The effect of matrine against biofilm formation in Escherichia coli

Objective:To investigate the effect of matrine against biofilm formation of Escherichia coli(E.coli)in the early stage.Methods:Biofilms of E.coli(ATCC25922)was induced by using a peritoneal dialysis catheter in 96-well plates.After treatment with matrine for 24 h,the formation of biofilm on the catheters was observed by scanning electron microscope.The expressions of the flagellar gene(fliC)and motility genes(motA and motB)were determined by qPCR,and the protein expression of fliC was detected by western blotting.Results:The biofilm formation of E.coli was suppressed by different concentrations(less than the minimal inhibitory concentration)of matrine,and the mRNA levels of motA and motB as well as the mRNA and protein expression levels of fliC were decreased in a dose-dependent manner.Conclusion:Matrine could inhibit biofilm formation of E.coli via downregulating the expression of motA,motB and fliC.

Polystyrene nanoplastics aggravated ecotoxicological effects of polychlorinated biphenyls in on zebrafish(Danio rerio)embryos

In view of the accumulation of nanoplastics(NPs)in the food chain of environment and animals,and the good adsorption properties of nano-plastics to toxic substances,it is necessary to explore the influence of NPs in living organisms.In this study,single and joint toxicological effects of polystyrene nanoplastics(PS-NPs,size 80 nm)and polychlorinated biphenyls(PCBs),were explored in freshwater aquatic animal model zebrafish(Danio rerio).Our study found that exposure to single PS-NPs induced mild acute toxicity,albeit the combined exposure of PS-NPs and polychlorinated biphenyls aggravated the toxicity of PCBs in a dose-dependent manner.Results from gene expression profiling showed that NPs exposure could activate detoxification process,resulting in a slight up-regulation of antioxidant genes(sod1,gstp1),bone development genes(bmp2,bmp4)and cardiac gene(tbx20);while PCBs suppressed the detoxification through down-regulation of these genes,and the addition of NPs will exacerbate the impact of PCBs on gene suppression.Importantly,the results of in vivo purification experiments found that NPs showed prolonged retention in liver,intestine and gills of zebrafish and they might have crossed biological barrier and accumulate in lipid-rich tissues and excretion does not appear as the significant pathway for their elimination.In conclusion,the toxic effects of polychlorinated biphenyls on chorionic protected embryos were not significant as zebrafish chorion plays an important role in resisting the invasion of pollutants;PCBs can seriously damage the bone and heart development of zebrafish,while the presence of NPs significantly enhanced the toxicity of PCBs in zebrafish,which is an alarming concern for growing NPs levels and ecological safety in aquatic environment.

Super-Resolution Displacement Spectroscopic Sensing over a Surface“Rainbow”

Subwavelength manipulation of light waves with high precision can enable new and exciting applications in spectroscopy,sensing,and medical imaging.For these applications,miniaturized spectrometers are desirable to enable the on-chip analysis of spectral information.In particular,for imaging-based spectroscopic sensing mechanisms,the key challenge is to determine the spatial-shift information accurately(i.e.,the spatial displacement introduced by wavelength shift or biological or chemical surface binding),which is similar to the challenge presented by super-resolution imaging.Here,we report a unique"rainbow"trapping metasurface for on-chip spectrometers and sensors.Combined with super-resolution image processing,the low-setting 4×optical microscope system resolves a displacement of the resonant position within 35 nm on the plasmonic rainbow trapping metasurface with a tiny area as small as0.002 mm2.This unique feature of the spatial manipulation of efficiently coupled rainbow plasmonic resonances reveals a new platform for miniaturized on-chip spectroscopic analysis with a spectral resolution of 0.032 nm in wavelength shift.Using this low-setting 4×microscope imaging system,we demonstrate a biosensing resolution of 1.92×109exosomes per milliliter for A549-derived exosomes and distinguish between patient samples and healthy controls using exosomal epidermal growth factor receptor(EGFR)expression values,thereby demonstrating a new on-chip sensing system for personalized accurate bio/chemical sensing applications.

PDA-BPs integrated mussel-inspired multifunctional hydrogel coating on PPENK implants for anti-tumor therapy,antibacterial infection and bone regeneration

Currently,many cancer patients with bone defects are still threatened by tumor recurrence,postoperative bacterial infection,and massive bone loss.Many methods have been studied to endow bone implants with biocompatibility,but it is difficult to find an implant material that can simultaneously solve the problems of anticancer,antibacterial and bone promotion.Here,a multifunctional gelatin methacrylate/dopamine methacrylate adhesive hydrogel coating containing 2D black phosphorus(BP)nanoparticle protected by polydopamine(pBP)is prepared by photocrosslinking to modify the surface of poly(aryl ether nitrile ketone)containing phthalazinone(PPENK)implant.The multifunctional hydrogel coating works in conjunction with pBP,which can deliver drug through photothermal mediation and kill bacteria through photodynamic therapy at the initial phase followed by promotion of osteointegration.In this design,photothermal effect of pBP control the release of doxorubicin hydrochloride loaded via electrostatic attraction.Meanwhile,pBP can generate reactive oxygen species(ROS)to eliminate bacterial infection under 808 nm laser.In the slow degradation process,pBP not only effectively consumes excess ROS and avoid apoptosis induced by ROS in normal cells,but also degrade into PO43to promote osteogenesis.In summary,nanocomposite hydrogel coatings provide a promising strategy for treatment of cancer patients with bone defects.