BACKGROUND:Nanocell vesicles possess functions such as re-epithelialization,antioxidation,anti-inflammation,and regulation of extracellular matrix remodeling.Meanwhile,apoptotic bodies have the immunomodulatory effects.Therefore,the combination of the two to form nanofusion vesicles can synergistically promote the healing of diabetic skin wounds.OBJECTIVE:To elucidate the impact of nanofusion vesicles on skin wound healing in a diabetic murine model.METHODS:(1)Material preparation and characterization:The primary bone marrow mesenchymal stem cells of C57BL/6J neonatal mice and the neutrophil apoptotic bodies of C57BL/6J mice were isolated and extracted.The nanofusion vesicles were prepared by micro-extrusion mechanism.(2)In vitro experiment:MTT assay was used to detect the proliferative effect of different concentrations of nanofusion vesicles on NIH-3T3 cells and human umbilical vein endothelial cells.Reactive oxygen species fluorescence probe was used to detect the antioxidant effect of nano-fusion vesicles on NIH-3T3 cells treated with hydrogen peroxide(H2O2).The inhibitory effect of nanofusion vesicles on RAW 264.7 macrophage inflammation induced by lipopolyside was detected by real-time quantitative RT-qPCR.(3)In vivo experiment:36 male C57BL/6J mice were employed to develop a murine model of diabetes mellitus.Following the successful induction of diabetes,two circular full-thickness wounds,each with a diameter of 6 mm,were created on either side of the diabetic mice's spine using a skin punch.The mice were divided into three groups by random number table method.The control group was injected with 0.1 mL of phosphate buffer solution.The nanovesicle group was injected with 0.1 mL nanovesicles(25 μg/mL).The nanofusion vesicle group was injected with 0.1 mL nanofusion(25 μg/mL)vesicles.After treatment for three consecutive days,the wound healing and histomorphological changes were observed.RESULTS AND CONCLUSION:(1)In vitro experiment:nanofusion vesicles,when administered at concentrations ranging from 0 to 100 μg/mL,exhibited no toxic effects and promoted the proliferation of NIH-3T3 and HUVEC cell lines.Notably,a concentration of 25 μg/mL nanofusion vesicle significantly enhanced the proliferation of NIH-3T3 cells.Furthermore,the survival rate of human umbilical vein endothelial cells was observed to increase in correlation with escalating concentrations of nanofusion vesicles.Nanofusion vesicles had a good antioxidant effect.In comparison to the H2O2 group,the fluorescence signal indicative of reactive oxygen species was progressively diminished in both the nanovesicle group and the nanofusion vesicle group.Furthermore,nanofusion vesicles possessed anti-inflammatory capabilities,effectively mitigating the inflammatory response in macrophages triggered by lipopolysaccharide stimulation.(2)In vivo experiment:Hematoxylin-eosin and Masson's trichrome staining revealed that in comparison to the control group,both the nanovesicle group and the nanofusion vesicle group exhibited a significant increase in granulation tissue formation and collagen fiber deposition within the wounds by day 6.Notably,the nanofusion vesicle group displayed the most pronounced effects.On day 12,the wound of nanofusion vesicle group was significantly reduced,and the healing rate was significantly faster than that of other groups(P＜0.01),and the effect of promoting wound healing was the most significant.Our findings demonstrated that nanofusion vesicles exhibited superior pro-cell proliferative,antioxidant,and anti-inflammatory properties,thereby exerting a beneficial effect on the promotion of skin wound healing in diabetic mouse models.

