Detection of coronary atherosclerotic plaques with superficial proteoglycans and foam cells using real-time intrinsic fluorescence spectroscopy

Abstract

Objectives-The protein components of low-density lipoprotein (LDL), oxidized LDL and proteoglycans such as versican contain tryptophan, an amino acid with characteristic fluorescence features at 308 nm excitation wavelength. We hypothesize that intrinsic fluorescence spectroscopy at 308 nm excitation wavelength (IFS 308 ), a method suitable for clinical use, can identify coronary artery lesions with superficial foam cells (SFCs) and/or proteoglycans.Methods-We subjected 119 human coronary artery specimens to in vitro fluorescence and reflectance spectroscopy. We used 5 basis spectra to model IFS 308 , and extracted their contributions to each individual IFS 308 spectrum. A diagnostic algorithm using the contributions of total tryptophan and fibrous cap to IFS 308 was built to identify specimens with SFCs and/or proteoglycans in their top 50 µm.Results-We detected SFCs and/or proteoglycans, such as versican or the glycosaminoglycan hyaluronan, in 24 fibrous cap atheromas or pathologic intimal thickening (PIT) lesions. An algorithm using the contributions of total tryptophan and fibrous cap to IFS 308 was able to identify these segments with 92% sensitivity and 80% specificity. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conclusion-WeThere are no conflicts of interest for any of the authors listed. NIH Public Access

In vivo label-free structural and biochemical imaging of coronary arteries using an integrated ultrasound and multispectral fluorescence lifetime catheter system

“…The presence of proteoglycans is identified by the alcian blue color in the 6 to 8 o’clock region of the Movat’s section. Reported fluorescence properties 20 are consistent with the increase in lifetime and intensity observed at this location in the channel 1 image.…”

Non‐destructive detection of matrix stabilization correlates with enhanced mechanical properties of self‐assembled articular cartilage

“…Sun et al, ). A number of endogenous biomolecules, including the extracellular matrix protein collagen (Alfonso‐Garcia, Haudenschild, & Marcu, ) and its crosslinks (Wagnieres, Star, & Wilson, ), and proteoglycans (Angheloiu et al, ) give rise to tissue autofluorescence. The relative concentration and distribution of individual fluorophores within the tissue create unique fluorescence emission profiles that can be quantified.…”

Detection of glycosaminoglycan loss in articular cartilage by fluorescence lifetime imaging

“…(c) Spectral channels of the FLIm instrument: channel 1 = 375 to 410 nm, channel 2 = 450 to 485 nm, and channel 3 = 530 to 565 nm. The reference emission spectrum of collagen (red) and GAG (blue)24 was also overlaid.…”