Biodegradable core-shell electrospun nanofibers containing bevacizumab to treat age-related macular degeneration.

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. In the present study, biodegradable core shell nanofibers containing bevacizumab were prepared by the coaxial electrospinning technique. It is thought that the shell could control the release of the drug, while the core would protect and store the drug. Poly(caprolactone) (PCL) and gelatin were used to form the shell of the nanofibers, while poly(vinyl alcohol) (PVA) and bevacizumab comprised the core. The nanofibers were characterized using microscopy techniques, thermal analysis, and FTIR. The results showed that core-shell nanofibers were produced as designed. Bevacizumab activity was evaluated using a chicken embryo chorioallantoic membrane (CAM) assay. An enzyme-linked immunosorbent assay was used to quantify the amount of the drug released from the different nanofibers in vitro. The toxicity of the nanofibers was evaluated in human retinal pigment epithelial (ARPE) cells. The CAM results demonstrated that bevacizumab maintained its antiangiogenic activity when incorporated into the nanofibers. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests revealed that the nanofibers showed no cellular toxicity, even in the presence of bevacizumab. The core-shell structure of the nanofibers reduced the release rate of bevacizumab compared with PVA nanofibers. The bevacizumab-loaded biodegradable nanofibers presented interesting properties that would potentially constitute an alternative therapy to intravitreal injections to treat AMD.

2-(benzylideneamino)phenol: a promising hydroxyaldimine with potent activity against dermatophytoses.

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. We determined the minimum inhibitory concentration, minimum fungicidal concentration, time-kill curves and fractional inhibitory concentration of the combination of 3A3, 3A4 and itraconazole against a set of isolates of T. rubrum and T. interdigitale. 3A3 was tested in a murine model of dermatophytoses caused by T. rubrum, and the effect on phagocytosis was assessed. The MIC values ranged from 8 to 32 µg/mL for 3A3 and from 64 to 256 µg/mL for 3A4. The interaction between 3A3 and 3A4 with itraconazole proved to be synergistic and indifferent, respectively. 3A3 was as efficient as itraconazole in reducing the fungal burden on the skin of mice, being this effect associated with the influx of neutrophil and macrophage. Also, 3A3 was able to increase the internalization of conidia by macrophages. Altogether, our data encourage future clinical studies with 3A3 to treat dermatophytoses.

Antiangiogenic activity of photobiomodulation in experimental model using chorioallantoic embryonic membrane of chicken eggs.

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 2.5 cm to the surface of the chorioallantoic embryonic membrane of chicken eggs in 2, 4, or 8 sessions for 90 s and analyzed the vascular network architecture using AngioTool software (National Cancer Institute, USA). We treated the negative control group with 50 µl phosphate-buffered-saline (pH 7.4) and the positive control group (Beva) with 50 µl bevacizumab solution (Avastin, Produtos Roche Químicos e Farmacêuticos, S.A., Brazil). RESULTS: We found a decrease in total vessel length in the Beva group (24.96% ± 12.85%) and in all the groups that received 670 nm red light therapy (2× group, 34.66% ± 8.66%; 4× group, 42.42% ± 5.26%; 8× group, 38.48% ± 6.96%), compared with the negative control group. The fluence of 5.4 J/cm2 in 4 sessions (4×) showed more regular vessels. The number of junctions in the groups that received a higher incidence of 670 nm red light (4× and 8×) significantly decreased (p<0.0001). CONCLUSION: Photo-biomodulation helps reduce vascularization in chorioallantoic embryonic membrane of chicken eggs and changes in the network architecture. Our results open the possibility of future clinical studies on using this therapy in patients with retinal diseases with neovascular components, especially age-related macular degeneration.

From the PnTx2-6 Toxin to the PnPP-19 Engineered Peptide: Therapeutic Potential in Erectile Dysfunction, Nociception, and Glaucoma.

