Publications by authors named "Armando Silva Cunha"

The purpose of this study was to determine corneal permeability and uptake in rabbit, porcine, and bovine corneas for twenty-five drugs using an N-in-1 (cassette) approach and relate these parameters to drug physicochemical properties and tissue thickness through quantitative structure permeability relationships (QSPRs). A twenty-five-drug cassette containing β-blockers, NSAIDs, and corticosteroids in solution at a micro-dose was exposed to the epithelial side of rabbit, porcine, or bovine corneas mounted in a diffusion chamber, and the corneal drug permeability and tissue uptake were monitored using an LC-MS/MS method. Data obtained were used to construct and evaluate over 46,000 quantitative structure-permeability (QSPR) models using multiple linear regression, and the best-fit models were cross-validated by Y-randomization.

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Background: Pseudophakic cystoid macular edema (PCME) is the most common cause of visual acuity deterioration after uncomplicated cataract surgery. There is no consensus regarding how to manage recurrent or refractory cases.

Report: A 54-year-old woman complained of decreased vision and central metamorphopsia in the right eye (OD) 3 months after uneventful cataract surgery.

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Background: Ocular toxoplasmosis is the leading cause of infectious posterior uveitis worldwide, accounting for 30-50% of all cases in immunocompetent patients. Conventional treatment is associated with adverse effects and does not prevent recurrence. Intravitreal drug administration can improve disease outcomes and reduce side effects.

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Intravitreal injections are the preferred choice for drug administration to the posterior segment of the eye. However, the required frequent injections may cause complications to the patient and low adherence to the treatment. Intravitreal implants are able to maintain therapeutic levels for a long period.

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Mometasone furoate (MF) is a medium-potency synthetic glucocorticosteroid with anti-inflammatory, antipruritic, and vasoconstrictive properties. However, its role in the treatment of ocular inflammation has not yet been explored. This work investigated the anti-inflammatory activity of MF in ocular tissues.

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Ocular chemical burns are prevalent injuries that must have immediate and effective treatment to avoid complications. Aiming to improve bioavailability and efficacy, a poloxamer-based thermoresponsive in-situ gelling system containing hyaluronic acid and indomethacin was developed. Formulations with different polymeric proportions were screened through rheological measurements resulting in an optimized system (F2) with gelling temperature of 34.

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Doxorubicin (DOX) is an antineoplastic agent clinically employed for treating breast cancer patients. Despite its effectiveness, its inherent adverse toxic side effects often limit its clinical application. To overcome these drawbacks, lipid-polymer hybrid nanoparticles (LPNP) arise as promising nanoplatforms that combine the advantages of both liposomes and polymeric nanoparticles into a single delivery system.

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Sodium butyrate-loaded nanoparticles coated chitosan (NaBu-loaded nanoparticles/CS) were developed to treat the choroidal neovascularization in wet age-related macular degeneration (AMD). The nanoparticles were produced by double emulsification and solvent evaporation technique, optimized by experimental statistical design, characterized by analytical methods, investigated in terms of in vitro and in vivo ocular biocompatibility, and evaluated as an antiangiogenic system in vivo. The NaBu-loaded nanoparticles/CS were 311.

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Article Synopsis
  • Researchers developed new lipid-polymer hybrid nanoparticles, called Spheroplexes, for delivering small interfering RNAs (siRNAs) to induce gene silencing more effectively than traditional lipid-based delivery systems.
  • The Spheroplexes consist of a hydrophobic PLGA core surrounded by a lipid layer that retains the characteristics of the original lipoplexes, and they showed high stability and efficiency in delivering siRNAs to cultured cells.
  • In animal studies, Spheroplexes targeting TNF-α demonstrated a significant regression of ulcerative colitis, suggesting their potential for oral siRNA delivery to the colon.
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The eye is an organ with limited drug access due to its anatomical and physiological barriers, and the usual forms of ocular administration are limited in terms of drug penetration, residence time, and bioavailability, as well as low patient compliance. Hence, therapeutic innovations in new drug delivery systems (DDS) have been widely explored since they show numerous advantages over conventional methods, besides delivering the content to the eye without interfering with its normal functioning. Polymers are usually used in DDS and many of them are applicable to ophthalmic use, especially biodegradable ones.

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Uveitis is a group of sight-threatening ocular inflammatory disorders, whose mainstay of therapy is associated with severe adverse events, prompting the investigation of alternative treatments. The peptide melittin (MEL) is the major component of bee venom and presents anti-inflammatory and antiangiogenic activities, with possible application in ophthalmology. This work aims to investigate the potential of intravitreal MEL in the treatment of ocular diseases involving inflammatory processes, especially uveitis.

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There have been major advances in the treatment of eye diseases over the last years [...

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Lupeol is a pentacyclic triterpene with known anti-inflammatory effects. However, its role in the treatment of noninfectious uveitis has not been explored. This work investigated anti-inflammatory activity of lupeol in ocular tissues with in vitro and in vivo models.

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Since the possibility of silencing specific genes linked to retinal degeneration has become a reality with the use of small interfering RNAs (siRNAs), this technology has been widely studied to promote the treatment of several ocular diseases. Despite recent advances, the clinical success of gene silencing in the retina is significantly reduced by inherent anatomical and physiological ocular barriers, and new strategies are required to achieve intraocular therapeutic effectiveness. In this study, we developed lipoplexes, prepared with sodium alginate as an adjuvant and strategically coated with hyaluronic acid (HA-LIP), and investigated the potential neuroprotective effect of these systems in a retinal light damage model.

