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Foods (Basel, Switzerland) Jun 2023There is an ongoing trend to design new kinds of food packaging materials with excellent properties which are environmentally friendly enough. The aim of this study was...
There is an ongoing trend to design new kinds of food packaging materials with excellent properties which are environmentally friendly enough. The aim of this study was to prepare and characterize egg white protein (EWP)-based composite films with and without ε-polylysine (Lys), as well as to compare their physical-chemical properties, structural properties, degradation and antibacterial properties. The results showed that with the addition of Lys, the composite films showed a decreasing tendency of the water permeability due to the enhanced interaction between proteins and water molecules. As indicated by the structural properties, stronger cross-linking and intermolecular interactions happened with increasing concentration of Lys. In addition, the composite films presented excellent antibacterial activities against and on chilled pork in the presence of Lys. Therefore, our prepared films might be used as a freshness-keeping material with an application in meat preservation. The biodegradation evaluation demonstrated that the composite films were environmental-friendly and have potential applications in the field of food packaging.
PubMed: 37372641
DOI: 10.3390/foods12122431 -
Biomolecules May 2023(Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to...
(Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy against pulmonary Mabs infection, due to the possibility to be aerosolically administrated and to tune their properties in order to increase nebulization resistance and retainment of encapsulated drug. In fact, liposome surface can be modified by decoration with mucoadhesive polymers to enhance its stability, mucus penetration and prolong its residence time in the lung. The aim of this work is to employ Chitosan or ε-poly-L-lysine decoration for improving the properties of a novel liposomes composed by hydrogenated phosphatidyl-choline from soybean (HSPC) and anionic 1,2-Dipalmitoyl-sn-glycero-3-phosphorylglycerol sodium salt (DPPG) able to entrap Rifampicin. A deep physicochemical characterization of polymer-decorated liposomes shows that both polymers improve mucoadhesion without affecting liposome features and Rifampicin entrapment efficiency. Therapeutic activity on Mabs-infected macrophages demonstrates an effective antibacterial effect of ε-poly-L-lysine liposomes with respect to chitosan-decorated ones. Altogether, these results suggest a possible use of ε-PLL liposomes to improve antibiotic delivery in the lung.
Topics: Humans; Liposomes; Rifampin; Polylysine; Chitosan; Mycobacterium abscessus; Anti-Bacterial Agents; Polymers
PubMed: 37371504
DOI: 10.3390/biom13060924 -
Antibiotics (Basel, Switzerland) Jun 2023Bacterial food poisoning cases due to and O157:H7 have been linked with the consumption of a variety of food products, threatening public health around the world. This...
Bacterial food poisoning cases due to and O157:H7 have been linked with the consumption of a variety of food products, threatening public health around the world. This study describes the combined effects of a phage cocktail (STG2, SEG5, and PS5), EDTA, nisin, and polylysine against the bacterial cocktail consisting of , , and O157:H7. Overall, phage cocktail (alone or in combination with nisin or/and polylysine) not only showed great antibacterial effects against bacterial cocktail at different temperatures (4 °C, 24 °C, and 37 °C), but also totally inhibited the emergence of phage resistance during the incubation period. These results suggest that the combination of phages with nisin or/and polylysine has great potential to simultaneously control , , and O157:H7.
PubMed: 37370397
DOI: 10.3390/antibiotics12061077 -
Toxins Jun 2023The binary () C2 toxin consists of two non-linked proteins. The proteolytically activated binding/transport subunit C2IIa forms barrel-shaped homoheptamers, which bind...
The binary () C2 toxin consists of two non-linked proteins. The proteolytically activated binding/transport subunit C2IIa forms barrel-shaped homoheptamers, which bind to cell surface receptors, mediate endocytosis, and translocate the enzyme subunit C2I into the cytosol of target cells. Here, we investigate whether C2IIa can be harnessed as a transporter for proteins/enzymes fused to polycationic tags, as earlier demonstrated for the related anthrax toxin transport subunit PA. To test C2IIa-mediated transport in cultured cells, reporter enzymes are generated by fusing different polycationic tags to the N- or C-terminus of other bacterial toxins' catalytic A subunits. C2IIa as well as PA deliver N-terminally polyhistidine-tagged proteins more efficiently compared to C-terminally tagged ones. However, in contrast to PA, C2IIa does not efficiently deliver polylysine-tagged proteins into the cytosol of target cells. Moreover, untagged enzymes with a native cationic N-terminus are efficiently transported by both C2IIa and PA. In conclusion, the C2IIa-transporter serves as a transport system for enzymes that harbor positively charged amino acids at their N-terminus. The charge distribution at the N-terminus of cargo proteins and their ability to unfold in the endosome and subsequently refold in the cytosol determine transport feasibility and efficiency.
Topics: Cytosol; Botulinum Toxins; Endosomes; Endocytosis
PubMed: 37368691
DOI: 10.3390/toxins15060390 -
Journal of Food Protection Jul 2023The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP),...
