Hydrogen Bonding Polarization Strengthening the Peptide-Based Hydrogels.

Peptide-based hydrogels form a kind of promising material broadly used in biomedicine and biotechnology. However, the correlation between their hydrogen bonding dynamics and mechanical properties remains uncertain. In this study, we found that the adoption of β-sheet and α-helix secondary structures by ECF-5 and GFF-5 peptides, respectively, could further form fiber networks to immobilize water molecules into hydrogels.

Double-Network Hydrogel with Strengthened Mechanical Property for Controllable Release of Antibacterial Peptide.

Developing double-network (DN) hydrogels with high mechanical properties and antibacterial efficacy to combat multidrug-resistant bacterial infections and serve as scaffolds for cell culture still remains an ongoing challenge. In this study, an ion-responsive antibacterial peptide (AMP) (C-WIIIKKK, termed as IK7) was synergistically combined with a photoresponsive gelatin methacryloyl (GelMA) polymer to fabricate a biocompatible DN hydrogel. The GelMA-IK7 DN hydrogel showed enhanced mechanical properties in contrast to the individual IK7 and GelMA hydrogels and demonstrated substantial antibacterial efficacy.

Biostable hydrogels consisting of hybrid β-sheet fibrils assembled by a pair of enantiomeric peptides.

The assembly of chiral peptides facilitates the formation of diverse supramolecular structures with unique physicochemical and biological properties. However, the effects of chirality on peptide assembly and resulting hydrogel properties remain underexplored. In this study, we systematically investigated the assembly propensity, morphology, and biostability of mixture of a pair of enantiomeric peptides ECAFF (ECF-5) and ECAFF (ecf-5) at various ratios.

Correction: Gram-selective antibacterial peptide hydrogels.

Correction for 'Gram-selective antibacterial peptide hydrogels' by Yangqian Hou , , 2022, , 3831-3844, https://doi.org/10.1039/D2BM00558A.

Gram-selective antibacterial peptide hydrogels.

The human microbiome plays fundamental roles in human health and disease. However, widely used broad-spectrum antibiotics severely disrupt human-related microbial communities, eventually leading to resistant bacteria, posing a growing threat to global medical health. Antimicrobial peptides (AMPs) are promising antimicrobial agents that barely cause bacterial resistance.

Controllable formation of bulk perfluorohexane nanodroplets by solvent exchange.

Perfluorocarbon (PFC) nanodroplets have rapidly developed into useful ultrasound imaging agents in modern medicine due to their non-toxic and stable chemical properties that facilitate disease diagnosis and targeted therapy. In addition, with the good capacity for carrying breathing gases and the anti-infection ability, they are employed as blood substitutes and are the most ideal liquid respirators. However, it is still a challenge to prepare stable PFC nanodroplets of uniform size and high concentration for their efficient use.

Gelation of a Pentapeptide in Alcohols.

Properties of solvents such as polarity and H-bond-forming ability are critical for the formation of an organogel and have a significant impact on the gel behavior, as solvents are the majority of organogel systems. However, so far, there is still a lack of systematic studies regarding the effects of molecular structures of solvents on the characteristics of organogels. Motivated by revealing such a relationship, in this paper, we studied the morphologies of assemblies, gelation behaviors, and secondary structures of a pentapeptide termed EAF-5 in a wide variety of alcohols.

Macrochirality of Self-Assembled and Co-assembled Supramolecular Structures of a Pair of Enantiomeric Peptides.

Although macrochirality of peptides' supramolecular structures has been found to play important roles in biological activities, how macrochirality is determined by the molecular chirality of the constituted amino acids is still unclear. Here, two chiral peptides, Ac-KHHQKLVFFAK-NH (KK-11) and Ac-KHHQKL VFFAK-NH (KKd-11), which were composed entirely of either L- or D-amino acids, were designed for studying the chiral characteristics of the supramolecular microstructures. It was found that monocomponent KK-11 or KKd-11 self-assembled into right- or left-handed helical nanofibrils, respectively.

Antimicrobial d-Peptide Hydrogels.

Biofilms are widely involved in human lives, such as in medical infection, environmental remediation, and industrial processes. However, the control of the biofilm has still been a challenge because of its strong drug resistance. Here, we designed and synthesized an amphipathic antimicrobial peptide (Ac-KHHQKLVFFAK-NH (KKd-11)) that was composed of d-amino acids (DAAs).

The effects of nanobubbles on the assembly of glucagon amyloid fibrils.

Some recent studies have shown that the surface and interface play an important role in the assembly and aggregation of amyloid proteins. However, it is unclear how the gas-liquid interface affects the protein assembly at the nanometer scale although the presence of gas-liquid interfaces is very common in in vitro experiments. Nanobubbles have a large specific surface area, which provides a stage for interactions with various proteins and peptides on the nanometer scale.

Generating Bulk Nanobubbles in Alcohol Systems.

Bulk nanobubbles (NBs) have attracted wide attention due to their peculiar physicochemical properties and great potential in applications in various fields. However, so far there are no reports on bulk NBs generated in pure organic systems, which we think is very important as NBs would largely improve the efficiency of gas-liquid mass transfer and facilitate chemical reactions to take place. In this paper, we verified that air and N NBs could be generated in a series of alcohol solutions by using various methods including acoustical cavitation, pressurization-depressurization, and vibration.

Reactive Oxygen Species Scavenging and Biodegradable Peptide Hydrogel as 3D Culture Scaffold for Cardiomyocytes.

Myocardial ischemia-reperfusion produces a large amount of reactive oxygen species (ROS), which damage the myocardial tissue. Therefore, localized scavenging of ROS from the myocardial tissue would reduce its damage and avoid metabolic abnormalities caused by systemic ROS. In this study, a free radical scavenging and biodegradable supramolecular peptide (ECAFF, named as ECF-5) hydrogel was designed as a culture scaffold for cardiomyocytes.

Self-assembly of pentapeptides in ethanol to develop organogels.

Organogels have a wide variety of applications in the fields of chemistry, electricity, biomedicine and environmental engineering, which call for robust strategies for designing and developing novel organogelators. Here, we reported a pentapeptide, ECAYF, which was capable of forming a self-healing ethanol gel exhibiting viscoelastic and solid-like properties. The ethanol gel of ECAYF was stable for at least several months, suggesting strong non-covalent interactions between ethanol and the peptide in the gel.

Peptides Co-Assembling into Hydrangea-Like Microstructures.

Supramolecular assembly is a simple and effective way to produce multi-level biostructures to mimic the self-assembly of biomolecules in organisms. The study on peptide assembly behaviors would benefit a lot to understand what goes on in life, as well as in the construction of plenty of functional biomaterials that have potential applications in various fields. Since cellular microenvironments are crowded and contain various biomolecules, studying protein and peptide co-assembly is of great interest.

Novel tyrosinase inhibitory peptide with free radical scavenging ability.

Tyrosinase is a key enzyme involved in melanin synthesis. Therefore, various tyrosinase inhibitors have been screened by researchers in recent years. In the present study, we discovered a novel tyrosinase inhibitor, a peptide ECGYF (named EF-5), with free radical scavenging ability.