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Purpose: Assessment of the anti-angiogenic activity and the safety of ophthalmic use of four pentacyclic triterpenes (friedelin, friedelinol, lupenone, and lupeol).

Methods: Triterpenes cytotoxicity (5-640 µmol L) was examined in ARPE-19 cells by sulforhodamine B colorimetric method, and the anti-angiogenic activity (50-1000 µmol L) was evaluated in the chorioallantoic membrane model. Full-field electroretinography and histological analysis were performed to evaluate intraocular effects of these four triterpenes (at 100 or 500 μmol L) in eyes of Wistar rats, for 15 days.

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Purpose: To report the first patient with ocular toxoplasmosis treated with a slow-release biodegradable intravitreal clindamycin implant.

Observations: A 39-year-old human immunodeficiency virus (HIV)-positive woman with recurrent toxoplasmic retinochoroiditis and vitritis for whom oral medication was medically contraindicated was treated with an intravitreal slow-release clindamycin implant and three monthly intravitreal injections of clindamycin and dexamethasone. Serial ophthalmologic examinations demonstrated gradual, complete resolution of posterior uveitis and healing of the retinochoroidal lesion with cicatricial changes, as well as gradual improvement of cells in the anterior chamber.

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Biodegradable polymeric nanofibers containing mometasone furoate can be a new approach to drug delivery to treat chronic rhinosinusitis, providing controlled steroid delivery to the sinonasal mucosa. This study aimed to develop biodegradable polymeric nanofibers and explore the safety of these fibers in an in vivo rabbit model. The nanofibers' development has been optimized using the Response Surface Methodology (RSM) obtained with Design of Experiments (DoE) with the best conditions related to the polymer concentration and proportion of solvents used in the electrospinning process.

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This study investigated the safety and therapeutic efficacy of licarin A (LCA) in the treatment of intraocular inflammation. safety of LCA in retinal pigmented epithelial cells (ARPE-19) and human embryonic stem cell derived-retinal pigmented epithelial cells (hES-RPE) was evaluated using CellTiter-Blue kit. The chorioallantoic membrane (CAM) assay was used to investigate LCA safety and antiangiogenic activity.

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Non-infectious uveitis, an ocular inflammatory condition that affects the iris, ciliary body, choroid, and adjacent tissues (retina, optic nerve, and vitreous), is an important cause of blindness worldwide. Sirolimus (SRL), a potent immunomodulatory drug, has shown promising results in the treatment of inflammatory ocular diseases. Despite this therapeutic potential, its clinical use is a major challenge due to low bioavailability and poor solubility.

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Article Synopsis
  • - The study focuses on human Pluripotent Stem Cell (hPSC) technology, specifically using human Embryonic Stem cell derived-Retinal Pigmented Epithelial Cells (hES-RPE) for applications like cell therapy and drug screening, aiming to address eye diseases with a high socioeconomic impact.
  • - Research findings indicate that hES-RPE cells more closely mimic natural Retinal Pigmented Epithelial (RPE) cells compared to the widely used ARPE-19 cell line, showcasing superior resilience when exposed to various immunosuppressive drugs.
  • - The results suggest that hES-RPE cells could perform a wider range of RPE functions than ARPE-19, making them a promising candidate for future drug
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Neurovespina is a synthetic peptide modified from Occidentalin-1202, a nine amino acid residue peptide isolated from the venom of the social wasp Polybia occidentalis. Previous studies showed that this peptide has a neuroprotective effect on the central nervous system, but its action on the eye has not been explored. So, the objective of this work was to investigate the neuroprotective effect of Neurovespina on the retina and its angiogenic potential in the chicken chorioallantoic membrane (CAM).

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Vancomycin-loaded N,N-dodecyl,methyl-polyethylenimine nanoparticles coated with hyaluronic acid (VCM-DMPEI nanoparticles/HA) were synthesized as an adjuvant for the treatment of bacterial endophthalmitis. The nanoparticles were formulated by experimental statistical design, thoroughly characterized, and evaluated in terms of bactericidal activity and both in vitro and in vivo ocular biocompatibility. The VCM-DMPEI nanoparticles/HA were 154 ± 3 nm in diameter with a 0.

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Tacrolimus (TAC), a potent immunosuppressive macrolide, has been investigated for ocular diseases due to promising results in the treatment of anterior and posterior segments eye diseases. Mesoporous and functionalized silica nanoparticles show potential as TAC delivery platforms owing to their interesting characteristic as large surface area, uniform pore size distribution, high pore volume, and excellent biocompatibility. The purpose of this study was to incorporate TAC in functionalized silica nanoparticles with 3-aminopropyltriethoxysilane (MSNAPTES) and investigate the safety and biocompatibility of the systems.

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Retinal ischemia, one of the most common cause of visual loss, is associated with blood flow inadequacy and subsequent tissue injury. In this setting, some treatments that can counteract glutamate increase, arouse interest in ischemic pathogenesis. Ketamine, a potent N-methyl-d-aspartate (NMDA) receptor antagonist, provides a neuroprotective pathway via decreasing the excitotoxicity triggered by excess glutamatergic.

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