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1.
Rev Soc Bras Med Trop ; 56: e05522022, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37222350

RESUMO

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. Herein, we conducted a systematic review and meta-analysis on the efficacy of intravitreal injections for treating ocular toxoplasmosis. METHODS: The systematic search was conducted using PubMed, SciELO, and Google Scholar with the descriptors "ocular toxoplasmosis" AND "intravitreal". We analyzed studies that met the inclusion criteria, i.e., experimental cases in patients treated intravitreally for ocular toxoplasmosis. Considering the systematic review, we focused on the number of intravitreal injections, the therapeutic drug class, and the presence of preexisting conditions. To assess the efficacy of intravitreal injections, a meta-analysis was performed using visual acuity, side effects, disease recurrence, and inflammatory responses as variables. RESULTS: Intravitreal injection-induced side effects were rarely observed (0.49% [0.00, 1.51%] ). The use of antiparasitic and anti-inflammatory drugs afforded improved visual acuity (99.81% [98.60, 100.00%]) and marked effectiveness in treating ocular toxoplasmosis. CONCLUSIONS: Intravitreal injections may facilitate the successful treatment of ocular toxoplasmosis. However, clinicians should carefully evaluate the presence of preexisting conditions for ocular toxoplasmosis or previous diseases, as these can impact the decision to administer intravitreal injections.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Infecções Oculares , Toxoplasmose , Humanos
2.
ACS Appl Bio Mater ; 6(5): 1787-1797, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37126648

RESUMO

Bioengineered corneal tissue is a promising therapeutic modality for the treatment of corneal blindness as a substitute for cadaveric graft tissue. In this study, we fabricated a collagen gel using ultraviolet-A (UV-A) light and riboflavin as a photosensitizer (PhotoCol-RB) as an in situ-forming matrix to fill corneal wounds and create a cohesive interface between the crosslinked gel and adjacent collagen. The PhotoCol-RB gels supported corneal epithelialization and exhibited higher transparency compared to physically crosslinked collagen. We showed that different riboflavin concentrations yielded gels with different mechanical and biological properties. In vitro experiments using human corneal epithelial cells (hCECs) showed that hCECs are able to proliferate on the gel and express corneal cell markers such as cytokeratin 12 (CK12) and tight junctions (ZO-1). Using an ex vivo burst assay, we also showed that the PhotoCol-RB gels are able to seal corneal perforations. Ex vivo organ culture of the gels filling lamellar keratectomy wounds showed that the epithelium that regenerated over the PhotoCol-RB gels formed a multilayer compared to just a double layer for those that grew over physically cross-linked collagen. These gels can be formed either in situ directly on the wound site to conform to the geometry of a defect, or can be preformed and then applied to the corneal wound. Our results indicate that PhotoCol-RB gels merit further investigation as a way to stabilize and repair deep and perforating corneal wounds.


Assuntos
Colágeno , Córnea , Humanos , Colágeno/farmacologia , Regeneração , Riboflavina/farmacologia , Géis/farmacologia
3.
Cornea ; 42(1): 97-104, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35965399

