Xiaoyu Xia,Xiaoyi Tan,Chao Wu,Yao Li,Guanghua Zhao,Ming Du
The aggregation-induced emission (AIE) material has been widely used in biological detection due to their unique property of fluorescing in aggregation state. However, the poor dispersion and biocompatibility limit its application in in vivo real-time imaging. Here, a novel strategy is designed to obtain pH-responsive AIE nanomaterials, working through 4-Undecoxy Tetraphenyl Ethylene Methacrylate (PM1) block, with excellent features (dispersion, biocompatibility, self-reconstruction and cancer specific recognition). The recombinant human H-ferritin (rHuHF) was used to prepare rHuHF-PM1 nanocomposites which effectively supported the dispersion and transfer of PM1 in the biological environment, even making it target tumor cells due to the overexpression of ferritin receptors on tumor cells. To simulate the changes of rHuHF in intracellular lysosomes, particle size and fluorescence of rHuHF-PM1 were analyzed, which reflected the loose structural changes of rHuHF nanocages in weak acid system that facilitated the degradation of macromolecular rHuHF in intracellular lysosomes and following release of PM1. The released PM1 molecules aggregated and emitted brilliant blue fluorescence. Several cell lines, Hela, HT-29, HepG2, L-O2 and HUVEC have all been sensitively detected and distinguished. Accordingly, this nanocage has a potential to be applied to disease diagnosis and provides a novel sensing platform for the identification of cancer.
Bulk PM2.5 measurements are widely used to assess the oxidative toxicity of particulate matter, but they integrate size fractions that differ in composition and respiratory deposition. We show that mixing PM1 and PM1-2.5 from a roadside site produces pronounced antagonistic effects on oxidative potential (OP) and reactive oxygen species (ROS) generation, with interaction factors (IFs) below 1 across all end points: OP by the ascorbic acid assay (IF = 0.65-0.81), OP by the dithiothreitol assay (IF = 0.80-0.93), ROS (IF = 0.10-0.88), and mitochondrial superoxide (IF = 0.43-0.78). This antagonism requires metal-organic interactions as metal-free biomass burning PM exhibits strictly additive behaviors. Cu2+-humic acid experiments reproduce the antagonistic effects seen in ambient PM (IFs = 0.22-0.95). Electron paramagnetic resonance spectroscopy confirms the formation of complexed Cu and reveals that the conversion of free Cu to complexed Cu is nonlinear with respect to the HA:Cu ratio, providing a mechanistic explanation for the divergent interaction effects reported across studies. These results indicate that bulk PM2.5 measurements can mask the oxidative toxicity of metal-organic interactions, highlighting the need for size-resolved OP and ROS characterization.
Airborne microbes play critical roles in atmospheric ecology and human health, while the connections of microbial community with anthropic activity , such as heating supply patterns and chemical compositions of particulate matter (PM), remain unclear. The present study demonstrated that district heating supply regions exhibited higher microbial richness than non-district heating supply regions, and microbial richness in PM 1 (aerodynamic diameter ≤ 1 µm) was significantly lower than that in PM 10 (aerodynamic diameter ≤ 10 µm). Gram-positive bacteria were dominant, and Bacilli accounts for 85% of the noted bacteria. The total concentrations of heavy metals, polycyclic aromatic hydrocarbons (PAHs) and water-soluble ions increased with PM sizes. Heavy metals and PAHs in non-district heating supply regions showed significantly higher concentrations than that in district heating supply regions. Most of tested chemical compositions negatively contributed to microbial community diversity, except for Zn, Cr, Pyrene (Pyr), and Benzo[ a ]pyrene (Bap). The above results were also affected by heating supply patterns (district heating supply and non-district heating supply). There was a positive correlation between microbial community richness and •OH concentration, and microbial community richness decreased as PM specific surface area increased. This work reveals connections between the properties of PMs and the microbial community diversity with heating supply patterns, and gives novel insights to atmospheric health and carbon neutrality.
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