Nanosystems for chemodynamic based combination therapy: Strategies and recent advances

Antitumor Therapy through Photothermal Performance Synergized with Catalytic Activity Based on the Boron Cluster Supramolecular Frameworks

Chemodynamic therapy (CDT) has received widespread attention as a tumor optical treatment strategy in the field of malignant tumor therapy. Nonmetallic multifunctional nanomaterials as CDT agents, due to their low toxicity, long-lasting effects, and safety characteristics, have promising applications in the integrated diagnosis and treatment of cancer. Here, we modified the supramolecular framework of boron clusters, coupled with a variety of dyes to develop a series of metal-free agent compounds, and demonstrated that these nonmetallic compounds have excellent CDT activities through experiments. Subsequently, the best performing Methylene Blue/[closo-B12H12]2- (MB@B12H12) was used as an example. Through theoretical calculations, electron paramagnetic resonance spectroscopy, and 808 nm light irradiation, we confirmed that MB@B12H12 exhibited photothermal performance and CDT activity further. More importantly, we applied MB@B12H12 to melanoma cells and subcutaneous tumor, demonstrating its effective suppression of melanoma growth in vitro and in vivo through the synergistic effects of photothermal performance and CDT activity. This study emphasizes the generalizability of the coupling of dyes to [closo-B12H12]2- with important clinical translational potential for CDT reagents. Among them, MB@B12H12 may have a brighter future, paving the way for the rapid development of metal-free CDT reagents.

Chiral ligands and photothermal synergistic effects of inorganic nanoparticles for bacteria-killing

As the drawbacks of antibiotics in treating bacterial infections emerged, physical methods such as near-infrared-activated (NIR-activated) bacterial killing, have attracted great interests for their advantages of no resistance, short action time and few side effects. In this manuscript, NIR-activated bacteria-killing performance of chiral copper sulphide nanoparticles (L-/d-CuS NPs) was investigated using linearly polarized light (LPL) and circularly polarized light (CPL) as illumination sources, respectively. Chiral CuS NPs showed enhanced NIR-activated bacteria-killing effect compared with achiral CuS NPs under the same conditions. Moreover, these chiral CuS NPs showed obvious chirality-related antibacterial effect: the bacterial killing was more efficient under CPL activation, and L- and d-CuS NPs had higher antibacterial efficiency under left circularly polarized light (LCPL) and right circularly polarized light (RCPL), respectively. The possible mechanism of bacteria-killing performance for chiral CuS NPs was discussed in detailed. Photothermal bacteria-killing tests of chiral CuS NPs "sealed" in polydimethylsiloxane (PDMS) demonstrated the individual influence of photothermal effect. These observations in this paper could provide ideas for the potential applications of chiral nanostructures with enhanced photothermal effect in efficient bacterial killing.

A Combination of Biocatalysis and Fenton-Like Reaction Induced OH• Burst for Cascade Amplification of Cancer Chemodynamic Therapy

Chemodynamic therapy (CDT) is a novel antitumor strategy that employs Fenton or Fenton-like reactions to generate highly toxic hydroxyl radical (OH•) from hydrogen peroxide (H2O2) for inducing tumor cell death. However, the antitumor efficacy of the CDT strategy is harshly limited by the redox homeostasis of tumor cells; especially the OH • is easily scavenged by glutathione (GSH) and the intracellular H2O2 level is insufficient in the tumor cells. Herein, we propose the Mn2+-menadione (also known as vitamin K3, MK3) cascade biocatalysis strategy to disrupt the redox homeostasis of tumor cells and induce a OH• storm, resulting in enhanced CDT effect. A nanoliposome encapsulating Mn-MK3 (Mn-MK3@LP) was prepared for the treatment of hepatic tumors in this study. After Mn-MK3@LPs were taken up by tumor cells, menadione could facilitate the production of intracellular H2O2 via redox cycling, and further the cytotoxic OH • burst was induced by Mn2+-mediated Fenton-like reaction. Moreover, high-valent manganese ions were reduced by GSH and the depletion of GSH further disrupted the redox homeostasis of tumor cells, thus achieving synergistically enhanced CDT. Overall, both cellular and animal experiments confirmed that the Mn-MK3@LP cascade biocatalysis nanoliposome exhibited excellent biosafety and tumor suppression efficacy. This study may provide deep insights for developing novel CDT-based strategies for tumor therapy.

