McIntosh Julie C, Yang Lin, Wang Ting, Zhou Haibo, Lockett Matthew R, Oldenburg Amy L
Department of Chemistry, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599, USA.
Co-first authors contributed equally and are listed alphabetically.
Biomed Opt Express. 2020 May 20;11(6):3181-3194. doi: 10.1364/BOE.382911. eCollection 2020 Jun 1.
3D paper-based cultures (PBCs) are easy-to-use and provide a biologically representative microenvironment. By stacking a sheet of cell-laden paper below sheets containing cell-free hydrogel, we form an assay capable of segmenting cells by the distance they invaded from the original cell-seeded layer. These invasion assays are limited to end-point analyses with fluorescence-based readouts due to the highly scattering nature of the paper scaffolds. Here we demonstrate that optical coherence tomography (OCT) can distinguish living cells from the surrounding extracellular matrix (ECM) or paper fibers based upon their intracellular motility amplitude (). is computed from fluctuation statistics of the sample, rejects shot noise, and is invariant to OCT signal attenuation. Using OCT motility analysis, we tracked the invasion of breast cancer cells over a 3-day period in 4-layer PBCs (160-300 µm thick) . The cell population distributions determined with OCT are highly correlated with those obtained by fluorescence imaging, with an intraclass correlation coefficient (ICC) of 0.903. The ability of OCT motility analysis to visualize live cells and quantify cell distributions in PBC assays and longitudinally provides a novel means for understanding how chemical gradients within the tumor microenvironment affect cellular invasion.
基于纸张的3D培养物（PBCs）易于使用，并能提供具有生物学代表性的微环境。通过在含有无细胞水凝胶的薄片下方堆叠一片载有细胞的纸张，我们形成了一种检测方法，能够根据细胞从原始接种细胞层侵入的距离对细胞进行分割。由于纸质支架具有高度散射的特性，这些侵袭检测仅限于基于荧光读数的终点分析。在这里，我们证明光学相干断层扫描（OCT）可以根据活细胞的细胞内运动幅度，将其与周围的细胞外基质（ECM）或纸纤维区分开来。运动幅度是根据样品的波动统计计算得出的，可抑制散粒噪声，并且不受OCT信号衰减的影响。使用OCT运动分析，我们在4层PBCs（160 - 300 µm厚）中跟踪了乳腺癌细胞3天的侵袭情况。通过OCT确定的细胞群体分布与通过荧光成像获得的数据高度相关，组内相关系数（ICC）为0.903。OCT运动分析在PBC检测中可视化活细胞并纵向量化细胞分布的能力，为理解肿瘤微环境中的化学梯度如何影响细胞侵袭提供了一种新方法。
