bims-mideyd 2025-12-28 papers

J Control Release. 2025 Dec 21. pii: S0168-3659(25)01177-0. [Epub ahead of print]390 114563

Engineered nanoparticles for subconjunctival delivery to the retinal pigment epithelium: A multi-target therapy for dry AMD.

Yao Li, Shiman Yuan, Cong Zhang, Pengcheng Hu, Xiaoying Huang, Jialin Zhou, Danning Liu, Xiyuan Zhou.

Dry age-related macular degeneration (dAMD) is a leading cause of irreversible blindness, driven by oxidative stress-induced retinal pigment epithelial (RPE) cell degeneration. Existing therapies suffer from poor bioavailability and insufficient multi-pathway modulation. To address this, we developed P(R)/T-Lf nanoparticles, a subconjunctivally administered nanotherapy co-loaded with resveratrol (Res) and dual-functionalized with trimethyl chitosan (TMC) and lactoferrin (Lf). The P(R)/T-Lf NPs exhibited: (1) prolonged ocular retention via TMC-mediated mucoadhesion and enhanced RPE targeting through Lf receptor binding; (2) sustained Res release over 35 days, effectively scavenging reactive oxygen species and inhibiting ferroptosis by downregulating NOX2, ACSL4, and COX2 while restoring GPX4; (3) superior therapeutic outcomes in NaIO₃-induced dAMD models, preserving retinal morphology and function. Comparative studies demonstrated that P(R)/T-Lf NPs outperformed non-targeted controls. This nanoplatform provides a translation-ready strategy to concurrently tackle oxidative stress, inflammation, and ferroptosis via sustained, targeted delivery, representing a transformative approach for dAMD therapy.

Keywords: Dry age-related macular degeneration; Ferroptosis; Lactoferrin; Oxidative stress; PLGA nanoparticles; Subconjunctival injection; Targeted drug delivery

DOI: https://doi.org/10.1016/j.jconrel.2025.114563

Cell Commun Signal. 2025 Dec 22.

Retinal pigment epithelium-derived extracellular vesicles mediate outer blood retinal barrier disruption in response to AMD-related stress.

Beatriz Martins, Raquel Boia, Diana Correia, Teresa Ribeiro-Rodrigues, José Ramalho, António Francisco Ambrósio, Henrique Girão, Rosa Fernandes.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of vision loss among the elderly, primarily affecting the central vision. This progressive degenerative disease is characterized by the dysregulation and degeneration of the retinal pigment epithelium (RPE), a crucial cell layer beneath the photoreceptors that maintains outer retinal homeostasis. Emerging evidence suggests that during AMD, stressed RPE cells release extracellular vesicles (EVs) carrying bioactive cargo, which may compromise the outer blood-retinal barrier (oBRB) and accelerate disease progression. This study explores the role of EVs released by RPE cells under pro-inflammatory conditions in disrupting retinal integrity.
METHODS: Highly polarized primary cultures of porcine RPE (pRPE) and porcine eyecups with the RPE exposed were treated with tumor necrosis factor (TNF), lipopolysaccharide (LPS), or EVs derived from inflamed RPE cells. Additionally, Balb/c mice were intravitreally injected with RPE-derived EVs.
RESULTS: We show that EVs secreted by the apical membrane domain of porcine RPE cells exposed to LPS or TNF impair the RPE monolayer in polarized cultures, disrupt the oBRB in ex vivo porcine eyecups, and induce retinal structural damage detected in vivo in Balb/c mice. Intravitreal injection of LPS-derived EVs triggers photoreceptor and RPE layers thinning, increases reactivity in astrocytes and Müller cells, promotes pro-inflammatory microglial activation and recruitment, particularly into the outer retina, and elevates retinal apoptosis. Mechanistically, matrix metalloproteinases (MMPs) activity mediates EV-induced RPE monolayer disruption, whereas MMPs activity inhibition mitigates these effects.
CONCLUSION: Our findings reveal a novel EV-driven mechanism contributing to retinal degeneration progression, highlighting inflammation-derived apical EVs as key players in diseases involving oBRB dysfunction. Targeting EV-mediated signaling and MMPs activity may offer therapeutic strategies for preserving retinal structure and function in inflammatory retinal diseases such as age-related macular degeneration.

Keywords: Age-related macular degeneration; Extracellular vesicles; Metalloproteinases; Neurodegeneration; Neuroinflammation; Outer blood-retinal barrier; Retinal pigment epithelial cells

DOI: https://doi.org/10.1186/s12964-025-02587-0

Mol Ther Methods Clin Dev. 2025 Dec 11. 33(4): 101620

Nanobody-based gene therapy targeting complement component C3 reduces choroidal neovascularization in mice.