BACKGROUND:Nanocell vesicles possess functions such as re-epithelialization,antioxidation,anti-inflammation,and regulation of extracellular matrix remodeling.Meanwhile,apoptotic bodies have the immunomodulatory effects.Therefore,the combination of the two to form nanofusion vesicles can synergistically promote the healing of diabetic skin wounds.OBJECTIVE:To elucidate the impact of nanofusion vesicles on skin wound healing in a diabetic murine model.METHODS:(1)Material preparation and characterization:The primary bone marrow mesenchymal stem cells of C57BL/6J neonatal mice and the neutrophil apoptotic bodies of C57BL/6J mice were isolated and extracted.The nanofusion vesicles were prepared by micro-extrusion mechanism.(2)In vitro experiment:MTT assay was used to detect the proliferative effect of different concentrations of nanofusion vesicles on NIH-3T3 cells and human umbilical vein endothelial cells.Reactive oxygen species fluorescence probe was used to detect the antioxidant effect of nano-fusion vesicles on NIH-3T3 cells treated with hydrogen peroxide(H2O2).The inhibitory effect of nanofusion vesicles on RAW 264.7 macrophage inflammation induced by lipopolyside was detected by real-time quantitative RT-qPCR.(3)In vivo experiment:36 male C57BL/6J mice were employed to develop a murine model of diabetes mellitus.Following the successful induction of diabetes,two circular full-thickness wounds,each with a diameter of 6 mm,were created on either side of the diabetic mice's spine using a skin punch.The mice were divided into three groups by random number table method.The control group was injected with 0.1 mL of phosphate buffer solution.The nanovesicle group was injected with 0.1 mL nanovesicles(25 μg/mL).The nanofusion vesicle group was injected with 0.1 mL nanofusion(25 μg/mL)vesicles.After treatment for three consecutive days,the wound healing and histomorphological changes were observed.RESULTS AND CONCLUSION:(1)In vitro experiment:nanofusion vesicles,when administered at concentrations ranging from 0 to 100 μg/mL,exhibited no toxic effects and promoted the proliferation of NIH-3T3 and HUVEC cell lines.Notably,a concentration of 25 μg/mL nanofusion vesicle significantly enhanced the proliferation of NIH-3T3 cells.Furthermore,the survival rate of human umbilical vein endothelial cells was observed to increase in correlation with escalating concentrations of nanofusion vesicles.Nanofusion vesicles had a good antioxidant effect.In comparison to the H2O2 group,the fluorescence signal indicative of reactive oxygen species was progressively diminished in both the nanovesicle group and the nanofusion vesicle group.Furthermore,nanofusion vesicles possessed anti-inflammatory capabilities,effectively mitigating the inflammatory response in macrophages triggered by lipopolysaccharide stimulation.(2)In vivo experiment:Hematoxylin-eosin and Masson's trichrome staining revealed that in comparison to the control group,both the nanovesicle group and the nanofusion vesicle group exhibited a significant increase in granulation tissue formation and collagen fiber deposition within the wounds by day 6.Notably,the nanofusion vesicle group displayed the most pronounced effects.On day 12,the wound of nanofusion vesicle group was significantly reduced,and the healing rate was significantly faster than that of other groups(P＜0.01),and the effect of promoting wound healing was the most significant.Our findings demonstrated that nanofusion vesicles exhibited superior pro-cell proliferative,antioxidant,and anti-inflammatory properties,thereby exerting a beneficial effect on the promotion of skin wound healing in diabetic mouse models.

AIM To prepare the borneol-menthol eutectic mixture-loaded nanoemulsion gel of tetramethylpyrazine.METHODS The equilibrium solubilities of tetramethylpyrazine in different oil phases,emulsifiers and co-emulsifiers were determined,after which compatibility experiment was performed,and pseudo-ternary phase diagram was drawn.With Km value,oil phase proportion and water phase consumption as influencing factors,particle size,PDI and saturated drug loading as evaluation indices,the formulation was optimized by central composite design-response surface method.The drug-loaded nanoemulsion was dispersed into carbomer 940 gel matrix to prepare nanoemulsion gel,then the physicochemical properties,in vitro drug release and transdermal absorption properties were investigated.RESULTS The optimal formulation was determined to be 3.31∶6.16∶1.56∶88.97 for eutectic mixture-EL-40-1,2-propylene glycol-water ratio,the particle size,PDI and saturated drug loading were 37.85 nm,23.04 and 5.82 mg/g,respectively.The obtained white,semi-solid nanoemulsion gel demonstrated the average pH value and viscosity of 6.68±0.07 and(289.69±1.06)mPa·s,respectively,whose in vitro drug release accorded with Higuchi equation,and the accumulative permeability per unit area was(2 048.23±55.6)μg/cm2 within 24 h,which were 3.72 and 1.21 times higher than those of hydrogel and aqueous solution,respectively.CONCLUSION The borneol-menthol eutectic mixture-loaded nanoemulsion gel of tetramethylpyrazine meets preparation requirements,thus can achieve the effective transdermal delivery of raw medicine.

