The Controversial Role of TGF-β in Neovascular Age-Related Macular Degeneration Pathogenesis

The multifunctional transforming growth factors-beta (TGF-βs) have been extensively studied regarding their role in the pathogenesis of neovascular age-related macular degeneration (nAMD), a major cause of severe visual loss in the elderly in developed countries. Despite this, their effect remains somewhat controversial. Indeed, both pro- and antiangiogenic activities have been suggested for TGF-β signaling in the development and progression of nAMD, and opposite therapies have been proposed targeting the inhibition or activation of the TGF-β pathway. The present article summarizes the current literature linking TGF-β and nAMD, and reviews experimental data supporting both pro- and antiangiogenic hypotheses, taking into account the limitations of the experimental approaches.

Advances in Retinal Optical Imaging

Retinal imaging has undergone a revolution in the past 50 years to allow for better understanding of the eye in health and disease. Significant improvements have occurred both in hardware such as lasers and optics in addition to software image analysis. Optical imaging modalities include optical coherence tomography (OCT), OCT angiography (OCTA), photoacoustic microscopy (PAM), scanning laser ophthalmoscopy (SLO), adaptive optics (AO), fundus autofluorescence (FAF), and molecular imaging (MI). These imaging modalities have enabled improved visualization of retinal pathophysiology and have had a substantial impact on basic and translational medical research. These improvements in technology have translated into early disease detection, more accurate diagnosis, and improved management of numerous chorioretinal diseases. This article summarizes recent advances and applications of retinal optical imaging techniques, discusses current clinical challenges, and predicts future directions in retinal optical imaging.

Antagonist of nucleolin, N6L, inhibits neovascularization in mouse models of retinopathies

Retinal vascular diseases (RVD) have been identified as a major cause of blindness worldwide. These pathologies, including the wet form of age-related macular degeneration, retinopathy of prematurity, and diabetic retinopathy are currently treated by intravitreal delivery of anti-vascular endothelial growth factor (VEGF) agents. However, repeated intravitreal injections can lead to ocular complications and resistance to these treatments. Thus, there is a need to find new targeted therapies. Nucleolin regulates the endothelial cell (EC) activation and angiogenesis. In previous studies, we designed a pseudopeptide, N6L, that binds the nucleolin and blocks the tumor angiogenesis. In this study, the effect of N6L was investigated in two experimental models of retinopathies including oxygen-induced retinopathy (OIR) and choroidal neovascularization (CNV). We found that in mouse OIR, intraperitoneal injection of N6L is delivered to activated ECs and induced a 50% reduction of pathological neovascularization. The anti-angiogenic effect of N6L has been tested in CNV model in which the systemic injection of N6L induced a 33% reduction of angiogenesis. This effect is comparable to those obtained with VEGF-trap, a standard of care drug for RVD. Interestingly, with preventive and curative treatments, neoangiogenesis is inhibited by 59%. Our results have potential interest in the development of new therapies targeting other molecules than VEGF for RVD.

Pegaptanib sodium treatment in neovascular age-related macular degeneration: clinical experience in Germany

BACKGROUND

The VEGF Inhibition Study In Ocular Neovascularisation (VISION) reported the efficacy of intravitreal (ITV) vascular endothelial growth factor (VEGF) inhibition with pegaptanib sodium (Macugen((R))) for the treatment of neovascular age-related macular degeneration (AMD). This paper reports clinical experience with pegaptanib sodium for the treatment of occult or minimally classic choroidal neovascularization (CNV) due to AMD.

MATERIAL AND METHODS

The study included 50 eyes (in 49 patients) with either occult CNV or minimally classic CNV secondary to neovascular AMD who were not eligible for photodynamic therapy (PDT). Study data were analyzed retrospectively. During the 6-month study, patients were administered an average 2.74 injections of 0.3 mg ITV pegaptanib sodium. Angiography and optical coherence tomography (OCT) examinations were carried out and intraocular pressure (IOP) and visual acuity (VA) were measured at baseline, at 3 months and at 6 months. An eye examination was performed and VA was measured the 2 days following treatment and then again at weeks 4-6, and at 3 and 6 months. OCT, VA, and IOP were also assessed at 1 month.

