pH-Responsive mineralized nanoparticles for bacteria-triggered topical release of antibiotics

We report on doxycycline (DOXY)-loaded calcium carbonate (CaCO₃) mineralized nanoparticles (DOXY-MNPs) that can induce selective topical release of antibiotics to target oral plaque biofilms with acidic pH (ca. 4.5–5.5). The DOXY-MNPs were fabricated through a block copolymer-templated mineralization approach with simultaneous loading of an antibacterial drug, DOXY. The CaCO₃ mineral core of DOXY-MNPs inhibited the leakage of entrapped DOXY in environments with normal salivary pH. However, in acidic pH, the DOXY release was triggered by the dissolution of CaCO₃ mineral cores. The DOXY-MNPs showed effective antibacterial therapeutic activity to Prevotella intermedia bacterial cells with a potent treatment of biofilms.