The venom of the "armed" spider Phoneutria nigriventer comprises several potent toxins. One of the most toxic components from this venom is the neurotoxin PnTx2-6 (LD50 = ∼ 0.7 µg/mouse, 48 residues, five disulfide bridges, MW = 5,289.31 Da), which slows down the inactivation of various Na+ channels. In mice and rats, this toxin causes priapism, an involuntary and painful erection, similar to what is observed in humans bitten by P. nigriventer. While not completely elucidated, it is clear that PnTx2-6 potentiates erectile function via NO/cGMP signaling, but it has many off-target effects. Seeking to obtain a simpler and less toxic molecule able to retain the pharmacological properties of this toxin, we designed and synthesized the peptide PnPP-19 (19 residues, MW = 2,485.6 Da), representing a discontinuous epitope of PnTx2-6. This synthetic peptide also potentiates erectile function via NO/cGMP, but it does not target Na+ channels, and therefore, it displays nontoxic properties in animals even at high doses. PnPP-19 effectively potentiates erectile function not only after subcutaneous or intravenous administration but also following topical application. Surprisingly, PnPP-19 showed central and peripheral antinociceptive activity involving the opioid and cannabinoid systems, suggesting applicability in nociception. Furthermore, considering that PnPP-19 increases NO availability in the corpus cavernosum, this peptide was also tested in a model of induced intraocular hypertension, characterized by low NO levels, and it showed promising results by decreasing the intraocular pressure which prevents retinal damage. Herein, we discuss how was engineered this smaller active non-toxic peptide with promising results in the treatment of erectile dysfunction, nociception, and glaucoma from the noxious PnTx2-6, as well as the pitfalls of this ongoing journey.

Chromatographic bioanalysis of antiglaucoma drugs in ocular tissues.

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. The study of ocular pharmacokinetics of antiglaucoma drugs, crucial for better understanding of ocular distribution, bioavailability, and pharmacodynamic parameters, can benefit the development of antiglaucoma drugs or formulations. Bioanalysis of drugs in ocular matrices is still underestimated, since it is challenging and rarely performed. Therefore, this review summarized the chromatographic methods employed for the quantification of several antiglaucoma drugs in different ocular matrices, discussing bioanalytical steps, such as sample preparation, separation, and detection. Animals and matrices as well as the challenges faced in ocular bioanalysis were also discussed. Ocular bioanalysis has been performed mainly in rabbits, the most adequate animal model for ocular studies. The matrix most used is aqueous humor, because it is cleaner and easier to sample. Sample preparation was carried out primarily employing classic techniques, such as liquid-liquid extraction, protein precipitation, and solid-phase extraction, with conventional solvents and sorbents. Chromatographic separation was achieved predominantly by reversed-phase liquid chromatography. Ultraviolet spectrophotometry and tandem mass spectrometry prevailed for detection, although other techniques, such as fluorimetry, have also been used. It was evidenced that more efforts must be directed towards miniaturized, eco-friendly, and non-terminal sampling for sample preparation. In its turn, ultra high-performance liquid chromatography and mass spectrometry should gain prominence in ocular bioanalysis for separation and detection, respectively, since it combines high separation capacity with selectivity and sensitivity, in addition to being an environmental friendly approach.

Antiangiogenic activity of photobiomodulation in experimental model using chorioallantoic embryonic membrane of chicken eggs / Atividade antiangiogênica da fotobiomodulação em modelo experimental usando membrana embrionária corioalantóide de ovos de galinhas

ABSTRACT 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 2.5 cm to the surface of the chorioallantoic embryonic membrane of chicken eggs in 2, 4, or 8 sessions for 90 s and analyzed the vascular network architecture using AngioTool software (National Cancer Institute, USA). We treated the negative control group with 50 μl phosphate-buffered-saline (pH 7.4) and the positive control group (Beva) with 50 μl bevacizumab solution (Avastin, Produtos Roche Químicos e Farmacêuticos, S.A., Brazil). Results: We found a decrease in total vessel length in the Beva group (24.96% ± 12.85%) and in all the groups that received 670 nm red light therapy (2× group, 34.66% ± 8.66%; 4× group, 42.42% ± 5.26%; 8× group, 38.48% ± 6.96%), compared with the negative control group. The fluence of 5.4 J/cm2 in 4 sessions (4×) showed more regular vessels. The number of junctions in the groups that received a higher incidence of 670 nm red light (4× and 8×) significantly decreased (p<0.0001). Conclusion: Photo-biomodulation helps reduce vascularization in chorioallantoic embryonic membrane of chicken eggs and changes in the network architecture. Our results open the possibility of future clinical studies on using this therapy in patients with retinal diseases with neovascular components, especially age-related macular degeneration.