The continuous accumulation of plastic waste such as polyethylene in the environment has caused serious environmental pollution issues.Considering the high similarity in the molecular structure of petroleum and polyolefin,it is feasible to apply rare earth-zeolite catalysts in polyolefin plastic upcycling,which is commonly used in fluid catalytic cracking(FCC)in the field of petroleum refining.In this study,Ce-modified HY(Ce-HY)zeolites were synthesized and characterized by a series of analytical methods,such as high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM),Fourier infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),etc.When introducing 5% Ce species into HY zeolites,the 5Ce-HY showed excellent catalytic performance in the catalytic cracking of low-density polyethylene(LDPE),which achieved 98.4% LDPE conversion with 91.5% selectivity of gaseous alkanes at 300℃,and 75.4% of them were isoparaffins.In addition,the effect of the location of rare earth species in Y zeolites on the catalytic performance was explored by fine X-ray diffraction(XRD)in the range of 11°-13°and in situ-Raman analyses.The Ce species located in the supercage of Y zeolites were more important,which enhanced the adsorption capacity and accessibility of substrate molecules,thus facilitating the entire catalytic cracking process.This method could be used to detect the location of rare earth elements in Y zeolites to understand the mechanism of rare earth catalysis.

As a serine protease,thrombin can convert soluble fibrinogen into insoluble fibrin and plays a pivotal role in the coagulation cascade.Therefore,the accurate quantitative assay of thrombin levels is of great value in the evaluation of coagulation function,clinical screening and prognostic monitoring of coagulation-related diseases,and screening of drugs for targeted therapy.Existing methods for thrombin detection can be divided into two categories,e.g.,the assay of concentration levels using nucleic acid aptamers as the affinity elements and the assay of activity levels based on the hydrolytic cleavage of substrate peptides.In recent years,electrochemical biosensors have attracted much attention in thrombin detection due to high sensitivity,high selectivity,simple instrument,fast response,and good portability.In this review,the latest research progress in methods for electrochemical detection of thrombin was summarized,focusing on the detection principles and the applied signal amplification strategies of related electrochemical biosensors.In addition,the challenges with respect to the practical use of electrochemical thrombin biosensors and the prospects were discussed.

