The use of enzyme catalysis to power of micro-and nanomotors exploiting biocompatible fuels has opened new ventures for biomedical applications such as the active transport and delivery of specific drugs to the site of interest. Here, urease powered nanomotors (nanobots) for the doxorubicin (Dox) anti-cancer drug loading, release and efficient delivery to cells are presented.These mesoporous silica-based core-shell nanobots are able to self-propel in ionic media, as confirmed by optical tracking and dynamic light scattering analysis. A four-fold increase in drug release is achieved by nanobots after 6 hours compared to their passive counterparts.2 Furthermore, the use of Dox-loaded nanobots presents an enhanced anti-cancer efficiency towards HeLa cells, which arises from a synergistic effect of the enhanced drug release and the ammonia produced at high concentrations of urea substrate. A higher content of Dox inside HeLa cells is detected after 1, 4, 6 and 24 hours incubation with active nanobots compared to passive dox-loaded nanoparticles. The improvement in drug delivery efficiency achieved by enzyme-powered nanobots may hold potential towards their use in future biomedical applications such as the substrate-triggered release of drugs in target locations.

The integration of biological systems into robotic devices might provide them with capabilities acquired from natural systems and significantly boost their performance. These abilities include real‐time bio‐sensing, self‐organization, adaptability, or self‐healing. As many muscle‐based bio‐hybrid robots and bio‐actuators arise in the literature, the question of whether these features can live up to their expectations becomes increasingly substantial. Herein, the force generation and adaptability of skeletal‐muscle‐based bio‐actuators undergoing long‐term training protocols are analyzed. The 3D‐bioprinting technique is used to fabricate bio‐actuators that are functional, responsive, and have highly aligned myotubes. The bio‐actuators are 3D‐bioprinted together with two artificial posts, allowing to use it as a force measuring platform. In addition, the force output evolution and dynamic gene expression of the bio‐actuators are studied to evaluate their degree of adaptability according to training protocols of different frequencies and mechanical stiffness, finding that their force generation could be modulated to different requirements. These results shed some light into the fundamental mechanisms behind the adaptability of muscle‐based bio‐actuators and highlight the potential of using 3D bioprinting as a rapid and cost‐effective tool for the fabrication of custom‐designed soft bio‐robots.

Light-regulated drugs allow remotely photoswitching biological activity and enable plausible therapies based on small molecules. However, only freely diffusible photochromic ligands have been shown to work directly in endogenous receptors and methods for covalent attachment depend on genetic manipulation. Here we introduce a chemical strategy to covalently conjugate and photoswitch the activity of endogenous proteins and demonstrate its application to the kainate receptor channel GluK1. The approach is based on photoswitchable ligands containing a short-lived, highly reactive anchoring group that is targeted at the protein of interest by ligand affinity. These targeted covalent photoswitches (TCPs) constitute a new class of light-regulated drugs and act as prosthetic molecules that photocontrol the activity of GluK1-expressing neurons, and restore photoresponses in degenerated retina. The modularity of TCPs enables the application to different ligands and opens the way to new therapeutic opportunities.

We've combined the pharmacological properties of the dynamin inhibitor dynasore and the photochromic properties of an azobenzene group, to obtain the first light-regulated small-molecule inhibitor of endocytosis.

Correction for ‘Photoswitchable dynasore analogs to control endocytosis with light’ by Núria Camarero et al., Chem. Sci., 2020, 11, 8981–8988, DOI: 10.1039/d0sc03820b.