RESUMO

PURPOSE: We recently showed that in situ-forming collagen gels crosslinked through multifunctional polyethylene glycol (PEG) supported corneal epithelialization 7 days after treatment of lamellar keratectomy wounds. In this study, we aimed to evaluate the longer-term regenerative effects of this gel in animals. METHOD: Corneal wound healing was assessed 60 days after lamellar keratectomy and gel treatment using slitlamp examination, optical coherence tomography (OCT), pachymetry, corneal topography, an ocular response analyzer, and tonometry. The corneas were evaluated for the presence of beta-tubulin, cytokeratin 3, zonula occludens-1, and alpha smooth muscle actin (SMA) markers. Gene expression of aldehyde dehydrogenase 3A1 (ALDH3A1), cluster of differentiation 31, CD163, alpha-SMA, hepatocyte growth factor, and fibroblast growth factor 2 (FGF-2) and protein expression of CD44 and collagen VI were evaluated. RESULTS: Intraocular pressure, corneal thickness, and hysteresis for the corneas treated with collagen-PEG gels did not significantly change compared with the saline group. However, placido disk topography revealed greater regularity of the central cornea in the gel-treated group compared to the saline group. The gel-treated group exhibited a lower degree of epithelial hyperplasia than the saline group. Immunohistochemical and gene expression analysis showed that the gel-treated corneas exhibited lower alpha-SMA expression compared with the saline group. CD163 and CD44 were found to be elevated in the saline-treated group compared with normal corneas. CONCLUSIONS: The in situ-forming collagen-PEG gel promoted epithelialization that improved central corneal topography, epithelial layer morphology, and reduced expression of fibrotic and inflammatory biomarkers after 60 days compared to the saline group.


Assuntos
Lesões da Córnea , Hidrogéis , Animais , Polietilenoglicóis , Seguimentos , Colágeno/metabolismo , Córnea/metabolismo
4.
Rev. Soc. Bras. Med. Trop ; 56: e0552, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1441077

RESUMO

ABSTRACT 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. Herein, we conducted a systematic review and meta-analysis on the efficacy of intravitreal injections for treating ocular toxoplasmosis. Methods: The systematic search was conducted using PubMed, SciELO, and Google Scholar with the descriptors "ocular toxoplasmosis" AND "intravitreal". We analyzed studies that met the inclusion criteria, i.e., experimental cases in patients treated intravitreally for ocular toxoplasmosis. Considering the systematic review, we focused on the number of intravitreal injections, the therapeutic drug class, and the presence of preexisting conditions. To assess the efficacy of intravitreal injections, a meta-analysis was performed using visual acuity, side effects, disease recurrence, and inflammatory responses as variables. Results: Intravitreal injection-induced side effects were rarely observed (0.49% [0.00, 1.51%] ). The use of antiparasitic and anti-inflammatory drugs afforded improved visual acuity (99.81% [98.60, 100.00%]) and marked effectiveness in treating ocular toxoplasmosis. Conclusions: Intravitreal injections may facilitate the successful treatment of ocular toxoplasmosis. However, clinicians should carefully evaluate the presence of preexisting conditions for ocular toxoplasmosis or previous diseases, as these can impact the decision to administer intravitreal injections.

5.
Transl Vis Sci Technol ; 11(10): 22, 2022 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-36239965

RESUMO

Purpose: Millions worldwide suffer vision impairment or blindness from corneal injury, and there remains an urgent need for a more effective and accessible way to treat corneal defects. We have designed and characterized an in situ-forming semi-interpenetrating polymer network (SIPN) hydrogel using biomaterials widely used in ophthalmology and medicine. Methods: The SIPN was formed by cross-linking collagen type I with bifunctional polyethylene glycol using N-hydroxysuccinimide ester chemistry in the presence of linear hyaluronic acid (HA). Gelation time and the mechanical, optical, swelling, and degradation properties of the SIPN were assessed. Cytocompatibility with human corneal epithelial cells and corneal stromal stem cells (CSSCs) was determined in vitro, as was the spatial distribution of encapsulated CSSCs within the SIPN. In vivo wound healing was evaluated by multimodal imaging in an anterior lamellar keratectomy injury model in rabbits, followed by immunohistochemical analysis of treated and untreated tissues. Results: The collagen-hyaluronate SIPN formed in situ without an external energy source and demonstrated mechanical and optical properties similar to the cornea. It was biocompatible with human corneal cells, enhancing CSSC viability when compared with collagen gel controls and preventing encapsulated CSSC sedimentation. In vivo application of the SIPN significantly reduced stromal defect size compared with controls after 7 days and promoted multilayered epithelial regeneration. Conclusions: This in situ-forming SIPN hydrogel may be a promising alternative to keratoplasty and represents a step toward expanding treatment options for patients suffering from corneal injury. Translational Relevance: We detail the synthesis and initial characterization of an SIPN hydrogel as a potential alternative to lamellar keratoplasty and a tunable platform for further development in corneal tissue engineering and therapeutic cell delivery.


