resumo
In this work we investigate the effect of spherical and rod-shaped Au nanoparticles (NPs) in the microstructure, thermomechanical and release properties of thermosensitive K-carrageenan hydrogels. Thermal and mechanical analyses of the composites revealed that the Au NPs reinforce the structure of the hydrogel and the mechanism of gel reinforcement is discussed. The effect of the NPs on the microstructure and strength of the hydrogel had implications in the mechanism of controlled release as demonstrated by in vitro release studies using a drug model (methylene blue: MB). Noteworthy, the mechanism of MB release followed either a diffusion or polymer relaxation mechanism, depending on the morphology of the Au NPs incorporated in the hydrogel. Consequently, kappa-carrageenan hydrogels containing Au NPs exhibited not only optical features modulated by the fillers morphology, but also showed a behavior as drug carriers that can be also adjusted by Au NPs characteristics. (C) 2012 Elsevier Ltd. All rights reserved.
palavras-chave
GOLD NANORODS; DRUG-DELIVERY; METHYLENE-BLUE; NANOPARTICLES; MECHANISM; ALGINATE; SYSTEMS
categoria
Chemistry; Polymer Science
autores
Salgueiro, AM; Daniel-da-Silva, AL; Fateixa, S; Trindade, T
nossos autores
Ana Luísa Daniel da Silva
Investigador Principal
Ana Margarida Martins Salgueiro Carta
Estudante de doutoramento
Sara Fateixa
Investigador Júnior
Tito Trindade
Professor CatedráticoProjectos
agradecimentos
The authors acknowledge FCT (ERA-Eula/0003/2009), Pest-C/CTM/LA0011/2011, FSE and POPH for funding. We thank the RNME (National Electronic Microscopy Network) for SEM and TEM images and the National Program for Scientific Equipment Renewal (REED/515/CTM/2005) for DMA measurements. The authors are very grateful to Dr. A.V. Girao, MSc. M.C. Azevedo and MSc. S. Magina for technical support.