RESULTS

ITV pegaptanib sodium was well tolerated and no treatment complications arose. Mean VA was measured as: 0.37 +/- 0.24 at baseline; 0.37 +/- 0.25 at 1 month; 0.37 +/- 0.25 at 3 months and 0.40 +/- 0.26 at 6 months. VA was stabilized in approximately 90% of eyes treated with pegaptanib sodium. OCT examination showed a minimal change in central retinal thickness (CRT) during the course of the study, from 251.19 mum at baseline to 251.63 mum at 6 months. No elevation in IOP was measured during treatment at 4-6 months in patients receiving pegaptanib sodium.

CONCLUSIONS

ITV therapy with pegaptanib sodium for occult and minimally classic CNV secondary to neovascular AMD offered good efficacy with a favorable adverse events profile. The majority of patients showed stabilization in all assessed parameters. In clinical practice, careful consideration should be given to the use of nonselective VEGF inhibition in patients with a high cardiovascular risk profile or in those with a history of thromboembolic events.

Factors for Visual Acuity Improvement After Anti-VEGF Treatment of Wet Age-Related Macular Degeneration in China: 12 Months Follow up

Purpose: To evaluate the treatment solutions and effectiveness of intravitreal ranibizumab (RBZ) or conbercept in patients with wet age-related macular degeneration (wAMD) in a real-life setting in China.

Methods: The medical records of 368 patients with wAMD who started RBZ or conbercept treatment between 1 May 2014 and 30 April 2018 were evaluated. All patients were defined on fundus angiography at baseline to determine the subtype of AMD (PCV or CNV). We report visual acuity (VA) and central retinal thickness (CRT) measurements at baseline and 12 months.

Results: The average number of anti-VEGF injections was 2.1 ± 1.2. The BCVA improvement of these two groups was similar with a difference of 1.00 letter (95% CI: −1.4~3.4, p = 0.8505). At the end of the study, a BCVA increase of at least 5 letters was determined to be a satisfactory efficacy endpoint. Several factors were related to the possible improvement in the satisfactory efficacy endpoint, including female sex (OR 2.07, 95% CI 1.22~3.51), number of injections (OR 1.40, 95% CI 1.12~1.75) and VA change at the first month (OR 13.75, 95% CI 7.41~25.51). Additionally, some factors were related to the possible reduction in the satisfactory efficacy endpoint, including diabetes (OR 0.27, 95% CI 0.10~0.73) and disease history (OR 0.75, 95% CI 0.57~0.98).

Conclusion: Our study demonstrates that anti-VEGF drugs can effectively improve BCVA and reduce CRT in AMD patients. Sex, number of injections, VA change at the first month, diabetes and disease history are the most important factors affecting visual acuity.

Immunosenescence in Choroidal Neovascularization (CNV)-Transcriptional Profiling of Naïve and CNV-Associated Retinal Myeloid Cells during Aging

Immunosenescence is considered a possible factor in the development of age-related macular degeneration and choroidal neovascularization (CNV). However, age-related changes of myeloid cells (MCs), such as microglia and macrophages, in the healthy retina or during CNV formation are ill-defined. In this study, Cx3cr1-positive MCs were isolated by fluorescence-activated cell sorting from six-week (young) and two-year-old (old) Cx3cr1^GFP/+ mice, both during physiological aging and laser-induced CNV development. High-throughput RNA-sequencing was performed to define the age-dependent transcriptional differences in MCs during physiological aging and CNV development, complemented by immunohistochemical characterization and the quantification of MCs, as well as CNV size measurements. These analyses revealed that myeloid cells change their transcriptional profile during both aging and CNV development. In the steady state, senescent MCs demonstrated an upregulation of factors contributing to cell proliferation and chemotaxis, such as Cxcl13 and Cxcl14, as well as the downregulation of microglial signature genes. During CNV formation, aged myeloid cells revealed a significant upregulation of angiogenic factors such as Arg1 and Lrg1 concomitant with significantly enlarged CNV and an increased accumulation of MCs in aged mice in comparison to young mice. Future studies need to clarify whether this observation is an epiphenomenon or a causal relationship to determine the role of immunosenescence in CNV formation.