Assuntos
Lesões da Córnea , Hidrogéis , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/uso terapêutico , Colágeno/química , Colágeno/farmacologia , Colágeno/uso terapêutico , Colágeno Tipo I , Ésteres , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Ácido Hialurônico/uso terapêutico , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polietilenoglicóis/uso terapêutico , Polímeros/química , Coelhos
6.
Ocul Surf ; 23: 148-161, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34537415

RESUMO

Severe corneal wounds can lead to ulceration and scarring if not promptly and adequately treated. Hyaluronic acid (HA) has been investigated for the treatment of corneal wounds due to its remarkable biocompatibility, transparency and mucoadhesive properties. However, linear HA has low retention time on the cornea while many chemical moieties used to crosslink HA can cause toxicity, which limits their clinical ocular applications. Here, we used supramolecular non-covalent host-guest interactions between HA-cyclodextrin and HA-adamantane to form shear-thinning HA hydrogels and evaluated their impact on corneal wound healing. Supramolecular HA hydrogels facilitated adhesion and spreading of encapsulated human corneal epithelial cells ex vivo and improved corneal wound healing in vivo as an in situ-formed, acellular therapeutic membrane. The HA hydrogels were absorbed within the corneal stroma over time, modulated mesenchymal cornea stromal cell secretome production, reduced cellularity and inflammation of the anterior stroma, and significantly mitigated corneal edema compared to treatment with linear HA and untreated control eyes. Taken together, our results demonstrate supramolecular HA hydrogels as a promising and versatile biomaterial platform for corneal wound healing.


Assuntos
Lesões da Córnea , Hidrogéis , Córnea , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Cicatrização
7.
Am J Ophthalmol Case Rep ; 22: 101093, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33981913

RESUMO

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. There was no significant change in electroretinography waves after treatment with the implant. The presence of the implant, or part of it, was detectable in the vitreous cavity for 4 months. To date, the patient has been monitored for 30 months, and there has been no reactivation of ocular toxoplasmosis. CONCLUSION: The slow-release clindamycin implant was safe for intravitreal use in this patient and may have contributed to the long-term control of toxoplasmosis chorioretinitis.

8.
Cytotherapy ; 23(6): 500-509, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33752960

RESUMO

BACKGROUND AIMS: Corneal inflammation after alkali burns often results in vision loss due to corneal opacification and neovascularization. Mesenchymal stem cells (MSCs) and their secreted factors (secretome) have been studied for their anti-inflammatory and anti-angiogenic properties with encouraging results. However, topical instillation of MSCs or their secretome is often accompanied by issues related to delivery or rapid washout. Polyethylene glycol (PEG) and collagen are well-known biomaterials used extensively in scaffolds for tissue engineering. To effectively suppress alkaline burn-induced corneal injury, the authors proposed encapsulating MSCs within collagen gels cross-linked with multi-functional PEG-succinimidyl esters as a means to deliver the secretome of immobilized MSCs. METHODS: Human MSCs were added to a neutralized collagen solution and mixed with a solution of four-arm PEG-N-hydroxysuccinimide. An ex vivo organ culture was conducted using rabbit corneas injured by alkali burn. MSCs were encapsulated within PEG-collagen hydrogels and injected onto the wounded cornea immediately following alkali burn and washing. Photographs of the ocular surface were taken over a period of 7 days after the alkali burn and processed for immunohistochemical evaluation. Samples were split into three groups: injury without treatment, MSCs alone, and MSCs encapsulated within PEG-collagen hydrogels. RESULTS: All corneas in ex vivo organ culture lost their transparency immediately after alkali burn, and only the groups treated with MSCs and MSCs encapsulated within PEG-collagen hydrogels recovered some transparency after 7 days. Immunohistochemical analysis revealed increased expression of vimentin in the anterior corneal stroma of the group without treatment indicative of fibrotic healing, whereas less stromal vimentin was detected in the group containing MSCs encapsulated within the PEG-collagen hydrogels. CONCLUSIONS: PEG-collagen hydrogels enable the encapsulation of viable MSCs capable of releasing secreted factors onto the ocular surface. Encapsulating MSCs within PEG-collagen hydrogels may be a promising method for delivering their therapeutic benefits in cases of ocular inflammatory diseases, such as alkali burn injuries.


