Biodegradable nanoparticles (NPs) have received considerable attention because of their possible use in the development of strategies for the topical delivery of oils and therapeutic drugs, particularly when drug penetration in dermis is desired. Zein is a prolamine and is a promising material for the design of drug delivery systems. In this study, NPs were prepared with zein and were used to encapsulate and release terpinen-4-ol, which is a therapeutic agent for the treatment of melanoma. The results show that the zein NPs are promising nanostructured systems for the prolonged delivery of T4OL with potential applications in anti-melanoma therapy.

Apresenta-se neste trabalho um processo brando de extração de queratina de penas de frango em solução aquosa contendo uréia, 2-mercaptoetanol e um surfactante (pH 9,0). Foram realizadas as determinações das massas molares, do perfil de aminoácidos e da estabilidade térmica da queratina extraída. Resultados preliminares relativos às propriedades mecânicas de filmes de queratina obtidos por casting também são apresentados. A extração proporcionou um rendimento de 94% em relação à queratina presente inicialmente nas penas secas. As massas molares dos compostos presentes na solução de queratina extraída foram determinadas por eletroforese e variaram entre 10 e 14.000 g mol-1. A termogravimetria da queratina extraída mostrou que o processo de extração não modificou a temperatura de degradação da queratina. Os filmes de queratina obtidos apresentaram propriedades que estão de acordo com dados da literatura.

The objective of this study was to extract and to determine the average molecular weight, the amino acids profile, and the thermal stability of feather keratin and the basic properties of the obtained films. The extraction, carried out with an aqueous solution containing urea, 2-mercaptoethanol and surfactant (pH 9.0), allowed the extraction of 94% of the keratin presented in the dry feather. The keratin molecular weights were determined by electrophoresis and ranged from 10 to 14,000 g mol-1. Thermogravimetric analyses of keratin showed that the extraction process did not change the degradation temperatures of keratin. The films of feather keratin presented lower tensile strength and about the same elongation at break than films of wool keratin cited by the literature.