Controlled Delivery of Signaling Molecules Using Magnetic Microrobots

_Magnetically-actuated microrobots have many potential applications in biological environments. Microrobots have many uses in cellular environments since they can be remotely actuated and precisely manipulated in biochemical fluids. Most cellular phenomena depend on biochemical signals. Therefore, various techniques have been developed for encapsulation and release of drugs, nutrients or other cargo using microrobots. However, localized targeting without payload leakage during transport is challenging. In this work, we present a light-controlled delivery system integrated with magnetic microrobots which overcomes this challenge. We synthesize a photolabile linker which releases a cell-to-cell signaling molecule when exposed to light. This system is integrated with magnetic micro-robots, which can be steered to target locations in the cell culture. We demonstrate that gene expression in engineered bacterial cells is successfully activated when the signaling molecule is cleaved. This proposed method can be used for wide-ranging applications in the fields of engineering, biology, and medicine, in which the ability to target and release molecules on-demand to a particular location is important.