Publications by authors named "Armando Da Silva-Cunha Junior"

Ursolic acid (UA) is an abundant natural product and has shown great promise for treating diseases related to the appearance of new blood vessels. However, its clinical use is limited due to its low solubility in aqueous media, resulting in reduced bioavailability. The present study aimed to synthetize poly(lactic-co-glycolic acid) nanoparticles loaded with UA by nanoprecipitation method and to evaluate the toxicity and anti-angiogenic activity using the chorioallantoic model.

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Glaucoma, a leading cause of irreversible blindness, affects about 70 million people globally. Its treatment focuses on reducing intraocular pressure. Acetazolamide, a potent anti-glaucoma drug, is currently used only systemically due to low solubility and permeation, which cause severe side effects.

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Purpose: The purpose of this study was to investigate the vascular effects of photobiomodulation using a light-emitting diode on the chorioallantoic embryonic membrane of chicken eggs grouped into different times of exposure and to detect the morphological changes induced by the light on the vascular network architecture using quantitative metrics.

Methods: We used a phototherapy device with light-emitting diode (670 nm wavelength) as the source of photobiomodulation. We applied the red light at a distance of 2.

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The venom of the "armed" spider comprises several potent toxins. One of the most toxic components from this venom is the neurotoxin PnTx2-6 (LD = ∼ 0.7 μg/mouse, 48 residues, five disulfide bridges, MW = 5,289.

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Glaucoma is a heterogeneous group of multifactorial optic neuropathies and the leading cause of irreversible blindness and visual impairment. Epidemiological data has estimated that in 2020 there will be more than 80 million individuals affected by the disease worldwide. Nowadays, intraocular pressure (IOP) lowering is carried out mainly by pharmacotherapy, with different drugs.

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Considering the many biological activities of nitric oxide (NO), some lines of research focused on the modulation of these activities through the provision of this mediator by designing and synthesizing compounds coupled with an NO donor group. Thus, the objectives of the present study were to carry out an electrochemical investigation of the nitrooxy compound 4-((nitrooxy) methyl)-3-nitrobenzoic acid (1) and evaluate its activities and putative mechanisms in experimental models of pain and inflammation. Voltammetric studies performed in aprotic medium (mimetic of membranes) showed important electrochemical reduction mechanisms: nitroaromatic reduction, self-protonation, and finally reductive elimination, which leads to nitrate release.

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Bacterial keratitis is an ocular infection that can lead to severe visual disability. is a major pathogen of the eye. We recently demonstrated the strong antimicrobial activity of LyeTxI-b, a synthetic peptide derived from a toxin.

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Age-related macular degeneration (AMD) is a degenerative ocular disease that affects the central retina. It is considered the main cause of blindness and loss of vision worldwide. Angiogenic factors are associated with AMD, which has led to the use of antiangiogenic drugs, such as bevacizumab, to treat the disease using frequent intravitreal injections.

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Angiogenesis, the complex process of formation of new blood vessels from pre-existing blood vessels, which involves the participation of several pro- and anti-angiogenic factors, is implicated in many physiological and pathological conditions. Nanoparticle-based anti-angiogenic activity at the tumour tissue, harnessed by the Enhanced Permeability and Retention Effect (EPR effect), could potentially become a breakthrough therapy to halt tumour progression. Herein, we evaluate the anti-angiogenic effect of ZnWO nanoparticles (NPs).

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Despite advances in the development of new therapeutic agents and diagnostic imaging techniques, the 5-year survival of osteosarcoma, the most common type of bone cancer, remains practically unaltered for the last three decades at around 60%. Nanoparticle-based carriers have emerged as new class of drug delivery systems that could potentially overcome conventional chemotherapy limitations, by promoting a better drug biodistribution profile by allowing a preferential accumulation of the drug in the desired tissue, while minimising non-targeted tissue toxicity, thus resulting in an improved overall therapeutic effectiveness. Hydroxyapatite nanoparticles (HANP) are known to be biocompatible and non-immunogenic and have shown to be preferentially accumulated in bone tissues being considered a promising carrier to bone tissues.

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Purpose: To evaluate the safety and feasibility of a 25-gauge biodegradable implant containing 350 μg of dexamethasone (DDS-25) for the treatment of decreased vision due to macular edema associated with central or branch retinal vein occlusion.