RESUMO Objetivo: investigar os efeitos vasculares da foto-biomodulação com diodo emissor de luz utilizando membrana embrionária corioalantóide de ovos de galinhas em grupos com diferentes tempos de exposição e detectar as alterações morfológicas por meio de métricas quantitativas promovidas pela luz na arquitetura da rede vascular. Métodos: Um aparelho de fototerapia com diodo emissor de luz no comprimento de onda de 670 nm foi usado como fonte de fotobiomodulação. A luz vermelha foi aplicada a uma distância de 2,5 cm da superfície da membrana embrionária corioalantóide em 2, 4 ou 8 sessões de 90 s a arquitetura da rede vascular foi analisada por meio do software AngioTool (National Cancer Institute, USA). Usamos um grupo controle negativo tratado com 50 µL de solução salina tamponada com fosfato (PBS) pH 7,4 e um grupo controle positivo (Beva) tratado com 50 µL de solução de bevacizumabe (Avastin, Produtos Roche Químicos e Farmacêuticos S.A., Brasil). Resultados: Uma diminuição no comprimento total do vaso foi detectada para o grupo Beva (24,96 ± 12,85%), e para todos os grupos que receberam terapia de luz vermelha de 670 nm, 34,66 ± 8,66% (2x), 42,42 ± 5,26% (4x) e 38,48 ± 6,96% (8x) em comparação ao grupo controle. A incidência de 5,4 J/cm2 em 4 sessões (4x) mostrou vasos mais regulares. A redução foi mais intensa nos grupos que receberam maior incidência de luz vermelha de 670 nm (4x e 8x). Conclusão: A fotobiomodulação contribui para a redução da vascularização nos vasos da membrana embrionária corioalantóide de ovos de galinhas e mudanças na arquitetura da rede. Os achados deste experimento abrem a possibilidade de considerar um estudo clínico usando esta terapia em pacientes com doenças retinais com componentes neovasculares, especialmente degeneração macular relacionada à idade.

SAFETY AND FEASIBILITY OF A NOVEL 25-GAUGE BIODEGRADABLE IMPLANT OF DEXAMETHASONE FOR TREATMENT OF MACULAR EDEMA ASSOCIATED WITH RETINAL VEIN OCCLUSION: A PHASE I CLINICAL TRIAL.

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. RESULTS: Mean best-corrected visual acuity was 0.72 ± 0.1 logMAR (20/100) at baseline and improved by 7 early treatment diabetic retinopathy study letters to 0.58 ± 0.08 logMAR (20/80 + 1) at 24 weeks (P = 0.049), with 3 central retinal vein occlusion and 3 branch retinal vein occlusion patients improving between 1 and 4 early treatment diabetic retinopathy study lines. Significant central subfield thickness reduction was observed at 24 weeks compared with baseline (P = 0.011); mean ± standard error (range) central subfield thickness (µm) was 461.2 ± 41.3 (288-701) at baseline, and 439.6 ± 40.4 (259-631), 442.5 ± 44.6 (255-632), 354.6 ± 31.2 (228-537), and 316.5 ± 26.4 (226-441) at 1, 4, 12, and 24 weeks, respectively. No significant changes in electroretinography responses or area of retinal nonperfusion were observed during 24 weeks of follow-up. There was no significant change in mean intraocular pressure at any of the study visits compared with baseline. One patient had mild anterior chamber inflammation (1-5 cells) at one week after DDS-25 insertion. CONCLUSION: In this Phase I study demonstrating the feasibility of intravitreal DDS-25 insertion for the treatment of decreased vision due to macular edema associated with retinal vein occlusion, no safety concerns were observed. A larger prospective randomized study with longer follow-up is warranted to confirm these findings.

[Drug delivery systems for the posterior segment of the eye: fundamental basis and applications]. / Sistemas de transporte de drogas para o segmento posterior do olho: bases fundamentais e aplicações.

