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Antibiotics (Basel, Switzerland) Feb 2024In recent years, traditional antibiotic efficacy outcomes have rapidly diminished due to the advent of drug resistance, and the dose limitation value has increased due...
In recent years, traditional antibiotic efficacy outcomes have rapidly diminished due to the advent of drug resistance, and the dose limitation value has increased due to the severe side effect of globalized healthcare. Therefore, novel strategies are required to resensitize resistant pathogens to antibiotics existing in the field and prevent the emergence of drug resistance. In this study, cationic hyperbranched polylysine (HBPL-6) was synthesized using the one-pot polymerization method. HBPL-6 exhibited excellent non-cytotoxicity and bio-solubility properties. The present study also showed that HBPL-6 altered the outer membrane (OM) integrity of O157:H7, , and by improving their permeability levels. When administered at a safe dosage, HBPL-6 enhanced the accumulation of rifampicin (RIF) and erythromycin (ERY) in bacteria to restore the efficacy of the antibiotics used. Moreover, the combination of HBPL-6 with colistin (COL) reduced the antibiotic dosage, which was helpful in preventing further drug-resistance outcomes. Therefore, this research provides a new strategy for reducing the dosage of drugs used to combat Gram-negative (G) bacteria through their synergistic effects.
PubMed: 38534651
DOI: 10.3390/antibiotics13030217 -
Biosensors Feb 2024Development of an efficient technique for accurate and sensitive dibutyl phthalate (DBP) determination is crucial for food safety and environment protection. An...
Ultrasensitive, Label-Free Voltammetric Detection of Dibutyl Phthalate Based on Poly-l-lysine/poly(3,4-ethylenedioxythiophene)-porous Graphene Nanocomposite and Molecularly Imprinted Polymers.
Development of an efficient technique for accurate and sensitive dibutyl phthalate (DBP) determination is crucial for food safety and environment protection. An ultrasensitive molecularly imprinted polymers (MIP) voltammetric sensor was herein engineered for the specific determination of DBP using poly-l-lysine/poly(3,4-ethylenedioxythiophene)/porous graphene nanocomposite (PLL/PEDOT-PG) and poly(o-phenylenediamine)-imprinted film as a label-free and sensing platform. Fabrication of PEDOT-PG nanocomposites was achieved through a simple liquid-liquid interfacial polymerization. Subsequently, poly-l-lysine (PLL) functionalization was employed to enhance the dispersibility and stability of the prepared PEDOT-PG, as well as promote its adhesion on the sensor surface. In the presence of DBP, the imprinted poly(o-phenylenediamine) film was formed on the surface of PLL/PEDOT-PG. Investigation of the physical properties and electrochemical behavior of the MIP/PLL/PEDOT-PG indicates that the incorporation of PG into PEDOT, with PLL uniformly wrapping its surface, significantly enhanced conductivity, carrier mobility, stability, and provided a larger surface area for specific recognition sites. Under optimal experimental conditions, the electrochemical response exhibited a linear relationship with a logarithm of DBP concentration within the range of 1 fM to 5 µM, with the detection limit as low as 0.88 fM. The method demonstrated exceptional stability and repeatability and has been successfully applied to quantify DBP in plastic packaging materials.
Topics: Dibutyl Phthalate; Molecularly Imprinted Polymers; Electrochemical Techniques; Graphite; Polylysine; Porosity; Nanocomposites; Molecular Imprinting; Limit of Detection; Electrodes; Phenylenediamines; Polymers; Bridged Bicyclo Compounds, Heterocyclic
PubMed: 38534228
DOI: 10.3390/bios14030121 -
Science Bulletin May 2024Adequate drug delivery across the blood-brain barrier (BBB) is a critical factor in treating central nervous system (CNS) disorders. Inspired by swimming fish and the...
