Bionic micro/nanomotor systems, which combine biomimetic design with the motion performance, have shown great potential in many fields. However, so far, it remains a challenge to design and fabricate biomimetic micro/nanomotors with high flexibility to perform complex tasks in complicated and changeable environments. In this work, inspired by the suckerfishes (guest)–shark (host) motion behavior, we designed and prepared a kind of intelligent two-stage micro@nanomotor with weak acid-triggered release of nanomotor. When the suckerfishes, who clinged to the surface of large fish or the bottom of boat and marched with them, reached bait-rich waters, they detached from the host to engage in foraging behavior. Inspired by the suckerfishes–shark system and the coordinated bond interaction, a large amount of Janus Au-Pt nanomotors with hydrogen peroxide (H₂O₂)-driven capacity, analogous to suckerfishes, were attached onto immovable yolk–shell structured polydopamine-mesoporous silica (PDA-MS) micromotor as the host to create two-stage PDA-MS@Au-Pt micro@nanomotor. PDA-MS@Au-Pt micro@nanomotor moved directionally by self-thermophoresis under the propulsion of near infrared ray (NIR) light with low power density. When the PDA-MS@Au-Pt entered into the weak acidic environment formed by a low concentration of H₂O₂, most small Au-Pt nanomotors were detached from the surface of PDA-MS due to the weak acidic sensitivity of the coordinated bond, and then performed self-diffusiophoresis in the environment containing a low concentration of H₂O₂ as a chemical fuel. This bionic intelligent system, which consists of a large-sized micromotor and lots of small-sized nanomotors, should provide a new insight for active two-stage cargo delivery.

Most of the current nanomedicine-based treatments for critical limb ischemia (CLI) only aim at promoting angiogenesis, ignoring the negative influence on the therapeutic effects caused by the complex pathological micro-environment of ischemic tissue. Herein, near-infrared (NIR) light-driven metal ion (Cu²⁺)-loaded polydopamine (PDA) nanomotors (JMPN@Cu²⁺) is designed and prepared. Due to the good antioxidant and anti-inflammatory activities of PDA, JMPN@Cu²⁺ exhibits excellent biocompatibility and significantly improves the ischemic micro-environment. Additionally, based on superior photothermal conversion effect and jellyfish-like structure, the nanomotors are quickly propelled under NIR laser with low energy intensity to acquire the ability of movement and facilitate intracellular uptake of JMPN@Cu²⁺ by endothelial cells, resulting in the enhanced pro-angiogenic effect of Cu²⁺. Moreover, in vivo experimental findings show that JMPN@Cu²⁺ combined with NIR irradiation can successfully accelerate blood flow recovery and improve muscle repair. Taking these results together, this kind of nanomotor can promote angiogenesis along with ischemic micro-environment amelioration, holding great potential applications for the treatment of limb ischemia.

Yolk@shell mesoporous nanoparticles have received close attention due to their controllable structures and integrated functions. However, most yolk@shell nanosystems lack self-propulsion. Herein, yolk@spiky-shell structured carbon@silica nanomotors are fabricated with near-infrared (NIR) light self-thermophoretic propulsion as lipase nanocarriers for fuel-free triglyceride degradation. The light propulsion accelerates the accumulation of nanomotors on the droplet interface, and the efficient lipase loading further facilitates the rapid degradation of tributyrin droplets. By adjusting the yolk and spiky structure, the obtained semi-yolk@spiky-shell structured nanomotors exhibit the highest capacity of lipase (442 mg/g) and the highest light-driven diffusion coefficient (ca. 55% increase under 2 W/cm² irradiation), thus improving the degradation efficiency of triglyceride (93.1% under NIR light vs. 66.7% without NIR light within 20 min). This work paves the way to rationally design yolk@shell structured nanomotors for diverse applications.