Controlled Release of DNA from Self-Degrading Microcapsules

Self‐disintegrating microcapsules were prepared by encapsulating a highly active mix of proteases (Pronase®) into biodegradable polyelectrolyte shells. Pronase was captured by micron‐sized calcium carbonate particles that were subsequently embedded into onion‐like shells of poly(L‐arginine) and poly(L‐aspartic acid). EDTA treatment was used to extract the calcium carbonate constituents from the resulting core‐shell particles. As a consequence, Pronase was released into the capsule interior and started to digest the surrounding polyelectrolyte shell. Lifetimes of such self‐disintegrating capsules could be successfully adjusted to seconds, hours or days by varying the amount of encapsulated Pronase. The enzyme‐mediated, sustained release of encapsulated DNA is presented as a prospective application in drug delivery.