Single Amino‐Acid Based Self‐Assembled Biomaterials with Potent Antimicrobial Activity

Abstract

The design and development of soft biomaterials based on amino acid and short-peptide have gained much attention due to their potent biomedical applications. A slight alteration in the side-chain of single amino acid in a peptide or protein sequence has a huge impact on the structure and function. Phenylalanine is one of the most studied amino acids, which contains an aromatic phenyl group connected through a flexible À CH 2 À unit. In this work, we have examined whether flexibility and aromatic functionality of phenylalanine (Phe) are important in gel formation of model gelator Fmoc-Phe-OH or not. To examine this hypothesis, we synthesized Fmoc-derivatives of three analogues unnatural amino acids including cyclohexylalanine, phenylglycine, and homophenylalanine; which are slightly varied from Phe. Interestingly, all these three new analogues formed hydrogels in phosphate buffer at pH 7.0 having different gelation efficacy and kinetics. This study suggests that the presence of aromatic side-chain and flexibility are not mandatory for the gelation of this model gelator. Newly synthesized unnatural amino acid derivatives have also exhibited promising antimicrobial activity towards gram-positive bacteria by inhibiting cellular oxygen consumption. We further determined the biocompatibility of these amino acid derivatives by using a hemolysis assay on human blood cells. Overall studies described the development of single amino acid-based new injectable biomaterials with improved antimicrobial activity by the slight alteration in the side-chain of amino acid.

Tuning of the Supramolecular Helicity of Peptide-Based Gel Nanofibers

“…In mixed solvent (90% water in DMSO) and at 3 mM concentration, the hydrogels were examined through frequency sweep experiments. In each case, the storage modulus ( G ′) values are higher than the loss modulus ( G ″) values at a constant strain, suggesting the formation of soft-solid-like gel material ,− (Figure S16).…”

Hydrogels with intrinsic antibacterial activity prepared from naphthyl anthranilamide (NaA) capped peptide mimics

“…6). This hydrogel demonstrated improved activity when compared to previously reported short peptidebased hydrogels in combating S. aureus [58][59][60][61] . Additionally, hydrogel 2 exhibited significant bacteria reduction (5.5 Log 10 ) even when it was tested against a higher inoculum of 10 8 CFUs/mL S. aureus colonies (Fig.…”

A new amino acid, hybrid peptides and BODIPY analogs: synthesis and evaluation of 2-aminotroponyl-l-alanine (ATA) derivatives

“…11 Recently, a phenylalanine analog has been reported to form a hydrogel even with single amino acid derivatives that exhibit potent antimicrobial activity. 12 Parang has synthesized a series of cyclic peptides comprising the diphenylalanine residue and evaluated their transportation efficiency. 13 Tannenbaum has evaluated aromatic amino acids as potential biomarkers in breast cancer by Raman spectroscopy analysis.…”