Antimicrobial Peptide-Driven Colloidal Transformations in Liquid-Crystalline Nanocarriers

Abstract

Designing efficient colloidal systems for the delivery of membrane active antimicrobial peptides requires in-depth understanding of their structural and morphological characteristics. Using dispersions of inverted type bicontinuous cubic phase (cubosomes), we examine the effect of integrating the amphiphilic peptide LL-37 at different concentrations on the self-assembled structure and evaluate its bactericidal ability against Escherichia coli. Small-angle X-ray scattering, dynamic light scattering, and cryogenic transmission electron microscopy show that LL-37 integrates into the bicontinuous cubic structure, inducing colloidal transformations to sponge and lamellar phases and micelles in a concentration-dependent manner. These investigations, together with in vitro evaluation studies using a clinically relevant bacterial strain, established the composition-nanostructure-activity relationship that can guide the design of new nanocarriers for antimicrobial peptides and may provide essential knowledge on the mechanisms underlying the bacterial membrane disruption with peptide-loaded nanostructures.

Transition Metal Ion–Mediated Tyrosine‐Based Short‐Peptide Amphiphile Nanostructures Inhibit Bacterial Growth

“…From our experimental observations, it could be surmised that the transformation of the fibrous morphology is highly dependent on the properties of the metal ions used. sPA loaded with metal ion(s) shows the morphological transformations, and this therefore leads to less solubility in polar biologically used solvents such as water and ethanol, hence providing emulsified liquid, which has recently generated great interest in the pharmaceutical delivery field . Peptide‐based colloidal systems can potentially act as carriers for controlled and targeted release of encapsulated bioactive metal ions through control of their internal nanostructures .…”

Current state of a dual behaviour of antimicrobial peptides—Therapeutic agents and promising delivery vectors

“…Carriers components AMP Micro-organisms assessed Refs. [91] Liquid crystalline system GMO-based cubosomes LL-37 E. coli [93] Liquid crystalline system TTO/PPCA/water; TTO/PPCA/PP dispersion (0.5%) p1025 [94] Mesoporous silica nanoparticles Unmodified and SH-modified mesoporous silica; negatively and positively charged mesoporous silica nanoparticles; non-porous silica nanoparticles LL-37 E. coli ATCC 25922, S. aureus ATCC 29213 [65,95] Microsphere/ hydrogel PF-127, PLGA microspheres KSL-W S. epidermidis [96] Nanoclays of various methods can be used to obtain their analogues by optimizing the length and content of their sequences: namely, by replacing amino acid residues, changing the chirality of peptide molecules and hybridizing different peptide segments to form new or de novo peptide designs. [67] The substitution of naturally occurring L-amino acids in the original AMPs' formula with their D-amino acid enantiomers could enhance peptide stability.…”

A vesicle-to-sponge transition via the proliferation of membrane-linking pores in ω-3 polyunsaturated fatty acid-containing lipid assemblies

“…Lamellar-to-cubic and lamellar-to-sponge phase transitions present current interest from both theoretical and experimental view points [45][46][47][48][49][50][51]. Four major axes of previous research on the topology and the mechanism of such liquid crystalline phase transitions can be highlighted:…”