Photonics for Life

Light is strictly connected with life, and its presence is fundamental for any living environment. Thus, many biological mechanisms are related to light interaction or can be evaluated through processes involving energy exchange with photons. Optics has always been a precious tool to evaluate molecular and cellular mechanisms, but the discovery of lasers opened new pathways of interactions of light with biological matter, pushing an impressive development for both therapeutic and diagnostic applications in biomedicine. The use of light in different fields has become so widespread that the word photonics has been utilized to identify all the applications related to processes where the light is involved. The photonics area covers a wide range of wavelengths spanning from soft X-rays to mid-infrared and includes all devices related to photons as light sources, optical fibers and light guides, detectors, and all the related electronic equipment. The recent use of photons in the field of telecommunications has pushed the technology toward low-cost, compact, and efficient devices, making them available for many other applications, including those related to biology and medicine where these requirements are of particular relevance. Moreover, basic sciences such as physics, chemistry, mathematics, and electronics have recognized the interdisciplinary need of biomedical science and are translating the most advanced researches into these fields. The Politecnico school has pioneered many of them, and this article reviews the state of the art of biomedical research at the Politecnico in the field internationally known as biophotonics.

Skin Tumor Detection by Fluorescence Lifetime Imaging

Fluorescence techniques for tumor detection can take advantage of endogenous fluorophores, widely present in biological tissues, or can rely on specific exogenous markers with suitable fluorescent properties. Sensitizers used for the photodynamic therapy of tumors (PDT) combine tumor-localizing properties and strong fluorescence. For these reasons, besides being used for therapy, they offer valuable opportunities for tumor detection by fluorescence imaging.