Effect of ionic strength solution on the stability of chitosan-DNA nanoparticles

Chitosan-DNA nanoparticles employed in gene therapy protocols consist of a neutralised, stoichiometric core and a shell of the excess of chitosan which stabilises the particles against further coagulation. At low ionic strength, these nanoparticles possess a high stability; however, as the ionic strength increases, it weakens the electrostatic repulsion which can play a decisive part in the formation of highly aggregated particles. In this study, new results about the effect of ionic strength on the colloidal stability of chitosan-DNA nanoparticles were obtained by studying the interaction between chitosans of increasing molecular weights (5, 10, 16, 29, 57 and 150 kDa) and calf thymus DNA. The physicochemical properties of polyplexes were investigated by means of dynamic light scattering, static fluorescence spectroscopy, optic microscopy, transmission electronic microscopy and gel electrophoresis. After subsequent addition of salt to the nanoparticles solution, secondary aggregation increased the size of the polyplexes. The nanoparticles stability decreased drastically at the ionic strengths 150 and 500 mM, which caused the corresponding decrease in the thickness of the stabilising shell. The morphologies of chitosan/DNA nanoparticles at those ionic strengths were a mixture of large spherical aggregates, toroids and rods. The results indicated that to obtain stable chitosan-DNA nanoparticles, besides molecular weight and N/P ratio, it is quite important to control the ionic strength of the solution. © 2013 Copyright Taylor and Francis Group, LLC.

Acute phase protein profile in agoutis (Dasyprocta azarae; Lichtenstein, 1823) in captivity, determined by sodium dodecyl sulfate polyacrilamyde gel electrophoresis

The acute phase response refers to a nonspecific and complex systemic reaction of the organism that occurs shortly after any tissue injury. The acute phase response is considered a part of the innate host defense system, which is responsible for the survival of the host during the critical early stages of attack, and in evolutionary terms, it precedes the acquired immune response. The purpose of this study was to determine serum protein concentrations, including the acute phase protein profile in agoutis (Dasyprocta azarae) in captivity, by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis. Blood samples from 11 adult healthy animals (nine females and two males) were obtained. The serum proteinogram had 21 proteins with molecular weights ranging from 15 to 240 kD. The acute phase proteins identified were: ceruloplasmin, transferrin, albumin, haptoglobin, α-1-acid glycoprotein, and hemoglobin. IgA, IgG heavy and light chains, and nonnominal identified proteins of 240, 210, 140, 98, 78, 48, 35, 31, 23, and 15 kD were also identified. The determination of the acute phase protein concentrations is a useful method for the early detection of subclinical disease or changes in the healthy animal, with predictive information on the development of disease in the future. It is possible to standardize the reference values of the serum protein profile of agoutis, which can be used for diagnosis and prognosis, treatment and clinical follow-up of nutritional disorders, and immune-mediated inflammatory diseases that may affect these animals. © 2012 Springer-Verlag London Limited.

Estudo físico-químico de nanopartículas de DNA com derivado de quitosana contendo grupos fosforilcolina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isolado protéico de farinha de semente de goiaba (Psidium guajava): caracterização de propriedades funcionais e térmicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eletroforetograma de proteínas séricas de cães linfomatosos, submetidos ao protocolo quimioterápico de Madison-Wisconsina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação dos parâmetros espermáticos e caracterização do perfil bioquímico do plasma seminal de cães (Canis familiaris – LINNAEUS, 1758) com hiperplasia prostática benigna, tratados com toxina botulínica A

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da segurança e estudo da permeação e retenção cutânea de géis de ácido hialurônico

Pós-graduação em Ciências Farmacêuticas - FCFAR

Adaptabilidade diferencial das variantes moleculares slow e fast da esterase-5 de Drosophila mulleri

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Isolamento e caracterização parcial de adesina de Paracoccidioides brasiliensis ligante de fibronectina

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

Síntese, caracterização e atividade antifúngica de derivados anfifílicos de dietilaminoetil-quitosana contra Aspergillus flavus e Aspergillus parasiticus

Pós-graduação em Química - IBILCE

Caracterização eletroforética do perfil protéico e análise bioquímica do plasma seminal canino

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo clínico, hematológico, bioquímico sérico, parasitológico, imunológico e patológico de bovinos experimentalmente infectados com Trypanosoma evansi Steel, 1885 (Sarcomastigophora: Trypanosomatidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação da atividade leishmanicida, antiproteolítica e antioxidante de Arrabidaea brachypoda

Pós-graduação em Ciências Farmacêuticas - FCFAR

Mecanismo de transdução de sinal na próstata de cão: avaliação nas vias da p-ERK1/2 e da CYR61

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Semen parameters and seminal plasma protein and biochemical profiles of dogs with benign prostatic hyperplasia after botulinum toxin type A intraprostatic injection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)