Corneal retention using a nanorobot-based eyedrop.

Eyedrop-based delivery of therapeutic agents provides promising benefits in treating ocular diseases. Conventional topical delivery strategies rely on the passive diffusion of drugs, which is limited in the retention of the drug on the cornea of the eye. The application of nanoparticles promises ocular delivery but is constrained by the physiological barriers of the ocular surface. Here, we demonstrate the application of an eyedrop containing nanorobots for the active retention of drugs for ocular therapy. The nanorobots were fabricated by encapsulating AmB in poly(lactic-co-glycolic acid) PLGA nanoparticles, followed by urease surface functionalization. The individual and swarm movement of the nanorobots is driven by enzymatic reactions through the catalytic decomposition of urease in tears. This active mobility prolonged drug retention by 4-fold compared with passive nanoparticles and promoted corneal healing in fungal keratitis models. Thus, the AmB-loaded nanorobots effectively prolong corneal retention and enhance the therapeutic effect against fungal keratitis.