Peripheral blood CD163(+) monocytes and soluble CD163 in dry and neovascular age-related macular degeneration

Macrophages are the main infiltrating immune cells in choroidal neovascularization (CNV), a hallmark of the human wet, or neovascular age-related macular degeneration (AMD). Due to their plasticity and ability to adapt to the local microenvironment in a tissue-dependent manner, macrophages display polar functional phenotypes characterized by their cell surface markers and their cytokine profiles. We found accumulation of hemoglobin-scavenging cluster of differentiation 163 (CD163)(+) macrophages in laser-induced CNV lesions and higher expression of CD163(+) monocytes in the peripheral blood on day 7 post injury in mice. In comparison, CD80(+) macrophages did not differ with laser-injury in young or aged mice and did not significantly change in the peripheral blood of CNV mice. We examined the percentages of CD163(+), CD206(+), and CD80(+) monocytes in the peripheral blood of patients with wet AMD, patients with dry AMD, and in age-matched individuals without AMD as controls. Percentages of peripheral blood CD163(+) monocytes in both dry AMD (P < .001) and wet AMD (P < .05) were higher than in age-matched non-AMD controls, while there was no difference between the groups in the percentages of peripheral CD206(+) and CD80(+) monocytes. Further, serum level of soluble CD163 (sCD163) was elevated only in patients with wet AMD (P < .05). An examination of 40 cytokine levels across the study groups revealed that anti-VEGF treated patients with wet AMD, who showed no exudative signs on the day of blood drawing had a cytokine profile that was similar to that of non-AMD individuals. These results indicate that CD163 could be further evaluated for its potential as a useful marker of disease activity in patients with neovascular AMD. Future studies will address the origin and potential mechanistic role of CD163(+) macrophages in wet AMD pathologies of angiogenesis and leakage of blood components.

The Harvard angiogenesis story

I shall discuss the work of researchers at Harvard Medical School who came together in the early 1990s. Scattered across various Harvard-affiliated hospitals and research centers, these individuals were unified by their interest in ocular neovascularization. Together and separately, they investigated models of ocular neovascularization, exploring tumor angiogenesis in eye development and disease.

Activated Protein C (APC) and 3K3A-APC-Induced Regression of Choroidal Neovascularization (CNV) Is Accompanied by Vascular Endothelial Growth Factor (VEGF) Reduction

The activated protein C (APC) ability to inhibit choroidal neovascularization (CNV) growth and leakage was recently shown in a murine model. A modified APC, 3K3A-APC, was designed to reduce anticoagulant activity while maintaining full cytoprotective properties, thus diminishing bleeding risk. We aimed to study the ability of 3K3A-APC to induce regression of CNV and evaluate vascular endothelial growth factor (VEGF) role in APC's activities in the retina. CNV was induced by laser photocoagulation on C57BL/6J mice. APC and 3K3A-APC were injected intravitreally after verification of CNV presence. CNV volume and vascular penetration were evaluated on retinal pigmented epithelium (RPE)-choroid flatmount by fluorescein isothiocyanate (FITC)-dextran imaging. VEGF levels were measured using immunofluorescence anti-VEGF staining. We found that 3K3A-APC induced regression of pre-existing CNV. VEGF levels, measured in the CNV lesion sites, significantly decreased upon APC and 3K3A-APC treatment. Reduction in VEGF was sustained 14 days post a single APC injection. As 3K3A-APC retained APCs' activities, we conclude that the anticoagulant properties of APC are not mandatory for APC activities in the retina and that VEGF reduction may contribute to the protective effects of APC and 3K3A-APC. Our results highlight the potential use of 3K3A-APC as a novel treatment for CNV and other ocular pathologies.

An enhanced OCT image captioning system to assist ophthalmologists in detecting and classifying eye diseases

Human eye is affected by the different eye diseases including choroidal neovascularization (CNV), diabetic macular edema (DME) and age-related macular degeneration (AMD). This work aims to design an artificial intelligence (AI) based clinical decision support system for eye disease detection and classification to assist the ophthalmologists more effectively detecting and classifying CNV, DME and drusen by using the Optical Coherence Tomography (OCT) images depicting different tissues. The methodology used for designing this system involves different deep learning convolutional neural network (CNN) models and long short-term memory networks (LSTM). The best image captioning model is selected after performance analysis by comparing nine different image captioning systems for assisting ophthalmologists to detect and classify eye diseases. The quantitative data analysis results obtained for the image captioning models designed using DenseNet201 with LSTM have superior performance in terms of overall accuracy of 0.969, positive predictive value of 0.972 and true-positive rate of 0.969using OCT images enhanced by the generative adversarial network (GAN). The corresponding performance values for the Xception with LSTM image captioning models are 0.969, 0.969 and 0.938, respectively. Thus, these two models yield superior performance and have potential to assist ophthalmologists in making optimal diagnostic decision.

Can macular translocation be a satisfactory management of subfoveal choroidal neovascular membrane?

PURPOSE

To report histopathological observations regarding one of our macular translocation cases.