Assuntos
Células-Tronco Mesenquimais , Álcalis , Animais , Materiais Biocompatíveis , Colágeno , Córnea , Hidrogéis , Técnicas de Cultura de Órgãos , Polietilenoglicóis , Coelhos
9.
Sci Rep ; 10(1): 16671, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028837

RESUMO

Visually significant corneal injuries and subsequent scarring collectively represent a major global human health challenge, affecting millions of people worldwide. Unfortunately, less than 2% of patients who could benefit from a sight-restoring corneal transplant have access to cadaveric donor corneal tissue. Thus, there is a critical need for new ways to repair corneal defects that drive proper epithelialization and stromal remodeling of the wounded area without the need for cadeveric donor corneas. Emerging therapies to replace the need for donor corneas include pre-formed biosynthetic buttons and in situ-forming matrices that strive to achieve the transparency, biocompatibility, patient comfort, and biointegration that is possible with native tissue. Herein, we report on the development of an in situ-forming hydrogel of collagen type I crosslinked via multi-functional polyethylene glycol (PEG)-N-hydroxysuccinimide (NHS) and characterize its biophysical properties and regenerative capacity both in vitro and in vivo. The hydrogels form under ambient conditions within minutes upon mixing without the need for an external catalyst or trigger such as light or heat, and their transparency, degradability, and stiffness are modulated as a function of number of PEG arms and concentration of PEG. In addition, in situ-forming PEG-collagen hydrogels support the migration and proliferation of corneal epithelial and stromal cells on their surface. In vivo studies in which the hydrogels were formed in situ over stromal keratectomy wounds without sutures showed that they supported multi-layered surface epithelialization. Overall, the in situ forming PEG-collagen hydrogels exhibited physical and biological properties desirable for a corneal stromal defect wound repair matrix that could be applied without the need for sutures or an external trigger such as a catalyst or light energy.


Assuntos
Materiais Biocompatíveis/química , Colágeno Tipo I/química , Lesões da Córnea/terapia , Hidrogéis/química , Polietilenoglicóis/química , Animais , Ceratectomia , Coelhos
10.
Acta Biomater ; 99: 247-257, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31539656