Adequate drug delivery across the blood-brain barrier (BBB) is a critical factor in treating central nervous system (CNS) disorders. Inspired by swimming fish and the microstructure of the nasal cavity, this study is the first to develop swimming short fibrous nasal drops that can directly target the nasal mucosa and swim in the nasal cavity, which can effectively deliver drugs to the brain. Briefly, swimming short fibrous nasal drops with charged controlled drug release were fabricated by electrospinning, homogenization, the π-π conjugation between indole group of fibers, the benzene ring of leucine-rich repeat kinase 2 (LRRK2) inhibitor along with charge-dipole interaction between positively charged poly-lysine (PLL) and negatively charged surface of fibers; this enabled these fibers to stick to nasal mucosa, prolonged the residence time on mucosa, and prevented rapid mucociliary clearance. In vitro, swimming short fibrous nasal drops were biocompatible and inhibited microglial activation by releasing an LRRK2 inhibitor. In vivo, luciferase-labelled swimming short fibrous nasal drops delivered an LRRK2 inhibitor to the brain through the nasal mucosa, alleviating cognitive dysfunction caused by sepsis-associated encephalopathy by inhibiting microglial inflammation and improving synaptic plasticity. Thus, swimming short fibrous nasal drops is a promising strategy for the treatment of CNS diseases.
Topics: Animals; Administration, Intranasal; Nasal Mucosa; Blood-Brain Barrier; Drug Delivery Systems; Mice; Nasal Cavity; Polylysine; Swimming; Male; Brain; Mucociliary Clearance; Microglia; Humans
PubMed: 38522998
DOI: 10.1016/j.scib.2024.03.013 -
Bioprocess and Biosystems Engineering Apr 2024To improve the ε-PL production in wild-type strains of Streptomyces. albulus, Streptomyces. noursei, Streptomyces. rochei and Streptomyces. yunnanensis, the...
To improve the ε-PL production in wild-type strains of Streptomyces. albulus, Streptomyces. noursei, Streptomyces. rochei and Streptomyces. yunnanensis, the interspecific hybridization based on protoplast fusion was first performed. Two-species hybridizations failed to obtain hybrids with significant increase in ε-PL production, but four-species hybridizations succeed in acquiring many high-yield hybrids. 16S rDNA homology alignment and RAPD confirmed that the hybrid HX17 was restructured by integrating gene fragments from S. albulus and S. rochei with S. noursei as the carrier. S. noursei HX17 was subsequently suffered from mutagenesis and genome shuffling combining with multiple antibiotic resistance, and a mutant S. noursei GX6 was obtained with ε-PL yield of 2.23 g/L in shake-flask fermentation. In fed-batch fermentation, the ε-PL production of GX6 reached 47.2 g/L, which was increased by 95.6% to 136.8% over the wild parents. Ribosomal genes associated with antibiotics were sequenced and majority of mutant strains had mutations at different sites, indicating that the increase of antibiotic resistance was strongly associated with them. This research proved that combining interspecific hybridization with multiple antibiotic resistance was as an effective approach to rapidly improve the ε-PL production in Streptomyces species.
Topics: Polylysine; DNA Shuffling; Random Amplified Polymorphic DNA Technique; Drug Resistance, Microbial; Fermentation; Streptomyces
PubMed: 38499687
DOI: 10.1007/s00449-024-02983-9 -
Carbohydrate Polymers Jun 2024Large-pore hydrogels are better suited to meet the management needs of nutrient transportation and gas exchange between infected burn wounds and normal tissues. However,...
Large-pore hydrogels are better suited to meet the management needs of nutrient transportation and gas exchange between infected burn wounds and normal tissues. However, better construction strategies are required to balance the pore size and mechanical strength of hydrogels to construct a faster substance/gas interaction medium between tissues. Herein, we developed spongy large pore size hydrogel (CS-TA@Lys) with good mechanical properties using a simple ice crystal-assisted method based on chitosan (CS), incorporating tannic acid (TA) and ε-polylysine (Lys). A large-pore and mechanically robust hydrogel medium was constructed based on hydrogen bonding between CS molecules. On this basis, a pro-restorative functional platform with antioxidation and pro-vascularization was constructed using TA and Lys. In vitro experiments displayed that the CS-TA@Lys hydrogel possessed favorable mechanical properties and fast interaction performances. In addition, the CS-TA@Lys hydrogel possessed the capacity to remove intra/extracellular reactive oxygen species (ROS) and possessed antimicrobial and pro-angiogenic properties. In vivo experiments displayed that the CS-TA@Lys hydrogel inhibited wound inflammation and promoted wound vascularization. In addition, the CS-TA@Lys hydrogel showed the potential for rapid hemostasis. This study provides a potential functional wound dressing with rapid interaction properties for skin wound repair.
