Apoptotic Induction of Mitochondria-Anchored Aggregation-Induced Emission Luminogens through the Intrinsic Mitochondrial Pathway.

Gastric cancer has the third highest mortality rate globally. Chemotherapy is the primary treatment used in advanced gastric cancer. Aggregation-induced emission luminogens (AIEgens) have been exploited as non-toxic and efficient chemotherapy agents for the treatment of cancer. Our previous research demonstrated that tetraphenylethene-substituted pyridinium salt (TPE-Py) is a kind of AIEgen that had the ability to lead to apoptosis in gastric cancer cells. However, it is currently unknown whether TPE-Py induced apoptosis in gastric cancer cells by the mitochondria-mediated pathway. This research confirmed that TPE-Py could target mitochondria and induce apoptotic cell death. In addition, several well-recognized indicators were detected to investigate the functional and morphological changes of mitochondria. We found that TPE-Py could diminish the mitochondrial membrane potential and increase the accumulation of reactive oxygen species and the discharge of cytochrome c, which was related to the mitochondrial apoptotic pathway. Meanwhile, morphological changes in mitochondria were also observed by transmission electron microscopy in gastric cancer cells after incubation with TPE-Py. In conclusion, we provided insights into the mechanism regulating apoptosis in gastric cancer cells and elucidated the mechanism of apoptosis induced by TPE-Py via the intrinsic mitochondrial pathway.

Superior in vitro anticancer effect of biomimetic paclitaxel and triptolide co-delivery system in gastric cancer.

As a well-known anticancer drug, paclitaxel (PTX), a first-line chemotherapeutic agent, remains unsatisfactory for gastric cancer therapy. It is reported that triptolide (TPL) could enhance the anti-gastric cancer effect of PTX. Considering the poor solubility of both drugs, we developed a red blood cell membrane-biomimetic nanosystem, an emerging tool in drug delivery, to co-load paclitaxel and triptolide (red blood cell membrane coated PTX and TPL co-loaded poly(lactic-co-glycolic acid) [PLGA] nanoparticles, RP(P/T)). The successful preparation was confirmed in terms of particle size, morphology, and surface markers assays. This biomimetic system could prolong circulation and escape immune surveillance. And these properties were verified by stability, in vitro drug release, and cellular uptake assays. Moreover, the MTT and colony formation assays demonstrated the superior anti-proliferation effect of the RP(P/T) to free drugs. The enhanced antitumor effects of RP(P/T) on migration and invasion were also evaluated by wound-healing and transwell assays. Overall, the bionic co-delivery nanoplatform with improved efficacy in vitro is a promising therapy for gastric cancer.

Ratiometric fluorescent test pen filled with a mixing ink of carbon dots and CdTe quantum dots for portable assay of silver ion on paper.

A ratiometric fluorescent test pen filled with a mixing ink of blue carbon dots (CDs) and red CdTe quantum dots (CdTe QDs) is introduced for portable assay of silver ion (Ag(I)) on paper. The mixing ink was tuned with ratiometric fluorescent intensity of 1:5, and then filled into a vacant commercial fluorescent pen core. Writing/painting a random word/figure on a blank paper can make the most portable nanoprobe determining Ag(I) by visualization. Ag(I) can adsorb onto the surface of CdTe QDs, which leads to the formation of surficial Ag2Te layer by an ion-exchanging reaction. This enables the red fluorescence of CdTe QDs (with excitation/emission maxima at 360/628 nm) to be quenched. Due to the unchanged blue fluorescence of CDs (with excitation/emission maxima at 360/440 nm) as internal standard, the solution color evolves gradually from red to blue with the increase of Ag(I) concentration with a detection limit of 3.48 nM. This is at least 2 orders of magnitude lower than the limit defined by World Health Organization (WHO) in drinkable water. The fluorescent test pen has also been used for the determination of Ag(I) in wastewater. Graphical abstract Ag(I) can adsorb on the surface of CdTe QDs to quench their fluorescence, while the fluorescent intensity of CDs keep constant, accompanying color change with the increase of Ag(I) concentration. The method offers a visual assay of Ag(I) in water.

A strong CD8+ T cell-stimulating supramolecular hydrogel.

The development of molecules with immune stimulatory properties is crucial for cancer immunotherapy. In this work, we combined two peptide-based molecules, tuftsin (TKPR) and Nap-GDFDFDY, to develop a novel self-assembling molecule Nap-GDFDFDYTKPR (Comp.3), which has strong CD8+ T cell stimulatory properties. Comp.3 could self-assemble into nanofibers and hydrogels, which significantly improved the stability of tuftsin against enzyme digestion. The nanofibers of Comp.3 enhanced the phagocytic activity of macrophages, promoted the maturation of DCs, and stimulated the expression of cytokines. In addition, it demonstrated an excellent anti-tumor efficacy in vivo by eliciting a strong CD8+ T immune response. Taken together, our observations revealed a powerful immune stimulating nanomaterial that is a promising compound for cancer immunotherapy.