Backbone Engineered gamma-Peptide Amphitropic Gels for Immobilization of Semiconductor Quantum Dots and 2D Cell Culture

摘要

We are reporting a spontaneous supramolecular assembly of backbone engineered gamma-peptide scaffold and its utility in the immobilization of semiconductor quantum dots and in cell culture. The stimulating feature of this gamma-peptide scaffold is that it efficiently gelates both aqueous phosphate buffers and aromatic organic solvents. A comparative and systematic investigation reveals that the greater spontaneous self-aggregation property of gamma-peptide over the alpha- and) beta-peptide analogues is mainly due to the backbone flexibility, increased hydrophobicity, and pi-pi stacking of gamma-phenylalanine residues. The hydrogels and organogels obtained from the gamma-peptide scaffold have been characterized through field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), FT-IR, circular dichroism (CD), wide-angle X-ray diffraction, and rheometric study. Additionally, the peptide hydrogel has displayed a stimuli-responsive and thixotropic signature, which leads to the injectable hydrogels. 2D cell culture studies using normal and cancer cell lines reveal the biocompatibility of gamma-peptide hydrogels. Further, the immobilization of semiconductor core shell quantum dots in the transparent gamma-peptide organogels showed ordered arrangement of quantum dots along the peptide fibrillar network with retaining photophysical property. Overall, gamma-peptide scaffolds may serve as potential templates for the design of new functional biomaterials.