Élaboration de copolymères à base de biopolyesters pour la libération contrôlée de principes actifs

Les poly(3-hydroxyalcanoate)s ou P(3-HA)s, sont des polyesters aliphatiques d'origine naturelle, comportant des chaînes latérales saturées ou insaturées de différentes longueurs, produits par des bactéries. Les propriétés de biodégradabilité et de biocompatibilité confèrent à ces polymères naturels de vastes possibilités d'utilisation, notamment dans le domaine biomédical. Notre objectif a consisté à élaborer de nouveaux matériaux à base de P(3-HA)s afin d'améliorer leurs propriétés. Pour cela, des copolymères à base de P(3-HA)s et de polymères semi-cristallins (poly( -caprolactone) ou poly(acide lactique)) de structures différentes telles que des copolymères à blocs, greffés et statistiques, ont été synthétisés. La présence d'insaturations sur les chaînes latérales a permis de préparer des copolymères fonctionnalisés. Les copolymères à blocs ont été utilisés pour préparer des nanoparticules par nanoprécipitation. Les nanoparticules obtenues sont susceptibles d'encapsuler et de libérer de manière contrôlée, en fonction du pourcentage de P(3-HA) dans le copolymère, de la doxorubicine, un agent anti-tumoral utilisé lors de thérapies des tumeurs de la vessie. Ces systèmes nanoparticulaires présentent des propriétés de mucoadhésivité particulièrement favorables pour des systèmes de vectorisation endocavitaire.Poly(3-hydroxyalkanoate)s (P(3-HA)s), are aliphatic biopolyesters with saturated and unsaturated side chains of different lengths. They are produced by a wide range of microorganisms. These biopolymers are biodegradable and biocompatible and can be used for biomedical applications. The aim of the study was to investigate and improve the properties of novel materials based on P(3-HA)s. Copolymers based on P(3-HA)s and semi-crystalline polymers (poly( -caprolactone) or poly(lactic acid)) with different structures e.g. block, graft or statistic copolymers, were synthesized. The presence of unsaturated units on side chains affords us the ability to prepare functionalised copolymers. Block copolymers were used to prepare mucoadhesive nanoparticles by nanoprecipitation and encapsulating doxorubicin. Doxorubicin is a chemotherapeutic agent used to treat bladder disease. The amount of P(3-HA) in the copolymers was used to control the release of doxorubicin.PARIS12-CRETEIL BU Multidisc. (940282102) / SudocSudocFranceF

Multifunctional Polyester-Based Materials with Controlled Degradability

4 - Chapitre de livreHydrolytic degradability can be fine-tuned in polyester-based materials by controlling the nature and placement of comonomers introduced within the polymer structures. This contribution describes how D,L-lactide-, ε-caprolactone-, and β-hydroxyoctanoate-containing polyesters can be used to design nanostructured drug delivery vehicles and mesoporous polymeric materials. In the first part, the efficient synthesis of poly(β-hydroxyoctanoate)-based block and graft copolymers is addressed. A versatile and straightforward approach toward mesoporous functional polymers via the partial hydrolysis of poly(D,L-lactide)-based Interpenetrating Polymer Networks (IPNs) is discussed in a second part

Multifunctional polyesters as key components in the design of nanostructured drug delivery and mesoporous materials

9 - Conference paper: 229th American Chemical Society National Meeting, 13-17 Mars 2005, San Diego (USA)International audienc

Tissue Response to, and Degradation Rate of, Photocrosslinked Trimethylene Carbonate-Based Elastomers Following Intramuscular Implantation

Cylindrical elastomers were prepared through the UV-initiated crosslinking of terminally acrylated, 8,000 Da star-poly(trimethylene carbonate-co-ε-caprolactone) and star-poly(trimethylene carbonate-co-D,L-lactide). These elastomers were implanted intramuscularly into the hind legs of male Wistar rats to determine the influence of the comonomer on the weight loss, tissue response, and change in mechanical properties of the elastomer. The elastomers exhibited only a mild inflammatory response that subsided after the first week; the response was greater for the stiffer D,L-lactide-containing elastomers. The elastomers exhibited weight loss and sol content changes consistent with a bulk degradation mechanism. The D,L-lactide-containing elastomers displayed a nearly zeroorder change in Young’s modulus and stress at break over the 30 week degradation time, while the ε-caprolactone-containing elastomers exhibited little change in modulus or stress at break