RESUMO
Stimuli-responsive materials are playing an increasingly important role in a wide range of applications such as drug delivery, diagnostics, sensors, and tissue engineering. Among them, gold nanoparticles responding to changes in their surrounding environment are of particular interest due to their size-related optical properties. Here, we present a novel strategy for the preparation of gold nanoparticles exhibiting a stimuli-responsive behavior. We rely on the use of a ligand consisting of only a single repeat of the elastin-based pentapeptide VPGVG. In this contribution, we describe a protocol for the solid-phase peptide synthesis of thiol-terminated VPGVG ligand, and for the preparation of gold nanoparticles covered with the pentapeptide through a ligand-exchange reaction.
Assuntos
Elastina/química , Ouro/química , Nanopartículas Metálicas/química , Oligopeptídeos/química , Espectroscopia de Ressonância MagnéticaRESUMO
Click chemistry is explored as a potential cost-effective and selective immobilization method for the production of an enzyme-linked immunosorbent assay (ELISA). Coatings were formulated containing either a terminal alkyne or a bicyclo[6.1.0]non-4-yne (BCN) chemical handle, and a diagnostic peptide was subsequently immobilized onto these coatings by the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) or copper-free strain-promoted azide-alkyne 1,3-dipolar cycloaddition (SPAAC), respectively. The terminal alkyne-containing coating showed high background levels in subsequent ELISA's due to the copper catalyst used in the immobilization step. The BCN-containing coating, however, was successfully employed and presents a cost-effective alternative to existing (strept)avidin-biotin immobilization methods. This technology was illustrated with an ELISA used for the diagnosis of rheumatoid arthritis (RA) but could be easily applied to a wide range of diagnostic tests.
Assuntos
Alcinos/química , Artrite Reumatoide/diagnóstico , Azidas/química , Química Click/métodos , Ensaio de Imunoadsorção Enzimática , Proteínas Imobilizadas , Peptídeos , Anticorpos/imunologia , Artrite Reumatoide/imunologia , Avidina/química , Avidina/metabolismo , Biotina/química , Biotina/metabolismo , Catálise , Citrulina/química , Citrulina/metabolismo , Cobre/química , Humanos , Proteínas Imobilizadas/síntese química , Proteínas Imobilizadas/imunologia , Estrutura Molecular , Peptídeos/síntese química , Peptídeos/imunologiaRESUMO
Gold nanoparticles covered with ligands consisting of only a single repeat of the elastin-based pentapeptide VPGVG exhibit a stimuli-responsive behaviour.
RESUMO
Silks are a widely studied class of naturally occurring structural proteins. Dragline spider silk, in particular, is considered to be nature's high-performance material due to its remarkable combination of strength and toughness. These mechanical properties stem from the protein secondary structure, a combination of well-defined beta-sheets in a less well-defined glycine-rich matrix. The translation of this structure into a synthetic polymer was the aim of this investigation. To achieve this, a peptide-based monomer containing the sequence alanine-glycine-alanine-glycine, a well-known beta-sheet-forming sequence found in silk, was synthesized. Using atom-transfer radical polymerization and a bifunctional initiator, a well-defined peptide-based polymer was prepared. This was then used as the macroinitiator for the polymerization of methyl methacrylate. The resulting well-defined triblock copolymer was analyzed using IR spectroscopy, which clearly showed beta-sheet secondary structure had been introduced.
