RESUMO
Paclitaxel (PTX) incorporation in poly(lactic-co-glycolic acid) (PLGA) matrices produce films with high tensile rigidity and slow release that fail to deliver the required release rate for most biomedical applications such as in drug eluting stents and cancer treatments. To modify and improve this behavior, a set of poly(diol sebacate)s were synthesized and fully characterized as possible additives. The tensile properties of PLGA blends were evaluated as these materials could be used as coatings in drug eluting stent applications. A significant improvement in mechanical flexibility was observed with 20% additive content, as it reduced the Young's modulus value and increased the maximum deformation at break. PTX release was studied and correlated with the release of additive from PLGA films. An increase in the initial burst release phase was observed on all blends when compared to the control films of PLGA. Modulation of PTX release was achieved by altering the hydrophilicity degree of the additive or its percentage content on the blend. This supports the possibility that PTX was partitioned into the additive phase. Cytotoxicity analyses of novel additives were performed on mouse embryonic fibroblasts NIH/3T3.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Materiais Biocompatíveis/química , Ácidos Decanoicos/química , Ácidos Dicarboxílicos/química , Portadores de Fármacos/química , Ácido Láctico/química , Paclitaxel/administração & dosagem , Ácido Poliglicólico/química , Polímeros/química , Animais , Materiais Biocompatíveis/toxicidade , Ácidos Decanoicos/toxicidade , Ácidos Dicarboxílicos/toxicidade , Portadores de Fármacos/toxicidade , Módulo de Elasticidade , Ácido Láctico/toxicidade , Camundongos , Células NIH 3T3 , Ácido Poliglicólico/toxicidade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/toxicidadeRESUMO
Biocompatible polymeric coatings for metallic stents are desired, as currently used materials present limitations such as deformation during degradation and exponential loss of mechanical properties after implantation. These concerns, together with the present risks of the drug-eluting stents, namely, thrombosis and restenosis, require new materials to be studied. For this purpose, novel poly(polyol sebacate)-derived polymers are investigated as coatings for metallic stents. All pre-polymers reveal a low molecular weight between 3000 and 18 000 g mol-1 . The cured polymers range from flexible to more rigid, with E-modulus between 0.6 and 3.8 MPa. Their advantages include straightforward synthesis, biodegradability, easy processing through different scaffolding techniques, and easy transfer to industrial production. Furthermore, electrospraying and dip-coating procedures are used as proof-of-concept to create coatings on metallic stents. Biocompatibility tests using adipose stem cells lead to promising results for the use of these materials as coatings for metallic coronary stents.