Davari Seyyed Ali, Masjedi Shirin, Ferdous Zannatul, Mukherjee Dibyendu
Nano-BioMaterials Laboratory for Energy Energetics & Environment (nbml-E3), University of Tennessee, Knoxville, TN 37996, USA.
Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
J Biophotonics. 2018 Jan;11(1). doi: 10.1002/jbio.201600288. Epub 2017 May 9.
Calcific aortic valve disease (CAVD) is a major cardiovascular disorder caused by osteogenic differentiation of valvular interstitial cells (VICs) within aortic valves. Conventional methods like colorimetric assays and histology fail to detect small calcium depositions during in-vitro VIC cultures. Laser-induced breakdown spectroscopy (LIBS) is a robust analytical tool used for inorganic materials characterizations, but relatively new to biomedical applications. We employ LIBS, for the first time, for quantitative in-vitro detection of calcium depositions in VICs at various osteogenic differentiation stages. VICs isolated from porcine aortic valves were cultured in osteogenic media over various days. Colorimetric calcium assays based on arsenazo dye and Von Kossa staining measured the calcium depositions within VICs. Simultaneously, LIBS signatures for Ca I (422.67 nm) atomic emission lines were collected for estimating calcium depositions in lyophilized VIC samples. Our results indicate excellent linear correlation between the calcium assay and our LIBS measurements. Furthermore, unlike the assay results, the LIBS results could resolve calcium signals from cell samples with as early as 2 days of osteogenic culture. Quantitatively, the LIBS measurements establish the limit of detection for calcium content in VICs to be ∼0.17±0.04 μg which indicates a 5-fold improvement over calcium assay. Picture: Quantitative LIBS enables in-vitro analysis for early stage detection of calcium deposition within aortic valvular interstitial cells (VICs).
钙化性主动脉瓣疾病（CAVD）是一种主要的心血管疾病，由主动脉瓣内的瓣膜间质细胞（VICs）向成骨细胞分化引起。比色测定法和组织学等传统方法在体外VIC培养过程中无法检测到微小的钙沉积。激光诱导击穿光谱（LIBS）是一种用于无机材料表征的强大分析工具，但在生物医学应用中相对较新。我们首次采用LIBS对处于不同成骨分化阶段的VICs中的钙沉积进行体外定量检测。从猪主动脉瓣分离的VICs在成骨培养基中培养不同天数。基于偶氮胂染料的比色钙测定法和冯·科萨染色法测量了VICs中的钙沉积。同时，收集Ca I（422.67 nm）原子发射线的LIBS信号，以估计冻干VIC样品中的钙沉积。我们的结果表明钙测定法与我们的LIBS测量结果之间具有良好的线性相关性。此外，与测定结果不同，LIBS结果能够在成骨培养仅2天的细胞样品中分辨出钙信号。在定量方面，LIBS测量确定VICs中钙含量的检测限为~0.17±0.04μg，这表明比钙测定法提高了5倍。图：定量LIBS能够对主动脉瓣间质细胞（VICs）内钙沉积的早期检测进行体外分析。