Topics: Humans; Chitosan; Antioxidants; Burns; Biocompatible Materials; Hydrogels; Neovascularization, Pathologic; Wound Healing; Anti-Bacterial Agents; Polyphenols
PubMed: 38494240
DOI: 10.1016/j.carbpol.2024.121991 -
Food Chemistry Jul 2024Biocomplex materials formed by oppositely charged biopolymers (proteins) tend to be sensitive to environmental conditions and may lose part functional properties of...
Formation mechanism, environmental sensitivity and functional characteristics of succinylated ovalbumin/ε-polylysine electrostatic complexes: The roles of succinylation modification and ε-polylysine combination.
Biocomplex materials formed by oppositely charged biopolymers (proteins) tend to be sensitive to environmental conditions and may lose part functional properties of original proteins, and one of the approaches to address these weaknesses is protein modification. This study established an electrostatic composite system using succinylated ovalbumin (SOVA) and ε-polylysine (ε-PL) and investigated the impact of varying degrees of succinylation and ε-PL addition on microstructure, environmental responsiveness and functional properties. Molecular docking illustrated that the most favorable binding conformation was that ε-PL binds to OVA groove, which was contributed by the multi‑hydrogen bonding and hydrophobic interactions. Transmission electron microscopy observed that SOVA/ε-PL had a compact spherical structure with 100 nm. High-degree succinylation reduced complex sensitivity to heat, ionic strength, and pH changes. ε-PL improved the gel strength and antibacterial properties of SOVA. The study suggests possible uses of SOVA/ε-PL complex as multifunctional protein complex systems in the field of food additives.
Topics: Polylysine; Ovalbumin; Static Electricity; Molecular Docking Simulation; Anti-Bacterial Agents
PubMed: 38489883
DOI: 10.1016/j.foodchem.2024.138951 -
Chemical Science Mar 2024Achieving long-lived room-temperature phosphorescence from pure organic amorphous polymers is attractive, and afterglow materials with colour-tunable and...
Achieving long-lived room-temperature phosphorescence from pure organic amorphous polymers is attractive, and afterglow materials with colour-tunable and multiple-stimuli-responsive afterglow are particularly important, but only few materials with these characteristics have been reported so far. Herein, a facile and general method is reported to construct a series of ε-polylysine (ε-PL)-based afterglow materials with tunable colour (from blue to red) and long life. By doping guest molecules into ε-PL to obtain composite materials, the polymer matrix provides a rigid environment for luminescent groups, resulting in amorphous polymers with different RTPs. In this system, the materials even have impressive humidity-stimulated responses, and the phosphorescence emission exhibits excitation-dependent and time-dependent properties. The humidity-responsive afterglow is caused by the destruction of hydrogen bonds and quenching of triplet excitons. The time-dependent afterglow should stem from the formation of diversified RTP emissive species with comparable but different lifetimes. 9,10-diaminophene has Ex-De properties in the film doping state. With the change of excitation wavelength (254 nm to 365 nm), the emission wavelength shifts from 461 nm to 530 nm, accompanied by the change of emission colour from blue to green. In addition, the phosphorescence life of the film is the longest, up to 2504.7 ms, and the afterglow lasts up to 15 s, which is conducive to its applications in anti-counterfeiting and information encryption.
PubMed: 38487222
DOI: 10.1039/d3sc06271f -
Advanced Science (Weinheim,... May 2024Non-antibiotic strategies are desperately needed to treat post-traumatic osteomyelitis (PTO) due to the emergence of superbugs, complex inflammatory microenvironments,...
