Suchergebnisse

The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol) (PEG) grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis). Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery. ; Authors would like to acknowledge the public funding from Fondo Social de la DGA (grupos DGA), Ministerio de la Economía y Competitividad del Gobierno de España for the public founding of ProyectosI+D+i—Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (project n. SAF2014-54763-C2-2-R), the European Seventh Framework Program (NAREB Project 604237), LLP/Erasmus fellowship 2013/2014, INA fellowship "Iniciación a la Investigación" 2014 and 2015, and the European Union's Horizon 2020 research and innovation program for MCSA Fellowship (Grant Agreement No. 660228). ; We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).

The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol) (PEG) grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis). Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery. ; Authors would like to acknowledge the public funding from Fondo Social de la DGA (grupos DGA), Ministerio de la Economía y Competitividad del Gobierno de España for the public founding of ProyectosI+D+i—ProgramaEstatal de Investigación, Desarrollo e InnovaciónOrientada a los Retos de la Sociedad (project n. SAF2014-54763-C2-2-R), the European Seventh Framework Program (NAREB Project 604237), LLP/Erasmus fellowship 2013/2014, INA fellowship "Iniciación a la Investigación" 2014 and 2015, and the European Union's Horizon 2020 research and innovation program for MCSA Fellowship (Grant Agreement No. 660228). The authors also acknowledge José Antonio Ainsa and Ainhoa Lucía for the fruitful discussions as well as Rodrigo Fernandez-Pacheco and Alfonso Ibarra from Advanced Microscopy Laboratories of the Universidad de Zaragoza and Iñigo Echaniz for their technical support. The costs to publish in open access have been covered by funds from NAREB Project (see before) ; We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).

Purpose: We aimed to evaluate the intestinal anti-inflammatory properties of silk fibroin nanoparticles, around 100 nm in size, when loaded with the stilbene compound resveratrol, in an experimental model of rat colitis. Methods: Nanoparticles were loaded with resveratrol by adsorption. The biological effects of the resveratrol-loaded nanoparticles were tested both in vitro, in a cell culture of RAW 264.7 cells (mouse macrophages), and in vivo, in the trinitrobenzenesulfonic acid model of rat colitis, when administered intracolonically. Results: The resveratrol liberation in 1× phosphate-buffered saline (PBS; pH 7.4) was characterized by fast liberation, reaching the solubility limit in 3 hours, which was maintained over a period of 80 hours. The in vitro assays revealed immunomodulatory properties exerted by these resveratrol-loaded nanoparticles since they promoted macrophage activity in basal conditions and inhibited this activity when stimulated with lipopolysaccharide. The in vivo experiments showed that after evaluation of the macroscopic symptoms, inflammatory markers, and intestinal barrier function, the fibroin nanoparticles loaded with resveratrol had a better effect than the single treatments, being similar to that produced by the glucocorticoid dexamethasone. Conclusion: Silk fibroin nanoparticles constitute an attractive strategy for the controlled release of resveratrol, showing immunomodulatory properties and intestinal anti-inflammatory effects. ; This work was supported by the Spanish Ministry of Science and Innovation (grant number SAF2011-29648) with funds from the European Union, and by the Junta de Andalucia (grant numbers AGR-6826 and CTS 164). Parts of the experiments were financed by funds of the European Regional Development Fund (ERDF) Operative Program of the Region of Murcia 2007–2013. The research contract of Dr A Abel Lozano-Pérez was partially supported (at 80%) by the FEDER Operative Program of the Region of Murcia 2007–2013. F Algieri is a predoctoral fellow of the Junta de Andalucia; J Garrido-Mesa is a predoctoral fellow of the Spanish Ministry of Education, Culture and Sport; N Garrido-Mesa is a postdoctoral fellow of the Ramon Areces Foundation; ME Rodríguez-Cabezas is a postdoctoral fellow of Centro de Investigaciones Biomédicas en Red – Enfermedades Hepáticas y Digest (CIBER-EHD), which is funded by the Instituto de Salud Carlos III.