The purpose of the study was to investigate the mechanism of inactivation of Serratia liquefaciens by different treatments, namely corona discharge plasma (CDP), ε-polylysine (ε-PL), and corona discharge plasma combined with ε-polylysine (CDP plus ε-PL). The results showed that the combined treatment of CDP and ε-PL exhibited significant antibacterial effects. The total number of colonies of S. liquefaciens dropped by 0.49 log CFU/mL following 4 min of CDP treatment, 4MIC ε-PL treatment for 6 h alone decreased the amounts of colonies by 2.11 log CFU/mL, and 6 h of treatment with 4MIC ε-PL after the bacterium was treated with CDP could decrease the number of colonies by 6.77 log CFU/mL. Scanning electron microscopy images showed that the combined treatment of CDP and ε-PL caused the most serious damage to the cell morphology. Electrical conductivity, nucleic acid, and PI staining indicated that the combined treatment dramatically enhanced the permeability of the cell membrane. In addition, the combined treatment led to a significant decrease in SOD and POD enzyme activities in S. liquefaciens, which prevented energy metabolism. Finally, the determination of free and intracellular ε-PL concentrations confirmed that the treatment of CDP could cause the bacteria to bind more ε-PL and exert more significant bacterial inhibition. Therefore, CDP and ε-PL had a synergistic effect in the inhibition of S. liquefaciens.
Topics: Polylysine; Serratia liquefaciens; Anti-Bacterial Agents; Cell Membrane; Microscopy, Electron, Scanning
PubMed: 37295216
DOI: 10.1016/j.jfp.2023.100078 -
Microbial Genomics Jun 2023We delineate the evolutionary plasticity of the ecologically and biotechnologically important genus , by analysing the genomes of 213 species. Streptomycetes genomes...
We delineate the evolutionary plasticity of the ecologically and biotechnologically important genus , by analysing the genomes of 213 species. Streptomycetes genomes demonstrate high levels of internal homology, whereas the genome of their last common ancestor was already complex. Importantly, we identify the species-specific fingerprint proteins that characterize each species. Even among closely related species, we observed high interspecies variability of chromosomal protein-coding genes, species-level core genes, accessory genes and fingerprints. Notably, secondary metabolite biosynthetic gene clusters (smBGCs), carbohydrate-active enzymes (CAZymes) and protein-coding genes bearing the rare TTA codon demonstrate high intraspecies and interspecies variability, which emphasizes the need for strain-specific genomic mining. Highly conserved genes, such as those specifying genus-level core proteins, tend to occur in the central region of the chromosome, whereas those encoding proteins with evolutionarily volatile species-level fingerprints, smBGCs, CAZymes and TTA-codon-bearing genes are often found towards the ends of the linear chromosome. Thus, the chromosomal arms emerge as the part of the genome that is mainly responsible for rapid adaptation at the species and strain level. Finally, we observed a moderate, but statistically significant, correlation between the total number of CAZymes and three categories of smBGCs (siderophores, e-Polylysin and type III lanthipeptides) that are related to competition among bacteria.
Topics: Genomics; Streptomyces; Codon; Multigene Family
PubMed: 37266990
DOI: 10.1099/mgen.0.001028 -
Molecules (Basel, Switzerland) May 2023Thin oxide layers form easily on the surfaces of titanium (Ti) components, with thicknesses of <100 nm. These layers have excellent corrosion resistance and good...
Thin oxide layers form easily on the surfaces of titanium (Ti) components, with thicknesses of <100 nm. These layers have excellent corrosion resistance and good biocompatibility. Ti is susceptible to bacterial development on its surface when used as an implant material, which reduces the biocompatibility between the implant and the bone tissue, resulting in reduced osseointegration. In the present study, Ti specimens were surface-negatively ionized using a hot alkali activation method, after which polylysine and polydopamine layers were deposited on them using a layer-by-layer self-assembly method, then a quaternary ammonium salt (QAS) (EPTAC, DEQAS, MPA-N) was grafted onto the surface of the coating. In all, 17 such composite coatings were prepared. Against and , the bacteriostatic rates of the coated specimens were 97.6 ± 2.0% and 98.4 ± 1.0%, respectively. Thus, this composite coating has the potential to increase the osseointegration and antibacterial performance of implantable Ti devices.
Topics: Titanium; Polylysine; Coated Materials, Biocompatible; Anti-Bacterial Agents; Escherichia coli; Ammonium Compounds; Surface Properties
PubMed: 37241863
DOI: 10.3390/molecules28104120 -
Biosensors Apr 2023The efficacies and toxicities of chiral drug enantiomers are often dissimilar, necessitating chiral recognition methods. Herein, a polylysine-phenylalanine complex...
