Short interfering ribonucleic acids (siRNAs) are proven research tools that have revolutionized our ability to suppress genes. However, delivery remains a major hurdle for their use in vivo, including the limited ability of siRNAs to traverse the highly effective epidermal barrier after topical application. The objective of this project is to optimize and evaluate a topically applied nanoparticle delivery system for siRNA that is able to penetrate the skin and selectively suppress gene expression. Such a delivery system would have the potential to selectively target even small mutations that lead to genetic disorders, with implications ranging from inhibiting cancer cell growth to suppressing inflammation. Our laboratories have engineered a novel nanoparticle conjugate utilizing siRNA duplexes that are densely packed on the surface of gold nanoparticles (siRNA-Au NPs) and which demonstrates a surprising ability to transit the mouse and human stratum corneum and suppress two tested targets, green fluorescent protein and the epidermal growth factor receptor. To date, no toxicity has been found when the siRNA-Au NPs are delivered either topically or intravenously into mice at concentrations that far exceed those needed to suppress genes. In our proposed work, we will determine the mechanism(s) by which siRNA-Au NPs penetrate into human skin, and use this information to optimize siRNA-Au NPs for gene suppression. Next, we will assess the ability of siRNA-Au NPs to suppress Ras signaling and reverse epidermal hyperplasia in a mouse model of skin-specific, inducible overexpression of H-Ras. Building on our in vitro and in vivo mouse studies with siRNA-Au NPs, we will test if topical application of siRNA-Au NPs to a human transplanted skin model of Ras overexpression will similarly suppress aberrant Ras signaling to cause clinically and histologically detectable epidermal normalization. This work will lay the foundation for clinical application of the siRNA nanoparticle conjugates, and establish a new paradigm for the topical application of gene therapies.
Small interfering RNAs (siRNAs) are a widely used research tool to inhibit the expression of genes, but the delivery of siRNAs to humans, including through topical application for skin disease, is a significant challenge. We have developed gold nanoparticles densely coated with siRNAs (siRNA-Au NPs) and have shown their ability to penetrate the stratum corneum and knock down gene expression in mouse and human skin. The results of this proposed preclinical investigation that seeks to reverse pathologic skin thickening will establish polyvalent siRNA-gold nanoparticles as a new modality for treating skin disorders.
|Briley, William E; Bondy, Madison H; Randeria, Pratik S et al. (2015) Quantification and real-time tracking of RNA in live cells using Sticky-flares. Proc Natl Acad Sci U S A 112:9591-5|
|Rouge, Jessica L; Sita, Timothy L; Hao, Liangliang et al. (2015) Ribozyme-Spherical Nucleic Acids. J Am Chem Soc 137:10528-31|
|Kouri, Fotini M; Hurley, Lisa A; Daniel, Weston L et al. (2015) miR-182 integrates apoptosis, growth, and differentiation programs in glioblastoma. Genes Dev 29:732-45|
|Wu, Xiaochen A; Choi, Chung Hang J; Zhang, Chuan et al. (2014) Intracellular fate of spherical nucleic acid nanoparticle conjugates. J Am Chem Soc 136:7726-33|
|Alhasan, Ali H; Patel, Pinal C; Choi, Chung Hang J et al. (2014) Exosome encased spherical nucleic acid gold nanoparticle conjugates as potent microRNA regulation agents. Small 10:186-92|
|Choi, Chung Hang J; Hao, Liangliang; Narayan, Suguna P et al. (2013) Mechanism for the endocytosis of spherical nucleic acid nanoparticle conjugates. Proc Natl Acad Sci U S A 110:7625-30|
|Jensen, Samuel A; Day, Emily S; Ko, Caroline H et al. (2013) Spherical nucleic acid nanoparticle conjugates as an RNAi-based therapy for glioblastoma. Sci Transl Med 5:209ra152|
|Zheng, Dan; Giljohann, David A; Chen, David L et al. (2012) Topical delivery of siRNA-based spherical nucleic acid nanoparticle conjugates for gene regulation. Proc Natl Acad Sci U S A 109:11975-80|
|Zhang, Ke; Hao, Liangliang; Hurst, Sarah J et al. (2012) Antibody-linked spherical nucleic acids for cellular targeting. J Am Chem Soc 134:16488-91|
|Young, Kaylie L; Scott, Alexander W; Hao, Liangliang et al. (2012) Hollow spherical nucleic acids for intracellular gene regulation based upon biocompatible silica shells. Nano Lett 12:3867-71|