We describe fuel-free, near-infrared (NIR)-driven Janus mesoporous silica nanoparticle motors (JMSNMs) with diameters of 50, 80, and 120 nm. The Janus structure of the JMSNMs is generated by vacuum sputtering of a 10 nm Au layer on one side of the MSNMs. Upon exposure to an NIR laser, a localized photothermal effect on the Au half-shells results in the formation of thermal gradients across the JMSNMs; thus, the generated self-thermophoresis can actively drive the nanomotors to move at an ultrafast speed, for instance, up to 950 body lengths/s for 50 nm JMSNMs under an NIR laser power of 70.3 W/cm(2). The reversible "on/off" motion of the JMSNMs and their directed movement along the light gradient can be conveniently modulated by a remote NIR laser. Moreover, dynamic light scattering measurements are performed to investigate the coexisting translational and rotational motion of the JMSNMs in the presence of both self-thermophoretic forces and strong Brownian forces. These NIR-powered nanomotors demonstrate a novel strategy for overcoming the necessity of chemical fuels and exhibit a significant improvement in the maneuverability of nanomotors while providing potential cargo transportation in a biofriendly manner.

Engineering natural macrophage cell membrane-camouflaged mesoporous silica nanocapsules can reduce the arrested percentage of immune cells and tissues, effectively prolong the survival time of nanoparticles in blood circulation system, and improve the accumulation in tumor.

Macrophage cell membrane (MPCM)-camouflaged gold nanoshells (AuNS) that can serve as a new generation of photothermal conversion agents for in vivo photothermal cancer therapy are presented. They are constructed by the fusion of biocompatible AuNSs and MPCM vesicles. The resulting MPCM-coated AuNSs exhibited good colloidal stability and kept the original near-infrared (NIR) adsorption of AuNSs. Because AuNS carried high-density coverage of MPCMs, the totally functional portions of macrophage cells membrane were grafted onto the surface of AuNSs. This surface functionalization provided active targeting ability by recognizing tumor endothelium and thus improved tumoritropic accumulation compared to the red blood cell membrane-coating approach. These biomimetic nanoparticles significantly enhance in vivo blood circulation time and local accumulation at the tumor when administered systematically. Upon NIR laser irradiation, local heat generated by the MPCM-coated AuNS achieves high efficiency to suppress tumor growth and selectively ablate cancerous cells within the illuminated zone. Therefore, MPCM-coated AuNSs remained the natural properties of their source cells, which may improve the efficacy of photothermal therapy modulated by AuNSs and other noble-metal nanoparticles.

We report the construction of erythrocyte membrane-cloaked Janus polymeric motors (EM-JPMs) which are propelled by near-infrared (NIR) laser irradiation and are successfully applied in thrombus ablation. Chitosan (a natural polysaccharide with positive charge, CHI) and heparin (glycosaminoglycan with negative charge, Hep) were selected as wall materials to construct biodegradable and biocompatible capsules through the layer-by-layer self-assembly technique. By partially coating the capsule with a gold (Au) layer through sputter coating, a NIR-responsive Janus structure was obtained. Due to the asymmetric distribution of Au, a local thermal gradient was generated upon NIR irradiation, resulting in the movement of the JPMs through the self-thermophoresis effect. The reversible “on/off” motion of the JPMs and their motile behavior were easily tuned by the incident NIR laser intensity. After biointerfacing the Janus capsules with an erythrocyte membrane, the EM-JPMs displayed red blood cell related properties, which enabled them to move efficiently in relevant biological environments (cell culture, serum, and blood). Furthermore, this therapeutic platform exhibited excellent performance in ablation of thrombus through photothermal therapy. As man-made micromotors, these biohybrid EM-JPMs hold great promise of navigating in vivo for active delivery while overcoming the drawbacks of existing synthetic therapeutic platforms. We expect that this biohybrid motor has considerable potential to be widely used in the biomedical field.

We report a near-infrared (NIR) light-powered Janus mesoporous silica nanomotor (JMSNM) with macrophage cell membrane (MPCM) cloaking that can actively seek cancer cells and thermomechanically percolate cell membrane. Upon exposure to NIR light, a heat gradient across the Janus boundary of the JMSNMs is generated by the photothermal effect of the Au half-shells, resulting in a self-thermophoretic force that propels the JMSNMs. In biological medium, the MPCM camouflaging can not only prevent dissociative biological blocks from adhering to JMSNMs but also improve the seeking sensitivity of the nanomotors by specifically recognizing cancer cells. The biofriendly propulsion and recognition capability enable JMSNMs to achieve the active seeking and bind to the membrane of cancer cells. Subsequent illumination with NIR then triggers the photothermal effect of MPCM@JMSNMs to thermomechanically perforate the cytomembranes for guest molecular injection. This approach integrates the functions of active seeking, cytomembranes perforating, and thermomechanical therapy in nanomotors, which may pave the way to apply self-propelled motors in biomedical fields.