Nanowire Assisted Mechanotyping of Cellular Metastatic Potential

On-Site Stimulation of Dendritic Cells by Cancer-Derived Extracellular Vesicles on a Core-Shell Nanowire Platform

Extracellular vesicles (EVs) contain a subset of proteins, lipids, and nucleic acids that maintain the characteristics of the parent cell. Immunotherapy using EVs has become a focus of research due to their unique features and bioinspired applications in cancer treatment. Unlike conventional immunotherapy using tumor fragments, EVs can be easily obtained from bodily fluids without invasive actions. We previously fabricated nanowire devices that were specialized for EV collection, but they were not suitable for cell culturing. In this study, we fabricated a ZnO/Al2O3 core-shell nanowire platform that could collect more than 60% of the EVs from the cell supernatant. Additionally, we could continue to culture dendritic cells (DCs) on the platform as an artificial lymph node to investigate cell maturation into antigen-presenting cells. Finally, using this platform, we reproduced a series of on-site immune processes that are among the pivotal immune functions of DCs and include such processes as antigen uptake, antigen presentation, and endocytosis of cancer-derived EVs. This platform provides a new ex vivo tool for EV-DC-mediated immunotherapies.

Revealing Low Amplitude Signals of Neuroendocrine Cells through Disordered Silicon Nanowires-Based Microelectrode Array

Today, the key methodology to study in vitro or in vivo electrical activity in a population of electrogenic cells, under physiological or pathological conditions, is by using microelectrode array (MEA). While significant efforts have been devoted to develop nanostructured MEAs for improving the electrophysiological investigation in neurons and cardiomyocytes, data on the recording of the electrical activity from neuroendocrine cells with MEA technology are scarce owing to their weaker electrical signals. Disordered silicon nanowires (SiNWs) for developing a MEA that, combined with a customized acquisition board, successfully capture the electrical signals generated by the corticotrope AtT-20 cells as a function of the extracellular calcium (Ca2+ ) concentration are reported. The recorded signals show a shape that clearly resembles the action potential waveform by suggesting a natural membrane penetration of the SiNWs. Additionally, the generation of synchronous signals observed under high Ca2+ content indicates the occurrence of a collective behavior in the AtT-20 cell population. This study extends the usefulness of MEA technology to the investigation of the electrical communication in cells of the pituitary gland, crucial in controlling several essential human functions, and provides new perspectives in recording with MEA the electrical activity of excitable cells.

Label-Free Morpho-Molecular Imaging for Studying the Differential Interaction of Black Phosphorus with Tumor Cells

Black phosphorus nanosheets (2D BP) are emerging as very promising, highly selective chemotherapeutic agents due to their fast degradation in the intracellular matrix of cancer cells. Here, optical diffraction tomography (ODT) and Raman spectroscopy were exploited as a powerful label-free approach to achieve integrated insights into the processes accompanying the administration of exfoliated 2D BP flakes in human prostatic adenocarcinoma and normal human prostate epithelial cells. Our ODT experiments provided unambiguous visualization of the 2D BP internalization in cancer cells and the morphological modifications of those cells in the apoptotic phase. The cellular internalization and damaging occurred, respectively, 18 h and 36–48 h after the 2D BP administration. Changes in the chemical properties of the internalized 2D BP flakes were monitored by Raman spectroscopy. Interestingly, a fast oxidation process of the 2D BP flakes was activated in the intracellular matrix of the cancer cells after 24 h of incubation. This was in sharp contrast to the low 2D BP uptake and minimal chemical changes observed in the normal cells. Along with the understanding of the 2D BP fate in the cancer cells, the proposed label-free morpho-molecular approach offers a powerful, rapid tool to study the pharmacokinetic properties of engineered nanomaterials in preclinical research.