Development of Targeted siRNA Nanocomplexes to Prevent Fibrosis in Experimental Glaucoma Filtration Surgery

Abstract

RNAi induced by double-stranded small interfering RNA (siRNA) molecules has attracted great attention as a naturally occurring approach to silence gene expression with high specificity. The myocardin-related transcription factor/serum response factor (MRTF/SRF) pathway is a master regulator of cytoskeletal gene expression and, thus, represents a promising target to prevent fibrosis. A major hurdle to implementing siRNA therapies is the method of delivery, and we have, thus, optimized lipid-peptide-siRNA (LPR) nanoparticles containing MRTF-B siRNAs as a targeted approach to prevent conjunctival fibrosis. We tested 15 LPR nanoparticle formulations with different lipid compositions, surface charges, and targeting or non-targeting peptides in human conjunctival fibroblasts. In vitro, the LPR formulation of the DOTMA/DOPE lipid with the targeting peptide Y (LYR) was the most efficient in MRTF-B gene silencing and non-cytotoxic compared to the non-targeting formulation. In vivo, subconjunctival administration of LYR nanoparticles containing MRTF-B siRNAs doubled bleb survival in a pre-clinical rabbit model of glaucoma filtration surgery. Furthermore, MRTF-B LYR nanoparticles reduced the MRTF-B mRNA by 29.6% in rabbit conjunctival tissues, which led to significantly decreased conjunctival scarring with no adverse side effects. LYR-mediated delivery of siRNA shows promising results to increase bleb survival and to prevent conjunctival fibrosis after glaucoma filtration surgery.

Direct Delivery of Apatite Nanoparticle-Encapsulated siRNA Targeting TIMP-1 for Intractable Abnormal Scars

“…Different types of nanoparticles have been developed to regulate ocular wound healing. 35 For topical treatment of skin diseases such as diabetic wounds, psoriasis, inflammatory diseases, and fibrosis, lipid nanoparticles, 36 a cationic star-shaped polymer, 37 spherical nucleic acid-gold nanoparticle conjugates, 38 and mesoporous silica-based nanoparticles 39 have been developed.…”

Silencing E3 Ubiqutin ligase ITCH as a potential therapy to enhance chemotherapy efficacy in p53 mutant neuroblastoma cells

“…In our experiments, we used nanoparticles as a carrier system to deliver the ITCH siRNA in vivo. This was based on our previous findings that the receptor-targeted liposome-peptide-siRNA nanoparticle is an efficient delivery system for ex vivo and in vivo applications [49][50][51][52][53] . The formulation of the nanoparticles contains peptide ME27 which can mediate receptor-specific targeting via its interaction with integrin αvβ3 and αvβ5 on cells.…”

USP10 Targeted Self-Deliverable siRNA to Prevent Scarring in the Cornea

“…RNAi to MRTF reduced scarring in the fibrotic "bleb" made during the glaucoma filtration surgery to relieve pressure in the eye. 83,84 Several other gene knockdown strategies for ocular scarring are also being tested in animals. 1,[9][10][11]14 In this study, we used the fully modified siRNA conjugate to achieve maximal activity and longevity of the effect in vivo.…”

“…RNAi to MRTF reduced scarring in the fibrotic “bleb” made during the glaucoma filtration surgery to relieve pressure in the eye. 83 , 84 Several other gene knockdown strategies for ocular scarring are also being tested in animals. 1 , 9 , 10 , 11 , 14 …”