Lipase and pH-responsive diblock copolymers featuring fluorocarbon and carboxyl betaine for methicillin-resistant staphylococcus aureus infections.

The emergence of multidrug-resistant bacteria along with their resilient biofilms necessitates the development of creative antimicrobial remedies. We designed versatile fluorinated polymer micelles with surface-charge-switchable properties, demonstrating enhanced efficacy against Methicillin-Resistant Staphylococcus Aureus (MRSA) in planktonic and biofilm states. Polymethacrylate diblock copolymers with pendant fluorocarbon chains and carboxyl betaine groups were prepared using reversible addition-fragmentation chain transfer polymerization.

Counterion-induced antibiotic-based small-molecular micelles for methicillin-resistant Staphylococcus aureus infections.

A new counterion-induced small-molecule micelle (SM) with surface charge-switchable activities for methicillin-resistant Staphylococcus aureus (MRSA) infections is proposed. The amphiphilic molecule formed by zwitterionic compound and the antibiotic ciprofloxacin (CIP), via a "mild salifying reaction" of the amino and benzoic acid groups, can spontaneously assemble into counterion-induced SMs in water. Through vinyl groups designed on zwitterionic compound, the counterion-induced SMs could be readily cross-linked using mercapto-3, 6-dioxoheptane by click reaction, to create pH-sensitive cross-linked micelles (CSMs).

Surface-Charge-Switchable and Size-Transformable Thermosensitive Nanocomposites for Chemo-Photothermal Eradication of Bacterial Biofilms and .

The appearance of multidrug-resistant bacteria and their biofilms presents a serious threat to modern medical systems. Herein, we fabricated a novel gold-nanorod-based chemo-photothermal-integrated antimicrobial platform with surface-charge-switchable and near-infrared (NIR)-induced size-transformable activities that show an enhanced killing efficiency against methicillin-resistant Staphylococcus aureus () in both planktonic and biofilm phenotypes. The nanocomposites are prepared by in situ copolymerization using -isopropyl acrylamide (NIPAM), acrylic acid (AA), and -allylmethylamine (MAA) as monomers on the surfaces of gold nanorods (GNRs).

Ciprofloxacin conjugated gold nanorods with pH induced surface charge transformable activities to combat drug resistant bacteria and their biofilms.

The ever-growing threat of drug-resistant pathogens and their biofilms based persistent, chronic infections has created an urgent call for new strategies to deal with multidrug resistant bacteria (MDR). Near-infrared (NIR) laser-induced photothermal treatment (PTT) of gold nanorods (AuNRs) disinfects microbes by local heating with low possibility to develop resistant. However, PTT disinfection strategy of AuNRs alone shows less efficiency in killing multidrug resistant strains (i.

Gold nanorods with surface charge-switchable activities for enhanced photothermal killing of bacteria and eradication of biofilm.

The increasing growth and severity of bacterial biofilm infections and the appearance of multidrug-resistant bacteria pose alarming threats to public healthcare systems, mainly due to their formidable tolerance to conventional antibiotics. Different from the antibacterial mechanisms of antibiotics, gold nanorods (AuNRs) disinfect microbes by local heating induced by near-infrared (NIR) light irradiation; thus, they are potential disinfection agents. In an attempt to increase the biocompatibility and antibacterial activities of AuNRs against organisms in both planktonic and biofilm phenotypes, polymethacrylate with pendant carboxyl betaine groups was decorated on AuNRs (PCB-AuNRs) to afford AuNRs with pH-induced surface charge-transformable activities.

Layer-by-Layer Assembled Multilayer Films with Multiple Antibacterial and pH-Induced Self-Cleaning Activities Based on Polyurethane Micelles.

Layer-by-layer assembled multilayer films with antifouling and pH induced self-cleaning activities were constructed by polyurethane micelles with dense PEG brush coronas (PEG--PUM) and polyethylenimine (bPEI). The dense PEG brush coronas and acidic induced surface charge transform activities of PEG--PUM rendered the multilayer films (PEG--PUM/bPEI) with antifouling and self-cleaning activities, respectively. Multilayer films constructed from polyurethane micelles without surface charge switchable properties (PEG--PUM, PEG--PUM), showed negligible pH induced surface release of PU micelles.

Silver nanoparticles with pH induced surface charge switchable properties for antibacterial and antibiofilm applications.

Silver nanoparticles (AgNPs) are widely used as antibacterial agents because of their significant antimicrobial activities and little sign of antimicrobial resistance. However, the relatively high toxicity to healthy cells and low penetration efficiency into bacterial biofilms prevent their further use in biomedical applications. In order to decrease the cytotoxicity of the AgNPs to mammalian cells while increasing their antibacterial and antibiofilm efficiency, a novel nanocomposite composed of AgNPs decorated with carboxyl betaine groups (AgNPs-LA-OB) was prepared.

Calpain inhibitor I attenuates atherosclerosis and inflammation in atherosclerotic rats through eNOS/NO/NF-κB pathway.

We previously reported that calpain, the Ca-sensitive cysteine protease, gets involved in atherogenesis. This study aimed to investigate the effects of calpain inhibitor I (CAI, 5 mg/kg per day) with or without N-nitro-l-arginine-methyl ester (l-NAME) (100 mg/kg per day), the inhibitor of nitric oxide synthase (NOS), on atherosclerosis and inflammation in a rat model induced by high-cholesterol diet (HCD). The results demonstrated HCD increased protein expression of calpain-1 but not calpain-2 in aortic tissue.

Downregulations of CD36 and Calpain-1, Inflammation, and Atherosclerosis by Simvastatin in Apolipoprotein E Knockout Mice.

Background: In the previous in vitro study, we found that simvastatin decreased the protein expression of CD36, the scavenger receptor, and calpain-1, the Ca2+-sensitive cysteine protease, in oxidized low-density lipoprotein (oxLDL)-treated macrophages. In this in vivo study, we investigated whether simvastatin downregulates the expression of CD36 and calpain-1 and inhibits the inflammation and atherosclerosis in apolipoprotein E knockout (ApoE KO) mice.

Methods: Twenty male 6-week-old ApoE KO mice were divided into 2 groups: the ApoE KO group and the ApoE KO + simvastatin (ApoE KO + Sim) group.

Simvastatin inhibited oxLDL-induced proatherogenic effects through calpain-1-PPARγ-CD36 pathway.

We previously reported that simvastatin, an inhibitor of HMG-CoA reductase, inhibits atherosclerosis in rats. The present study was designed to investigate the effect of simvastatin on mouse peritoneal macrophage foam cell formation, the early feature of atherosclerosis, and explore its mechanisms. The results showed that simvastatin decreased cholesterol content and DiI-oxLDL (1,1'-didodecyl 3,3,3',3'-indocarbocyanine perchlorate - oxidized low-density lipoprotein) uptake, reduced the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the medium, down-regulated the mRNA and protein expression of CD36 (a fatty acid receptor), and reduced the mRNA expressions of peroxisome proliferator-activated receptor gamma (PPARγ), TNF-α, and IL-6 in macrophages treated with oxLDL.

Application of micro-solid-phase extraction for the determination of persistent organic pollutants in tissue samples.

A novel, simple and efficient method for determining persistent organic pollutants (POPs) in tissue samples has been developed. This technique involves the use of simultaneous microwave-assisted digestion (MAD) and micro-solid-phase extraction (micro-SPE), in which the sorbent is held within a propylene membrane envelope, with gas chromatographic-mass spectrometric (GC-MS) analysis. The POPs studied included eleven organochlorine pesticides and five polychlorinated biphenyl congeners.