RESUMO
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. Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable polymer commonly used for ophthalmic drug delivery due to its suitable characteristics such as biocompatibility, good mechanical properties, and improvement of the pharmacokinetic profile of the drug. In the present study, we investigated the effects of SRL-PLGA implant on experimental autoimmune uveitis in rabbits. Clinical and histopathological examinations were performed, followed by assessment of protein levels and determination of myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activity in the aqueous humor/vitreous. As a result, treated eyes had decreased average inflammatory scores, protein significant decreases in treated eyes, assessed after 35 days. Histopathological examination showed less severe intraocular inflammation and decreased tissue damage in treated eyes. According to these results, the SRL-PLGA implant evaluated in this study was apparently safe, reducing inflammation in treated eyes, with an extended effect possibly associated with prolonged release of SRL in the posterior segment of the eye. Therefore, intravitreal SRL-PLGA implant could be a promising alternative for treatment of non-infectious uveitis.
Assuntos
Implantes de Medicamento , Imunossupressores/administração & dosagem , Sirolimo/administração & dosagem , Uveíte/tratamento farmacológico , Corpo Vítreo , Animais , Imunossupressores/uso terapêutico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Coelhos , Sirolimo/uso terapêutico , SolubilidadeRESUMO
Rosmarinic acid, a plant-derived compound with antiangiogenic activity, can be applied for the treatment of ocular diseases related to neovascularization, such as diabetic retinopathy, macular edema, and age-related macular degeneration. These diseases represent the leading causes of blindness worldwide if they are not properly treated. Intravitreal devices allow for localized drug delivery to the posterior segment, increasing the drug bioavailability and promoting extended release, thus, reducing side effects and enhancing the patient's compliance to the treatment. In this work, rosmarinic acid-loaded poly lactic-co-glycolic acid intraocular implants were developed with a view for the treatment of ocular neovascularization. Physical-chemical, biocompatibility, and safety studies of the implants were carried out in vitro and in vivo as well as an evaluation of the antiangiogenic activity in a chorioallantoic membrane assay. Data obtained showed that rosmarinic acid released from the implants was quantified in the vitreous for 6 weeks, while when it was in the solution formulation, after 24 h, no drug was found in the vitreous. The delivery device did not show any sign of toxicity after clinical evaluation and in electroretinographic findings. Histological analysis showed normal eye tissue. Rosmarinic acid released from implants reduced 30% of new vessel's formation. The intravitreal implant successfully allowed for the prolonged release of rosmarinic acid, was safe to rabbits eyes, and demonstrated activity in vessel reduction, thus demonstrating potential in preventing neovascularization in ophthalmic diseases.
Assuntos
Depsídeos , Corpo Vítreo , Animais , Cinamatos , Depsídeos/farmacologia , Humanos , Injeções Intravítreas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Ácido RosmarínicoRESUMO
The subretinal transplantation of retinal pigment epithelial cells (RPE cells) grown on polymeric supports may have interest in retinal diseases affecting RPE cells. In this study, montmorillonite based polyurethane nanocomposite (PU-NC) was investigated as substrate for human RPE cell growth (ARPE-19 cells). The ARPE-19 cells were seeded on the PU-NC, and cell viability, proliferation and differentiation were investigated. The results indicated that ARPE-19 cells attached, proliferated onto the PU-NC, and expressed occludin. The in vivo ocular biocompatibility of the PU-NC was assessed by using the HET-CAM; and through its implantation under the retina. The direct application of the nanocomposite onto the CAM did not compromise the vascular tissue in the CAM surface, suggesting no ocular irritancy of the PU-NC film. The nanocomposite did not elicit any inflammatory response when implanted into the eye of rats. The PU-NC may have potential application as a substrate for RPE cell transplantation.
Assuntos
Bentonita/química , Proliferação de Células , Poliuretanos/química , Epitélio Pigmentado da Retina/fisiologia , Alicerces Teciduais , Silicatos de Alumínio/síntese química , Silicatos de Alumínio/química , Silicatos de Alumínio/farmacologia , Animais , Bentonita/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Argila , Feminino , Humanos , Teste de Materiais , Nanocompostos/química , Poliuretanos/síntese química , Ratos , Ratos Endogâmicos BN , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Engenharia Tecidual/instrumentação , Engenharia Tecidual/métodos , Alicerces Teciduais/químicaRESUMO
Uveitis encompasses a heterogeneous and complex group of conditions characterized by intraocular inflammation, frequently affecting young individuals and representing an important cause of irreversible blindness worldwide. Animal models have been critical to understand etiology and pathogenesis of uveitis, being also employed to assess new therapeutic strategies, preceding human studies. However, there is still a need of developing and studying different models, due to the difficulties in recapitulating all forms of human uveitis effectively. Although corticosteroids are usually the first-line therapy for non-infectious uveitis, their long-term use is limited by potentially serious side effects in all possible delivery routes. Thus, thalidomide, a drug with anti-inflammatory and antiangiogenic properties, was investigated in a novel experimental model of uveitis, induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG), in rabbits. The experimental protocol consisted of two subcutaneous injections of BCG, followed by two intravitreal injections of the same antigen, inducing panuveitis. Animals were treated with a single intravitreal injection of thalidomide suspension or PBS. Clinical manifestations of uveitis improved after intravitreal thalidomide, involving both anterior and posterior segments. Protein content, N-acetyl-b-glucosaminidase (NAG) and myeloperoxidase (MPO) activities were elevated in ocular tissues after disease induction, further decreasing post-treatment with intravitreal thalidomide. This therapeutic response was also confirmed on ocular electrophysiology, as well as histopathology. This experimental model induced panuveitis in rabbits using a low-cost mycobacterial antigen, with intraocular inflammation subsequently improving after treatment. Intravitreal thalidomide may be a potential alternative to treat intraocular inflammation in corticosteroid-sparing therapies.
