A thermoresponsive coacervate enabling the sustained release of micelles and siRNA was developed using an appropriate blend of ABA/AB block copolymers. At room temperature, siRNA-loaded polyion complex (PIC) micelles were dispersed in solution. Upon mild heating ( ≈ 45 °C), they assembled into coacervate microparticles through a reversible phase transition. When maintained at 37 °C, the coacervates continuously and constantly release siRNA and micelles. Biological activities were evaluated using living cells, and cellular uptake and gene knockdown effects were confirmed. This concept highlights a coacervate-based depot platform for siRNA delivery system.
- Ziwei Ma
- Hiroshi Kamizawa
- Akihiro Kishimura