In vivo optical imaging of the viable epidermis around the nailfold capillaries for the assessment of heart failure severity in humans

Abstract

Heart failure (HF) is among the socially significant diseases, involving over 2% of the adult population in the developed countries. Diagnostics of the HF severity remains complicated due to the absence of specific symptoms and objective criteria. Here, we present an indicator of the HF severity based on the imaging of tissue parameters around the nailfold capillaries. High resolution nailfold video capillaroscopy was performed to determine the perivascular zone (PZ) size around nailfold capillaries, and 2-photon tomography with fluorescence lifetime imaging was used to investigate PZ composition. We found that the size of PZ around the nailfold capillaries strongly correlates with HF severity. Further investigations using 2-photon tomography demonstrated that PZ corresponds to the border of viable epidermis and it was suggested that the PZ size variations were due to the different amounts of interstitial fluid that potentially further translates in clinically significant oedema. The obtained results allow for the development of a quantitative indicator of oedematous syndrome, which can be used in various applications to monitor the dynamics of interstitial fluid retention. We therefore suggest PZ size measured with nailfold video capillaroscopy as a novel quantitative sensitive non-invasive marker of HF severity.

The Oxidation-Induced Autofluorescence Hypothesis: Red Edge Excitation and Implications for Metabolic Imaging

“…Autofluorescence (AF), i.e., intrinsic fluorescence of endogenous fluorophores, is extensively used in a range of biomedical applications [1]. Being non-invasive and label-free method, it has proven to be an indispensable tool for intraoperative diagnostics (fluorescence-guided surgery) [2], analysis of biofluids (blood [3,4], saliva [5], urine [6,7]), optical biopsy [8][9][10] etc. AF analysis is usually performed on a phenomenological basis, which means discrimination between objects (e.g., normal and pathological tissues, or between different components of the tissue) basing on differences in their AF intensity, spectral band shape or lifetime [11,12] and photobleaching rate [13].…”

Detection of HOCl-driven degradation of the pericardium scaffolds by label-free multiphoton fluorescence lifetime imaging

“…The fluorescence decay parameters of the endogenous fluorophores, such as NAD(P)H and FAD, allow evaluations of the metabolic status of cells and tissues 17 , the simultaneous use of cells’ morphology and their fluorescence decay parameters allows one to distinguish between different types of cells both in vitro and in vivo using FLIM 39 , 40 . The use of the multiphoton excitation in the near-infrared range permits to scan relatively deep tissue layers, hence to localize and characterize structural proteins, to determine the parameters of the microcapillaries and study physiological processes in vivo 27 , 41 . FLIM has also been used in the assessment of the properties of the engineered biomaterials 18 – 23 .…”

Raman spectroscopy in chronic heart failure diagnosis based on human skin analysis

“…However, the CHF progress is normally accompanied by some metabolic abnormalities that are particularly evident in the human skin content change. For example, Shirshin et al [16] reported on water and electrolyte content change in the viable skin epidermis that is controlled by interstitial fluid retention when diagnosing CHF. Other biomarkers in skin, including lipid and collagen parameters [4] have been put forward as potential chemical CHF‐related changes that also have a direct impact on the skin component concentrations.…”