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Yang S, Chen Y, Gu J, Harris A, Su RC, Ho EA. pH-sensitive dual-preventive siRNA-based nanomicrobicide reactivates autophagy and inhibits HIV infection in vaginal CD4+ cells. J Control Release 2024; 366:849-863. [PMID: 38176469 DOI: 10.1016/j.jconrel.2023.12.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 12/13/2023] [Accepted: 12/24/2023] [Indexed: 01/06/2024]
Abstract
Women are more susceptible to HIV transmission through unprotected heterosexual intercourse due to biological and social vulnerabilities. Intravaginal delivery of siRNAs targeting viral genes, host genes, or in combination has shown promising outcomes against HSV, HPV and HIV. Therefore, in this study, we designed, developed and evaluated a pH-sensitive RNAi-based combination nanomicrobide for the prevention/reduction of vaginal transmission of HIV. The nanomicrobide was composed of siRNA-PEI encapsulated PLGA-PEG nanoparticles (siRNA NP) loaded in a HEC gel dosage form with siRNA targeting host gene CCR5 and the viral gene Nef as a dual preventive strategy. Knocking down CCR5, a co-receptor for HIV could prevent HIV from attaching to and entering host cells and knocking down Nef could reactivate autophagy that was inhibited by Nef to improve the elimination of intracellular virus that escaped the first line of defense. The siRNA NP showed a desirable particle size and zeta potential for intravaginal delivery and a pH-dependent release profile whereby low amounts of siRNA was released under acidic vaginal conditions (vaginal fluid simulant; VFS, pH 4.2) (6.0 ± 0.4% released over 15 days) but significantly higher amounts of siRNA was released under neutral pH conditions (phosphate buffered saline; PBS, pH 7.4) (22.9 ± 0.4% released over 15 days). The CCR5-Nef-specific siRNA NP efficiently knocked down CCR5 and Nef protein expression by 43% and 63%, respectively, reactivated Nef-blocked autophagy and inhibited the replication of HIV in vitro (71.8% reduction in p24 expression). After being formulated into a gel dosage form, siRNA NP could be readily released from the gel, penetrate the vaginal epithelial layer, get taken up into the target cells and knockdown Nef and CCR5 without causing cytotoxicity in a vaginal mucosal co-culture model. Functionalization of siRNA NP with anti-CD4 antibody and loaded into a 0.5% HEC gel improved vaginal distribution and uptake of siRNA in a mouse model with distribution of siRNA restricted to the reproductive tract without any unwanted systemic uptake. The 0.5% HEC gel loaded with siRNA NP-(m)CD4 significantly downregulated approximately 40% of CCR5 protein in the lower vagina and 36% of CCR5 protein in the upper vaginal and cervical region. In contrast, 0.5% HEC gel loaded with siRNA NP-IgG did not result in significant gene knockdown.
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Affiliation(s)
- Sidi Yang
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Yufei Chen
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Jijin Gu
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Canada
| | - Angela Harris
- Department of Medical Microbiology & Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Canada; National HIV and Retrovirology Laboratory, JC Wilt Infectious Disease Research Centre, Public Health Agency of Canada, Canada
| | - Ruey-Chyi Su
- Department of Medical Microbiology & Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Canada; National HIV and Retrovirology Laboratory, JC Wilt Infectious Disease Research Centre, Public Health Agency of Canada, Canada
| | - Emmanuel A Ho
- Laboratory for Drug Delivery and Biomaterials, School of Pharmacy, Faculty of Science, University of Waterloo, Canada; Waterloo Institute for Nanotechnology, University of Waterloo, Canada.
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Watchorn J, Clasky AJ, Prakash G, Johnston IAE, Chen PZ, Gu FX. Untangling Mucosal Drug Delivery: Engineering, Designing, and Testing Nanoparticles to Overcome the Mucus Barrier. ACS Biomater Sci Eng 2022; 8:1396-1426. [PMID: 35294187 DOI: 10.1021/acsbiomaterials.2c00047] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Mucus is a complex viscoelastic gel and acts as a barrier covering much of the soft tissue in the human body. High vascularization and accessibility have motivated drug delivery to various mucosal surfaces; however, these benefits are hindered by the mucus layer. To overcome the mucus barrier, many nanomedicines have been developed, with the goal of improving the efficacy and bioavailability of drug payloads. Two major nanoparticle-based strategies have emerged to facilitate mucosal drug delivery, namely, mucoadhesion and mucopenetration. Generally, mucoadhesive nanoparticles promote interactions with mucus for immobilization and sustained drug release, whereas mucopenetrating nanoparticles diffuse through the mucus and enhance drug uptake. The choice of strategy depends on many factors pertaining to the structural and compositional characteristics of the target mucus and mucosa. While there have been promising results in preclinical studies, mucus-nanoparticle interactions remain poorly understood, thus limiting effective clinical translation. This article reviews nanomedicines designed with mucoadhesive or mucopenetrating properties for mucosal delivery, explores the influence of site-dependent physiological variation among mucosal surfaces on efficacy, transport, and bioavailability, and discusses the techniques and models used to investigate mucus-nanoparticle interactions. The effects of non-homeostatic perturbations on protein corona formation, mucus composition, and nanoparticle performance are discussed in the context of mucosal delivery. The complexity of the mucosal barrier necessitates consideration of the interplay between nanoparticle design, tissue-specific differences in mucus structure and composition, and homeostatic or disease-related changes to the mucus barrier to develop effective nanomedicines for mucosal delivery.
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Affiliation(s)
- Jeffrey Watchorn
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Aaron J Clasky
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Gayatri Prakash
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Ian A E Johnston
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Paul Z Chen
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Frank X Gu
- Department of Chemical Engineering & Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.,Institute of Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada
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