Scanning electron microscope image of the printed bioresorbable acoustic hydrogel microrobots. (Credit: Hong Han/Caltech)

In the future, delivering therapeutic drugs exactly where they are needed within the body could be the task of miniature robots.

Such robots would have a long and challenging list of requirements. For example, they would need to survive in bodily fluids, such as stomach acids, and be controllable, so they could be directed precisely to targeted sites. They also must release their medical cargo only when they reach their target and then be absorbable by the body without causing harm.

Now, microrobots that tick all those boxes have been developed. Using the bots, the team successfully delivered therapeutics that decreased the size of bladder tumors in mice.

The microrobots are spherical microstructures made of a hydrogel called poly(ethylene glycol) diacrylate. Hydrogels are materials that start out in liquid or resin form and become solid when the network of polymers found within them becomes cross-linked or hardens. This structure and composition enable hydrogels to retain large amounts of fluid, making many of them biocompatible. The additive manufacturing fabrication method also enables the outer sphere to carry the therapeutic cargo to a target site within the body.

In their final form, the microrobots incorporate magnetic nanoparticles and the therapeutic drug within the outer structure of the spheres. The magnetic nanoparticles allow the scientists to direct the robots to a desired location using an external magnetic field. When the robots reach their target, they remain in that spot, and the drug passively diffuses out.

Source 

Topics:
Drug Delivery Medical Nanotechnology Robotics

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