Minimally invasive method for the point-of-care quantification of lymphatic vessel function

Near‐Infrared Fluorescence Hydrogen Peroxide Assay for Versatile Metabolite Biosensing in Whole Blood

“…[ 16 ] As the fluorescence properties of ICG are furthermore strongly influenced by solubility‐enhancing molecules and proteins (e.g., albumin, amphiphiles), small amounts of free dye (e.g., due to liposomal leakage) may considerably affect the measured fluorescence intensity in whole blood. [ 14 ]…”

“…As these concentrations refer to the final lactate concentrations in the assay mixture (i.e., mixture of whole blood (25%, v/v) and liposome‐containing buffer), the linear range of our lactate assay spans from at least 1.25–20 × 10 −3 m , a range which includes commonly used blood lactate cut‐offs in emergency medicine (2–4 × 10 −3 m [ 32,33 ] ). If combined with a portable fluorometric device, [ 14 ] this assay has the potential for bedside lactate testing. A system combining a fluorometer, the liposomal solution, and a digital element (e.g., application software) would determine the blood lactate concentration by comparison with calibrators of known lactate concentrations.…”

“…For fluorescence detection, small and cost‐effective fluorometric devices reported for other near‐infrared fluorescent dyes, such as ICG could be employed. [ 14 ] Incubating a drop of blood with the analyte‐specific liposomes could therefore enable the medical professional or the patient to rapidly determine the blood concentration of the analyte of interest both in the in‐ and out‐patient‐setting. Larger molecules, such as bilirubin can potentially also be assessed by this platform if more permeable liposome formulations are employed.…”

“…A variety of assays for the determination of hydrogen peroxide in solution are available, mostly based on the enzymatic oxidation of organic molecules using hydrogen peroxide as the oxidant (e.g., horseradish peroxidase (HRP)‐mediated oxidation of Amplex red). [ 10–13 ] While fluorescence is a convenient read‐out due to the availability of small, inexpensive, and easy‐to‐handle fluorometric devices, [ 14 ] near‐infrared hydrogen peroxide sensing systems are needed for whole blood applications due to the interference by hemoglobin. [ 15 ] In the past, HRP was reported to be capable of oxidizing a limited number of fluorescent cyanine‐containing structures, of which one was in the near‐infrared range.…”

Effect of VEGFC on lymph flow and inflammation‐induced alveolar bone loss

“…Another concern is that despite being the only FDA-approved probe for use in humans [54], indocyanine green (ICG) still has several limitations for NIR lymphatic imaging, due to aggregation and change of spectral properties of the dye after injection upon the monomerization caused by complexation with endogenous proteins [55]. This limitation has recently been addressed by precomplexing ICG with Kolliphor HS15 (Sigma-Aldrich), an FDA-and EMAapproved surfactant, which significantly increases ICG fluorescence intensity in the application for NIR lymphatic imaging [56]. We found a similar trend in mice injected with ICG-water compared with those injected with ICG-Kolliphor HS15.…”