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. Because of the difficulties in delivering drugs to the posterior segment of the eye, the development of intraocular delivery systems that allow the delivery of therapeutic concentrations of drugs for long periods are being studied. These systems offer many advantages, such as increase in drug bioavailability, obtaining constant and sustained drug release, to achievement of elevated local concentrations of drugs without systemic side effects, targeting one specific tissue or cell type, reducing the frequency of intraocular injections. These advantages can increase the comfort of the patient and reduce the complications observed with intraocular injections. Several drug delivery systems are being developed with the above described purposes. These systems may be prepared with biodegradable or non-biodegradable polymers or they may be lipid formulations. The drug delivery systems are represented, mainly, by micro- e nanoparticles and implants, composed of different polymers; by liposomes, which are made of lipids and surfactants; and by iontophoresis, that is based on the application of an electric current. In this review, the main characteristics of the different drug delivery systems will be shown, with their potentialities of clinical application.

Safety and feasibility of the use of a bevacizumab-methylcellulose mixture as an adjunct to glaucoma surgery: a pilot study.

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 0.3 ml of BMM (bevacizumab 3.75 mg incorporated into 4% methylcellulose) at the surgical site. Bevacizumab release was evaluated in vitro using size-exclusion high performance liquid chromatography (HPLC). Intraocular pressure (IOP), bleb morphology, corneal endothelial cell count (CECC), and complications were evaluated at 6 months after surgery. Using HPLC, bevacizumab was detected in BMM for up to 72 h. Moreover, all surgical blebs remained expanded with hyaline material during the first week. A significant IOP reduction (mean ± SD= -10.3 ± 5.4 mmHg, P<0.001) and diffuse blebs were observed at the final follow-up period. Although CECC was slightly reduced (-7.4%), no complications were observed. In conclusion, bevacizumab was released from BMM, and the use of this innovative mixture yielded good results following DS with no complications. Further studies are required to determine its efficacy prior to establishing BMM as an adjunct treatment for penetrating and non-penetrating glaucoma surgeries.

Radiolabeling of cidofovir with technetium-99m and biodistribution studies

Radiolabeling cidofovir with technetium-99m (99mTc-CDV) is an innovative procedure that enables real-time monitoring of the drug. Essays were performed in vitro, showing high radiolabel stability within 24 h. Blood clearance, biodistribution studies, and scintigraphic images were performed in healthy mice in order to evaluate the profile of the drug in vivo. 99mTc-CDV showed biphasic blood circulation time and significant kidney uptake, indicating that 99mTc-CDV is preferentially eliminated by the renal route. Bones also showed important uptake throughout the experiment. In summary, cidofovir was successfully labeled with technetium-99m and might be used in further studies to track the drug.

Intravitreal injection of peptides PnPa11 and PnPa13, derivatives of Phoneutria nigriventer spider venom, prevents retinal damage

PnPa11 and PnPa13 are synthetic peptides derived from Phoneutria nigriventer spider venom, which display antinociceptive and neuroprotective properties. In this work, we evaluated the safety of intravitreal use and the neuroprotective effect of these peptides. Methods: The cytotoxicity and the antiangiogenic activity of these peptides were evaluated by the sulforhodamine-B method and chicken chorioallantoic membrane (CAM) assay, respectively. The in vivo safety was analyzed in Wistar rats that were intravitreally injected with different doses (0.50; 1.25; 2.50; 3.75 and 5.00 µg/mL) of these peptides (right eye, n = 6). The retinal function was assessed by electroretinography exams (ERG), intraocular pressure (IOP), and histological analyzes. In order to investigate the neuroprotective effect, Wistar rats received intravitreal injections (right eye, n = 6) of peptides at 1.25 µg/mL and then were exposed to blue LED light. In addition, the visual function and the retinal microstructure were verified. Results: Cytotoxicity analyses demonstrated that the peptides did not present any toxicity over ARPE-19 (adult retinal pigmented epithelial) cell line and the antiangiogenic study highlighted that the peptides promoted the reduction of blood vessels. The intravitreal injection did not cause major changes, neither induced any irreversible damage. In the retinal degeneration assay, the ERG records demonstrated that the prior treatment with PnPa11 and PnPa13 protected the retina from damage. Morphological analyses confirmed the ERG findings. Immunoblotting analyses revealed that PnPa11 increased Erk1/2, NR2A, and NR2B retinal expression after the light stress model, but did not cause Akt1 activation, while PnPa13 prevented Erk1/2 and Akt1 dephosphorylation. Conclusions: The intraocular administration of these peptides was well tolerated and presented protective activity against retinal degeneration, suggesting the potential use of these peptides as neuroprotectors in the ophthalmological field.(AU)

Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant.

