Investigation of a Single Tail Lysine Rich Peptide Amphiphile with an Ultra Short Peptide Head for its Nano Scale Self-assembly and Drug Loading Potential

Abstract

Peptide amphiphiles (PA) are highly biocompatible, unique designer molecules capable of self-assembling into nanostructures of diverse morphologies. They are attracting wider scientific interest for lipophilic drug’s solubilization and delivery owing to their amphiphilicity. This study reports the synthesis of a lysine containing PA with an ultra-short peptide head and its investigation for self-assembling into nanostructures and drug loading. The PA was synthesized through solution phase approach followed by characterization through mass spectrometry and 1H NMR and 13C NMR spectroscopy. Self-assembling behavior of the synthesized PA was investigated through circular dichroism spectroscopy followed by authentication through Atomic Force microscopy (AFM). UV visible spectrophotometer was used for determination of its critical micelle concentration (CMC). The amphiphile was evaluated for its drug loading potential using cefixime as a hydrophobic drug. Results show that the synthesized PA bearing an ultra-short peptide head has a CMC value of 0.061 mM and was capable of self-assembling into predominantly cylindrical nanostructures in aqueous medium having a size of 12.5 nm. Furthermore, PA loaded 52.26 ± 2.50% of the model hydrophobic drug in its nanostructures without altering its chemical identity. The results suggest that the synthesized PA with an ultra-short peptide backbone could be a promising vehicle for nanoscale drug delivery.