Combination therapy has been regarded as a promising strategy for cancer treatment due to the enhanced anticancer efficacy achieved by blocking multiple drug resistance pathways. In this work, a drug carrier based on nanoscale ZIF-90 for the codelivery of two anticancer drugs has been synthesized by covalently attaching doxorubicin (DOX) to the surface of ZIF-90 via Schiff base reaction of amino group in DOX and aldehyde group of imidazole-2-carboxaldehyde (ICA) ligand and encapsulating 5-fluorouracil (5-FU) into the pores of the framework. The results of drug loading measurements show that the loading amount of drugs was estimated as high as 36.35 and 11-13.5 wt % for 5-FU and DOX, respectively. Moreover, we demonstrated that the carrier had the potential of cancer-targeted delivery of drugs for the collapse of framework under the pH environment around cancer cells and subsequently releasing drugs. Drug release at pH 5.5, imitating the environment of tumor, can reach over 95%, and the release time is less 16 h, meaning a more effective and faster release of drugs around tumoral cells than that in a normal environment. This is the first report for cancer-targeted codelivery of two different chemical drugs based on nanoscale metal-organic frameworks (NMOFs).

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Carbon nanodots (CDs) have attracted enormous attention in the photocatalytic area for their high light-harvesting and outstanding electron transfer abilities. In this work, NH2–UiO-66 was first composited with g-C3N4 to construct an NH2–UiO-66/g-C3N4 heterojunction. Then, CDs were incorporated into the pores of NH2–UiO-66 by the pore space of the framework serving as confined nanoreactors to construct a CD@NH2–UiO-66/g-C3N4 ternary composite. The ultrasmall CDs transformed from incapsulated glucose in the pores of NH2–UiO-66 were uniformally distributed in MOFs and extensively improve the photocatalytic hydrogen evolution activity of the composite under visible-light irradiation. The optimum photocatalytic H2 evolution rate of the CD@NH2–UiO-66/g-C3N4 composite with a CD content of 2.77 wt % is 2.930 mmol·h–1·g–1 under visible-light irradiation, which is 32.4, 38.6, and 17.5 times as high as that of bulk g-C3N4, NH2–UiO-66, and NH2–UiO-66/g-C3N4, respectively. The remarkable enhancement of the photocatalytic activity should be that CDs as cocatalysts effectively increase the transport properties of electrons and efficient charge separation. Moreover, CD@NH–UiO-66/g-C3N4 nanocomposites showed excellent stability during the photocatalytic process as determined by XRD and TEM analyses for the sample after reaction. The results of the mechanism investigation reveal that CDs in the ternary composite serve as electron transfer mediation to facilitate charge separation, enhancing light absorption and extending the lifetime of photoinduced carriers. The present work shows that encapsulating CDs into the pores of MOFs is an efficient strategy to improve the activity of an MOF-based photocatalyst.

Tea waste could be used as an effective and economic substrate for oyster mushroom cultivation. This study also provided a useful way of dealing with massive amounts of tea waste.

The graphitic carbon nitride (g-C3N4) photocatalyst has drawn widespread attention owing to its excellent photocatalytic hydrogen production activity.