Current wound sealing systems such as nanoparticle‐based gluing of tissues allow almost immediate wound sealing. The assistance of a laser beam allows the wound sealing with higher controllability due to the collagen fiber melting which is defined by loss of tertiary protein structure and restoration upon cooling. Usually one employs dyes to paint onto the wound, if water absorption bands are absent. In case of strong bleeding or internal wounds such applications are not feasible due to low welding depth in case of water absorption bands, dyes washing off, or the dyes becoming diluted within the wound. One possible solution of these drawbacks is to use autonomously movable particles composing of biocompatible gold and magnetite nanoparticles and biocompatible polyelectrolyte complexes. In this paper a proof of principle study is presented on the utilization of thermophoretic Janus particles and capsules employed as dyes for infrared laser‐assisted tissue welding. This approach proves to be efficient in sealing the wound on the mouse in vivo. The temperature measurement of single particle level proves successful photothermal heating, while the mechanical characterizations of welded liver, skin, and meat confirm mechanical restoration of the welded biological samples.

A magnetically powered, star‐shaped poly(vinylalcohol)/alginate (PVA/ALG) hydrogel microswimmer is described as a biodegradable motile vehicle for potential biomedical applications. The star‐shaped microswimmer is fabricated by the addition of a mixture containing PVA, ALG, and magnetic nanoparticles in the optimal ratio into the designed star‐shape silicon pattern and subsequent gelation of the mixture inside the pattern. This hydrogel microswimmer displays efficient and controllable propulsion in biological media under a vertical rotating magnetic field. Such star‐shaped hydrogel microswimmers have excellent biodegradability and mechanical capability and thus show promise in biomedical applications such as drug transport and surgery.

As a less O 2 -dependent photodynamic therapy (PDT), type I PDT is an effective approach to overcome the hypoxia-induced low efficiency against solid tumors. However, the commonly used metal-involved agents suffer from the long-term biosafety concern. Herein, a metal-free type I photosensitizer, N-doped carbon dots/mesoporous silica nanoparticles (NCDs/ MSN, ≈40 nm) nanohybrid with peroxidase (POD)-like activity for synergistic PDT and enzyme-activity treatment, is developed on gram scale via a facile one-pot strategy through mixing carbon source and silica precursor with the assistance of template. Benefiting from the narrow bandgap (1.92 eV) and good charge separation capacity of NCDs/MSN, upon 640 nm light irradiation, the excited electrons in the conduction band can effectively generate O 2 •− by reduction of dissolved O 2 via a one-electron transfer process even under hypoxic conditions, inducing apoptosis of tumor cells. Moreover, the photoinduced O 2 •− can partially transform into more toxic • OH through a two-electron reduction. Moreover, the POD-like activity of NCDs/MSN can catalyze the endogenous H 2 O 2 to • OH in the tumor microenvironment, further synergistically ablating 4T1 tumor cells. Therefore, a mass production way to synthesize a novel metal-free type I photosensitizer with enzymemimic activity for synergistic treatment of hypoxic tumors is provided, which exhibits promising clinical translation prospects.

This communication sheds light on the production method and motion patterns of autonomous moving bubble propelled two dimensional micro-plate motors. The plate motors are produced by the well-known layer-by-layer self-assembly process in combination with micro-contact printing. The motion analysis covers instances of oscillating bubble development on one or more nucleation sites, which influence the motion speed and direction.