Vascularization of iNSC spheroid in a 3D spheroid-on-a-chip platform enhances neural maturation.

In vitro platforms for studying the human brain have been developed, and brain organoids derived from stem cells have been studied. However, current organoid models lack three-dimensional (3D) vascular networks, limiting organoid proliferation, differentiation, and apoptosis. In this study, we created a 3D model of vascularized spheroid cells using an injection-molded microfluidic chip. We cocultured spheroids derived from induced neural stem cells (iNSCs) with perfusable blood vessels. Gene expression analysis and immunostaining revealed that the vascular network greatly enhanced spheroid differentiation and reduced apoptosis. This platform can be used to further study the functional and structural interactions between blood vessels and neural spheroids, and ultimately to simulate brain development and disease.

Anchor-IMPACT: A standardized microfluidic platform for high-throughput antiangiogenic drug screening.

In vitro models are becoming more advanced to truly present physiological systems while enabling high-throughput screening and analysis. Organ-on-a-chip devices provide remarkable results through the reconstruction of a three-dimensional (3D) cellular microenvironment although they need to be further developed in terms of multiple liquid patterning principle, material properties, and scalability. Here we present a 3D anchor-based microfluidic injection-molded plastic array culture platform (Anchor-IMPACT) that enables selective, space-intensive patterning of hydrogels using anchor-island for high-throughput angiogenesis evaluation model. Anchor-IMPACT consists of a central channel and an anchor-island, integrating the array into an abbreviated 96-well plate format with a standard microscope slide size. The anchor-island enables selective 3D cell patterning without channel-to-channel contact or any hydrogel injection port using an anchor structure unlike conventional culture compartment. The hydrogel was patterned into defined regions by spontaneous capillary flow under hydrophilic conditions. We configured multiple cell patterning structures to investigate the angiogenic potency of colorectal cancer cells in Anchor-IMPACT and the morphological properties of the angiogenesis induced by the paracrine effect were evaluated. In addition, the efficacy of anticancer drugs against angiogenic sprouts was verified by following dose-dependent responses. Our results indicate that Anchor-IMPACT offers not only a model of high-throughput experimentation but also an advanced 3D cell culture platform and can significantly improve current in vitro models while providing the basis for developing predictive preclinical models for biopharmaceutical applications.

Miniaturized two-stack Blumlein pulser with a variable repetition-rate for non-thermal irreversible-electroporation experiments.

Non-thermal irreversible electroporation (NTIRE) to avoid thermal damage to cells during intense DC ns pulsed electric fields (nsPEFs) is a recent modality for medical applications. This mechanism, related to bioelectrical dynamics of the cell, is linked to the effect of a DC electric field and a threshold effect with an electrically stimulated membrane for the charge distribution in the cell. To create the NTIRE condition, the pulse width of the nsPEF should be shorter than the charging time constant of the membrane related to the cell radius, membrane capacitance, cytoplasm resistivity, and medium resistivity. It is necessary to design and fabricate a very intense nanosecond DC electric field pulser that is capable of producing voltages up to the level of 100 kV/cm with an artificial pulse width (∼ns) with controllable repetition rates. Many devices to generate intense DC nsPEF using various pulse-forming line technologies have been introduced thus far. However, the previous Blumlein pulse-generating devices are clearly inefficient due to the energy loss between the input voltage and the output voltage. An improved two-stage stacked Blumlein pulse-forming line can overcome this limitation and decrease the energy loss from a DC power supply. A metal oxide silicon field-effect transistor switch with a fast rise and fall time would enable a high repetition rate (max. 100 kHz) and good endurance against very high voltages (DC ∼ 30 kV). The load is designed to match the sample for exposure to cell suspensions consisting of a 200 Ω resistor matched with a Blumlein circuit and two electrodes without the characteristic RC time effect of the circuit (capacitance =0.174 pF).

Synthesis and anticancer activity of 4-aza-daurinol derivatives.

Daurinol, a natural aryl naphthalene lactone, has been reported to have antiproliferative activity against various cell lines, and has also been shown to be efficacious in an in vivo xenograft mouse model. In this study, we tried to discover a new scaffold that enables both rapid structure-activity relationship study of daurinol and scalable synthesis of active compounds. 4-Aza-daurinol, a bioisosterism-based scaffold of daurinol, was designed and 17 analogues were synthesized and evaluated against five representative cancer cell lines. Among them, the 2,3-dihydrobenzo[b][1,4]dioxinyl derivative was found to be the most potent and showed similar activity and tendency as daurinol.