Constructing Spatiotemporally Controllable Biocatalytic Cascade in RBC Nanovesicles for Precise Tumor Therapy Based on Reversibly Induced Glucose Oxidase-Magnetoferritin Dimers.

Chemodynamic therapy is a promising tumor treatment strategy. However, it remains a great challenge to overcome the unavoidable off-target damage to normal tissues. In this work, it is discovered that magnetoferritin (M-HFn, biomimic peroxidase) can form nanocomplexes with glucose oxidase (GOD) in the presence of glucose, thus inhibiting the enzyme activity of GOD. Interestingly, GOD&M-HFn (G-M) nanocomplexes can dissociate under near-infrared (NIR) laser, reactivating the enzyme cascade. Based on this new finding, a spatiotemporally controllable biocatalytic cascade in red blood cell (RBC) nanovesicles (G-M@RBC-A) is fabricated for precise tumor therapy, which in situ inhibits enzyme cascade between GOD and M-HFn during blood circulation and reactivates the cascade activity in tumor site by NIR laser irradiation. In RBC nanovesicles, GOD is grabbed by M-HFn to form G-M nanocomplexes in the presence of glucose, thus inhibiting the Fenton reaction and reducing side effects. However, after NIR laser irradiation, G-M nanocomplexes are spatiotemporally dissociated and the cascade activity is reactivated in the tumor site, initiating reactive oxygen species damage to cancer cells in vivo. Therefore, this work provides new insight into the fabrication of spatiotemporally controllable biocatalytic cascade for precise cancer therapy in the future.

Artificial Nanoplatelets Depend on Size for Precisely Inducing Thrombosis in Tumor Vessels.

Due to the heterogeneity of a tumor, the tumor vascular interruption-based therapy has become an ideal treatment strategy. Herein, artificial nanoplatelets are reported to induce selective thrombosis in tumor vessels, which can achieve rapid and large-scale necrosis of tumor cells. For one, the nanoplatelets are exploited to specially release thrombin into target regions without affecting the established coagulation factors system. For another, the thrombin elicits vascular infarction to provide tumor-ablation effects. More importantly, the size-dependent effect of nanoplatelets (with diameters of 200, 400, and 800 nm) in vivo on blocking the tumor vessels is evaluated. The results show that the nanoplatelets from nanometer to submicron have achieved different biodistribution and therapeutic effects through the vascular transport. Notably, 400 nm scale nanoplatelets can induce thrombosis in tumor vessels and achieve 83% of the tumor elimination rate, thus manifesting the effectiveness of anti-tumor strategy compared with the other two scales of nanoplatelets (200 and 800 nm). These findings highlight the need of concern about nanoparticle size, providing a promising strategy for the future design of advanced vascular targeting reagents and the clinical translation of tumor vascular interruption-based therapy.

Multifunctional Parachute-like Nanomotors for Enhanced Skin Penetration and Synergistic Antifungal Therapy.

Fungal infections in skin are extremely stubborn and seriously threaten human health. In the process of antifungal treatment, it is a huge challenge that the stratum corneum of the skin and fungal biofilms form the drug transport barrier. Herein, a near-infrared (NIR) laser-propelled parachute-like nanomotor loaded with miconazole nitrate (PNM-MN) is fabricated to enhance transdermal drug delivery for synergistic antifungal therapy. Due to asymmetrically spatial distribution, PNM can generate a thermal gradient under NIR laser irradiation, thereby forming effective self-thermophoretic propulsion. The self-propulsion and photothermal effect of PNM play a major role in promoting fungal uptake and biofilm adhesion. Moreover, under laser irradiation, PNM-MN can obliterate plankton Candida albicans and mature biofilms by combining pharmacological therapy and photothermal therapy. More importantly, the drug effectively penetrated the skin to reach the infected site using the nanomotor with NIR laser irradiation. Moreover, PNM-MN with a NIR laser can eradicate fungal infections caused by C. albicans and facilitate the abscess ablation, showing a therapeutic effect in vivo better than that of PNM with a NIR laser or free MN groups, with negligible histological toxicity. Taken together, NIR laser-propelled PNM-MN, as an antifungal nanoagent, provides a promising strategy for transdermal delivery and antifungal therapy.

Artificial M2 macrophages for disease-modifying osteoarthritis therapeutics.

