Influenza remains one of the major epidemic diseases worldwide, and rapid virus replication and collateral lung tissue damage caused by excessive pro-inflammatory host immune cell responses lead to high mortality rates. Thus, novel therapeutic agents that control influenza A virus (IAV) propagation and attenuate excessive pro-inflammatory responses are needed. Polysaccharide extract from Radix isatidis, a traditional Chinese herbal medicine, exerted potent anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2) and avian influenza viruses (H6N2 and H9N2) in vitro. The polysaccharides also significantly reduced the expression of pro-inflammatory cytokines (IL-6) and chemokines (IP-10, MIG, and CCL-5) stimulated by A/PR/8/34 (H1N1) at a range of doses (7.5 mg/mL, 15 mg/mL, and 30 mg/mL); however, they were only effective against progeny virus at a high dose. Similar activity was detected against inflammation induced by avian influenza virus H9N2. The polysaccharides strongly inhibited the protein expression of TLR-3 induced by PR8, suggesting that they impair the upregulation of pro-inflammatory factors induced by IAV by inhibiting activation of the TLR-3 signaling pathway. The polysaccharide extract from Radix isatidis root therefore has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection.

Multiple essential microdroplet operation units, including splitting, dispensing, oil-phase exchange, trapping, release and demulsification, were successfully implemented by combining hydrophobic ferrofluid with microfluidic chips.

Hepatic stellate cells (HSCs), a major component of the tumor microenvironment in liver cancer, play important roles in cancer progression as well as drug resistance. Here, we presented a microchannel plate-based co-culture model that integrated Hepa1–6 tumor spheroids with JS-1 stellate cells in three-dimensional (3D) concave microwells to mimic the in vivo tumor microenvironment by recapitulating epithelial–mesenchymal transition and chemoresistance. The expression of epithelial–mesenchymal transition (EMT)-related markers and factors was analyzed using immunofluorescent staining and the changes in viability following exposure to different concentrations of paclitaxel were measured. Cell spheroids formed 3D tumor spheroids within 3 days. Culture conditions were optimized for Hepa1–6 cells and JS-1 cells, and their appropriate interactions were confirmed by reciprocal activation. JS-1 under co-culture showed a change in cellular morphology and an increased expression of α-SMA. The expression of EMT-related markers, such as vimentin and TGF-β1, was higher in the co-cultured Hepa1–6 spheroids compared to that in mono-cultured spheroids. Following paclitaxel exposure, JS-1 cells showed significant changes in survival under both mono- and co-culture conditions, while Hepa1–6 presented negligible changes. The proposed microfluidic platform makes it possible to observe the positioned three-dimensional cell spheroids, which would be extensively used not only for well-organized spheroid creation, but also for better quantitative and qualitative understanding of the cell–cell interaction effect.

Exosomes are considered as potential biomarkers that can reflect information from their parent cell-associated cancer microenvironment. Recently, aptasensors have been widely used for cancer and tumor exosome detection. Aptamers related to exosome surface proteins are usually used to introduce a sequence; the aptamer is used for exosome recognition, and the introduced sequence is used to form G-quadruplexes and for signal amplification. In this paper, we found that the EpCAM aptamer is rich in guanine and unimolecular G-quadruplex with a two-layer G-tetrad under acidic conditions, and we investigated its topology, thermal stability and dissociation constant with hemin. Based on this, our proposed colorimetric aptamer sensor combines the unmodified EpCAM aptamer with hemin to construct a hemin/G-quadruplex DNAzyme and catalyze the TMB–H₂O₂ system to generate a strong colorimetric signal. Therefore, colorimetric signal changes were negatively correlated with the exosome concentration. The linear range of the 1 h assay was 10⁶–10⁸ particles per mL, and the detection limit was 3.94 × 10⁵ particles per mL. In addition, this method can detect exosomes in complex fetal bovine serum samples with good specificity and high sensitivity toward exosomes from breast, liver, and lung cancers with abnormal EpCAM protein expression.