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Physical Chemistry Chemical Physics :... Mar 2024Understanding polycation-lipid interaction is essential not only in molecular biology but also in the biomedical industry and pharmacology. However, the effect of the...
Understanding polycation-lipid interaction is essential not only in molecular biology but also in the biomedical industry and pharmacology. However, the effect of the polycation-lipid interaction on the molecular properties of lipids in biomembranes remains elusive. Here, two fluorescence correlation spectroscopies (FCSs), pulse-interleaved excitation (PIE) FCS and lifetime-based FCS, were performed to elucidate the change in the lipid diffusion of a model biomembrane induced by polylysine (PLL) adsorption. The results of PIE-FCS showed that the diffusions of both anionic and zwitterionic lipids become slower in the presence of PLL but the mobility of the anionic lipids is much reduced, suggesting the preferential interaction between the PLL and the anionic lipids due to the electrostatic attraction. Furthermore, leaflet-specific lipid diffusion analysis by lifetime-based FCS clearly showed that PLL adsorption on one leaflet of the membrane reduces the lipid diffusion of both leaflets in the same manner. This clearly indicates that the interleaflet coupling is strong in the presence of PLL.
Topics: Lipid Bilayers; Polylysine; Adsorption; Diffusion; Polyelectrolytes
PubMed: 38426343
DOI: 10.1039/d3cp04882a -
Frontiers in Nutrition 2024This study investigated the effects of nisin combined with ε-polylysine on microorganisms and the refrigerated quality of fresh-cut jackfruit. After being treated with...
This study investigated the effects of nisin combined with ε-polylysine on microorganisms and the refrigerated quality of fresh-cut jackfruit. After being treated with distilled water (control), nisin (0.5 g/L), ε-polylysine (0.5 g/L), and the combination of nisin (0.1 g/L) and ε-polylysine (0.4 g/L), microporous modified atmosphere packaging (MMAP) was carried out and stored at 10 ± 1°C for 8 days. The microorganisms and physicochemical indexes were measured every 2 days during storage. The results indicated that combined treatment (0.1 g/L nisin, 0.4 g/L ε-polylysine) had the best preservation on fresh-cut jackfruit. Compared with the control, combined treatment inhibited microbial growth (total bacterial count, mold and yeast), reduced the weight loss rate, respiratory intensity, polyphenol oxidase and peroxidase activities, and maintained higher sugar acid content, firmness, and color. Furthermore, it preserved higher levels of antioxidant compounds, reduced the accumulation of malondialdehyde and hydrogen peroxide, thereby reducing oxidative damage and maintaining high nutritional and sensory qualities. As a safe application of natural preservatives, nisin combined with ε-polylysine treatment has great application potential in the fresh-cut jackfruit industry.
PubMed: 38419851
DOI: 10.3389/fnut.2024.1299810 -
Advanced Healthcare Materials Jun 2024Intracellular bacteria are the major cause of serious infections including sepsis and peritonitis, but face great challenges in fighting against the stubborn...
Intracellular bacteria are the major cause of serious infections including sepsis and peritonitis, but face great challenges in fighting against the stubborn intracellular small colony variants (SCVs). Herein, the authors have developed nanogels (NGs) to destroy both planktonic bacteria and SCVs and eliminate excessive inflammations for peritonitis and sepsis therapies. Free gentamicin (GEN) and hydroxyapatite nanoparticles (NPs) with GEN loading and mannose grafts (mHA) are inoculated into ε-polylysine NGs to obtain NG@G1-mHA through crosslinking with phenylboronic acid and tannic acid. The HO consumption after reaction with phenylboronic esters and the elimination of free radicals by tannic acid alleviates the escalated inflammatory status to promote sepsis therapy. After mannose-mediated uptake into macrophages, the acid-triggered degradation of mHA NPs generates Ca to destabilize lysosomes and the efficient lysosomal escape leads to reversion of hypometabolic SCVs into normal phenotype and their sensitivity to GEN. In a peritonitis mouse model, NG@G1-mHA treatment provides strong and persistent bactericidal effects against both extracellular bacteria and intracellular SCVs and extends survival of peritonitis mice without apparent hepatomegaly, splenomegaly, pulmonary edema, and inflammatory cell infiltration. Thus, this study demonstrates a concise and versatile strategy to eliminate SCVs and relieve inflammatory storms for peritonitis and sepsis therapies without infection recurrence.
