A Multifunctional Layered Nickel Silicate Nanogenerator of Synchronous Oxygen Self-supply and Superoxide Radical Generation for Hypoxic Tumor Therapy

Abstract

Oxygen consumption but hypoxic tumor environment has been considered as the major obstacle in photodynamic therapy. Although oxygen-supplied strategies have been reported extensively, they still suffer from the complicated system and unsatisfied PDT efficiency. Herein, one-component layered nickel silicate nanoplatforms (LNS NPs) are successfully synthesized using natural vermiculite as the silica source, which can simultaneously supply oxygen (O2) and generate superoxide radicals (O2 –•) under near-infrared irradiation. The appropriate electron band structure endows LNS NPs with attractive optical properties, where the bandgap edges determine the performance of redox activity and spectral response characteristic. Evidenced by both in vitro and in vivo investigations, LNS NPs can generate sufficient superoxide radicals under 660 nm laser irradiation to induce tumor cell apoptosis even in a severe hypoxic environment, which benefits from self-supplied oxygen. Besides, the photoacoustic oxy-hem imaging and histologic assay further demonstrated that the generated oxygen can relieve the inherent intratumoral hypoxia. Therefore, LNS NPs not only serve as superoxide radical generator but also produce oxygen to modulate hypoxia, suggesting that it can be used for superoxide radical-mediated photodynamic therapy with enhanced antitumor effect.

Growth of ZIF-8 Nanoparticles In Situ on Graphene Oxide Nanosheets: A Multifunctional Nanoplatform for Combined Ion-Interference and Photothermal Therapy

“…The conclusions drawn from our results will remind us that the Zn 2+ -interference effect should be considered in the therapeutic efficacy assessment of Zn 2+ -containing nanocomposites, especially when Zn 2+ -based nanomaterials are used as drug carriers. We would like to underline that the design of multifunctional nanoparticles is in line with other recent studies where different types of complex nanosystems have been explored for intratumoral anticancer therapies. − Finally, ZIF-8 core–shell nanostructures with smaller size coated with GQDs or polydopamine will be designed to broaden cancer therapy modalities (e.g., exploiting intravenous injection).…”

“…Since NIR irradiation alone had no effect on cancer cells, this group was not set in vivo . The intratumoral administration of complex functional nanomaterials is an efficient method to treat solid tumor as being reported in several recent studies. − A total of 5 injections were performed over 12 days. Notably, after this period, the tumor size visibly decreased in the BSArGO@ZIF-8 NSs group without irradiation compared to the saline group, while NIR irradiation synergistically further decreased the tumor size (Figure a–c).…”

Multi-Mimic Activities of Co3O4 Nanopolyhedrons and Application in Regulating the Content of Intracellular Hydrogen Peroxide/Oxygen

“…Then, the substrate in the 96-well plate was poured out and washed three times with PBS, and the serum-free solution containing different concentrations of Co 3 O 4 and Co 3 O 4 @PDA was added with an incubation of 24 h. After the culture base was poured out, 200 μL of serum-free solution containing the standard MTT assay (20 μL, 5 mg·mL –1 ) was added into the well for another incubation of 4 h. Finally, the MTT solution was poured out, and 150 μL of DMSO was added. The absorbance at 570 nm was measured with a microplate reader to evaluate the cytotoxicity. , Also, the cell viability can be evaluated by the ratio of the mean absorbance value of the treatment group and the mean absorbance value of the control . The cell viability was calculated using the ratio of the mean of the absorbance value for the treatment and control groups …”

“…The absorbance at 570 nm was measured with a microplate reader to evaluate the cytotoxicity. 38,39 Also, the cell viability can be evaluated by the ratio of the mean absorbance value of the treatment group and the mean absorbance value of the control. 39 The cell viability was calculated using the ratio of the mean of the absorbance value for the treatment and control groups. )…”

2D Copper(II) Metalated Metal–Organic Framework Nanocomplexes for Dual-enhanced Photodynamic Therapy and Amplified Antitumor Immunity

“…Currently, the PDT alone can hardly achieve satisfactory cancer immunotherapy due to the following intractable problems: (1) most PSs possess poor tumor targeting and accumulation capability, low payloads, easy aggregation, photoinduced quenching, etc. ; , (2) the GSH levels in cancer cells are much higher (100–1000 fold) than in normal cells, and the overexpressed GSH serves as an antioxidant to scavenge the produced ROS under light irradiation; , (3) tumor hypoxia is recognized as a typical feature of solid tumors that severely reduces the therapeutic efficacy because of the O 2 -dependent nature of PDT. − To address the first problem mentioned above, metal–organic frameworks (MOF) that integrate a photosensitizer into the periodic structure have opened a new door for PDT of tumors due to a high PS loading ratio, facile diffusion of singlet oxygen ( 1 O 2 ), intrinsic biodegradability, controllable sizes/shapes, and inhibited photoinduced quenching of the photosensitizer. − According to the second problem of PDT, tremendous efforts have been devoted to developing GSH-depleting materials. For instance, copper ion-based nanocomplexes (Cu 2+ - g -C 3 N 4 , Cu 2+ MOF, Cu-TCPP), manganese ion-based nanosystems (MnO 2 , MnFe 2 O 4 @MOF core–shell nanostructure, Mn III -sealed MOF nanostructure), Fe-doped nanoplatforms, and enzymes were prepared to intracellularly decrease GSH levels and thus enhance the PDT effect. − To solve the intrinsic bottleneck of PDT around tumor hypoxia, researchers have explored different methods to ameliorate tumor hypoxia, including the direct delivery of oxygen, in situ generation of oxygen (catalase, MnO 2 , Pt nanoparticles, CaO 2 , carbon nitride, carbon dots), and the inhibition of tumor vascular recurrence. − As a low-cost, efficient, and stable catalyst, metal nanomaterials are widely applied in biosensors, cancer therapy, and environmental protection.…”