Decabromodiphenyl ether(BDE-209)and decabromodiphenyl ethane(DBDPE)are widely used brominated flame retardants,which have been detected in the atmosphere,water,soil,and various organisms.In this study,a method based on high-performance liquid chromatography-inductively coupled plasma-mass spectrometry(HPLC-ICP-MS)was developed for determination of BDE-209 and DBDPE in sediment.Firstly,the target compounds in the sediments were extracted by accelerated solvent extraction(ASE),and the extraction solvent was hexane/dichloromethane(1∶1,V/V).The extract was concentrated by rotary evaporation and purified by a composite silica gel column(6 g neutral silica gel,8 g acidic silica gel,and 4 g anhydrous sodium sulfate),concentrated by nitrogen blowing,and then re-dissolved with 1 mL of toluene for instrumental determination.The chromatographic separation was carried out on a TC-C18(2)column(250 mm×4.6 mm)with isocratic elution using methanol-isopropanol-water(89∶6∶5,V/V)as the mobile phase,and the samples were separated within 20 min.Further,the Br element was quantified by ICP-MS to realize the detection of the target.The results showed that the method established in this study exhibited good linearity(R2>0.999)in the range of 100-10000 ng/mL,and the limits of quantification(LOQs)of the method were 2.0 ng/g for BDE-209 and 10.0 ng/g for DBDPE,with the relative standard deviations(RSDs,n=3)lower than 10%,and the recoveries were in the acceptable range(80.9%-120.7%).The matrix effect was effectively controlled within 10%.In addition,by analyzing the actual sediment samples from Guangxi,a background point,and Taizhou,Zhejiang,a typical contaminated area,it was found that neither BDE-209 nor DBDPE was detected in the sediment from Guangxi,while the concentrations of BDE-209 and DBDPE in the sediment from Zhejiang ranged from 1591.8 to 3362.9 ng/g,which further demonstrated the applicability and reliability of the method for analyzing actual environmental samples.This study provided a strong technical support for the accurate detection of POPs in the environment.

Objective To evaluate the effect of pneumatic logistics transport system(PTS)on the trans-portation efficiency of the transferred samples and the accuracy of the results.Methods The transportation speed,temperature and humidity change of PTS were analyzed by temperature and humidity transmitter.Anti-coagulant samples containing disodium ethylenediaminetetraacetate(EDTA-K2),sodium citrate,lithium hepa-rin and samples containing inert separation gel coagulant were selected.and used respectively for complete blood cell analysis,prothrombin time(PT),activated partial prothrombin time(APTT),troponin T(TnT)and other myocardial markers,as well as the detection of items such as glucose(Glu)and lactate dehydrogen-ase(LDH).According to the transfer mode,they were divided into the manual transfer group and the PTS transfer group,and according to the number of PTS transfers,they were divided into the one-time transfer group,the three-time transfer group and before transfer(control).The differences among each group were statistically analyzed,and 1/3 allowable total error(1/3TEa)was adopted as the criterion for determining the clinical application value.Results There was no statistically significant difference in the changes of tempera-ture and humidity during the transportation process of PTS compared with manual transportation(P＞0.05),but it was significantly faster than manual transportation in terms of transportation time(P＜0.05).Com-pared with before transfer,the differences between the PT,APTT,Glu and LDH items in the one-time trans-fer group and the three-time transfer group were statistically significant(P＜0.01),and their deviations were all much greater than 1/3TEa.However,in the plasma samples,compared with before transport,there were statistically significant differences in Glu and LDH between the one-time transfer group and the three-time transfer group(P＜0.05),but the deviations were all less than 1/3TEa.For the items of TnT,red blood cell count and hematocrit,compared with before transfer,there were statistically significant differences between some groups of the one-time transfer group and the three-time transfer group(P＜0.05),but the deviations were all less than 1/3TEa.Conclusion PTS can significantly improve the transportation efficiency of sam-ples,but it significantly affects the detection of Glu and LDH in plasma samples,which can be improved by u-sing serum sample transportation instead.In addition,PTS also affects the detection of PT and APTT,and it is not recommended to use PTS to transport coagulation specimen.