Osteoarthritis (OA) is one of the most common joint diseases worldwide and the focus is shifting to disease prevention and the pharmaceutical and surgical treatment of early OA. However, at present few have proven ability to block or delay the progression of OA. Nevertheless, M2 macrophages present an anti-inflammatory function and promote cartilage repair, thereby alleviating OA in mice. However, it is a significant challenge to regulate the helpful secretion of M2 macrophages on demand toward disease-modifying osteoarthritis therapeutics. Here, artificial M2 macrophage (AM2M) with yolk-shell structure was proposed and fabricated to enhance the therapeutic efficacy of M2 macrophages in the treatment of OA. AM2M was composed of macrophage membrane as "shell" and inflammation-responsive nanogel as "yolk". The nanogel was prepared via physical interaction of gelatin and chondroitin sulfate (ChS) through ionic bond and hydrogen bond, achieving burst release to down-regulate inflammation during acute flares and sustainable release to repair cartilage during low inflammatory activity. Furthermore, AM2M exhibited the targeting and long-term residence in the inflamed area and blocked the immune stimulation of macrophages by ChS. Therefore, our fabrication provided a new insight that artificial M2 macrophages are expected to break a vicious and self-perpetuating cycle of OA.

Advanced biomimetic nanoreactor for specifically killing tumor cells through multi-enzyme cascade.

Although the enzyme catalytic nanoreactors reported so far have achieved excellent therapeutic efficacy, how to accurately exert enzyme activity in the tumor microenvironment to specifically kill tumor cells and avoid systemic oxidative damage would be an inevitable challenge for catalytic nanomedicine. At the present study, we fabricate an advanced biomimetic nanoreactor, SOD-Fe0@Lapa-ZRF for tumor multi-enzyme cascade delivery that combined specifically killing tumor cells and protect cells from oxidative stress. Methods: We first synthesized the FeNP-embedded SOD (SOD-Fe0) by reduction reaction using sodium borohydride. Next, SOD-Fe0 and Lapa cargo were encapsulated in ZIF-8 by self-assembly. In order to protect the cargo enzyme from digestion by protease and prolong blood circulating time, SOD-Fe0@Lapa-Z was further cloaked with RBC membrane and functionalized with folate targeting, resulting in the final advanced biomimetic nanoreactor SOD-Fe0@Lapa-ZRF. Results: Once internalized, ZIF-8 achieves pH-triggered disassembly in weakly acidic tumor microenvironment. The released SOD-Fe0 and Lapa were further endocytosed by tumor cells and the Lapa produces superoxide anion (O2-•) through the catalysis of NQO1 that is overexpressed in tumor cells, while O2-• is converted to H2O2 via SOD. At this time, the released ferrous ions from SOD-Fe0 and H2O2 are further transformed to highly toxic hydroxyl radicals (•OH) for specifically killing tumor cells, and there was no obvious toxicological response during long-term treatment. Importantly, SOD-Fe0@Lapa-ZRF enhanced the normal cell's anti-oxidation ability, and thus had little effect on the secretion of TNF-α, IL-6 and IL-1ß pro-inflammatory cytokines, while effectively reversed the decreased activity of T-SOD and GSH-Px and remained stable MDA content after tumor treatment. In vitro and in vivo results indicate that the tumor microenvironment-responsive release multi-enzyme cascade have high tumor specificity and effective anti-tumor efficacy, and can protect cells from oxidative stress damage. Conclusion: The biomimetic nanoreactor will have a great potential in cancer nanomedicine and provide a novel strategy to regulate oxidative stress.

In Situ Cell Membrane Fusion for Engineered Tumor Cells by Worm-like Nanocell Mimics.

Cell-based therapy is a promising clinic strategy to address many unmet medical needs. However, engineering cells faces some inevitable challenges, such as limited sources of cells, cell epigenetic alterations, and short shelf life during in vitro culture. Here, the worm-like nanocell mimics are fabricated to engineer effectively the tumor cells in vivo through the synergistic combination of nongenetic membrane surface engineering and inside encapsulation using in situ cell membrane fusion. The specific targeting and deformability of nanocell mimics play a vital role in membrane fusion mechanisms. The engineered primary tumor cells improved the tumor penetration of therapeutic cargoes via extracellular vesicles, while the engineered circulating tumor cells (CTCs) can capture the homologous cells to form the CTC clusters in the bloodstream and eliminate the CTC clusters in the lung, thus achieving excellent antitumor and antimetastasis efficacy. Above all, we find an intriguing phenomenon, in situ cell membrane fusion by the worm-like nanocell mimics, and our finding of in situ cell membrane fusion inspired us to engineer tumor cells in vivo. The present study would be a particularly meaningful strategy to directly engineer cells in vivo for cell-based therapy.