Microplastics can traverse human physiological barriers, infiltrate and accumulate in critical organs and tissues (e.g., brain, blood, and heart) over extended periods, posing significant threats to human health. While microplastic degradation in aquatic environments (e.g., contaminated water) has been extensively studied, research on bloodstream microplastic degradation remains largely unexplored, leaving a critical gap in remediation strategies. To fill this gap, we pioneered the fabrication of biocompatible magnetically driven Fe3O4@polydopamine (PDA)-lipase microrobots by functionalizing Fe3O4 nanoparticles with PDA and lipase for blood-borne microplastic degradation. In vitro blood experiments confirmed that this platform holds promise for future detoxification of circulating microplastics. The microrobots integrate synergistic functions: Fe3O4 enables magnetic responsiveness for precise movement control; PDA provides adhesive properties for robust microplastic binding; and lipase mediates enzymatic microplastic degradation. Guided by an external rotating magnetic field, the microrobots achieve targeted microplastic capture and in situ enzymatic degradation in blood without releasing harmful substances, addressing a pivotal safety concern for biomedical applications. Performance evaluations showed ~25% microplastic degradation efficiency in blood after 7 days of incubation. Additionally, the microrobots can be effectively recycled via magnetic separation postdegradation, reducing residuals and improving practicality. Hemolysis assays using rabbit blood and toxicity evaluations using human umbilical vein endothelial cells and immunofluorescence experiments confirmed their excellent biocompatibility and immunogenicity, an indispensable prerequisite for potential in vivo translation. As a proof-of-concept study, this work provides a promising biocompatible approach for blood microplastic degradation and clearance, simultaneously overcoming the technical challenge of blood-specific targeted degradation and meeting safety requirements, thus laying a foundation for microrobot-based mitigation of microplastic health hazards.

Postoperative metastatic recurrence and wound infection pose significant threats to survival after breast cancer (BC) surgery. To address these challenges, an ideal therapeutic strategy should incorporate minimally invasive multifunctional biomaterials capable of simultaneously preventing tumor recurrence and promoting wound healing. Herein, we report a novel 2-stage microneedle (MN) platform engineered via the integration of nanotechnology and tumor-microenvironment-responsive design. This system is fabricated using a stepwise casting strategy and features tip-to-base architecture equipped with on-demand smart nanocarriers for synergistic therapy against postoperative BC recurrence and wound complications. The MN consists of a photo-crosslinked hydrogel tip encapsulating chitosan-based self-assembled nanocarriers and a gelatin–polydopamine hydrogel backing layer. Owing to its hierarchical structural design, the MN exhibits excellent mechanical strength with a compression force of up to 4.48 N per needle, sufficient for efficient skin penetration. Moreover, the platform demonstrates sustained pH-responsive behavior and specific tumor microenvironment targeting, enabling controlled drug release. The MN also displays outstanding biocompatibility and multifunctional therapeutic properties, including antibacterial adhesion, self-healing capability, swelling performance, and biodegradability, greatly broadening its potential as a precision medicine tool. Both in vitro and in vivo studies validated the robust and integrated therapeutic efficacy of the MN system in suppressing metastatic BC recurrence and enhancing infected wound healing. This work provides a significant advance in the design of smart 2-stage MNs with comprehensive functionality for minimally invasive adjuvant therapy after BC surgery.

Wound infection remains a critical challenge in clinical practice, frequently leading to delayed healing and increased risks of complications. Herein, we first screened silver nanowires (Ag NWs) with excellent antibacterial, antioxidant, and cell migration-promoting properties from silver-based nanomaterials with distinct dimensional morphologies, including Ag nanowires (NWs), Ag nanoparticles (NPs), nitrogen-doped graphene (NGC) supported Ag nanoparticles (Ag NPs/NGC), and Ag single atoms (Ag1/NGC), as candidates for wound dressing applications. To further enhance therapeutic efficacy, we developed a composite film (Ag NWs@SF) by incorporating Ag NWs into silk fibroin (SF). Under near-infrared light, it generates localized heat to provide a synergistic antibacterial effect to accelerate wound healing. Interestingly, the robust electrical stimulation responsiveness of Ag NWs endows the film with the potential for real-time wound monitoring. This composite film demonstrates outstanding antibacterial activity against common wound pathogens, which maintains biocompatibility and fostering tissue regeneration. In vitro and in vivo studies reveal that the Ag NWs@SF membrane accelerates wound closure by stimulating cell migration, mitigating bacterial infection, and reducing inflammatory responses. These findings offer a novel approach for effective clinical wound management, potentially addressing the unmet clinical needs in infection combating and wound healing promoting.