Non-antibiotic strategies are desperately needed to treat post-traumatic osteomyelitis (PTO) due to the emergence of superbugs, complex inflammatory microenvironments, and greatly enriched biofilms. Previously, growing evidence indicated that quorum sensing (QS), a chemical communication signal among bacterial cells, can accelerate resistance under evolutionary pressure. This study aims to develop a medical dressing to treat PTO by inhibiting QS and regulating the inflammatory microenvironment, which includes severe oxidative stress and acid abscesses, through a reactive oxygen species (ROS)-responsive bond between N1- (4-borobenzoyl)-N3-(4-borobenzoyl)-the N1, the N1, N3, N3-tetramethylpropane-1,3-diamine (TSPBA) and polyvinyl alcohol (PVA), and the amino side chain of hyperbranched polylysine (HBPL). Physically enclosed QS inhibitors subsequently exerted the antibacterial effects. This hydrogel can scavenge hydrogen peroxide (HO), superoxide anion free radical (·O ), hydroxyl radicals (·OH) and 2,2-di(4-tert-octylphenyl)-1-picryl-hydrazyl (DPPH) to reduce oxidative stress and inhibit "bacteria-to-bacteria communication", thus clearing planktonic bacteria and biofilms, accelerating bacterial plasmolysis, reducing bacterial virulence and interfering with membrane transport. After in vivo treatment with hydrogel, nearly all bacteria are eliminated, inflammation is effectively inhibited, and osteogenesis and bone repair are promoted to facilitate recovery from PTO. The work demonstrates the clinical translational potential of the hydrogel in the treatment of drug-resistant bacteria induced PTO.
Topics: Quorum Sensing; Hydrogels; Osteomyelitis; Animals; Mice; Disease Models, Animal; Anti-Bacterial Agents; Oxidative Stress; Biofilms; Reactive Oxygen Species; Rats; Male
PubMed: 38482752
DOI: 10.1002/advs.202307969 -
International Journal of Biological... Apr 2024In this study, an active and intelligent nanofilm for monitoring and maintaining the freshness of pork was developed using ethyl cellulose/gelatin matrix through...
In this study, an active and intelligent nanofilm for monitoring and maintaining the freshness of pork was developed using ethyl cellulose/gelatin matrix through electrospinning, with the addition of natural purple sweet potato anthocyanin. The nanofilm exhibited discernible color variations in response to pH changes, and it demonstrated a higher sensitivity towards volatile ammonia compared with casting film. Notably, the experimental findings regarding the wettability and pH response performance indicated that the water contact angle between 70° and 85° was more favorable for the smart response of pH sensitivity. Furthermore, the film exhibited desirable antioxidant activities, water vapor barrier properties and also good antimicrobial activities with the incorporation of ε-polylysine, suggesting the potential as a food packaging film. Furthermore, the application preservation outcomes revealed that the pork packed with the nanofilm can prolong shelf life to 6 days, more importantly, a distinct color change aligned closely with the points indicating the deterioration of the pork was observed, changing from light pink (indicating freshness) to light brown (indicating secondary freshness) and then to brownish green (indicating spoilage). Hence, the application of this multifunctional film in intelligent packaging holds great potential for both real-time indication and efficient preservation of the freshness of animal-derived food items.
Topics: Swine; Animals; Gelatin; Pork Meat; Red Meat; Animal Feed; Anthocyanins; Food Packaging; Hydrogen-Ion Concentration; Cellulose
PubMed: 38479667
DOI: 10.1016/j.ijbiomac.2024.130813 -
Journal of Materials Chemistry. B Mar 2024Over the past few decades, the critical role played by cellular contractility associated mechanotransduction in the regulation of cell functions has been revealed. In...
Over the past few decades, the critical role played by cellular contractility associated mechanotransduction in the regulation of cell functions has been revealed. In this case, numerous biomaterials have been chemically or structurally designed to manipulate cell behaviors through the regulation of cellular contractility. In particular, adhesive proteins including fibronectin, poly-L-lysine and collagen type I have been widely applied in various biomaterials to improve cell adhesion. Therefore, clarifying the effects of adhesive proteins on cellular contractility has been valuable for the development of biomaterial design. In this study, reference-free traction force microscopy with a well-organized microdot array was designed and prepared to investigate the relationship between adhesive proteins, cellular contractility, and mechanotransduction. The results showed that fibronectin and collagen type I were able to promote the assembly of focal adhesions and further enhance cellular contraction and YAP activity. In contrast, although poly-L-lysine supported cell spreading and elongation, it was inefficient at inducing cell contractility and activating YAP. Additionally, compared with cellular morphogenesis, cellular contraction was essential for YAP activation.
Topics: Fibronectins; Mechanotransduction, Cellular; Microscopy, Atomic Force; Collagen Type I; Polylysine; Traction; Cell Adhesion; Biocompatible Materials
PubMed: 38466580
DOI: 10.1039/d4tb00065j