Chemical/magnetic dual-responsive nanorobots with flower-like structure for drug delivery

In this paper, a facile method was used to synthesize flower-like silica (SiO2) nanoparticles. Given the advantages of porous structure for molecule decoration and drug carrying, chemical/magnetic dual-responsive nanorobots were fabricated based on these flower-like nanoparticles. Urease served as a chemical engine using urea as fuel, which provided chemical driving force for nanorobots by its biocatalytic degradation ability. Fe304 nanoparticles as a magnetic engine were responsible for the control over advance direction of nanorobots. Furthermore, dual-responsive nanorobots showed a good synergistic motion behavior without negative effect. Compared with traditional imporous nanoparticles, the flower-like structure displayed a great improvement in drug-loading properties owing to the large surface area. Furthermore, dual-responsive nanorobots lead to a higher mortality of cancer cells through an enhanced endocytosis caused by autonomous motion. Thus, the reported nanorobots are promising candidates for targeting drug delivery.