Synthèse et caractérisation de capsules multicouches fonctionnelles à base de polysaccharides modifiés

• Main Author: Cui, Di
• Language: fra
• Published: Université de Grenoble 2011
• Subjects: [SDV] Life Sciences; [SDV] Sciences du Vivant; Multicouches; Polysaccharide; Microcapsules; Activité antimicribienne; Encapsulation des médicaments hydrophobes; Biodegradabilité
• Online Access: http://tel.archives-ouvertes.fr/tel-00621208; http://tel.archives-ouvertes.fr/docs/00/62/12/08/PDF/Cui_di_2011_archivage.pdf

This work focused on the design of functional capsules made of chemically modified polysaccharides. The layer-by-layer capsules have attracted great interest due to their Indeed, as an advanced multifunctionality which can be advantageously used for pharmaceutical and biomedical applications. Polysaccharides, which are generally biocompatible and biodegradable, are very attractive materials for the construction of bio-related multilayer systems. Considering the intrinsic antibacterial properties of chitosan (CHI), this polysaccharide was selected and quaternized to prepare in physiological conditions contact-killing capsules by combination with hyaluronic acid (HA). The relationship between the antibacterial activity of the quaternized chitosan derivatives (QCHI) and that of QCHI-based capsules was investigated. Then, in order to encapsulate small hydrophobic drugs within the wall of capsules, alkylated derivatives of HA were used as the negatively charged partner of QCHI for the capsules formation. The encapsulation of the hydrophobic dye, nile red (NR), in the hydrophobic shell of capsules was determined. At last, to release the payload under mild conditions was studied by synthesizing rapidly degradable capsules composed of hydrolysable cationic dextran derivatives and HA. The degradation of the layer-by-layer assemblies, both multilayer films and microcapsules is discussed.