitations in terms of field-of-view (FOV), imaging speed, complexity and cost, which are major barriers to clinical adoption. The goal of this Phase I proposal is to develop and test the technical feasibility for in vivo human skin imaging of a MPM system that is highly optimized for rapid, label-free, macroscopic imaging of human skin with microscopic resolution. The Fast Large Area Multiphoton Exoscope (FLAME) imaging platform will incorporate the innovative optical engine of a benchtop prototype developed at BLI. InfraDerm will innovate on this design to transform it into a compact, portable device, suitable for human skin imaging in clinical setting. Key innovations include: 1) a compact engineering design based on integrating a compact fs fiber laser into the imaging head along with a customized folded optical design to reduce complexity and cost and enhance portability; 2) hardware and software strategies that include a customized patient interface and a combination of optical and mechanical scanning mechanisms with deep learning image restoration to allow millimeter-to-centimeter scale imaging within minutes while maintaining sub-micron resolution. This approach will expand the in vivo imaging area from mm to cm scale, which will be scanned within minutes with sub- cellular resolution. In Aim 1 we will develop the FLAME prototype that incorporates these features. In Aim 2 we will test its technical feasibility for in vivo human skin imaging by evaluating potential effects of motion artifacts. In Aim 3, we will demonstrate the FLAME system potential for non-invasive assessment of melanin content, an ability with potential impact in differential diagnosis and early assessment of treatment efficacy of pigmentary skin disorders, such as melasma. Phase II will refine the technological approach and will test the device feasibility in a first clinical application, differential diagnosis of patients with melasma, a long time dermatology challenge and a particular interest for pharma companies developing therapies for this skin condition.NarrativeInfraDerm LLC proposes to develop and test the technical feasibility for in vivo human skin imaging of a laser scanning microscope based on multiphoton microscopy (MPM) that addresses fundamental and technical limitations of existing optical imaging technologies for sub-surface skin imaging, extending the area of applicability beyond skin lesions that can be diagnosed through morphological assessment alone. The proposed Fast Large Area Multiphoton Exoscope (FLAME) prototype will be highly optimized for rapid, label- free, macroscopic imaging of human skin with microscopic resolution. An MPM clinical platform, uniquely equipped with this combination of features would embody an innovative and commercially viable product that will broadly impact clinical diagnosis and research in dermatology as well as in cosmetic and pharmaceutical research.