RESUMEN
A 34-amino acid long collagen-like peptide rich in proline, hydroxyproline, and glycine, and with four photoreactive N-acyl-7-nitroindoline units incorporated into the peptide backbone was synthesized by on-resin fragment condensation. Its circular dichroism supports a stable triple helix structure. The built-in photochemical function enables the decomposition of the peptide into small peptide fragments by illumination with UV light of 350 nm in aqueous solution. Illumination of a thin film of the peptide, or a thin film of a photoreactive amino acid model compound containing a 5-bromo-7-nitroindoline moiety, with femtosecond laser light at 710 nm allows for the creation of well-resolved micropatterns. The cytocompatibility of the peptide was demonstrated using human mesenchymal stem cells and mouse embryonic fibroblasts. Our data show that the full-length peptide is cytocompatible as it can support cell growth and maintain cell viability. In contrast, the small peptide fragments created by photolysis are somewhat cytotoxic and therefore less cytocompatible. These data suggest that biomimetic collagen-like photoreactive peptides could potentially be used for growing cells in 2D micropatterns based on patterns generated by photolysis prior to cell growth.
Asunto(s)
Materiales Biomiméticos/química , Péptidos/química , Animales , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/efectos de la radiación , Materiales Biomiméticos/toxicidad , Colágeno/química , Fibroblastos/efectos de los fármacos , Fluorescencia , Humanos , Indoles/síntesis química , Indoles/química , Indoles/efectos de la radiación , Indoles/toxicidad , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/toxicidad , Péptidos/síntesis química , Péptidos/efectos de la radiación , Péptidos/toxicidad , Rayos UltravioletaRESUMEN
N-acyl-7-nitroindolines have been used as caged compounds to photorelease active molecules by a one- or two-photon excitation mechanism in biological systems. Here, we report the photolysis of a polypeptide that contains 7-nitroindoline units as linker moieties in its peptide backbone for potential materials engineering applications. Upon two-photon excitation with femtosecond laser light at 710 nm the photoreactive amide bond in N-peptidyl-7-nitroindolines is cleaved rendering short peptide fragments. Thus, this photochemical process changes the molecular composition at the laser focal volume. Gel modifications of this peptide can potentially be used for three-dimensional microstructure fabrication.