RESUMO
PURPOSE: To assess the in vivo release profile and the retinal toxicity of a poly (lactic-co-glycolic acid) (PLGA) sustained-release sirolimus (SRL) intravitreal implant in normal rabbit eyes. METHODS: PLGA intravitreal implants containing or not SRL were prepared, and the viability of ARPE-19 and hES-RPE human retinal cell lines was examined after 24 and 72 h of exposure to implants. New Zealand rabbits were randomly divided into two groups that received intravitreal implants containing or not SRL. At each time point (1-8 weeks), four animals from the SRL group were euthanized, the vitreous was collected, and drug concentration was calculated. Clinical evaluation of the eyes was performed weekly for 8 weeks after administration. Electroretinography (ERG) was recorded in other eight animals, four for each group, at baseline and at 24 h, 1, 4, 6, and 8 weeks after the injection. ERG was carried out using scotopic and photopic protocols. The safety of the implants was assessed using statistical analysis of the ERG parameters (a and b waves, a and b implicit time, B/A ratio, oscillatory potential, and Naka-Rushton analysis) comparing the functional integrity of the retina between the PLGA and SRL-PLGA groups. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology was realized. RESULTS: After 24 and 72 h of incubation with PLGA or SRL-PLGA implants, ARPE-19 and hES-RPE cells showed viability over 70%. The maximum concentration of SRL (199.8 ng/mL) released from the device occurred within 4 weeks. No toxic effects of the implants or increase in the intraocular pressure was observed through clinical evaluation of the eye. ERG responses showed no significant difference between the eyes that received PLGA or SRL-PLGA implants at baseline and throughout the 8 weeks of follow-up. No remarkable difference in retinal histopathology was detected in rabbit eyes treated with PLGA or SRL-PLGA implants. CONCLUSIONS: Intravitreal PLGA or SRL-PLGA implants caused no significant reduction in cell viability and showed no evident toxic effect on the function or structure of the retina of the animals. SRL was released from PLGA implant after application in the vitreous of rabbits during 8 weeks.
Assuntos
Imunossupressores/farmacocinética , Imunossupressores/toxicidade , Epitélio Pigmentado da Retina/efeitos dos fármacos , Sirolimo/farmacocinética , Sirolimo/toxicidade , Corpo Vítreo/metabolismo , Implantes Absorvíveis , Animais , Disponibilidade Biológica , Linhagem Celular , Sobrevivência Celular , Sistemas de Liberação de Medicamentos , Implantes de Medicamento , Eletrorretinografia , Células-Tronco Embrionárias/efeitos dos fármacos , Humanos , Injeções Intravítreas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Coelhos , Retina/efeitos dos fármacosRESUMO
Alpha-synuclein (SNCA) oligomers have been reported to inhibit autophagy. Aminochrome-induced SNCA oligomers are neurotoxic, but the flavoenzyme DT-diaphorase prevents both their formation and their neurotoxicity. However, the possible protective role of DT-diaphorase against autophagy impairment by aminochrome-induced SNCA oligomers remains unclear. To test this idea, we used the cell line RCSN-3NQ7SNCA, with constitutive expression of a siRNA against DT-diaphorase and overexpression SNCA, and RCSN-3 as control cells. A significant increase in LC3-II expression was observed in RCSN-3 cells treated with 20 µM aminochrome and 10 µM rapamycin followed by a decrease in cell death compared to RCSN-3 cells incubated with 20 µM aminochrome alone. The incubation of RCSN-3NQ7SNCA cells with 20 µM aminochrome and 10 µM rapamycin does not change the expression of LC3-II in comparison with RCSN-3NQ7SNCA cells incubated with 20 µM aminochrome alone. The incubation of both cell lines preincubated with 100 nM bafilomycin and 20 µM aminochrome increases the level of LC3-II. Under the same conditions, cell death increases in both cell lines in comparison with cells incubated with 20 µM aminochrome. These results support the protective role of DT-diaphorase against SNCA oligomers-induced autophagy inhibition.
Assuntos
Autofagia/fisiologia , Indolquinonas/toxicidade , NAD(P)H Desidrogenase (Quinona)/metabolismo , Degeneração Neural/induzido quimicamente , Neuroproteção/fisiologia , alfa-Sinucleína/metabolismo , Animais , Autofagia/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Macrolídeos/toxicidade , Proteínas Associadas aos Microtúbulos/metabolismo , NAD(P)H Desidrogenase (Quinona)/genética , Degeneração Neural/enzimologia , Neuroproteção/efeitos dos fármacos , RNA Interferente Pequeno , Ratos , Sirolimo/toxicidade , alfa-Sinucleína/genéticaRESUMO
Curcumin is considered to be a potential component for drug-eluting stents due to its anti-inflammatory properties. In this study we compared the mutagenicity and blood compatibility of curcumin to first generation drug eluting stent components: paclitaxel and sirolimus. The Ames test was used to assess mutagenicity. Blood compatibility was tested by measuring platelet activation and fibrinogen adsorption on poly (DL-lactide-co-glycolide, PLGA) films. We discovered that there was no significant increase in the number of revertants/plate following treatment with curcumin (up to 0.5mg/plate) or sirolimus (up to 0.5 µg/plate). However, a significant induction in the frequency of bacterial his(+) revertant colonies by paclitaxel at concentrations of 0.02, 0.05, 0.1, 0.2 and 0.5 µg/plate was observed. We also discovered a significant reduction in platelet activation by PLGA films containing 30% and 50% by weight curcumin. A similar reduction in platelet activation was also observed for PLGA films containing 1% by weight paclitaxel. In addition, we observed an increase of fibrinogen adsorption to PLGA-films containing curcumin. This would compromise the potential use of curcumin as a component of drug-eluting stents. Moreover, our data challenges the current view that paclitaxel does not significantly induce mutagenesis.
