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Despite the existing effective treatment methods, tuberculosis (TB) is the second most deadly infectious disease, its carriers in the latent and active phases accounting for more than 20% of the world population. An effective method for controlling TB and reducing TB mortality is regular population screening aimed at diagnosing the latent form of TB and taking preventive and curative measures. Numerous methods allow diagnosing TB by directly detecting Mycobacterium tuberculosis (M.tb) biomarkers, including M.tb DNA, proteins, and specific metabolites or antibodies produced by the host immune system in response to M.tb. PCR, ELISA, immunofluorescence and immunochemical analyses, flow cytometry, and other methods allow the detection of M.tb biomarkers or the host immune response to M.tb by recording the optical signal from fluorescent or colorimetric dyes that are components of the diagnostic systems. Current research in biosensors is aimed at increasing the sensitivity of detection, a promising approach being the use of fluorescent quantum dots as brighter and more photostable optical tags. Here, we review current methods for the detection of M.tb biomarkers using quantum dot-based nanosensors and summarize data on the M.tb biomarkers whose detection can be made considerably more sensitive by using these sensors. [ABSTRACT FROM AUTHOR]

Fibroblasts are among the most common cell types in the stroma responsible for creating and maintaining the structural organization of the extracellular matrix in the dermis, skin regeneration, and a range of immune responses. Until now, the processes of fibroblast adaptation and functioning in a varying environment have not been fully understood. Modern laser microscopes are capable of studying fibroblasts in vitro and ex vivo. One‐photon‐ and two‐photon‐excited fluorescence microscopy, Raman spectroscopy/microspectroscopy are well‐suited noninvasive optical methods for fibroblast imaging in vitro and ex vivo. In vivo staining‐free fibroblast imaging is not still implemented. The exception is fibroblast imaging in tattooed skin. Although in vivo noninvasive staining‐free imaging of fibroblasts in the skin has not yet been implemented, it is expected in the future. This review summarizes the state‐of‐the‐art in fibroblast visualization using optical methods and discusses the advantages, limitations, and prospects for future noninvasive imaging. [ABSTRACT FROM AUTHOR]

This paper addresses the application of multimodal nonlinear optical (MNLO) microscopy to clinical research within the context of label-free non-invasive molecular imaging. Here, a compact MNLO microscope based on a laser scanning microscope, a femtosecond laser, a time-correlated single-photon counting system, and a photonic crystal fiber are introduced for biomedical applications. By integrating two-photon fluorescence, two-photon fluorescence lifetime imaging, second-harmonic generation, and coherent anti-Stokes Raman scattering microscopy, the proposed scheme provides profound insights into the physicochemical properties related to 3D molecular orientation distribution, inter- and intra-molecular interactions, and disease progression in biological systems and organs. The high peak power and the low average intensity of near-infrared laser pulses allow for deep-penetration imaging without compromising sample vitality. Linking nonlinear optical phenomena with time/spectral/polarization-resolved imaging also makes it possible to obtain multidimensional information to address complex biomedical questions. [ABSTRACT FROM AUTHOR]

A quantitative assessment of wound status in a murine model was developed using phasor plot presentation of fluorescence lifetime imaging microscopy (FLIM) data. The quantitative assessment is based on calculating Bhattacharyya distance between g coordinates of FLIM data phasor plot density distributions of wound and healthy skin. The approach was validated for both diabetic and non-diabetic mice wounds, including during low-dose photodynamic therapy (LDPDT). Analysis revealed a shift in the FLIM data phasor plot g coordinates, suggesting altered metabolic processes involved in wound healing. Bhattacharyya distances in the LDPDT groups were closer to zero compared to the control group, which was not treated by LDPDT. Bhattacharyya distances in the non-diabetic LDPDT groups were closer to zero compared to the diabetic LDPDT groups that is consistent with the literature regarding the positive role of LDPDT in accelerating wound healing and the role of diabetes mellitus in impairing wound healing., (© 2024 Wiley‐VCH GmbH.)