Ultrasound-Assisted Self-Assembly of Peptides and Amino Acids

Amino acids and peptides are biological molecules capable of self-assembling into multifunctional nanostructures, offering great potential for biomedical applications. However, controlling the morphology and size of these nanostructures is crucial for optimizing their functionality in biological environments. Traditional methods often involve salts, metal ions, or organic solvents, highlighting the need for green, one-pot synthesis techniques.

My PhD research, which constitutes my thesis entitled “Sono-Assembled Peptide Biofunctional Nanoparticles and Ultrasound-driven Metal Nanostructures,” explores the use of high-frequency ultrasound to facilitate the controlled self-assembly of peptides and the bioconjugation of naturally occurring amino acids, such as tryptophan, with magnetic nanoparticles. This method aims to fabricate well-defined nanostructures suitable for various biomedical applications.

We demonstrated the controlled self-assembling of octapeptides to form nanoparticles. These sono-assembled nanoparticles have shown multifunctionality, indicating their potential in bio-imaging and drug delivery. Furthermore, the synthesized nanoparticles serve as nanocarriers for hydrophobic or negatively charged drugs, including chemotherapeutics and nucleic acids.

Additionally, we investigated the bioconjugation of tryptophan with superparamagnetic iron oxide nanoparticles (SPIONs) to form hybrid nanoparticles using ultrasound at 490 kHz. These nanoparticles exhibited unique optical properties, making them suitable for cellular dissolution studies and **MRI **sensitivity analysis.

This research also explored the formation of tunable 2D gold nanosheets (AuNSs), driven by the anisotropic growth of gold nuclei facilitated by in-situ dimerized tryptophan upon sonication. The resulting AuNSs displayed superior catalytic activities with excellent recycling efficacy, providing a possible mechanism for their formation.