Micropipet-Based Navigation in a Microvascular Model for Imaging Endothelial Cell Topography Using Scanning Ion Conductance Microscopy

Abstract

Scanning ion conductance microscopy (SICM) has enabled cell surface topography at a high resolution with low invasiveness. However, SICM has not been applied to the observation of cell surfaces in hydrogels, which can serve as scaffolds for three-dimensional cell culture. In this study, we applied SICM for imaging a cell surface in a microvascular lumen reconstructed in a hydrogel. To achieve this goal, we developed a micropipet navigation technique using ionic current to detect the position of a microvascular lumen. Combining this navigation technique with SICM, endothelial cells in a microvascular model and blebs were visualized successfully at the single-cell level. To the best of our knowledge, this is the first report on visualizing cell surfaces in hydrogels using a SICM. This technique will be useful for furthering our understanding of the mechanism of intravascular diseases.

Topography and Permeability Analyses of Vasculature‐on‐a‐Chip Using Scanning Probe Microscopies

“…We recently reported topographical images in an extracellular matrix-embedded vascular model using SICM under static culture conditions. [18] In this study, we showed that SICM is also applicable for shear-induced topographical analysis in MPS.…”

“…[15] By combining SICM with SECM or other techniques, local chemical information of single cells [16] or cell membranes can be acquired at the nanoscale. [17] These topographical and functional evaluations using SPM are promising for the analysis of MPS, [18] and for SPM-compatible microfluidic devices, removable slabs, [19] ultrathin membranes, [20] and open-top microfluidic devices [18] were developed for the access of SPM into microfluidic devices. By combining these devices with atomic force microscopy (AFM), an analysis of the mechanical properties of circulating tumor cells [19b] and selective mRNA extraction from single cells [20] was realized.…”

“…[19a] Using SICM, our group recently reported the topographical analysis of a microvascular model in an opentop microfluidic device. [18] However, the target cells in these studies were isolated single cells or cell aggregates, and the morphological and functional changes in vascular MPS have not yet been evaluated by SPM.…”

Recent Advances in the Glass Pipet: from Fundament to Applications

“…These findings could provide a basis to further understand the correlation between the dynamic reassembly of neurons and memory. Nashimoto et al reported an important application of nanopipette in revealing the topography of 3D cultured cell surface for the first time 26 (Figure 4B). They established a microvascular 3D-like models of endothelial cells, where microvascular lumen was reconstructed in a hydrogel.…”

Ion Conductance-Based Perfusability Assay of Vascular Vessel Models in Microfluidic Devices

“…The detection mechanism is based on the increase in the electrical resistance of the pore in response to the excluded volume resulting from the introduced objects when applying electrical voltages. In scanning ion conductance microscopy, the ion conductance at a nanocapillary is used to measure the height of a sample [19,20]. In the present study, ion currents between channels separated by endothelial monolayers were monitored to evaluate their perfusion during vessel formation.…”