Nanocatalysts for modulating antitumor immunity: fabrication, mechanisms and applications

Immunotherapy harnesses the inherent immune system in the body to generate systemic antitumor immunity, offering a promising modality for defending against cancer. However, tumor immunosuppression and evasion seriously restrict the immune response rates in clinical settings. Catalytic nanomedicines can transform tumoral substances/metabolites into therapeutic products in situ, offering unique advantages in antitumor immunotherapy. Through catalytic reactions, both tumor eradication and immune regulation can be simultaneously achieved, favoring the development of systemic antitumor immunity. In recent years, with advancements in catalytic chemistry and nanotechnology, catalytic nanomedicines based on nanozymes, photocatalysts, sonocatalysts, Fenton catalysts, electrocatalysts, piezocatalysts, thermocatalysts and radiocatalysts have been rapidly developed with vast applications in cancer immunotherapy. This review provides an introduction to the fabrication of catalytic nanomedicines with an emphasis on their structures and engineering strategies. Furthermore, the catalytic substrates and state-of-the-art applications of nanocatalysts in cancer immunotherapy have also been outlined and discussed. The relationships between nanostructures and immune regulating performance of catalytic nanomedicines are highlighted to provide a deep understanding of their working mechanisms in the tumor microenvironment. Finally, the challenges and development trends are revealed, aiming to provide new insights for the future development of nanocatalysts in catalytic immunotherapy.

Nanoparticles loaded withβ-Lapachone and Fe3+exhibit enhanced chemodynamic therapy by producing H2O2through cascaded amplification

The rapid, irreversible change of active Fe2+to inactive Fe3+after the Fenton reaction occurring reduces the chemodynamic therapeutic (CDT) effect. Therefore, manipulation of the tumor microenvironment to provide sufficient hydrogen peroxide (H2O2) while maintaining metal ion catalyst activity is critical for effective CDT. Here,β-Lapachone (LPC) was loaded by mesoporous silica nanoparticles (MSNs) and coated with polydopamine (PDA) to further chelate Fe3+and link aptamer AS1411, and a pH-controlled released, chemotherapy-photothermal therapy (PTT)-enhanced CDT-small molecule therapy combination drug delivery system with passive and active tumor targeting was engineered (designated asβ-LPC@MSN@PDA/Fe3+-AS1411, LMPFA). The results showed that LFMPA nanoparticles massively accumulated in tumor tissues to achieve tumor targeting through AS1411 mediating and enhanced permeability and retention (EPR) effect. Subsequently, PDA released Fe3+and LPC through acid response to exhibited CDT and chemotherapeutic therapy. Meanwhile, the photothermal effect of PDA promoted the release of LPC from the pores of MSN. LPC exerted chemotherapy effect and cyclically producing of H2O2by the catalysis of NQO1, which enhanced the CDT activated by Fe3+. In addition, while serving as a targeted ligand, AS1411 could also exhibit a small molecule therapeutic effect by binding to nucleoli of tumor cells. This unique nano delivery system achieved the combination of chemotherapy, PTT, enhanced CDT and small molecule therapy, and fought against malignant tumors synergistically through multi-target and multi-dimension.

An injectable PC10ARGD/Cu2+/DOX hydrogel for combined chemodynamic and chemotherapy of tumors

Nowadays, chemotherapy is a common clinical treatment for cancer, but it still faces many limitations and challenges. Therefore, the combination of chemotherapy and other treatments often enhances the effectiveness of treatments. Herein, an injectable hydrogel of PC10ARGD/Cu2+/DOX based on Cu2+, hydrophilic doxorubicin (DOX), and genetically engineered polypeptide PC10ARGD was prepared. First, Cu2+ was attached to the histidines in the PC10ARGD polypeptide by the coordination reaction to form PC10ARGD/Cu2+ hydrogel, then the PC10ARGD/Cu2+/DOX hydrogel was prepared by encapsulating the DOX into the PC10ARGD/Cu2+ hydrogel. The results of scanning electron microscopy showed that the PC10ARGD/Cu2+/DOX hydrogel displayed loose porous morphology. In vitro, reactive oxygen species production results showed that the PC10ARGD/Cu2+/DOX hydrogel could continuously produce ·OH in the presence of H2O2. In vitro MTT results showed that the PC10ARGD/Cu2+/DOX hydrogel had a good inhibitory effect on cell activity. Flow cytometry further confirmed the antitumor effect of the PC10ARGD/Cu2+/DOX hydrogel. In vivo experiment results showed that the tumor volume of mice treated with the PC10ARGD/Cu2+/DOX hydrogel was significantly inhibited compared with control groups, which was due to the combination of chemodynamic and chemotherapy. The results of body weight and blood analysis of mice showed that the PC10ARGD/Cu2+/DOX hydrogel possessed good biocompatibility.

