Sequence isomerism-dependent self-assembly of glycopeptide mimetics with switchable antibiofilm properties

Supramolecular Self-Assembled Nanostructures Derived from Amplified Structural Isomerism of Zn(II)-Sn(IV)-Zn(II) Porphyrin Triads and Their Visible Light Photocatalytic Degradation of Pollutants

Two structural isomeric porphyrin-based triads (Zn(II)porphyrin-Sn(IV)porphyrin-Zn(II)porphyrin) denoted as T1 and T2 were prepared from the reaction of meso-[5-(4-hydroxyphenyl)-10,15,20-tris(3,5-di-tert-butylphenyl)porphyrinato]zinc(II) (ZnL) with trans-dihydroxo-[5,10-bis(3-pyridyl)-15,20-bis(phenyl)porphyrinato]tin(IV) (SnP1) and trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP2), respectively. All the compounds were characterized using UV-vis spectroscopy, emission spectroscopy, ESI-MS, 1H NMR spectroscopy, and FE-SEM. Most importantly, the two structurally isomeric porphyrin-based triads supramolecularly self-assembled into completely different nanostructures. T1 exhibits a nanosphere morphology, whereas T2 exhibits a nanofiber morphology. The amplified geometric feature in the structural isomeric porphyrin-based triads dictates the physical and chemical properties of the two triads. Both compounds showed the morphology-dependent visible light catalytic photodegradation of rhodamine B dye (74-97% within 90 min) and tetracycline antibiotic (44-71% within 45 min) in water. In both cases, the photodegradation efficiency of T2 was higher than that of T1. The present investigation can significantly contribute to the remediation of wastewater by tuning the conformational changes in porphyrin-based photocatalysts.

Harnessing Glycolipids for Supramolecular Gelation: A Contemporary Review

Within the scope of this review, our exploration spans diverse facets of amphiphilic glycolipid-based low-molecular-weight gelators (LMWGs). This journey explores glycolipid synthesis, self-assembly, and gelation with tailorable properties. It begins by examining the design of glycolipids and their influence on gel formation. Following this, a brief exploration of several gel characterization techniques adds another layer to the understanding of these materials. The final section is dedicated to unraveling the various applications of these glycolipid-based supramolecular gels. A meticulous analysis of available glycolipid gelators and their correlations with desired properties for distinct applications is a pivotal aspect of their investigation. As of the present moment, there exists a notable absence of a review dedicated exclusively to glycolipid gelators. This study aims to bridge this critical gap by presenting an overview that provides novel insights into their unique properties and versatile applications. This holistic examination seeks to contribute to a deeper understanding of molecular design, structural characteristics, and functional applications of glycolipid gelators by offering insights that can propel advancements in these converging scientific disciplines. Overall, this review highlights the diverse classifications of glycolipid-derived gelators and particularly emphasizes their capacity to form gels.

Engineered assemblies from isomeric pentapeptides augment dry eye treatment

Changing positions of amino acid residues in the peptide sequence alters the peptide' s assembly behaviors, affording various nanostructures. However, it remains elusive that how subtle changes in the peptide sequence influence the in vivo bioactivity of peptide-based nanocarriers, further impacting the efficacy of the encapsulated drugs. We report here a class of isomeric pentapeptide amphiphiles that associate into filaments with different dimensions, which were further used as carriers of Diquafosol tetrasodium (DQS), for the treatment of dry eye disease. Our results suggest that subtle changes in peptide sequences resulted in dramatically different molecular packings and distinct morphologies, which were verified by molecular dynamics simulations. In vivo results show that the drug retention time could be prolonged by the peptidic nanostructures on the ocular surface but were highly morphological-dependent. The longer retention time promised better therapeutic efficacy. In terms of facile synthesis and good biocompatibility, we believe that these peptides could be used for eye disease treatments or other related areas.

Impact of cell-free supernatant of lactic acid bacteria on Staphylococcus aureus biofilm and its metabolites

Introduction

A safe bio-preservative agent, lactic acid bacteria (LAB) can inhibit the growth of pathogenic bacteria and spoilage organisms. Its cell-free supernatant (LAB-CFS), which is rich in bioactive compounds, is what makes LAB antibacterial work.

Methods

This study focused on the changes in biofilm activity and related metabolic pathways of S. aureus treated with lactic acid bacteria planktonic CFS (LAB-pk-CFS) and biofilm state (LAB-bf-CFS).

Results

The findings demonstrated that the LAB-CFS treatment considerably slowed Staphylococcus aureus (S. aureus) growth and prevented it from forming biofilms. Additionally, it inhibits the physiological traits of the S. aureus biofilm, including hydrophobicity, motility, eDNA, and PIA associated to the biofilm. The metabolites of S. aureus biofilm treated with LAB-CFS were greater in the LAB-bf-CFS than they were in the LAB-pk-CFS, according to metabolomics studies. Important metabolic pathways such amino acids and carbohydrates metabolism were among the most noticeably altered metabolic pathways.

