RESUMO
ABSTRACT Free films of pullulan-polymethacrylate associations were produced by casting process to develop a novel target-specific material. For characterization, tests of water vapor permeability, swelling index, infrared absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy and mechanical analysis were performed. The polysaccharide concentration directly influenced vapor permeability and swelling, increasing the values of the latter up to five times when added in a proportion of 20% (per weight). The individual properties of each polymer were maintained, and chemical interactions were not detected. The films were found to be thermally stable and they had unaltered mechanical properties with the addition of the polysaccharide. The microscopic analysis revealed rugosity that was proportional to pullulan and disorganization of the polymer network at pH 6.8. These results suggest that this novel material has potential for enteric drug release because of synergism between pH and enzyme dependence.
Assuntos
Comprimidos com Revestimento Entérico/farmacologia , Sistemas de Liberação de Medicamentos/efeitos adversos , GlucanosRESUMO
With the development of tissue engineering,the bone tissue engineering is developing rapidly. Engineering hone typically uses an artificial extracellular matrix (scaffold),osteoblasts or progenitors,and os- teoinductive factors which promote cell attachment,differentiation,and mineralized bone formation.Highly porous scaffolds play a critical role in cell seeding,proliferation,and new 3D-tissue formation.A variety of biodegradable polymer materials and scaffolding fabrication techniques for engineering bone have been developed over the past decade.This article reviews the scaffold design and fabrication methods tor engineering bone to analyze their ad- vantages and limitations.Various architectural parameters of scaffolds important for bone tissue engineering (e.g. porosity,pore size,interconnectivity) are discussed.