An in situ gelling liquid crystalline system based on monoglycerides and polyethylenimine for local delivery of siRNAs.

The development of delivery systems able to complex and release siRNA into the cytosol is essential for therapeutic use of siRNA. Among the delivery systems, local delivery has advantages over systemic administration. In this study, we developed and characterized non-viral carriers to deliver siRNA locally, based on polyethylenimine (PEI) as gene carrier, and a self-assembling drug delivery system that forms a gel in situ. Liquid crystalline formulations composed of monoglycerides (MO), PEI, propylene glycol (PG) and 0.1M Tris buffer pH 6.5 were developed and characterized by polarized light microscopy, Small Angle X-ray Scattering (SAXS), for their ability to form inverted type liquid crystalline phases (LC2) in contact with excess water, water absorption capacity, ability to complex with siRNA and siRNA release. In addition, gel formation in vivo was determined by subcutaneous injection of the formulations in mice. In water excess, precursor fluid formulations rapidly transformed into a viscous liquid crystalline phase. The presence of PEI influences the liquid crystalline structure of the LC2 formed and was crucial for complexing siRNA. The siRNA was released from the crystalline phase complexed with PEI. The release rate was dependent on the rate of water uptake. The formulation containing MO/PEI/PG/Tris buffer at 7.85:0.65:76.5:15 (w/w/w/w) complexed with 10 µM of siRNA, characterized as a mixture of cubic phase (diamond-type) and inverted hexagonal phase (after contact with excess water), showed sustained release for 7 days in vitro. In mice, in situ gel formation occurred after subcutaneous injection of the formulations, and the gels were degraded in 30 days. Initially a mild inflammatory process occurred in the tissue surrounding the gel; but after 14 days the tissue appeared normal. Taken together, this work demonstrates the rational development of an in situ gelling formulation for local release of siRNA.

Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro.

The efficacy of the fluoride-chlorhexidine association in the prevention of gingivitis and caries has been advocated for a number of years. The objective of the association of these therapeutic agents is a synergistic action. The aim of the present study was to determine the substantivity of chlorhexidine associated or not to sodium fluoride at different intervals of time, in vitro. Bovine enamel surfaces were treated with 0.12% chlorhexidine gluconate (Periogard--Colgate) or 0.05% sodium fluoride with 0.12% chlorhexidine (Duplak--Dentsply) solutions for one minute. Fragments were placed in distilled water and samples were collected at intervals of 5, 30 and 360 minutes and analyzed by spectrophotometry in the visible ultraviolet region. Substantivity was evaluated by the measurement of chlorhexidine desorption from the treated slabs. The mean values obtained were statistically analyzed by Student's t-test. The results showed that the concentration of chlorhexidine decreased when it was used in association with sodium fluoride. The difference between the groups was statistically significant (p < 0.05). These in vitro results suggest that the association between sodium fluoride and chlorhexidine in the studied concentrations appears to have no beneficial effect because of the decrease in the substantivity of chlorhexidine.

Self-assembling gelling formulation based on a crystalline-phase liquid as a non-viral vector for siRNA delivery.

Liquid crystalline systems (LCSs) form interesting drug delivery systems. These include in situ gelling delivery systems, which present several advantages for use as self-assembling systems for local drug delivery. The aim of this study was to develop and characterize in situ gelling delivery systems for local siRNA delivery. The influence of the components that form the systems was investigated, and the systems were characterized by polarized light microscopy, Small Angle X-ray Scattering (SAXS), swelling studies, assays of their ability to form a complex with genes and of the stability of the genes in the system, as well as assays of in situ gelling formation and local toxicity using an animal model. The system containing a mixture of monoglycerides (MO), oleylamine (OAM), propylene glycol (PG) and tris buffer (8.16:0.34:76.5:15, w/w/w/w) was considered the most appropriate for local siRNA delivery purposes. The molecular structure was characterized as hexagonal phase; the swelling studies followed a second order kinetic model and the water absorption was a fast process reaching equilibrium at 2 h. The system formed a complex with siRNA and remained in a stable form. The gel was formed in vivo after subcutaneous administration of a precursor fluid formulation in mice and was biodegradable in 30 days. The inflammatory process that took place was considered normal. Therefore, the developed liquid crystalline delivery system shows the appropriate characteristics for use as a local siRNA delivery method for gene therapy.

