Nanostructures from Single Amino Acid‐Based Molecules: Stability, Fibrillation, Encapsulation, and Fabrication of Silver Nanoparticles

Abstract

The small-sized molecules that have been developed from single hydrophobic amino acids (Phe, Trp, Tyr and Leu) by suitably protecting the -NH 2 and -CO 2 H groups generate diverse nanoscopic structures -such as nanorods, nanofi brils, nanotubes, and nanovesicles -depending upon the protection parameters and solvent polarity. The vesicular structures get disrupted in the presence of various salts, such as KCl, CaCl 2 , (NH 4 ) 2 SO 4 and N(n-Bu) 4 Br. Insertion of unnatural ( o / m / p )-aminobenzoic acids as a protecting group and the lack of conventional peptide bonds in the molecules give the nanostructures proteolytic stability. The nanostructures also show signifi cant thermal stability along with a morphological transformation upon heat treatment. Our in vitro studies reveal that the addition of micromolar concentration "curcumin" signifi cantly reduces the formation of amyloid-like fi brils. These diverse nanostructures are used as a template for fabricating silver nanoparticles on their outer surfaces as well as in the inner part, followed by calcination in air which helps to obtain a 1D silver nanostructure. Furthermore, the nanovesicles are observed to encapsulate a potent drug (curcumin) and other biologically important molecules, which could be released through salt-triggered disruption of vesicles.

Amino Acid Based Self‐assembled Nanostructures: Complex Structures from Remarkably Simple Building Blocks

“…[19] The derivatives formed vesicles in methanol, whereas fibers or nanorods were obtained in less polar solvents (Figure 1B, C, D). However, derivatives of less hydrophobic amino acids, such as glycine (Gly), Ala, βAla, and proline (Pro), failed to produce nanostructures.…”

“…Another important application of these vesicles was the encapsulation and release of curcumin by disrupting them using a biocompatible metal ion (K + ). [19]…”

“…(B–D) Scanning electron microscopy (SEM) images of the nanostructures formed by compound (1) in (B) methanol, (C) chloroform + petroleum ether (3 : 7), and (D) toluene (10 mM). [19] (E) Molecular structures of the modified amino acids (12, 13, 14). Figures reproduced with permission from reference.…”

Peptide‐Nanofiber‐Supported Palladium Nanoparticles as an Efficient Catalyst for the Removal of N‐Terminus Protecting Groups

“…[7] Another possibility is that the CO and NH of amide bonds, which do not participate in backbone hydrogen bonding, may play a crucial role in decoration. [8] We characterized the Pd nanoparticles by HRTEM. The HRTEM image shows clear lattice fringes with a d spacing of 0.228 nm, which is attributed to the (111) lattice planes [64] of face-centered cubic (fcc) Pd (Figure 8).…”

“…[4,5] Self-assembly plays a crucial role in constructing various nanostructures that have potential applications in nanoscience and nanotechnology. [6][7][8][9] Several stimuli have been used to tune the self-assembly process. [10] Hydrogel and organogel matrices have been extensively used as a nanoreactor for the synthesis and stabilization of metal nanoparticles.…”