Staecker, I. | Search bioRxiv

bioRxiv2026

iPS-CNM: an iPSC collection generated by base editing for centronuclear myopathy

Centronuclear myopathy (CNM) is a rare form of inherited diseases often caused by single base mutations. Modelling CNM is challenging due to the diversity of CNM mutations and genetic background of individual patient. To address this, we used base editing to introduce CNM mutations into an induced pluripotent stem cell (iPSC) line from a healthy donor, generating a collection of iPSC lines (iPS-CNM) carrying distinct CNM mutations. We found that the efficiency of base editing depended critically on selecting base editor (BE) variants and the target sequences. Optimization using different BE variant and sgRNA pair was required for each target site. Moreover, whole genome sequencing (WGS) was performed to confirm on-targets and detect off-targets in order to select iPSC clones for the collection. Our findings highlight the feasibility of base editing for generating an iPSC collection from one parental iPSC line combined with thorough evaluation of rare off-targets using WGS.

genetics↗

bioRxiv2026

Overcoming oxygen impermeability in PDMS-free organ-on-a-chip microfluidics with nanoporous thermoplastic

Oxygen availability is a critical yet all-too-often overlooked variable in organ-on-a-chip (OoC) systems. PDMS-based microfluidics remain the most common approach to facilitating oxygen equilibration with the incubator environment, but the materials tendency to ad- and absorb small hydrophobic molecules can pose significant concerns for pharmacological and toxicological studies. Yet there remains a lack of alternative gas-exchange materials feasible for OoC integration, even as the use of thermoplastic microfluidics in particular has otherwise proliferated. Here, we present commercially available track-etched nanoporous polycarbonate (50 nm pores, 1.18% porosity, [~]0.1 {euro}/cm2) as a practical alternative to polydimethylsiloxane (PDMS) for gas exchange in OoC. We show that nanoporous polycarbonate provides a thermoplastic material with an oxygen permeability of 3290 {+/-} 240 fs mol / kg, over an order of magnitude higher than PDMS. We demonstrate integration into existing lamination-based thermoplastic microfluidic fabrication workflows with sustained leak-free operation well above physiologically relevant pressures. We find that nanoporous polycarbonate does not compromise cell viability, but that high water vapor permeance necessitates a high-humidity environment around the device - though thickness-normalized water vapor permeability is notably similar to PDMS. We validate the OoC application with Caco-2 intestinal epithelial cells by monitoring oxygen levels during the critical cell attachment phase, with nanoporous polycarbonate allowing for maintenance of stable oxygen tension, in stark contrast to severe hypoxia in nonporous controls within 30 minutes. We further show that this uncontrolled hypoxia correlates with a time-delayed increase in cellular hypoxia inducible factor-1 reporter expression. Overall, our findings position nanoporous polycarbonate as a low-cost, mechanically robust, and fabrication-friendly alternative that can bring controlled oxygen availability to PDMS-free microfluidics and OoC.

bioengineering↗