Assuntos
Anti-Inflamatórios/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Pan-Uveíte/tratamento farmacológico , Retina/metabolismo , Talidomida/uso terapêutico , Uveíte/tratamento farmacológico , Animais , Humanos , Injeções Intravítreas , Modelos Animais , Mycobacterium bovis/imunologia , Pan-Uveíte/imunologia , Peroxidase/metabolismo , Coelhos , Retina/efeitos dos fármacos , Retina/patologiaRESUMO
The [18F]Fluorocholine ([18F]FCH) tracer for PET imaging has been proven to be effective for several malignances. However, there are only a few studies related to its breast tumor applicability and they are still limited. The aim of this study was investigate the efficacy of [18F]FCH/PET compared to [18F]FDG/PET in a murine 4T1 mammary carcinoma model treated and nontreated. [18F]FCH/PET showed its applicability for primary tumor and lung metastasis detection and their use for response monitoring of breast cancer therapeutics at earlier stages.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias Mamárias Experimentais/diagnóstico por imagem , Animais , Antineoplásicos/uso terapêutico , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Colina/análogos & derivados , Cinamatos/uso terapêutico , Depsídeos/uso terapêutico , Progressão da Doença , Feminino , Radioisótopos de Flúor , Fluordesoxiglucose F18 , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/terapia , Camundongos , Camundongos Endogâmicos BALB C , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Ácido RosmarínicoRESUMO
Uncontrolled angiogenesis is directly associated with ocular diseases such as macular degeneration and diabetic retinopathy. Implantable polymeric drug delivery systems have been proposed for intravitreal applications and in the present work, we evaluated the antiangiogenic potential of PLGA ocular implants loaded with the triterpene lupeol using in vitro and in vivo models. The drug/polymer physiochemical properties of the lupeol-loaded PLGA were validated as functionally similar using differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Interestingly, in an in vitro culture system, lupeol (100µg/mL and 250µg/mL) was capable to inhibited the proliferation as well as the migration of Human Umbilical Vein Endothelial Cells (HUVEC), without interfering in cell viability, promoting a significant reduction in the percentage of vessels (39.41% and 44.12%, respectively), compared with the control group. In vivo test, by using the chorioallantoic membrane (CAM) model, lupeol-loaded PLGA ocular implants showed antiangiogenic activity comparable to the FDA-approved anti-VEGF antibody Bevacizumab. Overall, our results suggest lupeol-loaded PLGA ocular implants were able to inhibit the angiogenic process by impairing both proliferation and migration of endothelial cells.
