Abstract: | A new design to synthesize thiol‐responsive degradable polylactide (PLA)‐based micelles having a disulfide linkage in the middle of triblock copolymers is reported. They were synthesized by a new method that centers on the use of a disulfide‐labeled diol as an initiator for ring‐opening polymerization, followed by controlled radical polymerization. These well‐controlled copolymers with monomodal and narrow molecular weight distribution (M w/M n < 1.15) self‐assembled to form aqueous micellar aggregates with disulfide‐containing PLA cores, which is not toxic to cells. Central disulfide linkages were cleaved in response to thiols; such thiol‐triggered degradation enhanced the release of encapsulated anticancer drugs. |