Topics: Animals; Peritonitis; Gentamicins; Mice; Sepsis; Lysosomes; Nanogels; Anti-Bacterial Agents; RAW 264.7 Cells; Nanoparticles; Polyethylene Glycols; Polyethyleneimine
PubMed: 38416744
DOI: 10.1002/adhm.202303671 -
Biofabrication Mar 2024Pressure ulcers (PUs) have emerged as a substantial burden on individuals and society. The introduction of innovative dressings that facilitate the healing of pressure...
Pressure ulcers (PUs) have emerged as a substantial burden on individuals and society. The introduction of innovative dressings that facilitate the healing of pressure ulcer wounds represents a cost-effective alternative for treatment. In this study, the emphasis is on the preparation of Carthamus tinctorius L. polysaccharide (CTLP) as hydrogel microspheres (MPs), which are then encapsulated within a hydrogel matrix crosslinked with phenylboronic acid gelatin (Gelatin-PBA) and-polylysine-grafted catechol (-PL-Cat) to enable sustained release for promoting pressure ulcer healing. The presented Gelatin-PBA/-PL-Cat (GPL)/CTLP-MPs hydrogel demonstrated outstanding self-healing properties. In addition,experiments revealed that the hydrogel exhibited remarkable antibacterial activity, excellent biocompatibility. And it showed the capacity to promote vascular formation, effectively scavenge reactive oxygen species, and facilitate macrophage polarization from the M1 to M2 phenotype.wound healing of mice PUs indicated that the prepared GPL/CTLP-MPs hydrogel effectively accelerated the formation of granulation tissue and facilitated the healing of the wounds. In summary,andexperiments consistently highlight the therapeutic potential of GPL/CTLP-MPs hydrogel in facilitating the healing process of PUs.
Topics: Animals; Mice; Hydrogels; Carthamus tinctorius; Gelatin; Polylysine; Pressure Ulcer; Reactive Oxygen Species; Angiogenesis; Macrophages; Anti-Bacterial Agents; Suppuration
PubMed: 38408382
DOI: 10.1088/1758-5090/ad2d2e -
Food Chemistry Jul 2024Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address...
Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address this limitation by combining carvacrol with whey protein isolate (WPI) to form nanoemulsion and enhancing antimicrobial properties and stability of nanoemulsion through ε-polylysine addition, thereby improving their application in fruit preservation. The results indicated that the nanoemulsion exhibited a double-layer structure. The physicochemical properties and storage stability were found to be favorable under the conditions of WPI (0.3 wt% v/v), Carvacrol (0.5 % v/v), and ε-polylysine (0.3 wt% v/v). In addition, the nanoemulsion had inhibitory effects on Staphylococcus aureus, Escherichia coli, and Aspergillus niger at concentrations of minimal inhibition concentration (32, 32, and 200 μg/mL, respectively). In addition, during a 7-day storage period, the nanoemulsion effectively preserved mangoes. Therefore, nanoemulsion could serve as a candidate for control of postharvest mangoes spoilage and extend its period of storage.
Topics: Polylysine; Emulsions; Mangifera; Anti-Infective Agents; Escherichia coli; Cymenes
PubMed: 38402759
DOI: 10.1016/j.foodchem.2024.138831 -
Carbohydrate Polymers May 2024Self-pumping wound scaffolds designed for directional biofluid transport are extensively investigated. They efficiently extract excessive biofluids from wounds, while...
