RESUMEN
Cage-like microstructures were obtained in two steps by sequential Ugi reactions. At the first stage, submicron colloidal particles based on carboxymethylcellulose and chitosan with a domain structure were obtained in an aqueous suspension. In the second stage, the Ugi reaction was carried out on the surface of the Pickering emulsions with toluene. Removal of toluene and redissolution in water resulted in colloidosomes with large holes on the surface. Varying the cross-link density during the Ugi reaction made it possible to obtain structures with different hole sizes.
RESUMEN
In this study, cross-linked carboxymethyl cellulose/chitosan submicron particles were employed to facilitate the stabilization of Pickering emulsion. The polymer particles were prepared using the polyelectrolyte self-assembly method in conjunction with isocyanide based multicomponent reactions and the characteristics were obtained using: nuclear magnetic resonance, Fourier-transform infrared spectroscopy and dynamic light scattering. Atomic force microscopy revealed the heterogeneous structure of the resulting submicron particles with domains of 20-30â¯nm in size. The average diameter was found to be in the range of 229-378â¯nm and they were found to be suitable for the fabrication of oil/water Pickering emulsion when proceeded via the homogenization method followed by sonication. The results obtained revealed that carboxymethyl cellulose/chitosan particles significantly stabilized the droplets at the oil/water interface. Even at low particle concentrations of 0.3â¯g/L (which is close to that of low molecular weight surfactants) stable Pickering emulsions have been obtained. Additionally, the resulting emulsions showed a high level of stability with regard to changes in pH, temperature and ionic strength. The natural alkaloid piperine was used as a model compound to load the resulting particles, which possessed encapsulation efficiency of 90.6±0.4%. Furthermore, the in vitro release profile of piperine from the Pickering emulsion revealed a much-controlled release in both acidic and neutral media as compared to the unformulated piperine. Additional findings in this work revealed important information on the application of carboxymethyl cellulose/chitosan submicron particles as Pickering stabilizers for creation of new delivery systems.
Asunto(s)
Alcaloides , Benzodioxoles , Quitosano , Nanopartículas , Piperidinas , Alcamidas Poliinsaturadas , Quitosano/química , Emulsiones/química , Celulosa/química , Carboximetilcelulosa de Sodio , Polímeros , Emulsionantes , Tamaño de la Partícula , Nanopartículas/químicaRESUMEN
In this article, we described a novel antituberculosis imidazotetrazine derivative designed in fucoidan-coated liposomes to reduce its cytotoxicity and investigate its mucoadhesive properties. Firstly, fucoidan extracted from Ascophyllum nodosum was used for additional stabilization of liposomal suspensions and to give it mucoadhesive properties. PEG-600 and/or Tween-80 were used to increase the shelf life of liposomal suspension. The ratio of the fucoidan: lipids 1:2 was found to be the optimum that produces stable fucoidan-coated liposomes. The particle size of the optimum formulation was 336.3 ± 5.4, the PDI was 0.33, and the zeta potential was -39.6. This size and the practical spherical shape of the particles were confirmed by atomic force microscopy. In addition, the in vitro release profiles from uncoated and fucoidan-coated liposomes revealed significant and faster release compared to free antituberculosis agent. Using the MTT assay test, the fucoidan-coated liposomes exhibited fourteen times lower cytotoxicity (IC50 7.14 ± 0.91 µg/ml) than the free drug (IC50 0.49 ± 0.06). Moreover, the mucoadhesive capabilities of these liposomal formulations were also confirmed using snail mucin, which highlighting their potential use as an effective delivery system for antituberculosis therapy, with notable improvements in dissolution rate and reduced cytotoxicity.