METHODS

We have performed macular translocation with 360 degree retinotomy since 1997, and limited macular translocation with or without subretinal membrane removal since 2002. One of our patients died on the fifth postoperative day, so extensive histological examination of the removed neovascular membrane and entire globe was performed.

RESULTS

We found that pigment epithelium remained attached to the neurosensory retina during retinal separation, in which case the rotated fovea will be relocated in a partially devoided pigment epithelial zone. In addition, even after complete surgical removal of the membrane during macular translocation, large membrane remnants are still detectable by histological examination.

CONCLUSION

In our opinion, macular translocation is not a satisfactory management of subfoveal neovascular membranes, because of changes in the pigment epithelium during surgery, and large subretinal neovascular membrane remnants.

Clinical features of focal choroidal excavation subtypes and their association with choroidal neovascularization

BACKGROUND

This study aimed to propose a new classification of focal choroidal excavation (FCE), summarize the clinical and multimodal imaging characteristics of FCE subtypes, and explore the relationship between FCE and choroidal neovascularization (CNV).

METHODS

In this retrospective observational study, patients diagnosed with FCE using spectral-domain optical coherence tomography (SD-OCT) were included. FCE was classified according to associated retinochoroidal diseases. Clinical and multimodal imaging features, as well as the association of CNV, were investigated for different subtypes of FCE.

RESULTS

The study included 105 eyes with FCE from 93 Chinese patients, with a mean age of 41.66 years (range: 15-75 years). Among the 93 eyes with comprehensive multimodal imaging data, FCE subtypes were classified as retractive (34.41%), inflammatory (18.28%), pachychoroidal (23.66%), atrophic (9.68%), and idiopathic (13.97%). Idiopathic FCE patients had significantly better best-corrected visual acuity compared to those with retinochoroidal disease-associated FCE (P<0.001). Inflammatory FCE was associated with higher myopia (median refractive error: -6.00 D, P<0.001) and reduced choroidal thickness (P=0.014), whereas pachychoroidal FCE showed increased choroidal thickness. Retractive FCE exhibited the highest CNV rate at baseline (P<0.001), with CNV more likely in larger greatest linear dimension (GLD) (P=0.004) and female patients (P=0.016). Although CNV was present in 50.54% of cases at baseline, it grew within FCE during follow-up in only 8.60% of cases, and 9.68% experienced CNV recurrence.

CONCLUSION

Different FCE subtypes exhibit distinct clinical features. Idiopathic FCEs are generally stable, while the emergence of secondary CNV is linked to anatomical alterations caused by FCE and associated retinochoroidal diseases.

Proteotranscriptomic analyses reveal distinct interferon-beta signaling pathways and therapeutic targets in choroidal neovascularization

Aim

To investigate the molecular mechanism underlying the onset of choroidal neovascularization (CNV).

Methods

Integrated transcriptomic and proteomic analyses of retinas in mice with laser-induced CNV were performed using RNA sequencing and tandem mass tag. In addition, the laser-treated mice received systemic interferon-β (IFN-β) therapy. Measurements of CNV lesions were acquired by the confocal analysis of stained choroidal flat mounts. The proportions of T helper 17 (Th17) cells were determined by flow cytometric analysis.

Results

A total of differentially expressed 186 genes (120 up-regulated and 66 down-regulated) and 104 proteins (73 up-regulated and 31 down-regulated) were identified. The gene ontology and KEGG pathway analyses indicated that CNV was mainly associated with immune and inflammatory responses, such as cellular response to IFN-β and Th17 cell differentiation. Moreover, the key nodes of the protein-protein interaction network mainly involved up-regulated proteins, including alpha A crystallin and fibroblast growth factor 2, and were verified by Western blotting. To confirm the changes in gene expression, real-time quantitative PCR was performed. Furthermore, levels of IFN-β in both the retina and plasma, as measured by enzyme-linked immunosorbent assay (ELISA), were significantly lower in the CNV group than in the control group. IFN-β treatment significantly reduced CNV lesion size and promoted the proliferation of Th17 cells in laser-treated mice.

Conclusions

This study demonstrates that the occurrence of CNV might be associated with the dysfunction of immune and inflammatory processes and that IFN-β could serve as a potential therapeutic target.