Objective To explore the regulation of the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)-mediated inflammatory response in chronic obstructive pulmonary disease(COPD)by modified Shengxian Decoction through the lung-gut axis.Methods Thirty rats were divided into three groups:Control group,COPD group,and COPD+modified Shengxian Decoction(SXT)group,with 10 rats in each.The COPD model was established using passive smoking combined with intratracheal instillation of lipopolysaccharide(LPS).General symptoms and signs of the rats were monitored during the modeling and intervention periods.Hematoxylin and eosin(HE)staining and immunohistochemistry(IHC)were used to observe lung tissue structure.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of inflammatory cytokines interleukin-6(IL-6)and tumor necrosis factor-alpha(TNF-α)in lung tissues.Flow cytometry was used to detect the number of type Ⅱ innate lymphoid cells(nILC2)and type 2 innate lymphoid cells(iILC2)in lung and intestinal tissues.Illumina MiSeq sequencing technology was used to perform 16S rRNA gene sequencing on rat feces to analyze the gut microbiota structure.Gas chromatography-mass spectrometry(GC-MS)was used to determine the content of short-chain fatty acids(SCFAs)in rat feces.Western blotting was used to detect the expressions of related proteins in the PI3K/AKT pathway.Results Compared with the Control group,the COPD group showed significantly reduced lung function indicators,increased heart rate and decreased body mass,while the SXT group showed significant improvement in lung function and general signs(P＜0.05).HE staining showed that the COPD group had lung tissue damage filled with inflammatory cells,while the SXT group had significantly fewer inflammatory cells.IHC results showed that the SXT group had significantly reduced expression of caspase-3 protein(P＜0.05).ELISA results showed that the levels of IL-6 and TNF-α were significantly increased in the COPD group,while the SXT group showed significant improvement in inflammatory damage.The ratio of nILC2 to iILC2 in lung and intestinal tissues was significantly reduced in the COPD group,indicating a significant inflammatory response,while the SXT group showed significant improvement(P＜0.05).The levels of ILC2 cytokines IL-13 and IL-4 were significantly increased in the COPD group,while the SXT group had significantly reduced IL-13 and IL-4 levels.The relative abundance of lung and gut microbiota in the SXT group was significantly higher than that in the Control and COPD groups(P＜0.05).Beta diversity index analysis showed significant differences in species diversity among the three groups(P＜0.05).GC-MS detected six types of SCFAs in rat feces:acetic acid,propionic acid,isobutyric acid,butyric acid,isovaleric acid,and valeric acid.Their levels were lower in the COPD group than in the Control group,but the levels in the SXT group were higher than those in the COPD group.Western blotting results showed that the expressions of p-PI3K,PI3K,p-AKT,AKT,p-NF-κB,and NF-κB proteins were significantly reduced in the SXT group compared to the COPD group(P＜0.05).ELISA results showed that the SXT group had significantly downregulated expression levels of IL-1β and IL-10 compared to the COPD group(P＜0.05).Conclusion Modified Shengxian Decoction can alleviate COPD inflammation.It may mediate the inflammatory response in COPD by inhibiting iILC2 cell activity and expressions of related proteins in the PI3K/AKT signaling pathway through gut microbiota metabolism.

Objective To investigate the molecular typing,virulence,and drug resistance characteristics of Staphylococcus aureus(SA)in bone and joint infections,providing basis for anti-infection treatment.Methods The SA strains isolated from inpatients with bone and joint infections in Beijing Jishuitan Hospital,Capital Medical University from January 2014 to December 2021 were collected.Multi-locus sequence typing(MLST)and Staphylococcal A protein(Spa)typing for all the strains and Staphylococcal cassette chromo-some mec(SCCmec)typing of methicillin-resistant Staphylococcus aureus(MRSA)were performed based on whole genome sequencing.The virulence genes and drug resistance genes of the strains were identified by online database.The antimicrobial susceptibility tests were carried by automatic microbiological assay system.Results MRSA accounted for 30.0％of the 100 isolated strains of SA.A total of 22 ST types and 39 Spa types were identified in the 100 