RESUMO
A new cholesteryl-cyclodextrin derivative, obtained by grafting a single cholesterol on a cyclodextrin, was proved suitable for the manufacture of nanocapsules. The chemical structure of Chol-betaCD-Ac was assessed using high resolution 1H-NMR. These nanocapsules were loaded with a lipophilic drug, i.e., vitamin A propionate (PRVA) which is a highly unstable and poorly water soluble molecule with a real interest in therapeutic. The oily nature of vitamin A propionate leads to the formation of nanocapsules with a reproductible size distribution and a long term stability. The colloidal suspension can be used to form a gel which allow to achieve penetration in the skin of the PRVA encapsulated.
Assuntos
Ciclodextrinas/química , Portadores de Fármacos/química , Nanoestruturas/química , Pele/metabolismo , Vitamina A/administração & dosagem , Vitamina A/química , Administração Tópica , Cristalização/métodos , Composição de Medicamentos/métodos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Técnicas In Vitro , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
We have raised antibodies against two methylated derivatives of beta-CD, heptakis(2,6-di-O-methyl)cyclomaltoheptaose (Dimeb) and heptakis(2,3,6-tri-O-methyl)cyclomaltoheptaose (Trimeb). These antibodies were used to develop two specific and sensitive enzyme immunoassays, presenting a detection limit close to 500 and 30 pg/mL for Trimeb and Dimeb, respectively. Cross reactivities of different linear and cyclic maltooligosaccharides were investigated, demonstrating a high specificity against the structural features of the secondary hydroxyls rim. Several commercial Dimeb samples, containing different mixtures of partially methylated beta-cyclodextrin derivatives including RAMEB, which contains only a few amount of pure Dimeb, could be easily evaluated by the Dimeb immunoassay. Both of these assays have been shown to allow accurate measurement in plasma and urine, thus appearing as useful tools for further applications in biological material.
Assuntos
Ciclodextrinas/química , Técnicas Imunoenzimáticas , Animais , Configuração de Carboidratos , Sequência de Carboidratos , Dados de Sequência Molecular , Coelhos , Sensibilidade e Especificidade , Relação Estrutura-AtividadeRESUMO
Recently, new cyclodextrin derivatives were synthesized and shown to exhibit strong amphiphilic properties. In this paper, we study the action of these new amphiphilic cyclodextrins on phospholipids. Mixed phospholipid/cyclodextrin derivative films were prepared and studied using X-ray reflectivity for various phospholipid/cyclodextrin ratios. A molar ratio of 3 provides a highly stable film the molecular structure of which has been investigated in detail. The cholesterol tail of the cyclodextrin molecule was found to be anchored into the phospholipid film. The cyclodextrin moieties exposed to the aqueous medium are prone to the addition of the guest molecule Dosulepin, making them of high interest for drug delivery. For this purpose and as an example of a potential application, this cyclodextrin molecular carrier property is also addressed to this complex film architecture.