Self-pumping wound scaffolds designed for directional biofluid transport are extensively investigated. They efficiently extract excessive biofluids from wounds, while maintaining an optimally humid wound environment, thus facilitating rapid wound healing. However, the existing designed scaffolds are insufficiently focused on stimulating the hydrophobic layer at the wound site, thereby exacerbating inflammation and impeding the wound healing process. Herein, we engineered and fabricated a hydrophilic-hydrophobic-hydrophilic sandwich-structured hydrogel-Janus nanofiber scaffold (NFS) employing a Layer-by-Layer (LbL) method. This scaffold comprises a hydrophilic carboxymethyl chitosan/silver (CMCS-Ag) hydrogel component in conjunction with a poly(caprolactone)/poly(caprolactone)-poly(citric acid)-co-ε-polylysine (PCL/PCL-PCE) Janus NFS. It is noteworthy that the hydrogel-Janus nanofiber scaffold not only demonstrates outstanding water absorption (202.2 %) and unidirectional biofluid transport capability but also possesses high breathability (308.663 m/m h kPa), appropriate pore size (6.7-7.5 μm), excellent tensile performance (270 ± 10 %), and superior mechanical strength (26.36 ± 1.77 MPa). Moreover, in vitro experimentation has convincingly demonstrated the impeccable biocompatibility of hydrogel-Janus NFS. The inherent dual-antibacterial properties in CMCS-Ag and PCE significantly augment fibroblast proliferation and migration. In vivo studies further underscore its capability to expedite wound healing by absorption and expulsion of wound exudates, thereby fostering collagen deposition and vascularization. As such, this work potentially provides fresh insights into the design and fabrication of multifunctional biomimetic scaffolds, holding immense potential in the medical field for efficient wound healing.
Topics: Hydrogels; Chitosan; Nanofibers; Wound Healing; Anti-Bacterial Agents; Drainage
PubMed: 38388058
DOI: 10.1016/j.carbpol.2024.121870 -
Macromolecular Bioscience Jun 2024Bacterial pneumonia is one of the major threats in clinical practice, and the reactive oxygen species (ROS) generated at the infection site can exacerbate the damage....
Bacterial pneumonia is one of the major threats in clinical practice, and the reactive oxygen species (ROS) generated at the infection site can exacerbate the damage. Currently, conventional antibiotic therapies have low utilization, and their excessive use can result in substantial toxicity. Nanocarrier systems provide an ideal approach for treating bacterial infection by facilitating more efficient utilization of antibiotics. In this study, the ROS-responsive amphiphilic nanoparticles (NPs) are developed and used to encapsulate the antibiotic doxycycline (DOXY) to achieve antibacterial and antioxidant functionalities. The NPs are prepared from poly(α-l-lysine) (α-PLL) and phenylboronic acid pinacol ester simultaneously conjugated carbonyldiimidazole (abbreviated as CDIPB). The phenylboronic acid ester groups on CDIPB could react with excessive ROS to suppress oxidative damage at the infection site. The ROS-responsive degradation of CDIPB also facilitates the rapid release of internal DOXY, effectively killing the accumulated bacteria. Additionally, in vitro cell experiments demonstrate the good biocompatibility of the NPs. These results suggest that the ROS-responsive amphiphilic nanoparticles can serve as a novel nanoplatform for the treatment of bacterial pneumonia.
Topics: Polylysine; Reactive Oxygen Species; Doxycycline; Nanoparticles; Oxidative Stress; Anti-Bacterial Agents; Animals; Humans; Mice; Drug Carriers; Antioxidants
PubMed: 38385581
DOI: 10.1002/mabi.202300580 -
Frontiers in Molecular Neuroscience 2024The growth cone, a motile structure located at the tip of growing axons, senses extracellular guidance cues and translates them into directional forces that drive axon...
