Investigation of Pulse electric field effect on HeLa cells alignment properties on extracellular matrix protein patterned surface

Recyclable Periodic Nanostructure Formed by Sublimable Liquid Crystals for Robust Cell Alignment

We demonstrate a facile method to fabricate a recyclable cell-alignment scaffold using nanogrooves based on sublimable liquid crystal (LC) material. Randomly and uniaxially arranged smectic LC structures are obtained, followed by sublimation and recondensation processes, which directly produce periodic nanogrooves with dimensions of a couple of hundreds of nanometers. After treatment with osmium tetroxide (OsO₄), the nanogroove can serve as a scaffold to efficiently induce directed cell growth without causing cytotoxicity, and it can be used repeatedly. Together, various cell types are applied to the nanogroove, proving the scaffold's broad applicability. Depending on the nanotopography of the LC structures, cells exhibit different morphologies and gene expression patterns, compared to cells on standard glass substrates, according to microscopic observation and qPCR. Furthermore, cell sheets can be formed, which consist of oriented cells that can be repeatedly formed and transferred to other substrates, while maintaining its organization. We believe that our cell-aligning scaffold may pave the way for the soft material field to bioengineering, which can involve fundamentals in cell behavior and function, as well as applications for regenerative medicine.

Microfluidic-Printed Microcarrier for In Vitro Expansion of Adherent Stem Cells in 3D Culture Platform

Microcarrier-based stem cell expansion cultures can increase the dimensions of in vitro stem cell cultures from 2D to 3D. The culture handling process then becomes more efficient compared with conventional 2D cultures. However, the use of spherical plastic microcarriers complicates the monitoring of cell culture. To facilitate monitoring, transparent disc-shaped microcarriers are manufactured using a light-initiated microfluidic printing system and the obtained microcarriers are named as 2.5D microcarrier. The 2.5D microcarriers (diameter/height ≈ 5) enable us to use conventional monitoring tools in 2D-based platform during the in vitro expansion on a 3D culture platform. Surface modification via a 1 h-long poly-dopamine (PDA) reaction can maintain the transparent nature of the microcarriers while optimizing the cell attachment. The surface marker expression and differentiation potential of the 2.5D microcarrier-expanded stem cells reveal that the characteristics and functionalities preserved during expansion. The 2.5D microcarrier is readily integrated into an on-bead assay to conserve reagents and permit a high number (n = 9) of repeated measurements with reliable results. These results demonstrate that the 2.5D microcarrier-based scale-up culture provides a valuable tool for the in vitro expansion of adherent stem cells, especially if repetitive monitoring is required.