Search

International audience; Spectroscopic approach with fluorescence time resolution allows one to determine the state of a brain tumor and its microenvironment via changes in the fluorescent dye’s fluorescence lifetime. Indocyanine green (ICG) is an acknowledged infra-red fluorescent dye that self-assembles into stable aggregate forms (ICG NPs). ICG NPs aggregates have a tendency to accumulate in the tumor with a maximum accumulation at 24 h after systemic administration, enabling extended intraoperative diagnostic. Fluorescence lifetime analysis of ICG and ICG NPs demonstrates different values for ICG monomers and H-aggregates, indicating promising suitability for fluorescent diagnostics of brain tumors due to their affinity to tumor cells and stability in biological tissue.

In this review, based on more than 70 articles of Russian and foreign authors, methods of skin engraftment monitoring are discussed. Main processes occurring in skin on cellular and subcellular levels at different stages of engraftment are considered. Optical methods which allow performing non-invasive analysis of blood vessels, collagen concentration and form of cellular respiration (by NADH fluorescence) are described. Comparative analysis of nuclear and optical methods for engraftment monitoring highly developed and widespread nowadays is presented. The advantages of optical methods includes multifunctionality, usability and clarity of results, safety and low cost. In contrast to X-ray CT, MRI and ultrasound, optical methods can be used in monitoring mode. One of the promising directions for improving quality of engraftment due to antibacterial effect, photodynamic therapy, is described in details. The use of crystalline organic nanophotosensitizers (particularly aluminum phthalocyanine) is shown to be the most promising. The main distinctive feature of its application is that nanoparticles injected into wound surface or contact area of tissue graft are not photoactive until the moment the inflammation starts. The development of method for assessing skin condition by spectroscopic properties of tissue components (using fluorescent dyes and photosensitizers in molecular and nanoforms), which allows analyzing physiological state of skin (degree and rate of engraftment or rejection) and controlling certain biochemical and physiological parameters of a tissue graft or an entire area of affected skin is shown to be crucial.