A nanoparticle formula for delivering siRNA or miRNAs to tumor cells in cell culture and in vivo

This protocol is for the preparation of hyaluronic acid–based nanoparticles that are coupled to a zinc(II)-dipicolylamine analog that binds to phosphate anions and can therefore deliver the RNA into cells. 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.