Nanoscale Methods for Longitudinal Extraction of Intracellular Contents.

Longitudinal analysis of intracellular contents including gene and protein expression is crucial for deciphering the fundamentally dynamic nature of cells. This offers invaluable insights into complex tissue composition and behavior, and drive progress in disease diagnosis, biomarker discovery and drug development. Traditional longitudinal analysis workflows, involving the destruction of cells at various timepoints, limit insights to singular moments and fail to account for cellular heterogeneity. Current non-destructive approaches, like temporal modelling with single-cell RNA-sequencing and live-cell fluorescence imaging, either rely on biological assumptions or possess risk of cellular perturbation. Recent advances in nanoscale technologies for non-destructive intracellular content extraction offer a promising solution to these challenges. These novel methods work at the nanoscale to non-destructively access cellular membranes and can be broadly classified into three mechanisms: tip-facilitated aspiration, membrane-based and probe-based methods. This perspective focuses on these emerging nanotechnologies for repeated intracellular content extraction. We discuss their potential in longitudinal analysis, address the critical requirements for effective repeated sampling, and explore the suitability of each technique for various applications. Furthermore, we highlight unresolved challenges in repeated sampling to encourage further research in this growing field. This article is protected by copyright. All rights reserved.