RESUMO

The therapeutic effects of secreted factors (secretome) produced by bone marrow-derived human mesenchymal stem cells (MSCs) were evaluated as a function of their growth in 2D culture conditions and on 3D electrospun fiber scaffolds. Electrospun fiber scaffolds composed of polycaprolactone and gelatin were fabricated to provide a 3D microenvironment for MSCs, and their mechanical properties were optimized to be similar to corneal tissue. The secretome produced by the MSCs cultured on 3D fiber matrices versus 2D culture dishes were analyzed using a Luminex immunoassay, and the secretome of MSCs cultured on the 3D versus 2D substrates showed substantial compositional differences. Concentrations of factors such as HGF and ICAM-1 were increased over 5 times in 3D cultures compared to 2D cultures. In vitro proliferation and scratch-based wound healing assays were performed to compare the effects of the secretome on corneal fibroblast cells (CFCs) when delivered synchronously from co-cultured MSCs through a trans-well co-culture system versus asynchronously after harvesting the factors separately and adding them to the media. Cell viability of CFCs was sustained for 6 days when co-cultured with MSCs seeded on the fibers but decreased with time under other conditions. Scratch assays showed 95% closure at 48 h when CFCs were co-cultured with MSCs seeded on fibers, while the control group only exhibited 50% closure at 48 h. Electrospun fibers seeded with MSCs were then applied to a rabbit corneal organ culture system, and MSCs seeded on fibers promoted faster epithelialization and less scarring. Corneas were fixed and stained for alpha smooth muscle actin (α-SMA), and then analyzed by confocal microscopy. Immunostaining showed that expression of α-SMA was lower in corneas treated with MSCs seeded on fibers, suggesting suppression of myofibroblastic transformation. MSCs cultured on electrospun fibers facilitate wound healing in CFCs and on explanted corneas through differential secretome profiles compared to MSCs cultured on 2D substrates. Future work is merited to further understand the nature and basis of these differences and their effects in animal models. STATEMENT OF SIGNIFICANCE: Previous studies have shown that the secretome of bone marrow-derived mesenchymal stem cells (MSC) is promotes corneal wound healing by facilitating improved wound closure rates and reduction of scarring and neovascularization. The present research is significant because it provides evidence for the modulation of the secretome as a function of the MSC culture environment. This leads to differential expression of therapeutic factors secreted, which can impact corneal epithelial and stromal healing after severe injury. In addition, this article shows that co-continuous delivery of the MSC secretome improves cell migration and proliferation over aliquoted delivery, and that MSCs grown on three-dimensional electrospun fiber constructs may provide a favorable microenvironment for cultured MSCs and as a carrier to deliver their secreted factors to the ocular surface.


Assuntos
Células da Medula Óssea/citologia , Córnea/patologia , Lesões da Córnea/terapia , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual/métodos , Cicatrização , Actinas/metabolismo , Animais , Diferenciação Celular , Sobrevivência Celular , Técnicas de Cocultura , Córnea/metabolismo , Fibroblastos/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Imageamento Tridimensional , Técnicas In Vitro , Molécula 1 de Adesão Intercelular/metabolismo , Microscopia Confocal , Miócitos de Músculo Liso/metabolismo , Técnicas de Cultura de Órgãos , Coelhos , Regeneração , Estresse Mecânico , Alicerces Teciduais
11.
Eur J Pharm Biopharm ; 142: 20-30, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31129274

RESUMO

Electrospinning technique has been explored to produce nanofibers incorporated with drugs as alternative drug delivery systems for therapeutic purposes in various organs and tissues. Before such systems could potentially be used, their biocompatibility must be evaluated. In this study, dexamethasone acetate-loaded poly(ɛ-caprolactone) nanofibers (DX PCL nanofibers) were developed for targeted delivery in the vitreous cavity in the treatment of retinal diseases. Ocular biocompatibility was tested in vitro and in vivo. DX PCL nanofibers were characterized by scanning electron microscopy (SEM) and Fourier Transform InfraRed spectroscopy (FTIR) and the in vitro drug release from nanofibers was evaluated. The in vitro biocompatibility of DX PCL nanofibers was tested on both ARPE-19 and MIO-M1 cells using the cytotoxicity (MTT) test by morphological studies based on staining of the actin fibers in ARPE-19 cells and GFAP in MIO-M1 cells. The in vivo biocompatibility of DX PCL nanofibers was investigated after intravitreous injection in the rat eye, using spectral domain Optical Coherence Tomography (OCT) imaging of the retina. SEM results indicated that nanometric fibers were interconnected in a complex network, and that they were composed of polymer. FTIR showed that polymer and drug did not chemically interact after the application of the electrospinning technique. PCL nanofibers provided controlled DX release for 10 days. DX PCL nanofibers were not cytotoxic to the ocular cells, allowing for the preservation of actin fibers and GFAP in the cytoplasm of ARPE-19 and MIO-M1 cells, respectively, which are biomarkers of these ocular cell populations. DX PCL nanofibers did not affect the retinal and choroidal structures, and they did not induce abnormalities, hemorrhages, or retinal detachment, suggesting that the nanofibers were well tolerated. In eyes receiving DX PCL nanofibers, SD-OCT images were corroborated with histological analysis of neuroretina and choroid, which are ocular tissues that are extremely sensitive to toxic agents. Finally, the preservation of cone and rod photoreceptors indicated the light sensitivity of the animals. In conclusion, DX PCL nanofibers exhibited ocular biocompatibility and safety in the rodent eye and allow the release of dexamethasone. Further studies are required to appreciate the potential of these new drug delivery systems for the treatment of retinal diseases.


