Gastrointestinal tract drug delivery using algae motors embedded in a degradable capsule

Summary

This experimental study combines long-swimming natural microalgae with a degradable oral capsule to improve active cargo delivery in the gastrointestinal tract. Many synthetic micromotors stop quickly, limiting how long they can redistribute a payload. The algae maintained steady movement in simulated intestinal fluid after 12 hours of continuous operation. Researchers attached either a fluorescent dye or cell-membrane-coated nanoparticles to the organisms and enclosed the motors in a pH-responsive capsule that protected them until release in the small intestine. After oral administration in mice, algae motors distributed the dye more broadly through the gastrointestinal tract than magnesium-based micromotors with shorter propulsion lifetimes. They also increased retention of a model chemotherapeutic cargo relative to a passive nanoparticle formulation. The principal finding is that prolonged biological propulsion and site-specific capsule release can work together to improve distribution and residence of two different model payloads. This supports a practical platform for active intestinal delivery, but it does not demonstrate therapeutic efficacy for a gastrointestinal disease. The abstract also does not address cargo release kinetics, algae clearance, repeated-dose safety, microbiome effects, or performance relative to conventional oral drug formulations.