Antibacterial and antibiofilm activity of mannose-modified chitosan/PMLA nanoparticles against multidrug-resistant Helicobacter pylori.

Because of the apparent stasis in antibiotic discoveries and the growth of multidrug resistance, Helicobacter pylori-associated gastric infections are difficult to eradicate. In the search for alternative therapy, the reductive amination of chitosan with mannose, followed by ionic gelation, produced mannose functionalized chitosan nanoparticles. Then, molecular docking and molecular dynamics (MD) simulations were conducted with H. pylori lectin (HPLectin) as a target protein involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. Changes in zeta potential and FTIR spectroscopy revealed that chitosan was functionalized with mannose. Time-kill, polystyrene adherence, and antibiofilm studies were utilized to assess nanoparticles as an alternative antibacterial treatment against a resistant gastric pathogen. Man-CS-Nps were discovered to have effective anti-adherence and biofilm disruption characteristics in suppressing the development of resistant H. pylori. In addition, bioimaging studies with CLSM, TEM, and SEM illustrated that Man-CS-Nps interacted with bacterial cells and induced membrane disruption by creating holes in the outer membranes of the bacterial cells, resulting in the leakage of amino acids. Importantly, molecular docking and 20 ns MD simulations revealed that Man-CS-Nps inhibited the target protein through slow-binding inhibition and hydrogen bond interactions with active site residues. As a consequence of the findings of this study, the Man-CS-Nps is an excellent candidate for developing alternative therapies for the increasing incidences of resistant gastric infections.

Metabolomics analysis of Semen Cuscutae protection of kidney deficient model rats using ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry.

The traditional Chinese medicine syndrome "Kidney yang deficiency" is a kind of chronic kidney disease. With the development of society, the incidence of chronic kidney disease is increasing year by year, which also brings great economic pressure to people. Semen Cuscutae is an important traditional Chinese medicine to tonify liver and kidney, mainly used to tonify deficiency of liver and kidney, spleen and kidney deficiency and diarrhea. Although there are a lot of research at the molecular and cellular level to study the Semen Cuscutae on the treatment of Kidney yang deficiency syndrome, but there's no comprehensive research complete with metabolomics method from plasma, feces and urine metabolites aspects. The purpose of this study is to find the potential differential biomarkers of the Kidney yang deficiency model and blank group rats in plasma, urine and feces, and to investigate the mechanism of Semen Cuscutae in the treatment of Kidney yang deficiency syndrome. In this study, ultra high-performance liquid chromatography-quadrupole time-of-flight Mass Spectrometry (UPLC-QTOF/MS) was used to identify potential biomarkers. Through the analysis of metabolic profiles of plasma, urine, and feces, as well as multivariate statistical analysis and pathway analysis, the therapeutic mechanism of Semen Cuscutae for Kidney yang deficiency syndrome was described. The results showed that there were 69 differential metabolites in plasma, 93 differential metabolites in feces and 62 differential metabolites in urine, and the changes of the levels of these biomarkers showed that Semen Cuscutae had a good therapeutic effect on Kidney yang deficiency syndrome. Through the analysis of the channel, the metabolite changes mainly affected the steroid hormone biosynthesis, arachidonic acid metabolism, primary bile acid biosynthesis, sheath lipid metabolism and biosynthesis of tyrosine, phenylalanine metabolism, retinol metabolism,taurine and hypotaurine metabolism, lysine degradation and vitamin B6 metabolism, tryptophan metabolism, terpenoid backbone biosynthesis and starch and sucrose metabolism. Therefore, the results suggested that Semen Cuscutae could exert a good therapeutic effect by reversing the levels of some biomarkers.

Hydrogen Evolution Activity of Ruthenium Phosphides Encapsulated in Nitrogen- and Phosphorous-Codoped Hollow Carbon Nanospheres.

RuPx nanoparticles (NPs) encapsulated in uniform N,P-codoped hollow carbon nanospheres (RuPx @NPC) have been synthesized through a facile route in which aniline-pyrrole copolymer nanospheres are used to disperse Ru ions followed by a gas phosphorization process. The as-prepared RuPx @NPC exhibits a uniform core-shell hollow nanospherical structure with RuPx NPs as the core and N,P-codoped carbon (NPC) as the shell. This strategy integrates many advantages of hollow nanostructures, which provide a conductive substrate and the doping of a nonmetal element. At high temperatures, the obtained thin NPC shell can not only protect the highly active phase of RuPx NPs from aggregation and corrosion in the electrolyte but also allows variation in the electronic structures to improve the charge-transfer rate greatly by N,P codoping. The optimized RuPx @NPC sample at 900 °C exhibits a Pt-like performance for the hydrogen evolution reaction (HER) and long-term durability in acidic, alkaline, and neutral solutions. The reaction requires a small overpotential of only 51, 74, and 110 mV at 10 mA cm-2 in 0.5 m H2 SO4 , 1.0 m KOH, and 1.0 m phosphate-buffered saline, respectively. This work provides a new way to design unique phosphide-doped carbon heterostructures through an inorganic-organic hybrid method as excellent electrocatalysts for HER.