Emerging Role of Adiponectin/AdipoRs Signaling in Choroidal Neovascularization, Age-Related Macular Degeneration, and Diabetic Retinopathy

Age-related macular degeneration (AMD), a leading cause of irreversible blindness in adults, may result in poor central vision, making it difficult to see, read, and drive. AMD is generally classified in either dry or wet types. Milder cases of dry AMD may progress to geographic atrophy (GA), leading to significant visual disability; wet, or neovascular AMD, which involves choroidal neovascularization (CNV), can lead to complete loss of central vision. Adiponectin (APN) discovery in the mid-1990's and, subsequently, its two cognate receptors (AdipoRs) in the early 2000s have led to a remarkable progress in better understanding metabolic disorders, as well as metabolism-associated ocular pathology. APN/AdipoRs signaling plays a central role in a variety of molecular and cellular physiological events, including glucose and lipid metabolism, whole-body energy regulation, immune and inflammation responses, insulin sensitivity and retinal cell biological functions. This review is an amalgamation of recent information related to APN/AdipoRs in the pathophysiology of retinal diseases and furthers its association with AMD and diabetic retinopathy. Additionally, we present our original research, where we designed control peptide and CNV inhibitory peptide from the globular region of APN to see the effect of these peptides on the mouse model of laser-induced CNV. The inhibitory peptide (APN1) inhibited CNV by more than 75% while the control peptide did not inhibit CNV.

Retinal Angiomatous Proliferation in a Patient with Retinitis Pigmentosa

Retinal angiomatous proliferation (RAP) and other types of choroidal neovascularization (CNV) are very rarely reported in patients with retinitis pigmentosa (RP). We present a case report of a 91-year-old patient with an obvious RP phenotype, who presented with a sudden onset of vision worsening and metamorphopsia in the left eye. Genetic testing on the UK inherited retinal disease panel did not identify a pathogenic variant. Multimodal imaging comprising optical coherence tomography (OCT), OCT angiography, and fluorescein and indocyanine green angiography showed a RAP lesion in the left macula. The patient received three treatments of monthly injections of aflibercept, with excellent morphological and functional outcomes. Taking into account the patient's age at presentation of the RAP lesion, it is not clear whether the RAP was associated or coincidental with RP. This case report highlights the importance of possessing an awareness that RAP lesions can occur in RP. Moreover, due to a good response and potential safety concerns with continuous anti-VEGF injections in RP patients, a pro re nata (PRN) regimen might be the safest option.

Reactive Oxygen Species Responsive Supramolecular Prodrug Eyedrops for the Treatment of Choroidal Neovascularization

Choroidal neovascularization (CNV) represents a hallmark of neovascular fundus diseases, including age-related macular degeneration and diabetic retinopathy. Traditional eyedrops have encountered formidable challenges in treating CNV, primarily due to their extremely poor intraocular bioavailability and potential adverse off-target effects. Herein, an ocular-permeable supramolecular prodrug eyedrop (Di-DAS/P-PCD) has been developed for the on-demand delivery of antiangiogenic agents in the oxidative microenvironment of CNV. The eyedrop nanoformulation is composed of cell-penetrating peptide-modified PEGylated cyclodextrin (P-PCD) and reactive oxygen species (ROS)-sensitive antiangiogenic dasatinib prodrug Di-DAS. In a laser-induced CNV mouse model, daily instillation of Di-DAS/P-PCD has achieved remarkable penetration into the choroid and significantly suppressed CNV growth while exhibiting a good biocompatibility profile. Our results highlight the potential of the supramolecular prodrug eyedrops as a versatile approach for the targeted treatment of CNV and other neovascular eye disorders.

Light-Activated Anti-Vascular Combination Therapy against Choroidal Neovascularization

Choroidal neovascularization (CNV) underlies the crux of many angiogenic eye disorders. Although medications that target vascular endothelial growth factor (VEGF) are approved for treating CNV, their effectiveness in destroying new blood vessels is limited, and invasive intravitreal administration is required. Additionally, other drugs that destroy established neovessels, such as combretastatin A-4, may have systemic side effects that limit their therapeutic benefits. To overcome these shortcomings, a two-pronged anti-vascular approach is presented for CNV treatment using a photoactivatable nanoparticle system that can release a VEGF receptor inhibitor and a vascular disrupting agent when irradiated with 690 nm light. The nanoparticles can be injected intravenously to enable anti-angiogenic and vascular disrupting combination therapy for CNV through light irradiation to the eyes. This approach can potentiate therapeutic effects while maintaining a favorable biosafety profile for choroidal vascular diseases.