Assuntos
Dexametasona/administração & dosagem , Dexametasona/química , Nanofibras/administração & dosagem , Nanofibras/química , Poliésteres/química , Retina/efeitos dos fármacos , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Feminino , Humanos , Ratos , Ratos Endogâmicos Lew , Doenças Retinianas/tratamento farmacológico , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Engenharia Tecidual/métodos , Alicerces Teciduais
12.
Stem Cells Transl Med ; 8(5): 478-489, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30644653

RESUMO

Severe corneal injuries often result in permanent vision loss and remain a clinical challenge. Human bone marrow-derived mesenchymal stem cells (MSCs) and their secreted factors (secretome) have been studied for their antiscarring, anti-inflammatory, and antiangiogeneic properties. We aimed to deliver lyophilized MSC secretome (MSC-S) within a viscoelastic gel composed of hyaluronic acid (HA) and chondroitin sulfate (CS) as a way to enhance corneal re-epithelialization and reduce complications after mechanical and chemical injuries of the cornea. We hypothesized that delivering MSC-S within HA/CS would have improved wound healing effects compared the with either MSC-S or HA/CS alone. The results showed that a once-daily application of MSC-S in HA/CS enhances epithelial cell proliferation and wound healing after injury to the cornea. It also reduced scar formation, neovascularization, and hemorrhage after alkaline corneal burns. We found that combining MSC-S and HA/CS increased the expression of CD44 receptors colocalized with HA, suggesting that the observed therapeutic effects between the MSC-S and HA/CS are in part mediated by CD44 receptor upregulation and activation by HA. The results from this study demonstrate a reproducible and efficient approach for delivering the MSC-S to the ocular surface for treatment of severe corneal injuries. Stem Cells Translational Medicine 2019;8:478-489.


Assuntos
Córnea/patologia , Lesões da Córnea/terapia , Células-Tronco Mesenquimais/metabolismo , Proteoma/metabolismo , Substâncias Viscoelásticas/uso terapêutico , Cicatrização/fisiologia , Animais , Feminino , Humanos , Ratos , Ratos Sprague-Dawley , Substâncias Viscoelásticas/farmacologia
13.
Invest Ophthalmol Vis Sci ; 57(4): 1671-9, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27054520

