乳液聚合制聚苯乙烯纳米薄膜的分子链状态

以阴离子表面活性剂十二烷基硫酸钠SDS(C12H25O4SNa)与电解质调节剂氯化钾(KCl)在水相体系中形成的层状胶束为模板,以苯乙烯(C8H8)为单体,过硫酸铵((NH4)2S2O8)为引发剂,采用乳液聚合的方式,制备得到聚苯乙烯纳米薄膜。通过采用差示扫描量热法(DSC)以及在特殊温度下淬冷后再进行的X射线衍射分析法(XRD)检测,对聚苯乙烯纳米薄膜的分子链状态进行了研究。结果表明,聚苯乙烯纳米薄膜具有一种新颖的分子链状态,它可以在适当的温度下形成有序结构。     

Cancer Immunotherapy Based on Cell Membrane-Coated Nanocomposites Augmenting cGAS/STING Activation by Efferocytosis Blockade

Innate immunity triggered by the cGAS/STING pathway has the potential to improve cancer immunotherapy. Previously, the authors reported that double-stranded DNA (dsDNA) released by dying tumor cells can trigger the cGAS/STING pathway. However, owing to efferocytosis, dying tumor cells are engulfed and cleared before the damaged dsDNA is released; hence, immunologic tolerance and immune escape occur. Herein, a cancer-cell-membrane biomimetic nanocomposites that exhibit tumor-immunotherapeutic effects are synthesized by augmenting the cGAS/STING pathway and suppressing efferocytosis. Once internalized by cancer cells, a combined chemo/chemodynamic therapy would be triggered, which damages their nuclear and mitochondrial DNA. Furthermore, the releasing Annexin A5 protein could inhibit efferocytosis effect and promote immunostimulatory secondary necrosis by preventing phosphatidylserine exposure, resulting in the burst release of dsDNA. These dsDNA fragments, as molecular patterns to immunogenic damage, escape from the cancer cells, activate the cGAS/STING pathway, enhance cross-presentation inside dendritic cells, and promote M1-polarization of tumor-associated macrophages. In vivo experiments suggest that the proposed nanocomposite could recruit cytotoxic T-cells and facilitate long-term immunological memory. Moreover, when combined with immune-checkpoint blockades, it could augment the immune response. Therefore, this novel biomimetic nanocomposite is a promising strategy for generating adaptive antitumor immune responses.     

Insights into mucosal innate responses to Escherichia coli O157 : H7 colonization of cattle by mathematical modelling of excretion dynamics

Mathematical model-based statistical inference applied to within-host dynamics of infectious diseases can help dissect complex interactions between hosts and microbes. This work has applied advances in model-based inference to understand colonization of cattle by enterohaemorrhagic Escherichia coli O157 : H7 at the terminal rectum. A mathematical model was developed based on niche replication and transition rates at this site. A nested-model comparison, applied to excretion curves from 25 calves, was used to reduce complexity while maintaining integrity. We conclude that, 5–9 days post inoculation, the innate immune response negates bacterial replication on the epithelium and either reduces attachment to or increases detachment from the epithelium of the terminal rectum. Thus, we provide a broadly applicable model that gives novel insights into bacterial replication rates in vivo and the timing and impact of host responses.