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Abstract Retinal pigment epithelial (RPE) cells are exclusive to the retina, critically multifunctional in maintaining the visual functions and health of photoreceptors and the retina. Despite their vital functions throughout lifetime, RPE cells lack regenerative capacity, rendering them vulnerable which can lead to degenerative retinal diseases. With advancements in stem cell technology enabling the differentiation of functional cells from pluripotent stem cells and leveraging the robust autocrine and paracrine functions of RPE cells, extracellular vesicles (EVs) secreted by RPE cells hold significant therapeutic potential in supplementing RPE cell activity. While previous research has primarily focused on the trophic factors secreted by RPE cells, there is a lack of studies investigating miRNA, which serves as a master regulator of gene expression. Profiling and defining the functional role of miRNA contained within RPE‐secreted EVs is critical as it constitutes a necessary step in identifying the optimal phenotype of the EV‐secreting cell and understanding the biological cargo of EVs to develop EV‐based therapeutics. In this study, we present a comprehensive profile of miRNA in small extracellular vesicles (sEVs) secreted during RPE maturation following differentiation from human embryonic stem cells (hESCs); early‐stage hESC‐RPE (20–21 days in culture), mid‐stage hESC‐RPE (30–31 days in culture) and late‐stage hESC‐RPE (60–61 days in culture). This exploration is essential for ongoing efforts to develop and optimize EV‐based intraocular therapeutics utilizing RPE‐secreted EVs, which may significantly impact the function of dysfunctional RPE cells in retinal diseases.

Abstract Retinal diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are characterized by unrelenting neuronal death. However, electrical stimulation has been shown to induce neuroprotective changes in the retina capable of slowing down the progression of retinal blindness. In this work, a multi-scale computational model and modeling platform were used to design electrical stimulation strategies to better target the bipolar cells (BCs), that along with photoreceptors are affected at the early stage of retinal degenerative diseases. Our computational findings revealed that biphasic stimulus pulses of long pulse duration could decrease the activation threshold of BCs, and the differential stimulus threshold between ganglion cells (RGCs) and BCs, offering the potential of targeting the BCs during the early phase of degeneration. In vivo experiments were performed to evaluate the electrode placement and parameters found to target bipolar cells and evaluate the safety and efficacy of the treatment. Results indicate that the proposed transcorneal Electrical Stimulation (TES) strategy can attenuate retinal degeneration in a Royal College of Surgeon (RCS) rodent model, offering the potential to translate this work to clinical practice.

Retinal degenerative diseases, including age-related macular degeneration and retinitis pigmentosa, significantly contribute to adult blindness. The Royal College of Surgeons (RCS) rat is a well-established disease model for studying these dystrophies; however, molecular investigations remain limited. We conducted a comprehensive analysis of retinal degeneration in RCS rats, including an immunodeficient RCS (iRCS) sub-strain, using ocular coherence tomography, electroretinography, histology, and molecular dissection using transcriptomics and immunofluorescence. No significant differences in retinal degeneration progression were observed between the iRCS and immunocompetent RCS rats, suggesting a minimal role of adaptive immune responses in disease. Transcriptomic alterations were primarily in inflammatory signaling pathways, characterized by the strong upregulation of Tnfa, an inflammatory signaling molecule, and Nox1, a contributor to reactive oxygen species (ROS) generation. Additionally, a notable decrease in Alox15 expression was observed, pointing to a possible reduction in anti-inflammatory and pro-resolving lipid mediators. These findings were corroborated by immunostaining, which demonstrated increased photoreceptor lipid peroxidation (4HNE) and photoreceptor citrullination (CitH3) during retinal degeneration. Our work enhances the understanding of molecular changes associated with retinal degeneration in RCS rats and offers potential therapeutic targets within inflammatory and oxidative stress pathways for confirmatory research and development.