Discussion

These findings show that LAB-CFS has a strong potential to combat S. aureus infections.

Natural Products-Based Botanical Bactericides Discovery: Novel Abietic Acid Derivatives as Anti-Virulence Agents for Plant Disease Management

The discovery of natural product-based pesticides is critical for agriculture. In this work, a series of novel tricyclic diterpenoid derivatives decorated with an amino alcohol moiety were elaborately prepared from natural abietic acid, and their antibacterial behavior was explored. Bioassay results indicated that compound C₂ exhibited the most promising bioactivity (EC₅₀ = 0.555 μg mL^-1) against Xanthomonas oryzae pv. oryzae (Xoo), about 73 times higher than the effect of commercial thiodiazole copper (TC). Results of in vivo bioassays showed that compound C₂ displayed significantly higher control of rice bacterial leaf blight (curative activity: 63.8%; protective activity: 58.4%) than TC (curative activity: 43.6%; protective activity: 40.8%), and their bioactivity could be improved maximally 16% by supplementing the auxiliaries. Antibacterial behavior suggested that compound C₂ could suppress various virulence factors. Overall, these findings suggested that new botanical bactericide candidates could control intractable plant bacterial diseases by suppressing virulence factors.

[Application of smart responsive materials in phosphopeptide and glycopeptide enrichment]

Phosphorylation and glycosylation of proteins, two of the most widely studied post-translational modifications (PTMs), have shown increasing potential in the early non-invasive diagnosis, prognosis, and therapeutic evaluation of diseases. Besides regulating the function of cell membranes and intracellular signal transduction, protein phosphorylation participates in mitochondrial function and cellular and transcriptional metabolism. Protein glycosylation plays an important role in both intracellular and extracellular signal transduction and intracellular endocytosis. Aberrant phosphorylation and glycosylation of proteins are frequently observed in clinical proteomic studies and in the discovery of disease-related biomarkers. There are generally three methods for detecting protein phosphorylation/glycosylation: isotope radiolabeling, western blotting, and mass spectrometry. Mass spectrometry has become the most important and advantageous detection method due to its high throughput and time- and labor-efficiency. However, phosphopeptides and glycopeptides have low stoichiometry and ionization efficiency, and a large number of non-phosphopeptides and -glycopeptides interference. These issues make it difficult to directly detect phosphopeptides and glycopeptides by mass spectrometry. Therefore, the enrichment of phosphopeptides and glycopeptides before mass spectrometry detection is a key step. At present, a variety of materials have been developed for enrichment studies of phosphopeptides and glycopeptides. For example, immobilized metal affinity (IMAC) and metal oxide affinity chromatography (MOAC) methods are mostly used for the enrichment of phosphopeptides. The IMAC mainly uses positively charged metal ions and negatively charged phosphate groups to attract each other for the purpose of enriching phosphopeptides. MOAC materials rely on the chelation of metal atoms and phosphate oxygens to capture phosphopeptides. IMAC and MOAC materials rely on strong interactions between metals and phosphate groups, which often lead to difficult elution. The enrichment method for glycopeptides is mainly based on the difference in hydrophilicity between glycopeptides and non-glycopeptides, which are mainly enriched by hydrophilic interaction chromatography (HILIC). In addition, materials containing compounds such as boronic acid and lectin materials are also widely used for the separation and enrichment of glycopeptides. Smart responsive materials have also been successively reported for the enrichment of phosphopeptides and glycopeptides due to their unique responsiveness and reversibility. Smart responsive materials can respond to external stimuli; undergo structural and property changes; and convert signals such as optical, electrical, thermal, and mechanical into biochemical signals. Responsive molecules are a prerequisite for determining the response properties of smart responsive materials, and their reversible isomerization under different stimuli (such as temperature, pH, light, mechanical stress, and electromagnetic field) will lead to dynamic changes in the physical and chemical properties of materials. Compared with traditional materials, smart responsive materials can be reversibly "turned on" and "off" with better controllability. Exogenous stimuli, including temperature, light, ultrasound, electromagnetic field, and mechanical stress, can be implemented in a specific time and space. Exogenous responsive materials do not depend on changes in the reaction system itself and are non-invasive. Enzymes, pH, redox, solution polarity, and ionic strength are endogenous stimuli. Endogenous responsive materials depend on changes in the reaction system itself, and sometimes the regulation process requires the introduction of other chemicals into the reaction system. The identification, capture, and release of phosphopeptides or glycopeptides can be achieved by modulating the interactions between smart responsive materials and phosphopeptides or glycopeptides (such as hydrogen bonds, and electrostatic and hydrophobic interactions). This review classifies smart responsive materials according to the types of stimuli, which are specifically divided into exogenous and endogenous responsive materials. The enrichment of phosphopeptides and glycopeptides of exogenous/endogenous responsive materials and endogenous/exogenous co-responsive materials are summarized. In addition, we discuss the development prospects of smart responsive materials in the enrichment of phosphopeptides and glycopeptides, and also raised the challenges existing in the application of smart responsive materials in other protein post-translational modifications.

