Ki Young Choi1,2,6, Oscar F Silvestre1,6, Xinglu Huang1,6, Naoki Hida1, Gang Liu1,3, Don N Ho1, Seulki Lee1,4, Sang Wook Lee5, Jong In Hong5 & Xiaoyuan Chen1
1Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), US National Institutes of Health (NIH), Bethesda, Maryland, USA. 2Department of Chemical Engineering and the David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. 3Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Fujian, Xiamen, China. 4Department of Radiology, the Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. 5Department of Chemistry, Seoul National University, Seoul, Korea. 6These authors contributed equally to this work.
Correspondence to: Xiaoyuan Chen
To improve RNA delivery, we present a protocol to produce an RNA carrier based on a Zn(II)-dipicolylamine (Zn-DPA) analog, which is an artificial receptor for phosphate anion derivatives. We further functionalized this Zn-DPA analog to hyaluronic acid (HA)-based self-assembled nanoparticles (HA-NPs) with a hydrodynamic diameter of 100 nm by conjugating amine-functionalized Zn-DPA molecules onto the HA-NPs through amide formation, resulting in efficient tumor-targeted delivery of RNAs (siRNAs, miRNA or other short oligoribonucleotides) and small-molecule drugs. The functional group of Zn-DPA can be converted into other groups such as a carboxylic or thiol group, and the DPA analog can be covalently attached to a variety of existing and novel platforms or formulations for the development of multifunctional materials via standard bioconjugation techniques. Protocols for RNA formulation and delivery into tumor tissues and tumor cells are also described. Our design strategy offers a versatile and practical method for delivering both RNA and chemotherapeutics to tumor cells and expands existing nanomaterial capabilities to further the field of drug and gene delivery.