Retinitis pigmentosa (RP) is a retinal degenerative disease associated with a diversity of genetic mutations. In a natural progression study (NPS) evaluating the molecular changes in Royal College of Surgeons (RCS) rats using lipidomic profiling, RNA sequencing, and gene expression analyses, changes associated with retinal degeneration from p21 to p60 were evaluated, where reductions in retinal ALOX15 expression corresponded with disease progression. This important enzyme catalyzes the formation of specialized pro-resolving mediators (SPMs) such as lipoxins (LXs), resolvins (RvDs), and docosapentaenoic acid resolvins (DPA RvDs), where reduced ALOX15 corresponded with reduced SPMs. Retinal DPA RvD2 levels were found to correlate with retinal structural and functional decline. Retinal RNA sequencing comparing p21 with p60 showed an upregulation of microglial inflammatory pathways accompanied by impaired damage-associated molecular pattern (DAMP) clearance pathways. This analysis suggests that ALXR/FPR2 activation can ameliorate disease progression, which was supported by treatment with an LXA4 analog, NAP1051, which was able to promote the upregulation of ALOX12 and ALOX15. This study showed that retinal inflammation from activated microglia and dysregulation of lipid metabolism were central to the pathogenesis of retinal degeneration in RP, where ALXR/FPR2 activation was able to preserve retinal structure and function.

Retinal pigment epithelial (RPE) cells are exclusive to the retina, critically multifunctional in maintaining the visual functions and health of photoreceptors and the retina. Despite their vital functions throughout lifetime, RPE cells lack regenerative capacity, rendering them vulnerable which can lead to degenerative retinal diseases. With advancements in stem cell technology enabling the differentiation of functional cells from pluripotent stem cells and leveraging the robust autocrine and paracrine functions of RPE cells, extracellular vesicles (EVs) secreted by RPE cells hold significant therapeutic potential in supplementing RPE cell activity. While previous research has primarily focused on the trophic factors secreted by RPE cells, there is a lack of studies investigating miRNA, which serves as a master regulator of gene expression. Profiling and defining the functional role of miRNA contained within RPE‐secreted EVs is critical as it constitutes a necessary step in identifying the optimal phenotype of the EV‐secreting cell and understanding the biological cargo of EVs to develop EV‐based therapeutics. In this study, we present a comprehensive profile of miRNA in small extracellular vesicles (sEVs) secreted during RPE maturation following differentiation from human embryonic stem cells (hESCs); early‐stage hESC‐RPE (20–21 days in culture), mid‐stage hESC‐RPE (30–31 days in culture) and late‐stage hESC‐RPE (60–61 days in culture). This exploration is essential for ongoing efforts to develop and optimize EV‐based intraocular therapeutics utilizing RPE‐secreted EVs, which may significantly impact the function of dysfunctional RPE cells in retinal diseases. [ABSTRACT FROM AUTHOR]

Retinal degenerative diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa, lack effective therapies. Conventional monotherapeutic approaches fail to target the multiple affected pathways in retinal degeneration. However, the retinal pigment epithelium (RPE) secretes several neurotrophic factors addressing diverse cellular pathways, potentially preserving photoreceptors. This study explored human embryonic stem cell-derived, polarized RPE soluble factors (PRPE-SF) as a combination treatment for retinal degeneration. PRPE-SF promoted retinal progenitor cell survival, reduced oxidative stress in ARPE-19 cells, and demonstrated critical antioxidant and anti-inflammatory effects for preventing retinal degeneration in the Royal College of Surgeons (RCS) rat model. Importantly, PRPE-SF treatment preserved retinal structure and scotopic b-wave amplitudes, suggesting therapeutic potential for delaying retinal degeneration. PRPE-SF is uniquely produced using biomimetic membranes for RPE polarization and maturation, promoting a protective RPE secretome phenotype. Additionally, PRPE-SF is produced without animal serum to avoid immunogenicity in future clinical development. Lastly, PRPE-SF is a combination of neurotrophic factors, potentially ameliorating multiple dysfunctions in retinal degenerations. In conclusion, PRPE-SF offers a promising therapeutic candidate for retinal degenerative diseases, advancing the development of effective therapeutic strategies for these debilitating conditions.

Purpose: This article aims to assess strategy and technology as key drivers of Greek businesses’ digital transformation and compare the results to those of international studies and sources.