Emilie Grarup Jensen, Thomas Stax Jakobsen, Gloriane Schnabolk, Kyrie Wilson, Mathias Rask-Pedersen, Nanna Jensen, Gregers Rom Andersen, Steffen Thiel, Lars Aagaard, Bärbel Rohrer, Anne Louise Askou, Thomas J Corydon.

Wet age-related macular degeneration (wAMD) is a leading cause of vision loss and is characterized by choroidal neovascularization (CNV). Current CNV management requires multiple treatments and lacks long-term efficiency, creating a need for better therapeutics. wAMD pathogenesis is associated with excessive activation of the complement system, contributing to retinal damage. Therefore, we generated a vector expressing the small alternative pathway-targeting nanobody, hC3Nb1, to treat wAMD. We demonstrate that hC3Nb1 is efficiently expressed and secreted by mammalian cells and shows full alternative pathway and partial classical pathway inhibition in vitro. A dual-promoter approach was used to generate a lentiviral-based vector for co-expression of hC3Nb1 and marker protein eGFP. Profound and safe hC3Nb1-expression, along with its secretion from the retinal pigment epithelium (RPE), was confirmed following subretinal injection of nanobody expressing-vector in mice. The therapeutic potential of vector-encoded hC3Nb1 was demonstrated in vitro by protecting RPE from complement-mediated stress, and in vivo by reducing laser-induced CNV sizes in a mouse model consistent with complement inhibition. For the first time, nanobodies expressed in the eye are used therapeutically, and our findings suggest that hC3Nb1-based gene therapy may be a safe and long-acting treatment for wAMD and other chorioretinal diseases with dysregulated complement activation.

Keywords: age-related macular degeneration; choroidal neovascularization; complement system; complement-inhibition; gene therapy; laser-induced CNV; lentivirus; nanobody; retina; viral vector

DOI: https://doi.org/10.1016/j.omtm.2025.101620

Regen Ther. 2025 Dec;30 503-514

Subretinal suspensions of hiPSC-derived retinal pigment epithelium cells form functional monolayers in NOD-SCID mice facilitating treatment of advanced retinal diseases.

Xiaojing Song, Guanjie Gao, Ke Ye, Ping Xu, Yuan Wang, Suai Zhang, Dandan Zheng, Jian Ge, Xiufeng Zhong.

Introduction: Transplantation of human induced pluripotent stem cells derived retinal pigment epithelium (hiPSC-RPE) is regarded as one of the most promising strategies for advanced retinal degenerative diseases leading to blindness, such as age-related macular degeneration. Despite its therapeutic potential, this approach is encumbered by critical challenges, notably the survival of donor RPE cells post-transplantation and the successful reconstruction of a functional RPE layer.
Methods: With our previously reported strategy, abundant hiPSC-RPEs were generated from human induced pluripotent stem cells. These cells were characterized in vitro by morphology, marker expression and function. Further, hiPSC-RPE cell suspensions were injected into the eyes of NOD-SCID mice. Animals were monitored by optical coherence tomography screening and color fundus imaging to evaluate the survival of hiPSC-RPEs. Polarity, maturity, integration and phagocytosis of hiPSC-RPEs were analyzed histologically.
Results: hiPSC-RPE cells exhibited a cobblestone morphology with abundant microvilli and tight junctions, expressed RPE specific molecular markers, and possessed ability to phagocytize photoreceptor outer segments (POS), thereby resembling the characteristics of the native human RPE cells. Following transplantation into NOD-SCID mice, the cells survived for the 8-week testing period and formed a highly organized monolayer in regions with an intact Bruch's membrane (BM) in the host retina. The reconstructed RPE layer expressed both human-specific and RPE-specific markers with POS phagocytic function. No severe adverse effects, such as malignant tumors or infections, were observed.
Conclusions: These findings demonstrate that hiPSC-RPE suspensions can survive and form RPE monolayers with morphological and functional features analogous to those of native human RPE cells in the host retina with a healthy BM. Our study may facilitate the development of cell-based therapies for treatment of advanced retinal degenerations.

Keywords: Age-related macular degeneration; Cell therapy; Human induced pluripotent stem cells; Monolayer; Retinal pigment epithelium

DOI: https://doi.org/10.1016/j.reth.2025.06.021