Azobenzene as Antimicrobial Molecules

Azo molecules, characterized by the presence of a -N=N- double bond, are widely used in various fields due to their sensitivity to external stimuli, ch as light. The emergence of bacterial resistance has pushed research towards designing new antimicrobial molecules that are more efficient than those currently in use. Many authors have attempted to exploit the antimicrobial activity of azobenzene and to utilize their photoisomerization for selective control of the bioactivities of antimicrobial molecules, which is necessary for antibacterial therapy. This review will provide a systematic and consequential approach to coupling azobenzene moiety with active antimicrobial molecules and drugs, including small and large organic molecules, such as peptides. A selection of significant cutting-edge articles collected in recent years has been discussed, based on the structural pattern and antimicrobial performance, focusing especially on the photoactivity of azobenzene and the design of smart materials as the most targeted and desirable application.

Chain-folding regulated self-assembly, outstanding bactericidal activity and biofilm eradication by biomimetic amphiphilic polymers

Chain-folding regulated hierarchical self-assembly of cationic host defense peptide mimicking amphiphilic polyurethanes exhibit excellent antibacterial activity and biofilm killing.

Advances in Application of Azobenzene as a Trigger in Biomedicine: Molecular Design and Spontaneous Assembly

Azobenzene is a well-known derivative of stimulus-responsive molecular switches and has shown superior performance as a functional material in biomedical applications. The results of multiple studies have led to the development of light/hypoxia-responsive azobenzene for biomedical use. In recent years, long-wavelength-responsive azobenzene has been developed. Matching the longer wavelength absorption and hypoxia-response characteristics of the azobenzene switch unit to the bio-optical window results in a large and effective stimulus response. In addition, azobenzene has been used as a hypoxia-sensitive connector via biological cleavage under appropriate stimulus conditions. This has resulted in on/off state switching of properties such as pharmacology and fluorescence activity. Herein, recent advances in the design and fabrication of azobenzene as a trigger in biomedicine are summarized.

Amphipathic design dictates self-assembly, cytotoxicity and cell uptake of arginine-rich surfactant-like peptides

Amphiphilicity is the most critical parameter in the self-assembly of surfactant-like peptides (SLPs), regulating the way by which hydrophobic attraction holds peptides together. Its effects go beyond supramolecular assembly and may also trigger different cell responses of bioactive peptide-based nanostructures. Herein, we investigate the self-assembly and cellular effects of nanostructures based on isomeric SLPs composed by arginine (R) and phenylalanine (F). Two amphipathic designs were studied: a diblock construct F4R4 and its bolaamphiphile analog R2F4R2. A strong sequence-dependent polymorphism emerges with appearance of globules and vesicle-like assemblies, or flat nanotapes and cylindrical micelles. The diblock construct possesses good cell penetrating capabilities and effectiveness to kill SK-MEL-28 melanoma tumor cells, in contrast to reduced intracellular uptake and low cytotoxicity exhibited by the bolaamphiphilic form. Our findings demonstrate that amphipathic design is a relevant variable for self-assembling SLPs to modulate different cellular responses and may assist in optimizing the production of nanostructures based on arginine-enriched sequences in cell penetrating and antimicrobial peptides.

Self-assembly of isomeric naphthalene appended glucono derivatives: nanofibers and nanotwists with circularly polarized luminescence emission

Two isomeric naphthalene appended glucono derivatives substituted at the 1 or 2-naphthyl positions (Nap-1 and Nap-2) were designed and their self-assembly behaviors and optical properties were investigated. Nap-1 and Nap-2 were found to self-assemble into nanofibers and nanotwists, respectively. While the molecular chirality of the glucono moiety could not be effectively transferred to the naphthalene moiety in the Nap-1 system, this was achieved in the Nap-2 assembly. Thus, the Nap-2 assembly showed obvious circular dichroism (CD) and circularly polarized luminescence (CPL) signals. From the XRD patterns and IR spectra of the supramolecular assemblies, it was found that Nap-2 packed in a more orderly fashion than Nap-1, leading to a hierarchical assembly forming nanotwist structures. Moreover, a light-harvesting system based on Nap-2 supramolecular gels and dyes was established, in which an efficient energy transfer was demonstrated from Nap-2 to an acceptor Eosin Y. It was further found that both chirality and energy transfer enhanced the dissymmetry factor of Eosin Y CPL emission.

Reversible modulation of plasmonic chiral signals of achiral gold nanorods using a chiral supramolecular template

We report here the fabrication of a multiple stimuli-responsive chiral plasmonic system based on the reversible self-assembly of phenylboronic acid-capped gold nanorods (PBA-Au NRs) guided by a supramolecular glycopeptide mimetic template. The plasmonic chiral signals of PBA-Au NRs can be reversibly switched on and off by temperature, light, pH and glucose concentration variations.