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Early and rapid diagnosis of tumors is essential for clinical treatment or management. In contrast to conventional means, bioimaging has the potential to accurately locate and diagnose tumors at an early stage. Fluorescent probe has been developed as an ideal tool to visualize tumor sites and to detect biological molecules which provides a requirement for noninvasive, real‐time, precise, and specific visualization of structures and complex biochemical processes in vivo. Rencently, the development of synthetic organic chemistry and new materials have facilitated the development of near‐infrared small molecular sensing platforms and nanoimaging platforms. This provides a competitive tool for various fields of bioimaging such as biological structure and function imaging, disease diagnosis, in situ at the in vivo level, and real‐time dynamic imaging. This review systematically focused on the recent progress of small molecular near‐infrared fluorescent probes and nano‐fluorescent probes as new biomedical imaging tools in the past 3–5 years, and it covers the application of tumor biomarker sensing, tumor microenvironment imaging, and tumor vascular imaging, intraoperative guidance and as an integrated platform for diagnosis, aiming to provide guidance for researchers to design and develop future biomedical diagnostic tools. [ABSTRACT FROM AUTHOR]

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.

The results of a fluorescent diagnosis programme in the monitoring of self-administered hormonal therapy using Alasens (3% solution - 10 ml injected into the uterine cavity) have been analyzed in 53 female patients of reproductive age with endometrial precancer or cancer. The time of exposition to Alasens was 2 hours. The fluorescent diagnostic procedure was carried out in this patient cohort at different stages of therapy: oncological and rehabilitative, as well as at one year after discontinuation of hormonal therapy After comparing the fluorescent and morphological examination data, an early relapse or ongoing process was diagnosed in 9 (16,9%) out of 53 patients

Conjugation between various small fluorophores and specific ligands has become one of the main strategies for bioimaging in disease diagnosis, medicinal chemistry, immunology, and fluorescence-guided surgery, etc. Herein, we present our review of recent studies relating to molecular fluorescent imaging techniques for various cancers in cell-based and animal-based models. Various organic fluorophores, especially near-infrared (NIR) probes, have been employed with specific ligands. Types of ligands used were small molecules, peptides, antibodies, and aptamers; each has specific affinities for cellular receptor proteins, cancer-specific antigens, enzymes, and nucleic acids. This review can aid in the selection of cancer-specific ligands and fluorophores, and may inspire the further development of new conjugation strategies in various cellular and animal models. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the prospects for central lung cancer (CLC) screening using fluorescent diagnostics and its treatment by endobronchial photodynamic therapy (PDT). Bronchoscopic fluorescent diagnostics using chlorin e6 photosensitizers and a developed instrumental system enable to reveal tumor changes in large bronchi mucosa at early stages, and a developed PDT technique performed under fluorescent control helps achieve personalized treatment. Such an approach is considered as a theranostic technique - photodynamic theranostics. central lung cancer screening requires a fluorescent dye characterized by availability and can be used directly within the examination. Indocyanine green can be used as a dye, its peculiarity is the necessity to excite and record fluorescence in the near-infrared (NIR) wavelength band. First experiments using NIR bands to diagnose a bronchoscopic system showed the detectability of tumor areas using on-site bronchoscopic photodynamic theranostics, which consists in NIR imaging of tumor foci when a standard dose of indocyanine green is administered during the examination., Conclusion: Further progress of early diagnostics and minimally invasive CLC therapy will be determined by the development of new photosensitizers, which should be characterized by a high absorption band in NIR area, quick accumulation in a tumor, high yield of single oxygen in NIR illumination, bright fluorescence, high potential in terms of the induction of an anti-tumor immune response., Competing Interests: Conflicts of interest. The authors declare no conflicts of interest related to the present study.