Sisir Debnath, Anshupriya Shome, D. Das
Mar 18, 2010
Citations
2
Influential Citations
127
Citations
Quality indicators
Journal
The journal of physical chemistry. B
Abstract
The present work reports a new class of antibacterial hydrogelators based on anti-inflammatory N-fluorenyl-9-methoxycarbonyl (Fmoc) amino acid/peptides functionalized cationic amphiphiles. These positively charged hydrogelators were rationally designed and developed by the incorporation of a pyridinium moiety at the C-terminal of Fmoc amino acid/peptides, because the pyridinium-based amphiphiles are a known antibacterial agent due to their cell membrane penetration properties. The Fmoc amino acid/peptide-based cationic amphiphiles efficiently gelate (minimum gelation concentration approximately 0.6-2.2%, w/v) water at room temperature. Judicious variation of amino acid and their sequences revealed the architectural dependence of the molecules on their gelation ability. Several microscopic techniques like field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to obtain the visual insight of the morphology of the gel network. A number of spectroscopic techniques like circular dichroism, FTIR, photoluminescence, and XRD were utilized to know the involvement of several noncovalent interactions and participation of the different segments of the molecules during gelation. Spectroscopic results showed that the pi-pi interaction and intermolecular hydrogen bonding are the major responsible factors for the self-assembled gelation process that are oriented through an antiparallel beta-sheet arrangement of the peptide backbone. These Fmoc-based cationic molecules exhibited efficient antibacterial activity against both Gram-positive and Gram-negative bacteria.