Acetal-Functionalized Pillar[5]arene: A pH-Responsive and Versatile Nanomaterial for the Delivery of Chemotherapeutic Agents.

Acetal-functionalized pillar[5]arene () was prepared as a pH-responsive biomaterial. This biomaterial could be fabricated into nanoparticles with a narrow size distribution by an emulsion protocol. PA[5]-based nanoparticles were used to deliver anti-tumor drugs (paclitaxel and doxorubicin) . PA[5]-based nanoparticles were discovered to be a versatile drug delivery system (DDS) to incorporate a fluorescent dye (fluorescein) or a targeting group (folic acid) host-guest interactions. The resulting DDS could be used for the purpose of bioimaging or targeted delivery. Acetal-functionalization renders the system acid-labile to release encapsulated cargo during cell internalization, which is confirmed by confocal laser scanning microscopy (CLSM). A folic-acid-modified DDS shows a 5.1-fold enhancement in bioactivity due to the targeting effect. This DDS is a platform to conveniently integrate multiple functions.