Optical tweezers system for live stem cell organization at the single-cell level.

Cell manipulation is one of the most impactful applications for optical tweezers, and derived from this promise, we demonstrate a new optical tweezers system for the study of cell adhesion and organization. This method utilizes photonic-crystal-enhanced optical tweezers to manipulate cells with low laser intensities. By doing so, it enables effective cell patterning and culturing within the conditions necessary for successful differentiation and colony formation of human pluripotent stem cells.

Gene-Edited Human Kidney Organoids Reveal Mechanisms of Disease in Podocyte Development.

A critical event during kidney organogenesis is the differentiation of podocytes, specialized epithelial cells that filter blood plasma to form urine. Podocytes derived from human pluripotent stem cells (hPSC-podocytes) have recently been generated in nephron-like kidney organoids, but the developmental stage of these cells and their capacity to reveal disease mechanisms remains unclear. Here, we show that hPSC-podocytes phenocopy mammalian podocytes at the capillary loop stage (CLS), recapitulating key features of ultrastructure, gene expression, and mutant phenotype.

Photonic Crystal Optical Tweezers with High Efficiency for Live Biological Samples and Viability Characterization.

We propose and demonstrate a new optical trapping method for single cells that utilizes modulated light fields to trap a wide array of cell types, including mammalian, yeast, and Escherichia coli cells, on the surface of a two-dimensional photonic crystal. This method is capable of reducing the required light intensity, and thus minimizing the photothermal damage to living cells, thereby extending cell viability in optical trapping and cell manipulation applications. To this end, a thorough characterization of cell viability in optical trapping environments was performed.