One-pot synthesis of poly(ethylene glycol) modified zeolitic imidazolate framework-8 nanoparticles: Size control, surface modification and drug encapsulation

Nanosize metal-organic frameworks (MOFs) are a class of promising porous nanomaterials for biomedical applications, in which their size control and surface modification are critical. Current approaches for fabrication of zeolitic imidazolate framework (ZIF-8) nanoparticles (NPs) with controlled size and poly(ethylene glycol) (PEG) surface modification are separated and time-consuming. Here, we report a simple and rapid synthetic method that combines the size control of ZIF-8 NPs and their surface modification of PEG at the same time. Monovalent amino PEG (PEG-NH2) was used as capping agent to control the size of ZIF-8 and simultaneously realize surface modification through coordination interaction. The size of ZIF-8 was tuned in a board range. The coated NPs showed intact crystalline structure with improved colloidal stability. By further adding the anticancer drug doxorubincin (DOX) into the reaction mixture, ZIF-8 NPs with encapsulated DOX and PEG surface modification ([email protected]/PEG) can be synthesized in one-pot. They showed pH-responsive drug release property and efficacy in killing of cancer cells. Our facile one-pot process can be used to design MOFs NPs as multifunctional delivery systems for a variety of cargos such as therapeutic and imaging agents.