Tumor-derived covalent organic framework nanozymes for targeted chemo-photothermal combination therapy.

Covalent organic frameworks (COFs) have garnered enormous attention in anti-cancer therapy recently. However, the intrinsic drawbacks such as poor biocompatibility and low target-specificity greatly restrain the full clinical implementation of COF. Herein, we report a biomimetic multifunctional COF nanozyme, which consists of AIEgen-based COF (TPE-s COF) with encapsulated gold nanoparticles (Au NPs). The nanozyme was co-cultured with HepG2 cells until the cell membrane was fused with lipophilic TPE-s COF-Au@Cisplatin. By using the cryo-shocking method, we fabricated an inactivated form of the TPE-s COF-Au@Cisplatin nanozyme endocytosed in the HepG2 cell membrane (M@TPE-s COF-Au@Cisplatin), which lost their proliferative ability and pathogenicity. Upon laser irradiation, the M@TPE-s COF-Au@Cisplatin nanozymes cleaved, thereby releasing the TPE-s COF-Au nanozyme and Cisplatin to exert their photothermal and drug therapeutic effect. This work opens a new avenue to the synthesis of tumor-derived fluorescent TPE-s COF-Au nanozymes for highly efficient, synergetic, and targeted chemo-photothermal combination therapy of liver cancer.

Mass Transfer Modulation and Gas Mapping Based on Covalent Organic Frameworks-Covered Theta Micropipette.

Covalent organic frameworks (COFs) consist nanochannels that are fundamentally important for their application. Up to now, the effect of gas phase on COF nanochannels are hard to explore. Here, TAPB-PDA-COFs (triphenylbenzene-terephthaldehyde-COFs) was synthesized in situ at the tip of a theta micropipette. The COF-covered theta micropipette (CTP) create a stable gas-liquid interface inside the COF nanochannels, through which the humidity-modulated ion mass transfer in the COF nanochannels can be recorded by recording the current across the two channels of the theta micropipette. Results show that the humid air changes the mobility of the ions inside the COF nanochannels, which leads to the change of ionic current. Humid air showed different effects on the ion transfer depending on the solvent polarity index and vapor pressure. Current decreases linearly with the increase of relative humidity (RH) from 11% to 98%. The CTP was also mounted on the scanning electrochemical microscopy as a probe electrode for mapping micrometer-scale humidity distribution.

Water-dispersible PEG-curcumin/amine-functionalized covalent organic framework nanocomposites as smart carriers for in vivo drug delivery.

Covalent organic frameworks (COFs) as drug-delivery carriers have been mostly evaluated in vitro due to the lack of COFs nanocarriers that are suitable for in vivo studies. Here we develop a series of water-dispersible polymer-COF nanocomposites through the assembly of polyethylene-glycol-modified monofunctional curcumin derivatives (PEG-CCM) and amine-functionalized COFs (APTES-COF-1) for in vitro and in vivo drug delivery. The real-time fluorescence response shows efficient tracking of the COF-based materials upon cellular uptake and anticancer drug (doxorubicin (DOX)) release. Notably, in vitro and in vivo studies demonstrate that PEG-CCM@APTES-COF-1 is a smart carrier for drug delivery with superior stability, intrinsic biodegradability, high DOX loading capacity, strong and stable fluorescence, prolonged circulation time and improved drug accumulation in tumors. More intriguingly, PEG350-CCM@APTES-COF-1 presents an effective targeting strategy for brain research. We envisage that PEG-CCM@APTES-COF-1 nanocomposites represent a great promise toward the development of a multifunctional platform for cancer-targeted in vivo drug delivery.