IKK2 inhibition using TPCA-1-loaded PLGA microparticles attenuates laser-induced choroidal neovascularization and
Subhash Gaddipati1, Qingxian Lu1, Ramesh Babu Kasetti2
1Departments of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Kentucky, United States of America; James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, Kentucky, United States of America.
Abstract:
The inhibition of NF-κB by genetic deletion or pharmacological inhibition of IKK2 significantly reduces laser-induced choroid neovascularization (CNV). To achieve a sustained and controlled intraocular release of a selective and potent IKK2 inhibitor, 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) (MW: 279.29), we developed a biodegradable poly-lactide-co-glycolide (PLGA) polymer-delivery system to further investigate the anti-neovascularization effects of IKK2 inhibition and in vivo biosafety using laser-induced CNV mouse model. The solvent-evaporation method produced spherical TPCA-1-loaded PLGA microparticles characterized with a mean diameter of 2.4 ¼m and loading efficiency of 80%. Retrobulbar administration of the TPCA-1-loaded PLGA microparticles maintained a sustained drug level in the retina during the study period. No detectable TPCA-1 level was observed in the untreated contralateral eye. The anti-CNV effect of retrobulbarly administrated TPCA-1-loaded PLGA microparticles was assessed by retinal fluorescein leakage and isolectin staining methods, showing significantly reduced CNV development on day 7 after laser injury. Macrophage infiltration into the laser lesion was attenuated as assayed by choroid/RPE flat-mount staining with anti-F4/80 antibody. Consistently, laser induced expressions of Vegfa and Ccl2 were inhibited by the TPCA-1-loaded PLGA treatment. This TPCA-1 delivery system did not cause any noticeable cellular or functional toxicity to the treated eyes as evaluated by histology and optokinetic reflex (OKR) tests; and no systemic toxicity was observed. We conclude that retrobulbar injection of the small-molecule IKK2 inhibitor TPCA-1, delivered by biodegradable PLGA microparticles, can achieve a sustained and controllable drug release into choroid/retina and attenuate laser-induced CNV development without causing apparent systemic toxicity. Our results suggest a potential clinical application of TPCA-1 delivered by microparticles in treatment of CNV in the patients with age-related macular degeneration and other retinal neovascularization diseases.
Insights
A novel biodegradable microparticle system delivers the IKK2 inhibitor TPCA-1 to treat choroidal neovascularization (CNV). This sustained release system effectively reduced CNV in mice without causing toxicity, suggesting potential for treating retinal diseases.
Area of Science:
- Ophthalmology and Visual Sciences
- Drug Delivery Systems
- Molecular Biology
Background:
- NF-κB signaling, specifically IKK2, plays a critical role in the pathogenesis of choroidal neovascularization (CNV).
- Targeting IKK2 offers a potential therapeutic strategy for neovascular eye diseases.
- Sustained intraocular drug delivery is crucial for effective management of chronic ocular conditions.
Purpose of the Study:
- To develop and evaluate a biodegradable poly-lactide-co-glycolide (PLGA) microparticle-based delivery system for the IKK2 inhibitor TPCA-1.
- To investigate the efficacy of sustained intraocular TPCA-1 delivery in reducing laser-induced CNV in a mouse model.
- To assess the in vivo biosafety and toxicity profile of the TPCA-1-loaded PLGA microparticles.
Main Methods:
- TPCA-1 loaded PLGA microparticles were fabricated using a solvent-evaporation method.
- Characterization of microparticles included size, morphology, and drug loading efficiency.
- Laser-induced CNV mouse model was used to evaluate anti-neovascularization effects via retinal fluorescein leakage, isolectin staining, and molecular markers (Vegfa, Ccl2). Ocular and systemic toxicity were assessed by histology and optokinetic reflex (OKR) tests.
Main Results:
- Spherical TPCA-1-loaded PLGA microparticles with a mean diameter of 2.4 µm and 80% loading efficiency were successfully produced.
- Retrobulbar administration achieved sustained TPCA-1 levels in the retina, significantly reducing CNV development, macrophage infiltration, and expression of Vegfa and Ccl2.
- The delivery system demonstrated no observable ocular or systemic toxicity.
Conclusions:
- Biodegradable PLGA microparticles enable sustained and controlled intraocular release of TPCA-1, effectively attenuating laser-induced CNV.
- The developed TPCA-1 delivery system is safe and shows potential for clinical application in treating age-related macular degeneration and other retinal neovascularization diseases.
- Targeting IKK2 with sustained drug delivery represents a promising therapeutic approach for neovascular ocular disorders.