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. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively). RESULTS: Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2. CONCLUSION: The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant.

New mucoadhesive chitosan film for ophthalmic drug delivery of timolol maleate: in vivo evaluation.

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. In addition, this study investigates the maximum release time of these implants in vivo. METHODS: The 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, and attenuated total reflectance fourier transformed infrared spectroscopy (ATR-FTIR). The developed formulations were evaluated for their pharmacodynamics in ocular normotensive albino rabbits, in which the intraocular pressure (IOP) was measured by means of applanation tonometer on alternative days (13 h) for 11 weeks. For 15 days, 0.5% TM commercial ophthalmic solution was administered twice a day (n=5) and compared to chitosan-coated TM (n=5). In the control group (n=5), saline was used twice a day. The maximum TM release time from chitosan films were also recorded. After euthanasia, the right eyes were removed from the 3 groups for histological analyses. RESULTS: In an in vitro study, TM was released over a 4-week period, in which 85% of the drug was released over the first 2 weeks. However, the film's release of TM lowered the in vivo IOP levels over a 10-week period. No significant difference in the lowering of IOP in rabbits treated with 0.5% TM commercial ophthalmic solution, as compared to those that received the films (P<0.05), could be observed. No signs of ocular discomfort or irritations could be identified upon ophthalmic examination by slit-lamp biomicroscopy. Ophthalmic structures that came in direct contact with the films revealed no alterations within the histopathological studies. Moreover, the animals showed no signs of ocular discomfort during the experimental assays. CONCLUSION: These findings suggest that the TM-loaded chitosan film is safe and efficient and presents a promising future as an ocular drug delivery system in the treatment and prevention of glaucoma.

Intravitreal injection of polysorbate 80: a functional and morphological study / Injeção intravítrea de polissorbato 80: estudo funcional e morfológico

ABSTRACT Objective : to determine the functional and morphological effects at rabbits retina of PS80 concentration used in the preparation of intravitreal drugs. Methods: eleven New Zealand rabbits received a intravitreal injection of 0.1ml of PS80. As control, the contralateral eye of each rabbit received the same volume of saline. Electroretinography was performed according to a modified protocol, as well as biomicroscopy and retina mapping before injection and seven and ten days after. Animals were euthanized in the 30th day and the retinas were analyzed by light microscopy. Results: eyes injected with PS80 did not present clinical signs of intraocular inflammation. Electroretinography did not show any alteration of extent and implicit time of a and b waves at scotopic and photopic conditions. There were no morphological alterations of retinas at light microscopy. Conclusion: intravitreal injection of PS80 in the used concentration for intravitreal drug preparations do not cause any functional or morphological alterations of rabbit retinas. These results suggest that PS80 is not toxic to rabbit retinas and may be safely used in the preparation of new lipophilic drugs for intravitreal injection.

RESUMO Objetivo: determinar os efeitos funcionais e morfológicos na retina de coelhos da concentração de PS80 utilizada na preparação de drogas intravítreas. Métodos: onze coelhos New Zealand receberam injeção intravítrea de 0,1ml de PS80. Como controle, o olho contralateral de cada coelho recebeu o mesmo volume de soro fisiológico. Foram realizados eletrorretinogramas de acordo com o protocolo modificado, biomicroscopia e mapeamento de retina antes da injeção, sete e dez dias depois. Os animais foram sacrificados no 30o dia e as retinas analisadas por microscopia de luz. Resultados: os olhos injetados com PS80 não apresentaram sinais clínicos de inflamação intraocular. O eletrorretinograma não apresentou alteração de amplitude e tempo implícito das ondas a e b nas condições escotópica e fotópica. Não houve alteração morfológica da retina na microscopia de luz. Conclusão: a injeção intravítrea de PS80 na concentração utilizada na preparação de drogas intravítreas não causa alterações funcionais e morfológicas na retina de coelhos. Esses resultados sugerem que o PS80 não é tóxico para a retina de coelhos e pode ser usado com segurança na preparação de novas drogas lipofílicas para injeção intravítrea.