RESUMO

PURPOSE: Targeted drug delivery to the ocular tissues remains a challenge. Biodegradable intraocular implants allow prolonged controlled release of drugs directly into the eye. In this study, we evaluated an anterior suprachoroidal polyurethane implant containing dexamethasone polyurethane dispersions (DX-PUD) as a drug delivery system in the rat model of endotoxin-induced uveitis (EIU). METHODS: In vitro drug release was studied using PUD implants containing 8%, 20%, and 30% (wt/wt) DX. Cytotoxicity of the degradation products of DX-PUD was assessed on human ARPE-19 cells using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) test. Short-term ocular biocompatibility of suprachoroidal DX-PUD implants was evaluated in normal rat eyes. Endotoxin-induced uveitis was then induced in rat eyes preimplanted with DX-PUD. Clinical examination was performed at 24 hours; eyes were used to assess inflammatory cell infiltration and macrophage/microglial activation. Cytokine and chemokine expression in the iris/ciliary body and in the retina was investigated using quantitative PCR. Feasibility of anterior suprachoroidal PUD implantation was also tested using postmortem human eyes. RESULTS: A burst release was followed by a sustained controlled release of DX from PUD implants. By-products of the DX-PUD were not toxic to human ARPE-19 cells or to rat ocular tissues. Dexamethasone-PUD implants prevented EIU in rat eyes, reducing inflammatory cell infiltration and inhibiting macrophage/microglial activation. Dexamethasone-PUD downregulated proinflammatory cytokines/chemokines (IL-1ß, IL-6, cytokine-induced neutrophil chemoattractant [CINC]) and inducible nitric oxide synthase (iNOS) and upregulated IL-10 anti-inflammatory cytokine. Polyurethane dispersion was successfully implanted into postmortem human eyes. CONCLUSIONS: Dexamethasone-PUD implanted in the anterior suprachoroidal space may be of interest in the treatment of intraocular inflammation.


Assuntos
Anti-Inflamatórios/administração & dosagem , Dexametasona/administração & dosagem , Modelos Animais de Doenças , Sistemas de Liberação de Medicamentos , Uveíte/prevenção & controle , Animais , Anti-Inflamatórios/farmacocinética , Linhagem Celular , Sobrevivência Celular , Corpo Ciliar/metabolismo , Corantes/farmacologia , Citocinas/genética , Citocinas/metabolismo , Dexametasona/farmacocinética , Implantes de Medicamento , Espaço Extracelular , Feminino , Humanos , Iris/metabolismo , Lipopolissacarídeos/toxicidade , Poliuretanos , Ratos , Ratos Endogâmicos Lew , Epitélio Pigmentado da Retina/efeitos dos fármacos , Salmonella typhimurium , Espectroscopia de Infravermelho com Transformada de Fourier , Sais de Tetrazólio/farmacologia , Tiazóis/farmacologia , Uveíte/induzido quimicamente , Uveíte/metabolismo
14.
J Pharm Sci ; 104(11): 3731-42, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26178442

RESUMO

In this study, the methotrexate (MTX) was incorporated into the poly(ε-caprolactone) (PCL) to design implants (MTX PCL implants) aiming the local treatment of inflammatory angiogenesis diseases without causing systemic side effects. Sponges were inserted into the subcutaneous tissue of mice as a framework for fibrovascular tissue growth. After 4 days, MTX PCL implants were also introduced, and anti-inflammatory, antiangiogenic, and antifibrogenic activities of the MTX were determined. MTX reduced the vascularization (hemoglobin content), the neutrophil, and monocyte/macrophage infiltration (MPO and NAG activities, respectively), and the collagen deposition in sponges. MTX reduced tumor necrosis factor-α and IL-6 levels, demonstrating its local antiangiogenic and anti-inflammatory effects. Furthermore, hepatotoxicity, nephrotoxicity, and myelotoxicity, which could be induced by the drug, were evaluated. However, MTX did not promote toxicity to these organs, as the levels of AST and ALT (hepatic markers) and creatinine and urea (renal markers) were not increased, and the complete blood count was not decreased. In conclusion, MTX PCL implants demonstrated to be effective in regulating the components of the inflammatory angiogenesis locally established, and presented an acceptable safety profile.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Preparações de Ação Retardada/química , Metotrexato/administração & dosagem , Poliésteres/química , Inibidores da Angiogênese/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Colágeno/análise , Citocinas/análise , Sistemas de Liberação de Medicamentos , Imunossupressores/administração & dosagem , Imunossupressores/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/tratamento farmacológico , Próteses e Implantes
15.
Eur J Pharm Sci ; 73: 9-19, 2015 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-25797289