Dietary intake of whale oil-containing ω-3 long-chain polyunsaturated fatty acids attenuates choroidal neovascularization in mice

Age-related macular degeneration (AMD) is a leading cause of blindness in Western and developing countries. Since antivascular endothelial growth factor (VEGF) therapy is available for the regression of choroidal neovascularization (CNV), it does not work for the pathophysiology of AMD so a cure is increasingly demanded. Whale oil promotes various bodily functions, such as anti-inflammatory effects for cardiovascular disease, but its physiological mechanisms are still unclarified. Here, we examined the effects of whale oil on a mouse model of AMD. The area of CNV measured in choroidal flat-mount preparations at 7 days after laser photocoagulation was significantly smaller in mice fed whale oil compared with control mice free of ω-3 long-chain polyunsaturated fatty acids (LCPUFAs). The plasma concentrations of ω-3 LCPUFAs were higher, whereas those of ω-6 LCPUFAs were lower in mice fed the diet containing whale oil than in those fed the control diet. The concentrations of various inflammatory cytokines and chemokines in the retina or choroid at 3 or 7 days after CNV induction differed between the two groups of mice. Furthermore, the concentration of VEGF was decreased in the retina but increased in the choroid at 7 or 3 days after photocoagulation, respectively. Our results thus show that dietary intake of whale oil-containing ω-3 LCPUFAs attenuated CNV in association with changes in inflammatory mediator levels and VEGF expression in the retina and choroid of mice, and it, therefore, warrants further study as a means to protect against AMD in humans.

Linking Adiponectin and Its Receptors to Age-Related Macular Degeneration (AMD)

In recent years, there has been a captivating focus of interest in elucidating the intricate crosstalk between adiponectin (APN), a versatile fat-associated adipokine and ocular pathologies. Unveiling the intricate relationship between adipocytokine APN and its receptors (AdipoRs) with aging eye disorders has emerged as a fascinating frontier in medical research. This review article delves into this connection, illuminating the hidden influence of APN on retinal health. This comprehensive review critically examines the latest findings and breakthroughs that underscore the pivotal roles of APN/AdipoRs signaling in maintaining ocular homeostasis and protecting against eye ailments. Here, we meticulously explore the intriguing mechanisms by which APN protein influences retinal function and overall visual acuity. Drawing from an extensive array of cutting-edge studies, the article highlights APN's multifaceted functions, ranging from anti-inflammatory properties and oxidative stress reduction to angiogenic regulation within retinal and macula tissues. The involvement of APN/AdipoRs in mediating these effects opens up novel avenues for potential therapeutic interventions targeting prevalent aging eye conditions. Moreover, this review unravels the interplay between APN signaling pathways and age-related macular degeneration (AMD). The single-cell RNA-seq results validate the expression of both the receptor isoforms (AdipoR1/R2) in retinal cells. The transcriptomic analysis showed lower expression of AdipoR1/2 in dry AMD pathogenesis compared to healthy subjects. The inhibitory adiponectin peptide (APN1) demonstrated over 75% suppression of CNV, whereas the control peptide did not exert any inhibitory effect on choroidal neovascularization (CNV). The elucidation of these relationships fosters a deeper understanding of adipose tissue's profound influence on ocular health, presenting new prospects for personalized treatments and preventative measures. Because APN1 inhibits CNV and leakage, it can be used to treat human AMD, although the possibility to treat human AMD is in the early stage and more clinical research is needed. In conclusion, this review provides a captivating journey into the enthralling world of APN, intertwining the realms of adipose biology and ophthalmology in aging.

A drug delivery system of HIF-1α siRNA nanoparticles loaded by mesenchymal stem cells on choroidal neovascularization

Aim: To assess mesenchymal stem cells (MSCs) as carriers for HIF-1α siRNA-loaded nanoparticles (NPs) for targeted therapy of experimental choroidal neovascularization (CNV).Materials & methods: A poly (lactic-co-glycolic acid) (PLGA)-core/lipid-shell hybrid NP was designed. The transfection efficacy of MSCs with the hybrid NPs was assessed. Mice were intravenously injected with MSCs after laser photocoagulation and CNV was assessed at 7 days post-injection.Results & conclusion: The transfection efficiency of hybrid NPs into MSCs was 72.7%. HIF-1α mRNA expression in 661w cells co-cultured with MSC-hybrid-siRNA NPs was significantly lower. Intravenous delivery of MSC-hybrid-siRNA NPs greatly reduced CNV area and length. Intravenous injection of MSC-hybrid-siRNA NPs achieved therapeutic efficacy in reducing CNV area. The MSC-mediated homing enabled targeted inhibition of ocular angiogenesis.