The efficacies and toxicities of chiral drug enantiomers are often dissimilar, necessitating chiral recognition methods. Herein, a polylysine-phenylalanine complex framework was used to prepare molecularly imprinted polymers (MIPs) as sensors with enhanced specific recognition capabilities for levo-lansoprazole. The properties of the MIP sensor were investigated using Fourier-transform infrared spectroscopy and electrochemical methods. The optimal sensor performance was achieved by applying self-assembly times of 30.0 and 25.0 min for the complex framework and levo-lansoprazole, respectively, eight electropolymerization cycles with -phenylenediamine as the functional monomer, an elution time of 5.0 min using an ethanol/acetic acid/HO mixture (2/3/8, //) as the eluent, and a rebound time of 10.0 min. A linear relationship was observed between the sensor response intensity (Δ) and logarithm of the levo-lansoprazole concentration (l-g ) in the range of 1.0 × 10-3.0 × 10 mol/L. Compared with a conventional MIP sensor, the proposed sensor showed more efficient enantiomeric recognition, with high selectivity and specificity for levo-lansoprazole. The sensor was successfully applied to levo-lansoprazole detection in enteric-coated lansoprazole tablets, thus demonstrating its suitability for practical applications.
Topics: Molecularly Imprinted Polymers; Phenylalanine; Polylysine; Polymers; Molecular Imprinting; Electrochemical Techniques; Limit of Detection
PubMed: 37232870
DOI: 10.3390/bios13050509 -
European Journal of Pharmaceutical... Aug 2023Owing to the difficult-to-penetrate blood-brain barrier (BBB), glioblastoma (GBM) doesn't respond well to the current chemical therapeutics. In this study, ultra-small...
Owing to the difficult-to-penetrate blood-brain barrier (BBB), glioblastoma (GBM) doesn't respond well to the current chemical therapeutics. In this study, ultra-small micelles (NMs) self-assembled by RRR-a-tocopheryl succinate-grafted-ε-polylysine conjugate (VES-g-ε-PLL) as the delivery vehicle of chemical therapeutics in conjunction with ultrasound-targeted microbubble destruction (UTMD) to surmount BBB and treat GBM. Docetaxel (DTX) as a hydrophobic model drug was incorporated into NMs. DTX-loaded micelles (DTX-NMs) with 3.08% of drug loading exhibited a hydrodynamic diameter (33.2 nm) and positive Zeta potential (16.9 mV), having a remarkable tumor-permeating capacity. Furthermore, DTX-NMs presented good stability in physiologic condition. The sustained- release profile of DTX-NMs was also displayed by dynamic dialysis. Treatment of DTX-NMs together with UTMD led to more pronounced apoptosis of C6 tumor cells than DTX-NMs alone. Moreover, compared with the DTX solution or DTX-NMs alone, the combination of DTX-NMs with UTMD had a stronger inhibitory effect on tumor growth for GBM-bearing rats. The median survival period of GBM-bearing rats was extended to 75 days in the DTX-NMs+UTMD group from under 25 days in the control group. The invasive growth of glioblastoma was largely inhibited by the combination of DTX-NMs with UTMD, which was demonstrated by staining of Ki67, caspase-3, and CD31, together with TUNEL assay. In conclusion, the combination of ultra-small micelles (NMs) with UTMD may be a promising strategy to overcome the limitations of the first-line chemotherapeutics against GBM.
Topics: Rats; Animals; Docetaxel; Micelles; Glioblastoma; Microbubbles; Apoptosis; Antineoplastic Agents; Cell Line, Tumor
PubMed: 37220818
DOI: 10.1016/j.ejps.2023.106468 -
ACS Nano Jun 2023The vaccine effect of radiation therapy (RT) has been shown to be limited in both preclinical and clinical settings, possibly due to the inadequacy of RT alone to...
The vaccine effect of radiation therapy (RT) has been shown to be limited in both preclinical and clinical settings, possibly due to the inadequacy of RT alone to stimulate vaccination in immunologically "cold" tumor microenvironments (TMEs) and the mixed effects of RT in promoting tumor infiltration of both effector and suppressor immune cells. To address these limitations, we combined intratumoral injection of the radiated site with IL2 and a multifunctional nanoparticle (PIC). The local injection of these agents produced a cooperative effect that favorably immunomodulated the irradiated TME, enhancing the activation of tumor-infiltrating T cells and improving systemic anti-tumor T cell immunity. In syngeneic murine tumor models, the PIC+IL2+RT combination significantly improved the tumor response, surpassing the single or dual combinations of these treatments. Furthermore, this treatment led to the activation of tumor-specific immune memory and improved abscopal effects. Our findings suggest that this strategy can be used to augment the vaccine effect of RT in clinical settings.
Topics: Humans; Animals; Mice; Interleukin-2; Polylysine; Injections, Intralesional; Neoplasms; CD8-Positive T-Lymphocytes; Antibodies; Vaccination; Nanoparticles; Cell Line, Tumor; Tumor Microenvironment
PubMed: 37216491
DOI: 10.1021/acsnano.3c00418