Preparation and Characterization of Biocompatible Iron/Zirconium/Polydopamine/Carboxymethyl Chitosan Hydrogel with Fenton Catalytic Properties and Photothermal Efficacy

In recent years, multifunctional hydrogel nanoplatforms for the synergistic treatment of tumors have received a great deal of attention. Here, we prepared an iron/zirconium/polydopamine/carboxymethyl chitosan hydrogel with Fenton and photothermal effects, promising for future use in the field of synergistic therapy and prevention of tumor recurrence. The iron (Fe)-zirconium (Zr)@ polydopamine (PDA) nanoparticles were synthesized by a simple one-pot hydrothermal method using iron (III) chloride hexahydrate (FeCl₃•6H₂O), zirconium tetrachloride (ZrCl₄), and dopamine, followed by activation of the carboxyl group of carboxymethyl chitosan (CMCS) using 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N(4)-hydroxycytidine (NHS). Finally, the Fe-Zr@PDA nanoparticles and the activated CMCS were mixed to form a hydrogel. On the one side, Fe ions can use hydrogen peroxide (H₂O₂) which is rich in the tumor microenvironment (TME) to produce toxic hydroxyl radicals (•OH) and kill tumor cells, and Zr can also enhance the Fenton effect; on the other side, the excellent photothermal conversion efficiency of the incorporated PDA is used to kill tumor cells under the irradiation of near-infrared light. The ability of Fe-Zr@PDA@CMCS hydrogel to produce •OH and the ability of photothermal conversion were verified in vitro, and swelling and degradation experiments confirmed the effective release and good degradation of this hydrogel in an acidic environment. The multifunctional hydrogel is biologically safe at both cellular and animal levels. Therefore, this hydrogel has a wide range of applications in the synergistic treatment of tumors and the prevention of recurrence.

Delivery of miR-3529-3p using MnO2 -SiO2 -APTES nanoparticles combined with phototherapy suppresses lung adenocarcinoma progression by targeting HIGD1A

BACKGROUND

The present study aimed to investigate the function of miR-3529-3p in lung adenocarcinoma and MnO2 -SiO2 -APTES (MSA) as a promising multifunctional delivery agent for lung adenocarcinoma therapy.

METHODS

Expression levels of miR-3529-3p were evaluated in lung carcinoma cells and tissues by qRT-PCR. The effects of miR-3529-3p on apoptosis, proliferation, metastasis and neovascularization were assessed by CCK-8, FACS, transwell and wound healing assays, tube formation and xenografts experiments. Luciferase reporter assays, western blot, qRT-PCR and mitochondrial complex assay were used to determine the targeting relationship between miR-3529-3p and hypoxia-inducible gene domain family member 1A (HIGD1A). MSA was fabricated using MnO2 nanoflowers, and its heating curves, temperature curves, IC50, and delivery efficiency were examined. The hypoxia and reactive oxygen species (ROS) production was investigated by nitro reductase probing, DCFH-DA staining and FACS.

RESULTS

MiR-3529-3p expression was reduced in lung carcinoma tissues and cells. Transfection of miR-3529-3p could promote apoptosis and suppress cell proliferation, migration and angiogenesis. As a target of miR-3529-3p, HIGD1A expression was downregulated, through which miR-3529-3p could disrupt the activities of complexes III and IV of the respiratory chain. The multifunctional nanoparticle MSA could not only efficiently deliver miR-3529-3p into cells, but also enhance the antitumor function of miR-3529-3p. The underlying mechanism may be that MSA alleviates hypoxia and has synergistic effects in cellular ROS promotion with miR-3529-3p.

CONCLUSIONS

Our results establish the antioncogenic role of miR-3529-3p, and demonstrate that miR-3529-3p delivered by MSA has enhanced tumor suppressive effects, probably through elevating ROS production and thermogenesis.

Multi-stimuli responsive Cu-MOFs@Keratin drug delivery system for chemodynamic therapy

Although the potential of metal-organic framework (MOF) nanoparticles as drug delivery systems (DDS) for cancer treatment has been established by numerous studies, their clinical applications are still limited due to relatively poor biocompatibility. We fabricated a multifunctional Cu-MOFs@Keratin DDS for loaded drug and chemodynamic therapy (CDT) against tumor cells. The Cu-MOFs core was prepared using a hydrothermal method, and then loaded with the anticancer drug DOX and wrapped in human hair keratin. The Cu-MOFs@Keratin was well characterized by transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and X-ray photoelectron spectroscopy (XPS). Characterization and pharmacokinetic studies of Cu-MOFs@Keratin were performed in vitro and in vivo. The keratin shell reduced the cytotoxicity and potential leakage of Cu-MOFs to normal cells, and allowed the drug-loaded nanoparticles to accumulate in the tumor tissues through enhanced permeability and retention effect (EPR). The particles entered the tumor cells via endocytosis and disintegrated under the stimulation of intracellular environment, thereby releasing DOX in a controlled manner. In addition, the Cu-MOFs produced hydroxyl radicals (·OH) by consuming presence of high intracellular levels of glutathione (GSH) and H₂O₂, which decreased the viability of the tumor cells.