Methods: Prospective, nonrandomized, open-label, Phase I clinical trial, including 10 patients with decreased vision (best-corrected early treatment diabetic retinopathy study visual acuity of 20/40 or worse) due to macular edema associated with central retinal vein occlusion (n = 4) or branch retinal vein occlusion (n = 6) for more than 4 months. Comprehensive ophthalmic evaluation, including best-corrected visual acuity, spectral domain optical coherence tomography (Spectralis Heidelberg Engineering) for determination of central subfield thickness, full-field electroretinography (ISCEV standard ERG), and fluorescein angiography, was performed at baseline, and 1, 4, 12, and 24 weeks after intravitreal DDS-25 insertion.

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Bevacizumab, a monoclonal anti-vascular endothelial growth factor antibody, has been suggested as a potential healing therapeutic following glaucoma surgery. Here, we aimed to improve the bioavailability of bevacizumab when used as an adjunct therapy to non-penetrating deep sclerectomy (DS) by using a bevacizumab-methylcellulose mixture (BMM). Ten previously non-operated eyes in ten patients diagnosed with primary open angle glaucoma underwent DS with a subconjunctival injection of 0.

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Infections caused by dermatophytes, mainly Trichophyton rubrum,are often vulnerable to relapses upon cessation of antifungal therapy, reinforcing the need of new antifungals. Aldimines have potential biological activities, but there are few reports on their antifungal profile. The aim of this study was to evaluate the antifungal activity of 2-(benzylideneamino)phenol (3A3) and 4-(benzylideneamino)phenol (3A4) against dermatophytes.

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Purpose: To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant.

Methods: A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear.

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Objective: The objective of the study is to evaluate the physical properties, in vitro release profile, and antibacterial efficiency of chitosan films prepared with ofloxacin.

Procedure: Mucoadhesive films were prepared by means of a casting and solvent evaporation technique performed in a 2 wt% acetic acid solution and distilled water. Physical properties were characterized by release and swelling studies, differential scanning calorimetry (DSC) analysis, and attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR) analysis.

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Unlabelled: In an attempt to improve the quality of life of patients with vitreous humor disease, ophthalmologists began offering steroid-eluting biodegradable implants to their patients. These implants can be used as an alternative treatment for CRS and this is why this experimental study was carried out on rabbit maxillary sinuses.

Objective: This study aims to assess the histology of the mucosa of the maxillary sinuses of rabbits after the placement of a prednisolone-eluting biodegradable implant.

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The purpose of this study was to develop triamcinolone acetonide-loaded polyurethane implants (TA PU implants) for the local treatment of different pathologies including arthritis, ocular and neuroinflammatory disorders. The TA PU implants were characterized by FTIR, SAXS and WAXS. The in vitro and in vivo release of TA from the PU implants was evaluated.

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Purpose: Chitosan, a cationic polysaccharide biopolymer with mucoadhesive properties, presents a promising future in the prolonged ocular delivery of drugs. The present study compared the efficacy and safety of chitosan-coated timolol maleate (TM) mucoadhesive film, using a 0.5% TM commercial ophthalmic solution in a rabbit model.

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Purpose: The present study aimed to evaluate an injectable extended-release formulation of prednisolone acetate (PA) for orbital administration.

Methods: Microspheres (MEs) of poly-e-caprolactone (PCL) containing PA were developed by the method of solvent evaporation. The MEs obtained were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), encapsulation efficiency and in vitro release profile.

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The diseases of the posterior segment of the eye are responsible for most cases of irreversible blindness worldwide. These conditions stimulate the development of new modalities of treatment for vitreoretinal diseases. The success in the treatment aims, mainly, the delivery of effective doses of pharmacological agents directly to the target sites.

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In this work we describe the development and characterization of a new formulation of insulin (INS). Insulin was complexed with cyclodextrins (CD) in order to improve its solubility and stability being available as a dry powder, after encapsulation into poly (D,L-lactic-co-glycolic acid) (PLGA) microspheres. The complex INS : CD was encapsulated into microspheres in order to obtain particles with an average diameter between 2 and 6 microm.

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