Document text
Principal Investigator: William R. Freeman
Organization: UNIVERSITY OF CALIFORNIA, SAN DIEGO
Fiscal Year: 2023
Award: $423,374
Funding agency: National Eye Institute
ABSTRACT
Diabetic retinopathy is a leading cause of blindness in the industrialized world and has a global prevalence of
an estimated 95 million people (1). Proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME)
originate from persistently elevated glucose levels leading to microvascular ischemia, retinal neovascularization
(RNV), and vascular leakage (2, 3). Antibodies and therapeutics designed to sequester free vascular endothelial
growth factor (VEGF) are the current standard of care (4-8). Due to the short half-life of anti-VEGF therapies,
monthly intravitreal injections are needed to maintain remission (4-7). Repeat injections risk intraocular
inflammation, infection, and ocular hemorrhage (9). An alternative approach is to use RNA interference (RNAi)
to silence the expression of the pathogenic proteins. The recent advancements in siRNA modifications (10) and
FDA approval of the third siRNA therapeutic in as many years demonstrate the renewed potential of RNAi,
though like other anti-VEGF therapies the duration of action is a key limitation. We propose to evaluate the
feasibility of intracellular RNA therapeutics delivered by intravitreal injection of a nanoparticle carrier to
inhibit neovascularization and extend the duration of therapeutic efficacy substantially relative to
current treatments. We recently demonstrated the effectiveness of intravitreally administered fusogenic porous
silicon nanoparticles (F-pSiNPs) for VEGF-siRNA delivery in a DL-alpha-aminoadipic acid (DL-AAA) rabbit
model of RNV. This project aims to rigorously test and optimize this system for extended efficacy. In Aim 1, we
will evaluate two methods of siRNA loading into the nanoparticles: calcium silicate condensation and grafting of
cyclic silanes. These systems will be optimized for loading capacity, encapsulation efficiency, and in vitro release
kinetics. The fusogenic-lipid membrane coating of the F-pSiNP system will be optimized using extrusion and
solvent exchange methods. The candidate formulations will be characterized by spectroscopic, DLS, and Cryo-
EM methods. Cellular uptake and duration of action will be validated in vitro using RT-qPCR and flow cytometry.
The most promising formulations will then be tested by intravitreal injection in Aim 2 using VEGF-siRNA and
Ang-2-siRNA payloads in the DL-AAA model of RNV (11, 12). F-pSiNPs will be given as a single dose and
monitored for 6 months for changes to vascular leakage using fluorescein angiography. These results will then
be benchmarked against commercially available antibody therapeutics aflibercept and faricimab. In Aim 3, F-
pSiNP formulations tested in Aim 2 will be conjugated with pendent surface peptides to test the hypothesis that
selective cellular targeting may dramatically improve efficacy. The targeting and internalization peptide iRGD
will be used for these studies. iRGD is currently in clinical development to improve chemotherapeutic uptake in
tumors, and was selected for its ability to target cell surface integrins and neuropilin-1, which are
characteristically overexpressed in neovascularization. This proposed project represents a first step in
developing and testing a novel platform for intraocular siRNA delivery with both clinical and scientific utility.
Terms: <A5 Antigen><Acids><Adverse effects><Affect><Age related macular degeneration><Age-Related Maculopathy><Amines><Animal Diseases><Animal Model><Animal Models and Related Studies><Anti-VEGF><Anti-VEGF Humanized Monoclonal Antibody><Anti-VEGF RhuMAb><Antibodies><Antibody Therapy><Assay><Autoregulation><Bacterial Infections><Benchmarking><Best Practice Analysis><Bioassay><Biologic Assays><Biological Assay><Biotinylation><Blindness><Blood Vessels><Body Tissues><Calcium><Cell Body><Cell Culture Techniques><Cell Line><Cell Membrane Lipids><Cell surface><CellLine><Cells><Cerubidin><Characteristics><Charge><Chemistry><Clinical><Cryo-electron Microscopy><Cryoelectron Microscopy><Cyclicity><D-Glucose><Data><Dauno-Rubidomycine><Daunoblastina><Daunoblastine><Daunomycin><Daunorrubicina><Daunorubicin><Development><Dexamethasone><Dextrose><Diabetic Retinopathy><Diffusion><Disease><Disease remission><Disorder><Domestic Rabbit><Dose><Drug Delivery><Drug Delivery