Assessing the maxillary sinus mucosa of rabbits in the presence of biodegradable implants.

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. METHOD: Eighteen rabbits were randomly divided into two groups: group 1 - subjects had drug-eluting implants placed on their left maxillary sinuses; group 2 - subjects had non-drug-eluting implants placed on their left maxillary sinuses. The right maxillary sinuses served as the controls. After seven, 14, and 28 days three rabbits in each group were randomly picked to have their tissue inflammatory response assessed. RESULTS: Levels of mucosal inflammation were not significantly different between the groups with and without drug-eluting implants and the control group, or when the groups with drug-eluting implants and non-drug-eluting implants were compared. CONCLUSION: Signs of toxicity or mucosal inflammation were not observed in the maxillary sinuses of rabbits given prednisolone-eluting implants or non-drug-eluting implants.

Safety and feasibility of the use of a bevacizumab-methylcellulose mixture as an adjunct to glaucoma surgery: a pilot study / Segurança e viabilidade do uso de uma mistura de bevacizumabe-metilcelulose como terapia adjuvante à cirurgia anti-glaucomatosa: um estudo piloto

ABSTRACT 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 0.3 ml of BMM (bevacizumab 3.75 mg incorporated into 4% methylcellulose) at the surgical site. Bevacizumab release was evaluated in vitro using size-exclusion high performance liquid chromatography (HPLC). Intraocular pressure (IOP), bleb morphology, corneal endothelial cell count (CECC), and complications were evaluated at 6 months after surgery. Using HPLC, bevacizumab was detected in BMM for up to 72 h. Moreover, all surgical blebs remained expanded with hyaline material during the first week. A significant IOP reduction (mean ± SD= -10.3 ± 5.4 mmHg, P<0.001) and diffuse blebs were observed at the final follow-up period. Although CECC was slightly reduced (-7.4%), no complications were observed. In conclusion, bevacizumab was released from BMM, and the use of this innovative mixture yielded good results following DS with no complications. Further studies are required to determine its efficacy prior to establishing BMM as an adjunct treatment for penetrating and non-penetrating glaucoma surgeries.

RESUMO O bevacizumabe (um agente anti-fator de crescimento endotelial vascular) tem sido sugerido como potencial modulador cicatricial na cirurgia do glaucoma. Este estudo objetivou melhorar a biodisponibilidade do bevacizumabe, investigando a viabilidade de uma nova mistura de bevacizumabe-metilcelulose (BMM) como terapia adjuvante para a esclerectomia profunda não-penetrante (DS). Dez olhos sem cirurgias prévias de 10 pacientes com glaucoma primário de ângulo aberto foram submetidos à DS associada à uma injeção subconjuntival de 0,3 ml da mistura de bevacizumabe-metilcelulose (bevacizumabe 3,75 mg incorporado em metilcelulose 4%) no sítio cirúrgico. A liberação de bevacizumabe foi avaliada in vitro através de cromatografia líquida de alta performance por exclusão de tamanho (HPLC). A pressão intraocular (PIO), a morfologia da ampola de filtração, a contagem de células endoteliais da córnea (CECC) e as complicações foram estudadas aos seis meses de seguimento. O bevacizumabe foi detectado a partir da mistura de bevacizumabe-metilcelulose por meio do HPLC até 72 horas. Além disso, todas as ampolas cirúrgicas permaneceram expandidas com material hialino durante a primeira semana. Uma redução significativa da pressão intraocular (média ± DP= -10,3 ± 5,4 mmHg, P<0,001) e ampolas difusas foram observadas ao final do período de seguimento. Embora a contagem de células endoteliais da córnea se mostrou discretamente diminuída (-7,4%), nenhuma complicação foi observada. Neste estudo, o bevacizumabe foi liberado da mistura de bevacizumabe-metilcelulose e o uso desta nova mistura se associou com bons resultados cirúrgicos e nenhuma complicação. Estudos futuros serão necessários para determinar sua eficácia, antes de se estabelecer a mistura de bevacizumabe-metilcelulose como um tratamento adjuvante às cirurgias penetrantes e não-penetrantes para o glaucoma.