Infecções sexualmente transmissíveis rastreados pelo pré-natal masculino* / Sexually transmitted infections tracked by male prenatal care

Objetivo: estimar a prevalência de infecções sexualmente transmissíveis nos exames de pré-natal masculino. Método: trata-se de um estudo quantitativo, retrospectivo, de casos novos de infecções sexualmente transmissíveis por rastreio de 335 exames pré-natais masculino. Utilizou-se como instrumento de pesquisa a ficha de registro do pré-natal masculino tendo as variáveis: idade, sexo, escolaridade, entre outros. Digitaram-se os dados em planilhas eletrônicas, analisando-os no programa SPSS, versão 22.0 Resultados: informa-se que os resultados foram considerados todos casos novos, uma vez que não havia relato anterior de diagnóstico ou tratamento das ISTs. Mostra-se que a idade média dos homens registrados foi de 30,55 anos. Dentre esta amostra houveram três casos reagentes para HIV/Aids, 22 para Sífilis, cinco casos reagentes para hepatite B, e três casos para hepatite C. Conclusão: conclui-se que mesmo diante de uma amostra não representativa numericamente do total de gestantes atendidas no município, observou-se que é importante realizar o rastreio positivo para casos novos de infecção por HIV/Aids, Hepatite B e C, sobretudo para Sífilis.(AU)

Objective: to estimate the prevalence of sexually transmitted infections in male prenatal examinations. Method: this is a retrospective quantitative study of new cases of sexually transmitted infections by screening 335 male prenatal examinations. The research instrument used was the male prenatal registration form with the variables: age, sex, education, among others. Data was entered into spreadsheets and analyzed using the SPSS program, version 22.0. Results: it is reported that the results were considered all new cases, since there was no previous report of diagnosis or treatment of STIs. The average age of registered men is shown to be 30.55 years. Among this sample there were three cases reactive for HIV/AIDS, 22 cases for Syphilis, five cases reactive for hepatitis B, and three cases for hepatitis C. Conclusion: it is concluded that even before a sample not numerically representative of the total number of pregnant women attended in the It was noted that positive screening for new cases of HIV/AIDS, Hepatitis B and C infection is important, especially for Syphilis.(AU)

Objetivo: estimar la prevalencia de infecciones de transmisión sexual en los exámenes prenatales masculinos. Método: este es un estudio cuantitativo retrospectivo de nuevos casos de infecciones de transmisión sexual mediante la detección de 335 exámenes prenatales masculinos. El instrumento de investigación utilizado fue el formulario de registro prenatal masculino con las variables: edad, sexo, escolaridad, entre otros. Los datos se ingresaron en hojas de cálculo y se analizaron utilizando el programa SPSS, versión 22.0 Resultados: se informa que los resultados se consideraron todos los casos nuevos, ya que no había un informe previo de diagnóstico o tratamiento de las ITS. La edad promedio de los hombres registrados es de 30.55 años. Entre esta muestra, hubo tres casos reactivos para el VIH/SIDA, 22 casos para la Sífilis, cinco casos reactivos para la hepatitis B y tres casos para la hepatitis C. Conclusión: se concluye que incluso antes de una muestra no representa numéricamente el número total de mujeres embarazadas atendidas en el municipio, se observó que la detección positiva de nuevos casos de infección por VIH/SIDA, Hepatitis B y C, especialmente para Sífilis, era importante.(AU)

Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro

A efetividade da associaçäo fluoreto-clorexidina na prevençäo da gengivite e da cárie vem sendo defendida desde alguns anos 5,7,14. O propósito dessa associaçäo é ter um desempenho sinergistico da mesma. O objetivo do presente estudo foi avaliar a substantividade da clorexidina em associaçäo ou näo ao fluoreto de sódio em diferentes intervalos de tempo, in vitro. Foram tratadas superfícies de esmalte bovino com soluções de digluconato de clorexidina 0,12 por cento, Periogardâ - Colgateâ ou fluoreto de sódio 0,5 por cento-clorexidina 0,12 por cento Duplakâ -Dentsplyâ durante um minuto. A substantividade foi medida pela dessorçäo da clorexidina a partir dos fragmentos previamente imersos nas soluções teste e colocados em água destilada. Alíquotas foram removidas em intervalos de 5`, 30` e 6 horas e analisadas através da espectroscopia na regiäo do ultravioleta visível. Os valores obtidos foram analisados estatisticamente pelo teste de T-student. Os resultados mostraram que a concentraçäo da clorexidina foi significativamente reduzida quando em associaçäo com fluoreto de sódio (p <0.05). Os resultados in vitro sugerem que a associaçäo da clorexidina com fluoreto de sódio nas concentrações estudadas parece näo ter efeito benéfico devido à reduçäo da substantividade da clorexidina