Self-Propelled Nanojets for Fenton Catalysts Based on Halloysite with Embedded Pt and Outside-Grafted Fe3O4

H2O2 self-supplying nanoparticles for chemodynamic and synergistic photodynamic therapy to augment cGAS/STING activation

Triple negative breast cancer (TNBC) characterized by easy metastasis and poor prognosis is one of the most intractable malignancies. Immunotherapy, as one of the most promising treatments for TNBC, has limited efficacy due to the immunosuppressive tumor microenvironment (ITME). Herein, copper peroxide nanodots (CPN) and chlorin e6 (Ce6) were encapsulated in a liposome with the cinnamaldehyde dimer (CDC) to improve the ITME and enhance anti-tumor activity. To be specific, after endocytosis by cancer cells, Ce6-CPN@CDC released H2O2 and Cu2+ in the acidic tumor environment. Next, Cu2+ was reduced by GSH to Cu+, and Cu+ catalyzed H2O2 to produce ˙OH for chemodynamic therapy (CDT). Meanwhile, under near-infrared laser irradiation, singlet oxygen (1O2) can be generated from the released Ce6, exerting a robust photodynamic anticancer effect. In addition, the high ROS-induced ICD and direct DNA damage activated the cGAS-STING pathway, which significantly improved the ITME to amplify the immunostimulatory effect. In vitro and in vivo studies showed that the Ce6-CPN@CDC nanoparticle could realize effective tumor inhibition with minimal toxic side effects. Together, Ce6-CPN@CDC provides a paradigm for combining PDT and CDT to activate immunotherapy and provides a new strategy to improve the efficacy of multimodal synergistic therapy for TNBC.

A Lifetime of Catalytic Micro-/Nanomotors

Microscopic and nanoscopic motors, often referred to as micro-/nanomotors, are autonomous devices capable of converting chemical energy from their surroundings into mechanical motion or forces necessary for propulsion. These devices draw inspiration from natural biomolecular motor proteins, and in recent years, synthetic micro-/nanomotors have attracted significant attention. Among these, catalytic micro-/nanomotors have emerged as a prominent area of research. Despite considerable progress in their design and functionality, several obstacles remain, especially regarding the development of biocompatible materials and fuels, the integration of intelligent control systems, and the translation of these motors into practical applications. Thus, a comprehensive understanding of the current advancements in catalytic micro-/nanomotors is critical. This review aims to provide an in-depth overview of their fabrication techniques, propulsion mechanisms, key influencing factors, control methodologies, and potential applications. Furthermore, we examine their physical and hydrodynamic properties in fluidic environments to optimize propulsion efficiency. Lastly, we evaluate their biosafety and biocompatibility to facilitate their use in biological systems. The review also addresses key challenges and proposes potential solutions to advance their practical deployment.

Metal-Organic Framework-Based Micro-/Nanomotors for Wastewater Remediation

Micro-/nanomotors (MNMs) in water remediation have garnered significant attention over the past two decades. More recently, metal-organic framework-based micro-/nanomotors (MOF-MNMs) have been applied for environmental remediation; however, a comprehensive summary of research in this research area is yet to be reported. Herein, a review is presented to cover the recent advances in MOF-MNMs and their various applications in wastewater remediation. The review presents a comprehensive introduction to MNMs, including different propulsion approaches, fabrication, and functionalization strategies, in addition to the unique features of MOF-MNMs. The conception and various synthetic routes of MOF-MNMs are extensively covered and the implementation of MOF-MNMs in water-related applications, including adsorption, degradation, sensing, and disinfection of different pollutants, is in depth discussed. Meanwhile, the propulsion and mechanism of action behind each MOF-MNM are systematically studied. Finally, the review provides insights into the challenges and perspectives to build more effective MOF-MNMs to cover versatile applications for wastewater treatment.

Hyaluronic acid coated mesoporous carbon-copper peroxide for H2O2 self-supplying and near-infrared responsive multi-mode breast cancer oncotherapy

It is challenging to develop the synergistic intelligent therapeutic nanoplatform to cure cancer. In the present study, a novel nanotherapeutic platform was constructed for H₂O₂ self-supplying and multimodal breast cancer therapy. In which, copper peroxide nanoparticles (CP NPs) were adsorbed on the surface of mesoporous carbon nanospheres (MCN) through electrostatic attraction, followed by loading doxorubicin (DOX) into the nanocomposite (MCN-CP) and coating hyaluronic acid (HA) on the surface, the DOX/MCN-CP-HA nanoplatform was obtained. In the system, the MCN not only possessed a high DOX loading capacity, but produced excellent photothermal therapy (PTT) effect. Importantly, the ultra-small CP NPs as the Fenton agent not only could selectively self-supplying H₂O₂ in acidic condition, but simultaneously release Cu²⁺ to catalyze the production of ·OH in the presence of H₂O₂. Meantime, the resulting Cu²⁺ possessed GSH-elimination property, which afforded enhanced chemodynamic therapy (CDT). Furthermore, the outer layer HA targeted to CD44 and achieved breast cancer cell targeting. The elevated temperature from PTT and acidic tumor microenvironment accelerated the release of DOX, which enabled DOX/MCN-CP-HA as an intelligent CDT-PTT-chemotherapy synergistic nanoplatform. In vitro and in vivo pharmacodynamic evaluations confirmed the potential of the nanoplatform for CDT-PTT-chemotherapy synergistic oncotherapy of breast cancer.

Halloysite-Based Nanorockets with Light-Enhanced Self-Propulsion for Efficient Water Remediation

Halloysite-based tubular nanorockets with chemical-/light-controlled self-propulsion and on-demand acceleration in velocity are reported. The nanorockets are fabricated by modifying halloysite nanotubes with nanoparticles of silver (Ag) and light-responsive α-Fe₂O₃ to prepare a composite of Ag-Fe₂O₃/HNTs. Compared to the traditional fabrication of tubular micro-/nanomotors, this strategy has merits in employing natural clay as substrates of an asymmetric tubular structure, of abundance, and of no complex instruments required. The velocity of self-propelled Ag-Fe₂O₃/HNTs nanorockets in fuel (3.0% H₂O₂) was ca. 1.7 times higher under the irradiation of visible light than that in darkness. Such light-enhanced propulsion can be wirelessly modulated by adjusting light intensity and H₂O₂ concentration. The highly repeatable and controlled "weak/strong" propulsion can be implemented by turning a light on and off. With the synergistic coupling of the photocatalysis of the Ag-Fe₂O₃ heterostructure and advanced oxidation in H₂O₂/visible light conditions, the Ag-Fe₂O₃/HNTs nanorockets achieve an enhanced performance of wastewater remediation. A test was done by the catalytic degradation of tetracycline hydrochloride. The light-enhanced propulsion is demonstrated to accelerate the degradation kinetics dramatically. All of these results illustrated that such motors can achieve efficient water remediation and open a new path for the photodegradation of organic pollutions.