Annealed ZnO/Al2O3 Core-Shell Nanowire as a Platform to Capture RNA in Blood Plasma

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.

Identifying high-grade serous ovarian carcinoma-specific extracellular vesicles by polyketone-coated nanowires

Cancer cell-derived extracellular vesicles (EVs) have unique protein profiles, making them promising targets as disease biomarkers. High-grade serous ovarian carcinoma (HGSOC) is the deadly subtype of epithelial ovarian cancer, and we aimed to identify HGSOC-specific membrane proteins. Small EVs (sEVs) and medium/large EVs (m/lEVs) from cell lines or patient serum and ascites were analyzed by LC-MS/MS, revealing that both EV subtypes had unique proteomic characteristics. Multivalidation steps identified FRα, Claudin-3, and TACSTD2 as HGSOC-specific sEV proteins, but m/lEV-associated candidates were not identified. In addition, for using a simple-to-use microfluidic device for EV isolation, polyketone-coated nanowires (pNWs) were developed, which efficiently purify sEVs from biofluids. Multiplexed array assays of sEVs isolated by pNW showed specific detectability in cancer patients and predicted clinical status. In summary, the HGSOC-specific marker detection by pNW are a promising platform as clinical biomarkers, and these insights provide detailed proteomic aspects of diverse EVs in HGSOC patients.

The therapeutic potential of γ-Al2O3 nanoparticle containing 5-fluorouracil in the treatment of colorectal cancer

5-Fluorouracil (5-FU) is being used in the treatment of several malignancies, but side effects are often reported and include: diarrhea, vomiting, nausea, poor appetite, watery eyes, and photophobia. We have developed and tested the cytotoxic activity of nanocrystalline powder of γ-alumina (γ-Al₂O₃) containing 5-FU in two-dimensional and three-dimensional (3D) CRC cell culture. γ-Al₂O₃ was prepared using a facile sol-gel method. The physicochemical properties of nanoparticles were investigated by Fourier Transform Infrared (FTIR) analysis, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Analysis (EDXA). Moreover, the particle size was monitored by Transmission Electron Microscopy (TEM). We used MTT and a scratch assay to assess the antiproliferative and anti-migratory of this agent. The effect of γ-Al₂O₃-5-FU on SOD, MDA, and total-thiols levels were evaluated. We assessed the expression of apoptotic markers in mRNA or proteins by RT-PCR and ELISA respectively. γ-Al₂O₃-5-FU inhibited cell growth in two-dimensional (2D) and three-dimensional (3D) cell culture and increased apoptosis as detected by DAPI stainning via modulation of caspases, BAx, BCl2 and cyclinD1. γ-Al₂O₃-5-FU also reduced the migratory activity of CRC cells relative to untreated controls. γ-Al₂O₃-5-FU increased the level of MDA, while reducing the level of SOD and total-thiols as well as inflamatory markers (e.g., TNF-s and IL-6). Our study demonstrated that γ-Al₂O₃-5-FU inhibited cell growth and migration, indicating its potential value in the treatment of colorectal cancer.

Tailoring ZnO nanowire crystallinity and morphology for label-free capturing of extracellular vesicles

Zinc oxide (ZnO) nanowires have shown their potential in isolation of cancer-related biomolecules such as extracellular vesicles (EVs), RNAs, and DNAs for early diagnosis and therapeutic development of diseases. Since the function of inorganic nanowires changes depending on their morphology, previous studies have established strategies to control the morphology and have demonstrated attainment of improved properties for gas and organic compound detection, and for dye-sensitized solar cells and photoelectric conversion performance. Nevertheless, crystallinity and morphology of ZnO nanowires for capturing EVs, an important biomarker of cancer, have not yet been discussed. Here, we fabricated ZnO nanowires with different crystallinities and morphologies using an ammonia-assisted hydrothermal method, and we comprehensively analyzed the crystalline nature and oriented growth of the synthesized nanowires by X-ray diffraction and selected area electron diffraction using high resolution transmission electron microscopy. In evaluating the performance of label-free EV capture in a microfluidic device platform, we found both the crystallinity and morphology of ZnO nanowires affected EV capture efficiency. In particular, the zinc blende phase was identified as important for crystallinity, while increasing the nanowire density in the array was important for morphology to improve EV capture performance. These results highlighted that the key physicochemical properties of the ZnO nanowires were related to the EV capture performance.

Oxide nanowire microfluidics addressing previously-unattainable analytical methods for biomolecules towards liquid biopsy

Nanowire microfluidics using a combination of self-assembly and nanofabrication technologies is expected to be applied to various fields due to its unique properties. We have been working on the fabrication of nanowire microfluidic devices and the development of analytical methods for biomolecules using the unique phenomena generated by the devices. The results of our research are not just limited to the development of nanospace control with "targeted dimensions" in "targeted arrangements" with "targeted materials/surfaces" in "targeted spatial locations/structures" in microfluidic channels, but also cover a wide range of analytical methods for biomolecules (extraction, separation/isolation, and detection) that are impossible to achieve with conventional technologies. Specifically, we are working on the extraction technology "the cancer-related microRNA extraction method in urine," the separation technology "the ultrafast and non-equilibrium separation method for biomolecules," and the detection technology "the highly sensitive electrical measurement method." These research studies are not just limited to the development of biomolecule analysis technology using nanotechnology, but are also opening up a new academic field in analytical chemistry that may lead to the discovery of new pretreatment, separation, and detection principles.