Purpose: To assess the transretinal penetration of intravitreally injected retinal multicell-derived exosomes and to develop exosome-based active targeting of choroidal neovascularization (CNV) by bioengineering with ASL, which is composed of a membrane Anchor (BODIPY), Spacer (PEG), and targeting Ligands (cyclic RGD peptide). Methods: Retinal multicell-derived exosomes were recovered from a whole mouse retina using differential ultracentrifugation. Their size, number, and morphology were characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Exosome markers were confirmed using an exosome detection antibody array. Intravitreal injection of fluorescent (PKH-26)-labeled or engineered ASL exosomes (1 × 106 exosomes/μL) were given to the wild-type mouse or laser-induced CNV mouse model. Retinal uptake of exosomes was assessed by in vivo retinal imaging microscopy and histological staining with DAPI, GSA, and anti-integrin αv for retinal sections or choroid/RPE flat mounts. Active targeting of CNV was assessed by comparing retinal uptake between areas with and without CNV and by colocalization analysis of ASL exosomes with integrin αv within CNV. Staining with anti-F4/80, anti-ICAM-1, and anti-GFAP antibodies on retinal sections were performed to identify intracellular uptake of exosomes and immediate reactive retinal gliosis after exosome treatment. Results: An average of 2.1 × 109 particles/mL with a peak size of 140 nm exosomes were recovered. Rapid retinal penetration of intravitreally injected exosomes was confirmed by retinal imaging microscopy at 3 and 24 h post-injection. Intravitreally delivered PKH-26-labeled exosomes reached inner and outer retinal layers including IPL, INL, OPL, and ONL at 1 and 7 days post-injection. Intravitreally injected ASL exosomes were predominantly delivered to the area of CNV including ONL, RPE, and choroid in laser-induced CNV mouse models with 89.5% of colocalization with integrin αv. Part of exosomes was also taken intracellularly to vascular endothelial cells and macrophages. After intravitreal injection, neither naive exosomes nor ASL exosomes induced immediate reactive gliosis. Conclusions: Intravitreally delivered retinal multicell-derived exosomes have good retinal penetration, and ASL modification of exosomes actively targets CNV with no immediate reactive gliosis. ASL exosomes have a great potential to serve as an intraocular drug delivery vehicle, allowing an active targeting strategy.

This paper discusses the defence Science, Technology & Innovation (STI) investment within NATO. As a complex process it involves multiple stakeholders with common interest in development of knowledge through R&D activities, connecting current and future military capabilities. The objective is to generate and provide evidence-based scientific advice to decision-makers and deliver advanced solutions to national and NATO challenges. This process can generate valuable intangible assets for the Alliance in form of information and knowledge-based capital. The challenge for NATO is to manage and exploit the advantages of collective defence STI on behalf of its 29 members. The article approaches defence STI policies in comparison with power of politics and national as well as industrial interests. The attempt to quantify scientific knowledge as added value with significant return on investment unfolds the dynamics and vulnerabilities within NATO’s corporate culture. Although complexity is the main argument and preassumption, multidisciplinary aspects (political, economic, social, technological, and legal) are carefully examined and explored, providing a comprehensive approach of its strategic value to the Alliance.

Purpose: To report a case of isolated medial orbital wall fracture with enophthalmos in a paediatric patient and describe the clinical presentation and findings by means of computed tomography (CT) of the head and eyes. Methods: We looked at the patient’s medical and ophthalmologic history, and an ophthalmologic examination and a CT of the head were performed at baseline. Results: A 14-year-old boy was admitted to the emergency department of our institution with ecchymosis of his right eyelids secondary to a sport accident. Physical examination revealed a moderate limitation of upgaze without diplopia. CT showed a medial orbital wall fracture without haemorrhage and a gross accumulation of air in the right eyelid with pressure exertion over the right globe and enophthalmos. The patient was treated conservatively with oral antibiotics and steroids showing dramatic improvement within 1 week. Enophthalmos and periorbital emphysema were completely resolved within 3 months after the accident as indicated by CT. Conclusions: We conclude that surgical intervention and intravenous treatment are not warranted in similar cases of medial orbital wall fracture. Medical history, clinical and paraclinical evaluations, and a regular follow-up, including CT, are needed though to avoid complications such as painful abduction, horizontal diplopia, pseudo sixth nerve paresis, or pseudo Duane.