Assuntos
Inibidores da Angiogênese/administração & dosagem , Membrana Corioalantoide/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Ácido Láctico/administração & dosagem , Triterpenos Pentacíclicos/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Inibidores da Angiogênese/isolamento & purificação , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Membrana Corioalantoide/metabolismo , Relação Dose-Resposta a Droga , Implantes de Medicamento , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Injeções Intravítreas , Maytenus , Triterpenos Pentacíclicos/isolamento & purificação , Extratos Vegetais/administração & dosagem , Extratos Vegetais/isolamento & purificação , Caules de Planta , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
PURPOSE: Excessive subconjunctival scarring is associated with increased angiogenesis and leads to filtration failure in glaucoma surgery. In this study, we describe that rosmarinic acid (RA) has anti-angiogenic activity during wound healing in a rabbit model of glaucoma surgery. METHODS: Forty New Zealand rabbits underwent an experimental trabeculectomy and were randomly allocated into two treatment groups: RA group - treated with subconjunctival injections of 0.1 ml RA (15 mg/ml; n = 20) - and control group - treated with subconjunctival injections of 0.1 ml balanced salt solution (n = 20). The in vivo effect of RA was investigated after 5 and 15 d by measuring the intraocular pressure (IOP; with Tonopen) and bleb area and vascularity (using the Moorfields Bleb Grading System). Vascularization was also studied by counting histological blood vessels and by immunohistochemistry of vascular endothelial growth factor (VEGF) at the surgical site and by quantification of vessels in chicken's chorioallantoic membrane (CAM), treated with AR 500 µg/ml for 48 h. RESULTS: On the fifth day, eyes of RA group displayed higher bleb area (3.6 ± 0.2 versus 1.8 ± 0.2; p = 0.004) and lower vascularity (3.0 ± 0.5 versus 4.0 ± 0.4; p = 0.009) than controls; however, difference in IOP reduction was not significant (-1.4 ± 0.3 versus -0.8 ± 0.3 mmHg; p = 0.226). Proportion of vessels/field (4.6 ± 0.5 versus 10.4 ± 0.9; p = 0.008) and VEGF immunostaining (15,347 ± 3788 versus 31,043 ± 3230; p = 0.019) also declined with RA treatment. However, at the 15th day, none of the parameters were different between the groups, except for vessels/field proportion (5.4 ± 1.0 versus 10.6 ± 1.6; p = 0.035). CAM exposed to AR inhibited vascularization (-45.67 ± 4.74%; p < 0.001). CONCLUSION: These data indicate RA has a short-term anti-angiogenic effect and could be a potential modulator of neovascularization during subconjunctival healing at glaucoma filtration surgical sites.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Antioxidantes/uso terapêutico , Cinamatos/uso terapêutico , Túnica Conjuntiva/irrigação sanguínea , Depsídeos/uso terapêutico , Glaucoma/cirurgia , Neovascularização Patológica/tratamento farmacológico , Trabeculectomia , Animais , Embrião de Galinha , Membrana Corioalantoide/irrigação sanguínea , Túnica Conjuntiva/metabolismo , Modelos Animais de Doenças , Feminino , Glaucoma/metabolismo , Glaucoma/fisiopatologia , Imuno-Histoquímica , Injeções Intraoculares , Pressão Intraocular/fisiologia , Coelhos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ácido RosmarínicoRESUMO
ABSTRACT: This study examined the efficacy of an intravitreal dexamethasone-loaded device for the control of postoperative ocular inflammation in dogs following phacoemulsification. Twenty dogs with bilateral mature senile cataracts were prepared for surgery using routine protocols. A biodegradable poly (lactic-co-glycolic acid) copolymer device was inserted through the pars plana into the vitreous chamber immediately before phacoemulsification (device group [DG], n=20). Following surgery, a conventional group (CG) received local and systemic steroids, mydriatics, and antibiotic therapy. The same treatment protocol was adopted in DG, except for steroids. All eyes were examined before surgery and at various times after phacoemulsification. Ultrasonography showed gradual device shrinkage, with only remnants remaining at postoperative day (POD) 60. Signs of uveitis were observed in 35% of the DG on POD 7, but by POD 14, 50% of eyes showed signs of uveitis and these eyes required local steroid therapy. The intraocular pressure (IOP) was higher in the DG than in the CG immediately after surgery. IOP did not differ on POD 7 and POD 14, but was lower during the late postoperative period (POD 30 to 90). Flare values were greater in the DG than in the CG immediately following surgery, but showed no subsequent differences. In summary, the intravitreal dexamethasone device did not adequately control intraocular inflammation in dogs undergoing phacoemulsification.
RESUMO: O estudo examinou a eficácia de um dispositivo intravítreo de liberação de dexametasona para o controle da inflamação ocular em cães, após facoemulsificação. Um dispositivo de copolímero poli (ácido lático-co-glicólico) foi implantado via pars plana na câmera vítrea, imediatamente antes da facoemulsificação (grupo dispositivo [GD], n=20). Após a cirurgia, o grupo controle (GC) recebeu terapia esteroide, midriático e antibiótico. O mesmo protocolo de tratamento foi adotado no GD, exceto pelos esteroides. Todos os olhos foram examinados antes do procedimento e em diferentes tempos após a facoemulsificação. A ultrassonografia mostrou que o dispositivo diminuiu em tamanho, sendo observado, apenas, remanescentes aos 60 dias de pós-operatório (DPO). Sinais de uveíte foram observados em 35% do GD no DPO 7, entretanto, no DPO 14, 50% dos olhos tiveram sinais de uveíte e requereram terapia esteroide local. A pressão intraocular (PIO) foi maior no GD, comparativamente ao GC, imediatamente após a cirurgia. A PIO não diferiu no DPO 7 e no DPO 14, entretanto foi menor nos momentos pós-operatórios mais tardios (DPO 30 a 90). Valores de flare foram maiores no GD que no GC, imediatamente após a cirurgia, mas não mostraram diferenças nos momentos subsequentes. Em suma, o dispositivo intravítreo de dexametasona não controlou adequadamente a inflamação intraocular em cães submetidos à facoemulsificação.