Solar-driven photocatalytic H2O2 production with water and O2 is an environmentally friendly process for producing H2O2, an important chemical. Compared with traditional photocatalysts, covalent organic frameworks (COFs) have received extensive...
It was shown that some nanomaterials may have anticancer properties, but lack of selectivity is one of challenges, let alone selective suppression of cancer growth by regulating the cellular microenvironment. Herein, we demonstrated for the first time that carbon quantum dots/Cu2O composite (CQDs/Cu2O) selectively inhibited ovarian cancer SKOV3 cells by targeting cellular microenvironment, such as matrix metalloproteinases, angiogenic cytokines and cytoskeleton. The result was showed CQDs/Cu2O possessed anticancer properties against SKOV3 cells with IC50 = 0.85 μg mL−1, which was approximately threefold lower than other tested cancer cells and approximately 12-fold lower than normal cells. Compared with popular anticancer drugs, the IC50 of CQDs/Cu2O was approximately 114-fold and 75-fold lower than the IC50 of commercial artesunate (ART) and oxaliplatin (OXA). Furthermore, CQDs/Cu2O possessed the ability to decrease the expression of MMP-2/9 and induced alterations in the cytoskeleton of SKOV3 cells by disruption of F-actin. It also exhibited stronger antiangiogenic effects than commercial antiangiogenic inhibitor (SU5416) through down-regulating the expression of VEGFR2. In addition, CQDs/Cu2O has a vital function on transcriptional regulation of multiple genes in SKOV3 cells, where 495 genes were up-regulated and 756 genes were down-regulated. It is worth noting that CQDs/Cu2O also regulated angiogenesis-related genes in SKOV3 cells, such as Maspin and TSP1 gene, to suppress angiogenesis. Therefore, CQDs/Cu2O selectively mediated of ovarian cancer SKOV3 cells death mainly through decreasing the expression of MMP-2, MMP-9, F-actin, and VEGFR2, meanwhile CQDs/Cu2O caused apoptosis of SKOV3 via S phase cell cycle arrest. These findings reveal a new application for the use of CQDs/Cu2O composite as potential therapeutic interventions in ovarian cancer SKOV3 cells.
Metals–organic
frameworks (MOFs) have been widely explored
in biomedicine, mostly in drug delivery, biosensing, and bioimaging
due to their large surface area, tunable porosity, readily chemical
functionalization, and good biocompatibility. However, the underlining
cellular mechanisms controlling the process for MOF cytotoxicity remains
almost completely unknown. Here, we demonstrate that pristine Cu-MOF
without any loaded drug selectively inhibited ovarian cancer mainly
through promoting tubulin polymerization and destroying the cell actin
cytoskeleton (F-actin) to trigger the mitotic catastrophe, accompanying
by conventional programmed cell death. To our knowledge, this is the
first report claiming that mitotic catastrophe may be an explaining
mechanism of MOF cytotoxicity. Cu-MOF with an intrinsic protease-like
activity also hydrolyzed cellular cytoskeleton proteins (F-actin).
The RNA sequencing data indicated the differential expressional mRNA
of cell proliferation and actin cytoskeleton (ACTA2, ACTN3, FSCN2,
and SCIN) and mitotic spindles (PLK1 and TPX2) related genes. We found
that Cu-MOF as a promising candidate in the disruption of cellular
cytoskeleton and the change of the gene expression could be actin
altering and antimitotic agents against cancer cells, allowing for
fundamental biological and biophysical studies of MOFs.
Whereas a variety of inorganic nanomaterials possessing intrinsic peroxidase‐like activity have recently attracted considerable interest, little attention is given to explore their intrinsic protease‐mimic activities. And the construction of efficient enzyme mimetics for the hydrolysis of peptide bonds in proteins still represents a major technical challenge due to the high stability of peptide bonds and the importance of proteases in biology and industry. Herein, it is described for the first time that Cu2O‐decorated carbon quantum dots (CQDs/Cu2O) possess an intrinsic protease‐mimic activity to hydrolyze proteins including bovine serum albumin (BSA) and casein under physiological conditions. CQDs/Cu2O also features a desirable stability and good reusability. CQDs/Cu2O has a much higher affinity for BSA than trypsin. To the best of knowledge, this is the first example of protein hydrolysis by stable composite nanomaterials under physiological conditions which may open this catalytic system for a multitude of potential applications in biological systems.
Nitrogen doping in combination with the brookite phase or a mixture of TiO 2 polymorphs nanomaterials can enhance photocatalytic activity under visible light. Generally, nitrogendopedanatase/brookite mixed phases TiO 2 nanoparticles obtained by hydrothermal or solvothermal method need to be at high temperature and with long time heating treatment. Furthermore, the surface areas of them are low (<125 m 2 /g). There is hardly a report on the simple and direct preparation of N-doped anatase/brookite mixed phase TiO 2 nanostructures using sol-gel method at low heating temperature. In this paper, the nitrogen-doped anatase/brookite biphasic nanoparticles with large surface area (240 m 2 /g) were successfully prepared using sol-gel method at low temperature (165 • C), and with short heating time (4 h) under autogenous pressure. The obtained sample without subsequent annealing at elevated temperatures showed enhanced photocatalytic efficiency for the degradation of methyl orange (MO) with 4.2-, 9.6-, and 7.5-fold visible light activities compared to P25 and the amorphous samples heated in muffle furnace with air or in tube furnace with a flow of nitrogen at 165 • C, respectively. This result was attributed to the synergistic effects of nitrogen doping, mixed crystalline phases, and high surface area.
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