RESUMO
Self-assembling peptide amphiphiles (PAs) have been extensively used in the development of novel biomaterials. Because of their propensity to form cylindrical micelles, their use is limited in applications where small spherical micelles are desired. Here we present a platform method for controlling the self-assembly of biofunctional PAs into spherical 50 nm particles using dendrimers as shape-directing scaffolds. This templating approach results in biocompatible, stable protein-like assemblies displaying peptides with native secondary structure and biofunctionality.
Assuntos
Nanosferas/química , Nanotecnologia/métodos , Peptídeos/química , Materiais Biocompatíveis/química , Biomimética , Dendrímeros/química , Células HeLa , Humanos , Micelas , Estrutura Secundária de Proteína , Proteínas/químicaRESUMO
Novel thermo-responsive cellulose (filter paper) surfaces of N-isopropylacrylamide (NIPAAm) and pH-responsive cellulose surfaces of 4-vinylpyridine (4VP) have been achieved via surface-initiated ATRP. Dual-responsive (pH and temperature) cellulose surfaces were also obtained through the synthesis of block-copolymer brushes of PNIPAAm and P4VP. With changes in pH and temperature, these "intelligent" surfaces showed a reversible response to both individual triggers, as indicated by the changes in wettability from highly hydrophilic to highly hydrophobic observed by water contact angle measurements. Adjusting the composition of the grafted block-copolymer brushes allowed for further tuning of the wettability of these "intelligent" cellulose surfaces.
Assuntos
Materiais Biocompatíveis/química , Celulose/química , Acrilamidas/química , Resinas Acrílicas/química , Cobre/química , Filtração , Concentração de Íons de Hidrogênio , Hidrólise , Polímeros/química , Piridinas/química , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura , MolhabilidadeRESUMO
Incorporation of orthogonal functional groups into biodegradable polymers permits the fabrication of multi-layered thin films with improved adhesion and tunable degradation profiles. The bi-layer structure also allows for accurate control over small molecule release.
Assuntos
Preparações Farmacêuticas/metabolismo , Polímeros/química , Ácido Láctico/química , Poliésteres/química , Ácido Poliglicólico/química , Polímeros/síntese químicaRESUMO
Superhydrophobic and self-cleaning cellulose surfaces have been obtained via surface-confined grafting of glycidyl methacrylate using atom transfer radical polymerization combined with postmodification reactions. Both linear and branched graft-on-graft architectures were used for the postmodification reactions to obtain highly hydrophobic bio-fiber surfaces by functionalization of the grafts with either poly(dimethylsiloxane), perfluorinated chains, or alkyl chains, respectively. Postfunctionalization using alkyl chains yielded results similar to those of surfaces modified by perfluorination, in terms of superhydrophobicity, self-cleaning properties, and the stability of these properties over time. In addition, highly oleophobic surfaces have been obtained when modification with perfluorinated chains was performed.