Dendrimer grafted persistent luminescent nanoplatform for aptamer guided tumor imaging and acid-responsive drug delivery.

Theranostic nano-drug delivery systems are promising candidates for early diagnosis and treatment of tumors. However, it is a great challenge to achieve accurate intracellular delivery and stimuli-responsive drug release with the enhanced anti-tumor effects and reduced side effects. Herein we report the fabrication of polyamide-amine (PAMAM) dendrimer grafted persistent luminescence nanoparticles (PLNPs) via in situ growth of PAMAM on the surface of PLNPs and its application in targeted bioimaging and drug delivery. The developed PLNPs-PAMAM possesses strong renewable near-infrared persistent luminescence for imaging and gives abundant terminal groups for further functionalization. Aptamer AS1411 coupled to the PLNPs-PAMAM surface can specifically bind to the over-expressed nucleolin on the membrane of tumor cells and improve the intracellular accumulation of the nanoparticles. Doxorubicin (DOX) is loaded on PLNPs-PAMAM by a pH-sensitive hydrazine, can be specifically released in the intracellular acid environment, leading to apoptosis of HeLa tumor cells and inhibition of tumor growth. The as-prepared smart drug delivery nanoplatform with persistent luminescence, PLNPs-PAMAM-AS1411/DOX, shows a good application prospect for precise cancer theranostics.