Stimuli-responsive hybrid composites based on CaCO3 microparticles and smart polyelectrolytes for controllable drug delivery

CaCO3/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 CaCO3 microparticles. The electrostatic interaction between PSS and aliphatic PUA under weak-acid condition improved the bonding force between PSS-doped CaCO3 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 CaCO3 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.