The growth cone, a motile structure located at the tip of growing axons, senses extracellular guidance cues and translates them into directional forces that drive axon outgrowth and guidance. Axon guidance directed by chemical cues on the extracellular adhesive substrate is termed haptotaxis. Recent studies reported that netrin-1 on the substrate functions as a haptotactic axon guidance cue. However, the mechanism mediating netrin-1-induced axonal haptotaxis remains unclear. Here, we demonstrate that substrate-bound netrin-1 induces axonal haptotaxis by facilitating physical interactions between the netrin-1 receptor, DCC, and the adhesive substrates. DCC serves as an adhesion receptor for netrin-1. The clutch-linker molecule shootin1a interacted with DCC, linking it to actin filament retrograde flow at the growth cone. Speckle imaging analyses showed that DCC underwent either grip (stop) or retrograde slip on the adhesive substrate. The grip state was more prevalent on netrin-1-coated substrate compared to the control substrate polylysine, thereby transmitting larger traction force on the netrin-1-coated substrate. Furthermore, disruption of the linkage between actin filament retrograde flow and DCC by shootin1 knockout impaired netrin-1-induced axonal haptotaxis. These results suggest that the directional force for netrin-1-induced haptotaxis is exerted on the substrates through the adhesion-clutch between DCC and netrin-1 which occurs asymmetrically within the growth cone.
PubMed: 38375502
DOI: 10.3389/fnmol.2024.1307755 -
ACS Applied Bio Materials Mar 2024The increasing severity of problems posed by drug-resistant pathogens has compelled researchers to explore innovative approaches for infection prevention. Among these...
The increasing severity of problems posed by drug-resistant pathogens has compelled researchers to explore innovative approaches for infection prevention. Among these strategies, conjugation methods stand out for their convenience and high efficacy. In this study, multiple covalent conjugates were synthesized, incorporating the natural antimicrobial peptide epsilon-poly-l-lysine (EPL) and two commonly used β-lactam antibiotics: penicillin G or ampicillin. Enhanced antimicrobial efficacy against typical Gram-negative pathogens, along with faster kill kinetics compared to combination approaches, was demonstrated by the EPL-Ampicillin covalent conjugates. Their antimicrobial mechanism was also substantiated through SEM and fluorescence tests in this work, confirming the inheritance of membrane-disrupting properties from EPL. Furthermore, the excellent biocompatibility of the raw materials was reserved in the covalent conjugates. This simplified conjugation method holds promise for the development of infection therapeutic drugs and potentially restores the sensitivity of conventional antibiotics to drug-resistant pathogens by introducing membrane-disrupting mechanisms.
Topics: beta Lactam Antibiotics; Polylysine; Anti-Bacterial Agents; Ampicillin; Penicillin G; Monobactams
PubMed: 38363728
DOI: 10.1021/acsabm.4c00093 -
Journal of Chromatography. A Mar 2024Dendrigraft poly(L-lysine) (DGL) constitutes a promising dendritic-like drug vehicle with high biocompatibility and straightforward access via ring-opening...
Dendrigraft poly(L-lysine) (DGL) constitutes a promising dendritic-like drug vehicle with high biocompatibility and straightforward access via ring-opening polymerization of N-carboxyanhydride in water. The characterization of the different generations of DGL is however challenging due to their heterogeneity in molar mass and branching ratio. In this work, free solution capillary electrophoresis was used to perform selective separation of the three first generations of DGL, and optimized conditions were developed to maximize inter-generation resolution. To reduce solute adsorption on the capillary wall, successive multiple ionic polymer layer coatings terminated with a polycation were deposited onto the inner wall surface. PEGylated polycation was also used as the last layer for the control of the electroosmotic flow (EOF), depending on the PEGylation degree and the methyl-polyethylene glycol (mPEG) chain length. 1 kDa mPEG chains and low grafting densities were found to be the best experimental conditions for a fine tuning of the EOF leading to high peak resolution. Molar mass polydispersity and polydispersity in effective electrophoretic mobility were successfully determined for the three first generations of DGL.
Topics: Polyelectrolytes; Polylysine; Polyethylenes; Electrophoresis, Capillary; Polyethylene Glycols
PubMed: 38340458
DOI: 10.1016/j.chroma.2024.464719