[Biodegradable systems containing prednisolone acetate for orbital administration]. / Sistemas biodegradáveis contendo acetato de prednisolona para administração orbitária.

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. The in vivo release profile was evaluated in rabbits after periocular injection of an aqueous suspension of MEs. The local biocompatibility of the system was verified by histopathologic analysis of the deployment region. RESULTS: After MEs preparation, morphological analysis by SEM showed the feasibility of the employed method. The content of PA encapsulated was 43+/-7% and can be considered as satisfactory. The system characterization by DSC technique, in addition to confirm the system stability, did not indicate the existence of interaction between the drug and the polymer. The in vitro release study showed the prolonged-release features of the developed system. Preliminary in vivo study showed the absence of local toxicity and confirmed the prolonged release profile of PA from MEs, suggesting the viability of the developed system for the treatment of orbital inflammatory diseases. CONCLUSION: The results obtained in this work are relevant and accredit the system developed as a possible alternative to the treatment of inflammatory orbitopathy.

Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant

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. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively). RESULTS: Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2. CONCLUSION: The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant. .

Sistema de liberação contendo ciclosporina para o tratamento de ceratoconjuntivite seca: estudo preliminar / Cyclosporine-loaded delivery system for the treatment of keratoconjunctivitis sicca: a pilot study

Objetivo: Este trabalho objetivou o desenvolvimento de um sistema mucoadesivo de liberação de ciclosporina A (CsA) para o tratamento de ceratoconjuntivite seca (CCS). Métodos: O sistema mucoadesivo foi preparado na forma de filme utilizando o polímero quitosana e CsA (25%p/v). Foram administrados no saco conjuntival do olho direito de coelhos normais (n=6) e a aferição da produção de lágrimas foi realizada diariamente antes e após a aplicação, de forma bilateral, durante sete dias, por meio do teste lacrimal de Schirmer. Avaliação oftalmológica foi realizada diariamente durante todo o estudo e seguido da análise histológica. Resultados: Os valores médios de produção de lágrimas foram alterados de 9,88 ± 0,37 mm/min para 16,02 ± 0,38 mm/min antes e após a administração do sistema respectivamente, significando um aumento de aproximadamente 60%. Todos os coelhos apresentaram hiperemia da conjuntiva palpebral e lacrimejamento. A hiperemia permaneceu durante 48 h após administração dos sistemas com resolução espontânea e o lacrimejamento foi diagnosticado até o final do experimento. Não foram observados outros sinais de reações indesejáveis. Nenhuma alteração histológica foi observada na mucosa conjuntival bulbar e palpebral à histopatologia. Conclusão: Os sistemas desenvolvidos são aparentemente seguros e eficientes criando expectativa para o tratamento da CCS. Novos estudos são necessários para avaliar a concentração de CsA liberada, assim como aceitabilidade e toxicidade dos sistemas em tratamentos mais prolongados.

Purpose: The present work aimed to present the development of a conjunctival mucosa system for the controlled delivery of cyclosporine A (CsA) in the treatment of keratoconjunctivitis sicca (KCS). Methods: The conjunctival mucosa system was prepared in the form of films containing chitosan as the polymer and CsA as the drug (25%w/v). The films were applied to the conjunctival sac of one eye from normal rabbits (n=6), and the evaluation of lachrymal production was performed daily, before and after application, for seven days. Clinical examination was executed daily on the eyes of each animal during the entire period of study. Histological analyses were carried out at the end of the study. Results: The average amount of lachrymal production changed from 9.88 ± 0.37 mm/min to 16.02 ± 0.38 mm/min, respectively, before and after applying the systems, which indicates an increase of approximately 60%. All rabbits presented hyperemia in the palpebral conjunctiva and tearing. Hyperemia continued for 48h after the application of the systems with spontaneous resolution, and tearing was diagnosed throughout the entire study. No other sign of undesirable reactions could be observed. Moreover, no histological changes could be identified in the bulbar and palpebral conjunctival mucosa. Conclusion: The developed systems proved to be safe and efficient in this pilot study and present a promising future for the treatment of KCS. Other studies are warranted to evaluate the released concentration of CsA as well as the feasibility and toxicity of these systems in a more prolonged treatment.