Delivery of Interference RNA Molecules to Ovarian Cancer Cells Using Gold‐Liposome Nanoparticle Conjugates

RNA interference is a therapeutic modality in which RNA molecules, such as small interference RNAs (siRNAs) and microRNAs (miRNAs) (inhibitors and mimics), are used to regulate the expression of target mRNAs. MiRNAs are multitargeting RNA molecules that are involved in the regulation of several targets and can therefore influence multiple pathways when deregulated. On the other hand, siRNAs repress a specific gene by sequence complementarity to the target mRNA. Although both miRNAs and siRNAs have an increasing therapeutic potential, systemic delivery of RNA‐based technologies is limited by the poor stability of RNA molecules in circulation. Hence, our main goal is to develop a carrier for the efficient and targeted delivery of RNA molecules to ovarian cancer cells. To achieve this, we propose a nanocarrier formulation of gold nanoparticle (AuNP)‐RNA conjugates encapsulated on folate receptor targeted liposomes that could achieve a double protection layer for the RNA while increasing delivery to ovarian cancer cells that overexpress the folate receptor on their surface. We prepared carriers for siRNAs and miRNA oligonucleotide mimics by conjugation of the RNA molecules to the surface of 15 nm diameter AuNPs via thiol linkages. We performed this conjugation in presence of polyethylene glycol (PEG‐2000) to avoid gold precipitation. Physical characterization of the carriers was conducted by dynamic light scattering (DLS) and quantification of conjugated RNA was assessed by fluorescence. The conjugation resulted in approximately 47 to 75 RNA molecules linked per nanoparticle and conjugates of 20 to 25 nm diameter with a slightly negative charge. In addition, encapsulation of the AuNP‐RNA conjugates into liposomes was attained with more than 70% encapsulation efficiency. These results indicate the feasibility of the development and production of our nanocarrier. As a proof of principle we are using this nanoparticle conjugate to target Integrin‐linked kinase (ILK). ILK is a pseudokinase that has been found to be aberrantly expressed in ovarian tumors. Further experiments of internalization, stability and toxicity demonstrate the efficacy of this nanocarrier as a delivery system for miRNA mimics and siRNAs to ovarian cancer cells. We conclude that siRNA‐based technologies are an alternative strategy to target ILK and other target proteins lacking specific chemical inhibitors. Support or Funding Information RCMI: U54 MD007600 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .