Selective Enrichment of Polydopamine in Mesoporous Nanocarriers for Nuclear-Targeted Drug Delivery

Abstract

Small particle size and strong host–guest interactions are prerequisites in the field of nuclear-targeting nanocarriers for overcoming the multidrug resistance of cancer cells. A novel scheme of synthesizing hybrid organic–inorganic nanocarriers with mesopores is introduced to enhance the delivery efficiency of therapeutic drugs. Specifically, inorganic silica and organic polydopamine (PDA) are integrated inside the pore framework by the assistance of organic silanes terminated by amino/thiol groups. Silica-etching by hydrothermal treatment leads to the selective enrichment of bioadhesive PDA and size reductions for the hybrids (to ≈30 nm). Interestingly, a high drug loading capacity (523 µg mg −1 for doxorubicin hydrochloride), as well as pH/ glutathione dual-responsive drug release properties, are realized by the nanocarriers, owing to their high surface area (825 m 2 g −1 ) and the π-stacking and/or hydrophobic–hydrophobic interactions stemming from PDA. More importantly, the conjugation of TAT peptide facilitates the intranuclear localization of the nanocarriers and the release of the encapsulated drugs directly within the nucleoplasm of the multidrug resistant MCF-7/ADR cancer cells. Therefore, these results provide a controllable method of engineering high-surface-area nanocarriers with bioadhesive polymers on the pore surface for advanced drug delivery applications.