RESUMO

Biocompatibility is a requirement for the development of nanofibers for ophthalmic applications. In this study, nanofibers were elaborated using poly(ε-caprolactone) via electrospinning. The ocular biocompatibility of this material was investigated. MIO-M1 and ARPE-19 cell cultures were incubated with nanofibers and cellular responses were monitored by viability and morphology. The in vitro biocompatibility revealed that the nanofibers were not cytotoxic to the ocular cells. These cells exposed to the nanofibers proliferated and formed an organized monolayer. ARPE-19 and MIO-M1 cells were capable of expressing GFAP, respectively, demonstrating their functionality. Nanofibers were inserted into the vitreous cavity of the rat's eye for 10days and the in vivo biocompatibility was investigated using Optical Coherence Tomography (OCT), histology and measuring the expression of pro-inflammatory genes (IL-1ß, TNF-α, VEGF and iNOS) (real-time PCR). The OCT and the histological analyzes exhibited the preserved architecture of the tissues of the eye. The biomaterial did not elicit an inflammatory reaction and pro-inflammatory cytokines were not expressed by the retinal cells, and the other posterior tissues of the eye. Results from the biocompatibility studies indicated that the nanofibers exhibited a high degree of cellular biocompatibility and short-term intraocular tolerance, indicating that they might be applied as drug carrier for ophthalmic use.


Assuntos
Olho/efeitos dos fármacos , Nanofibras/efeitos adversos , Poliésteres/farmacologia , Animais , Linhagem Celular , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Olho/citologia , Feminino , Expressão Gênica/efeitos dos fármacos , Inflamação/genética , Inflamação/metabolismo , Teste de Materiais , Neuroglia/efeitos dos fármacos , Tamanho da Partícula , Poliésteres/efeitos adversos , Ratos , Ratos Endogâmicos Lew , Retina/citologia , Retina/efeitos dos fármacos , Retina/metabolismo , Tomografia de Coerência Óptica , Corpo Vítreo/efeitos dos fármacos
16.
J Pharm Sci ; 104(11): 3731-42, 2015 11.
Artigo em Inglês | MEDLINE | ID: mdl-27524686

RESUMO

In this study, the methotrexate (MTX) was incorporated into the poly(e-caprolactone) (PCL) to design implants (MTX PCL implants) aiming the local treatment of inflammatory angiogenesis diseases without causing systemic side effects. Sponges were inserted into the subcutaneous tissue of mice as a framework for fibrovascular tissue growth. After 4days, MTX PCL implants were also introduced, and anti-inflammatory, antiangiogenic, and antifibrogenic activities of the MTX were determined. MTX reduced the vascularization (hemoglobin content), the neutrophil, and monocyte/macrophage infiltration (MPO and NAG activities, respectively), and the collagen deposition in sponges. MTX reduced tumor necrosis factor-a and IL-6 levels, demonstrating its local antiangiogenic and anti-inflammatory effects. Furthermore, hepatotoxicity, nephrotoxicity, and myelotoxicity, which could be induced by the drug, were evaluated. However, MTX did not promote toxicity to these organs, as the levels of AST and ALT (hepatic markers) and creatinine and urea (renal markers) were not increased, and the complete blood count was not decreased. In conclusion, MTX PCL implants demonstrated to be effective in regulating the components of the inflammatory angiogenesis locally established, and presented an acceptable safety profile. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3731-3742, 2015.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Metotrexato/administração & dosagem , Poliésteres/química , Acetilglucosaminidase/metabolismo , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/toxicidade , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/toxicidade , Proliferação de Células , Colágeno/química , Sistemas de Liberação de Medicamentos , Implantes de Medicamento , Liberação Controlada de Fármacos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Interleucina-6/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Metotrexato/farmacologia , Metotrexato/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Neovascularização Patológica/tratamento farmacológico , Infiltração de Neutrófilos/efeitos dos fármacos , Peroxidase/metabolismo , Distribuição Tecidual , Fator de Necrose Tumoral alfa/metabolismo
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