Assuntos
Antineoplásicos Fitogênicos/toxicidade , Curcumina/toxicidade , Mutagênicos/toxicidade , Paclitaxel/toxicidade , Adsorção , Antineoplásicos Fitogênicos/administração & dosagem , Curcumina/administração & dosagem , Stents Farmacológicos , Fibrinogênio/química , Humanos , Ácido Láctico/química , Testes de Mutagenicidade , Mutagênicos/administração & dosagem , Paclitaxel/administração & dosagem , Ativação Plaquetária/efeitos dos fármacos , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/genética , Sirolimo/administração & dosagem , Sirolimo/toxicidadeRESUMO
O sirolimus (Rapamune®) é uma droga imunossupressorautilizada em pacientes transplantados, principalmentenaqueles pacientes com função renal alterada ou nos queapresentam piora da função renal na vigência do tratamentoimunossupressor empregado. Relatamos um caso de um paciente pós-transplantado renal, que apresentou, quatro meses após início da terapia com sirolimus queda do estado geral, dispnéia e febre. Foi realizada investigação laboratorial e radiológica, sendo descartado um processo infeccioso como responsável pelo quadro clínico do paciente. Após excluir outras causas, a hipótese de farmacotoxidade pelo sirolimus foi aventada e confirmada com a melhora clínica e radiológica apresentada após a descontinuação dessa droga. A paciente teve alta hospitalar assintomática
Assuntos
Idoso , Humanos , Masculino , Pneumonia/diagnóstico , Pneumonia/induzido quimicamente , Sirolimo , Sirolimo/toxicidade , Imunossupressores/efeitos adversosRESUMO
We analyzed the effect of oral administration of cyclosporine-methylprednisone (CsA-MP) and sirolimus (SRL) on the lipid pattern of kidney-transplanted rats after a 7-day survival. A significant increase in plasma cholesterol in CsA-MP group (control: 26 +/- 3 mg/dl vs. 59 +/- 8 mg/dl, P < 0.05) and in triglyceride levels in SRL group (control: 53 +/- 4 mg/dl vs. 114 +/- 3 mg/dl, P < 0.05), was shown. Kidney microsomal membranes from both treated groups showed that cholesterol and triglyceride values and the relative percentage of arachidonic acid in the total amount of n-6 fatty acids decreased. A diminution of linoleic acid occurred in testis (control: 9.4 +/- 0.1 mg/dl vs. CsA-MP: 6.0 +/- 0.3 mg/dl and vs. SRL: 6.8 +/- 0.2 mg/dl, P < 0.05), liver (control: 17.7 +/- 0.6 mg/dl vs. CsA-MP: 15.1 +/- 0.6 mg/dl and SRL: 13.5 +/- 0.8 mg/dl, P < 0.05) and erythrocyte membranes (control:11.7 +/- 0.1% vs. CsA-MP: 10.6 +/- 0.2% and SRL: 10.0 +/- 0.4%, P < 0.01). The immunosuppressive therapies improved the rejection rate of the graft, fact that was remarkable in the SRL-treated group. However, lipid abnormalities still remain in spite of immunosuppressive therapies (150).
Assuntos
Imunossupressores/toxicidade , Transplante de Rim/imunologia , Transplante de Rim/fisiologia , Metabolismo dos Lipídeos , Animais , Colesterol/sangue , Creatinina/sangue , Ciclosporina/toxicidade , Membrana Eritrocítica/metabolismo , Hiperlipidemias/induzido quimicamente , Rim/metabolismo , Transplante de Rim/patologia , Lipídeos/sangue , Masculino , Lipídeos de Membrana/metabolismo , Metilprednisolona/toxicidade , Microssomos Hepáticos/metabolismo , Ratos , Ratos Wistar , Sirolimo/toxicidade , Testículo/metabolismo , Triglicerídeos/sangue , Ureia/sangueRESUMO
Avaliou-se os efeitos do Sirolimus (SIRO 3mg/kg/diaVO) isoladamente e associado a Ciclosporina A (CsA 3mg/kg/dia SC) em túbulos renais proximais isolados (TP) e sobre a função renal de ratos Wistar normais e submetidos à isquemia renal (30 min). SIRO não apresentou efeito tóxico em TP e nem potencializou a toxicidade da CsA. SIRO não afetou a recuperação da filtração glomerular (FG) após isquemia e foi capaz de prevenir a diminuição da FG induzida pela CsA, a despeito da persistência da vasoconstrição e maior infiltrado inflamatório /The effects of sirolimus (SIRO 3 mg/kg/day PO) alone or associated with ciclosporine (CsA 3 mg/kg/day SC) were evaluated in isolated proximal tubules suspensions (PT) and in control and ischemic (30 min) Wistar rats. SIRO was neither toxic to PT nor affected CsA toxicity. SIRO did not affect glomerular filtration rate (GFR) recovery after ischemia and it prevented CsA induced aggravation despite persistence of vasoconstriction and greater inflammatory infiltrate...