RESUMO
Up to 80% of the cost of vaccination programmes is due to the cold chain problem (that is, keeping vaccines cold). Inexpensive, biocompatible additives to slow down the degradation of virus particles would address the problem. Here we propose and characterize additives that, already at very low concentrations, improve the storage time of adenovirus type 5. Anionic gold nanoparticles (10-8-10-6 M) or polyethylene glycol (PEG, molecular weight â¼8,000 Da, 10-7-10-4 M) increase the half-life of a green fluorescent protein expressing adenovirus from â¼48 h to 21 days at 37 °C (from 7 to >30 days at room temperature). They replicate the known stabilizing effect of sucrose, but at several orders of magnitude lower concentrations. PEG and sucrose maintained immunogenicity in vivo for viruses stored for 10 days at 37 °C. To achieve rational design of viral-vaccine stabilizers, our approach is aided by simplified quantitative models based on a single rate-limiting step.
Assuntos
Vacinas contra Adenovirus/farmacologia , Estabilidade de Medicamentos , Excipientes/química , Imunogenicidade da Vacina , Vacinas contra Adenovirus/química , Vacinas contra Adenovirus/imunologia , Animais , Temperatura Baixa , Armazenamento de Medicamentos/métodos , Estudos de Viabilidade , Ouro/química , Meia-Vida , Nanopartículas Metálicas/química , Camundongos , Modelos Animais , Modelos Biológicos , Polietilenoglicóis/química , Sacarose/química , Fatores de TempoRESUMO
The activity of antivirals can be enhanced by their incorporation in nanoparticulate delivery systems. Peculiar polymeric nanoparticles, based on a ß-cyclodextrin-poly(4-acryloylmorpholine) monoconjugate (ß-CD-PACM), are proposed as acyclovir carriers. The experimental procedure necessary to obtain the acyclovir-loaded nanoparticles using the solvent displacement preparation method will be described in this chapter. Fluorescent labeled nanoparticles are prepared using the same method for cellular trafficking studies. The biocompatibility assays necessary to obtain safe nanoparticles are reported. Section 4 of this chapter describes the assessment of the antiviral activity of the acyclovir-loaded nanoparticles.
Assuntos
Resinas Acrílicas/química , Aciclovir/farmacologia , Antivirais/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Nanocápsulas/química , beta-Ciclodextrinas/química , Aciclovir/metabolismo , Animais , Antivirais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Ativação do Complemento/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Herpesvirus Humano 1/crescimento & desenvolvimento , Humanos , Teste de Materiais , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Pele/efeitos dos fármacos , Propriedades de Superfície , Técnicas de Cultura de Tecidos , Células Vero , Carga Viral , Ensaio de Placa ViralRESUMO
Novel polymeric nanoparticles based on a beta-cyclodextrin-poly(4-acryloylmorpholine) mono-conjugate (beta-CD-PACM), a tadpole-shaped polymer in which the beta-CD ring is the hydrophilic head and the PACM chain the amphiphilic tail, were prepared by the solvent injection technique. Acyclovir-loaded nanoparticles were prepared from inclusion complexes of Acyclovir with beta-CD-PACM. Both unloaded and drug-loaded nanoparticles were characterized in terms of particle size distribution, morphology, zeta potential, drug loading and in vitro drug release rate. The antiviral activity of Acyclovir loaded into beta-CD-PACM nanoparticles against two clinical isolates of HSV-1 was evaluated and found to be remarkably superior compared with that of both the free drug and a soluble beta-CD-PACM complex reported in a previous paper. Fluorescent nanoparticles loaded with coumarin 6 were also prepared in order to investigate the nanoparticle cell uptake by confocal laser microscopy. It was found that the nanoparticles are internalized in cells and locate in the perinuclear compartment.