Hybrid CaCO 3 microparticles coated by sodium poly(styrene sulfonate) (PSS) and aliphatic poly(urethane-amine) (PUA) were developed as thermal-/pH-responsive drug delivery vehicles via LbL self-assembly technique. The DOX release from the CaCO 3 microparticles was higher than 60% within 36 h, whereas the value of PUA/PSS-coated microparticles was only 20%. The results demonstrated that the PUA/PSS multilayer coating could reduce the drug release rate and significantly assuage the initial burst release of DOX. In addition, the drug release of the hybrid microparticles was found to be thermal-/pH-dual responsive. More interestingly, more than 90% of DOX was released in 36 h at pH 2.1 and 55 °C owing to the combined action of the dissolution of the CaCO 3 core and the shrinkage of aliphatic PUA.
CaCO 3 /aliphatic poly(urethane-amine) (PUA)/sodium polystyrene sulfonate (PSS) hybrid composites with dual-responsive controlled drug delivery property had been prepared via electrostatic interaction. Aliphatic PUA and PSS were employed as smart polyelectrolytes. PSS was also served as crystal growth additive to control the morphology of CaCO 3 microparticles. The electrostatic interaction between PSS and aliphatic PUA under weak-acid condition improved the bonding force between PSS-doped CaCO 3 microparticles and polyelectrolytes. pH-/thermo-responsive drug delivery property and the high drug loading capacity (around 90 %) could be achieved from the prepared hybrid composites. More importantly, the relative content of CaCO 3 microparticles and polyelectrolytes had a significant effect on the morphology and controllable release properties of the hybrid composites. The smart drug release mechanism of the hybrid composites was also analyzed by fitting the cumulative release data to Retger–Peppas equation.
危险品化学品经营许可证（带存储）