Systems><Drug Kinetics><Drug Therapy><Drugs><ELISA><Effectiveness><Electron Cryomicroscopy><Emergent Technologies><Emerging Technologies><Encapsulated><Endosomes><Enzyme-Linked Immunosorbent Assay><Extravasation><Eye Hemorrhage><Eye diseases><Flow Cytofluorometries><Flow Cytofluorometry><Flow Cytometry><Flow Microfluorimetry><Flow Microfluorometry><Fluorescein><Fluorescein Angiography><Food and Drug Administration><Formulation><Frequencies><Glucose><Goals><Half-Life><Hemophthalmos><Homeostasis><Image><Immunoblotting><Immunohistochemistry><Immunohistochemistry Cell/Tissue><Immunohistochemistry Staining Method><In Vitro><Industrialization><Infection><Inflammation><Injections><Injury><Integrins><Integrins Extracellular Matrix><Ischemia><Kinetics><Label><Leakage><Leukaemomycin C><Lipids><Lytotoxicity><Measurable><Measures><Medication><Membrane Lipids><Methodology><Methods><MoAb VEGF><Modeling><Modification><Monitor><Monoclonal Antibody Anti-VEGF><NRP1 Protein><Nature><Neuropilin-1><Non-Polyadenylated RNA><Npn-1 Protein><Ondena><Oryctolagus cuniculus><Outcome><Pathogenicity><Penetration><Peptides><Periodicity><Persons><Pharmaceutic Preparations><Pharmaceutical Preparations><Pharmacokinetics><Pharmacotherapy><Physical condensation><Physiological Homeostasis><Porosity><Post-Transcriptional Gene Silencing><Posttranscriptional Gene Silencing><Prevalence><Protein Biosynthesis><Proteins><Quelling><RNA><RNA Gene Products><RNA Interference><RNA Interference Therapy><RNA Sequences><RNA Silencing><RNA based therapeutics><RNA based therapy><RNA delivery><RNA interference therapeutics><RNA interference-based therapy><RNA therapy><RNAi><RNAi therapeutics><RNAi therapy><RNAi-based therapeutics><RNAi-based therapy><Rabbits><Rabbits Mammals><Rapamune><Rapamycin><Receptosomes><Recombinant Humanized Anti-VEGF Monoclonal Antibody><Recombinant Humanized Monoclonal Antibody to Vascular Endothelial Growth Factor><Remission><Research><Retina><Retinal Neovascularization><RhuMAb VEGF><Rhythmicity><Ribonucleic Acid><Ribosomal Peptide Biosynthesis><Ribosomal Protein Biosynthesis><Ribosomal Protein Synthesis><Risk><Rubidomycin><Rubilem><Rubomycin><Rubomycin C><Safety><Sema III Receptor><Semaphorin III Receptor><Sequence-Specific Posttranscriptional Gene Silencing><Short interfering RNA><Si element><Silanes><Silicates><Silicon><Sirolimus><Site><Small Interfering RNA><Solvents><Specificity><Spillage><Strains Cell Lines><Structure><Subgroup><Surface><System><Technology><Testing><Therapeutic><Therapeutic Agents><Therapeutic antibodies><Time><Tissues><Treatment Efficacy><USFDA><United States Food and Drug Administration><VEGF><VEGFs><Vascular Endothelial Cell Growth Factor 165 Receptor><Vascular Endothelial Growth Factors><Western Blotting><Western Immunoblotting><age related macular dystrophy><amine><animal tissue><antibody based therapies><antibody treatment><antibody-based therapeutics><antibody-based treatment><bacteria infection><bacterial disease><benchmark><bevacizumab><biocompatibility><biological systems><biomaterial compatibility><cell culture><cell cultures><cellular targeting><cerubidine><clinical development><condensation><cryo-EM><cryoEM><cryogenic electron microscopy><cultured cell line><cytotoxicity><delivery vector><delivery vehicle><design><designing><developmental><diabetic><diffused><diffuses><diffusing><diffusions><drug treatment><drug/agent><enzyme linked immunoassay><eye disorder><eye toxicity><flow cytophotometry><geographic atrophy><imaging><improved><in vivo><injuries><interest><intervention efficacy><intravitreal injection><knock-down><knockdown><macular edema><model of animal><nano particle><nano sized><nano-sized particle><nanoparticle><nanoparticle therapy><nanosized><nanosized particle><neovascular><neovascularization><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><novel><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel therapeutics><novel therapy><ocular disease><ocular disorder><ocular hemorrhage><ocular toxicity><ophthalmopathy><overexpress><overexpression><particle><physical property><proliferative diabetic retinopathy><protein blotting><protein synthesis><randomized, clinical trials><retinal toxicity><rhuMabVEGF><senile macular disease><siRNA><side effect><standard of care><therapeutic RNA><therapeutic efficacy><therapeutic nanoparticles><therapy duration><therapy efficacy><tumor><uptake><vascular><vision loss><visual loss>