strains of S.aureus,among which ST59(16.0％)and ST239(14.0％)were the dominant ST types,and t437(13.0％)and t030(10.0％)were the dominant Spa types.ST239-SCCmecⅢ-t030/t037 clone(46.7％)was the main epidemic clone in MRSA isolates.The biofilm gene(icaA,icaB,icaC,icaD,icaR),hemolysin gene(hlb,hld,hlgA,hlgB,hlgC),adhesion gene(clfA,clfB,fnbA,fnbB,ebp),and immune escape gene(adsA,sbi,scn)were widespread in all SA strains,with detection rates ranging from 89.0％to 100.0％.The detection rates of enterotoxin genes seb(43.3％),selk(93.8％)and selq(83.3％)in MRSA were significantly higher than those in methicillin-sensitive Staphylococcus aureus(MSSA)(all P＜0.05).In terms of drug-resistance characteristics,the detection rate of the resistance gene blaZ(87.0％)was the highest among all the S.aureus strains.In the isolated MRSA strains,the detection rate of resistance genes for erm(A),tet(M),aph(3')-Ⅲ,ant(6)-Ⅰa,ant(9)-Ⅰa,and aac(6')-aph(2")ranged from 43.3％to 50.0％,which were significantly higher than those in MSSA(all P＜0.05).The results of the drug-sensitivity test showed that the resistant rates of S.aureus strains to penicillin,erythromycin,and clindamycin were relatively high(89.0％,67.0％,and 51.0％,respectively).The resistant rates of MRSA to the antimicrobial agents commonly used in clinical practice were significantly higher than those of MSSA(all P＜0.05).Conclusion The molecular epidemiological char-acteristics of SA strains isolated from bone and joint infections were diversified in our hospital.ST239-SCCmecⅢ-t030/t037 was the most common epidemic clone among the strains.There were significant differences in the resistance genes and drug resistance rates be-tween MRSA and MSSA strains,for which clinical attention should be paid.

Objective To explore the regulation of the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)-mediated inflammatory response in chronic obstructive pulmonary disease(COPD)by modified Shengxian Decoction through the lung-gut axis.Methods Thirty rats were divided into three groups:Control group,COPD group,and COPD+modified Shengxian Decoction(SXT)group,with 10 rats in each.The COPD model was established using passive smoking combined with intratracheal instillation of lipopolysaccharide(LPS).General symptoms and signs of the rats were monitored during the modeling and intervention periods.Hematoxylin and eosin(HE)staining and immunohistochemistry(IHC)were used to observe lung tissue structure.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of inflammatory cytokines interleukin-6(IL-6)and tumor necrosis factor-alpha(TNF-α)in lung tissues.Flow cytometry was used to detect the number of type Ⅱ innate lymphoid cells(nILC2)and type 2 innate lymphoid cells(iILC2)in lung and intestinal tissues.Illumina MiSeq sequencing technology was used to perform 16S rRNA gene sequencing on rat feces to analyze the gut microbiota structure.Gas chromatography-mass spectrometry(GC-MS)was used to determine the content of short-chain fatty acids(SCFAs)in rat feces.Western blotting was used to detect the expressions of related proteins in the PI3K/AKT pathway.Results Compared with the Control group,the COPD group showed significantly reduced lung function indicators,increased heart rate and decreased body mass,while the SXT group showed significant improvement in lung function and general signs(P＜0.05).HE staining showed that the COPD group had lung tissue damage filled with inflammatory cells,while the SXT group had significantly fewer inflammatory cells.IHC results showed that the SXT group had significantly reduced expression of caspase-3 protein(P＜0.05).ELISA results showed that the levels of IL-6 and TNF-α were significantly increased in the COPD group,while the SXT group showed significant improvement in inflammatory damage.The ratio of nILC2 to iILC2 in lung and intestinal tissues was significantly reduced in the COPD group,indicating a significant inflammatory response,while the SXT group showed significant improvement(P＜0.05).The levels of ILC2 cytokines IL-13 and IL-4 were significantly increased in the COPD group,while the SXT group had significantly reduced IL-13 and IL-4 levels.The relative abundance of lung and gut microbiota in the SXT group was significantly higher than that in the Control and COPD groups(P＜0.05).Beta diversity index analysis showed significant differences in species diversity among the three groups(P＜0.05).GC-MS detected six types of SCFAs in rat feces:acetic acid,propionic acid,isobutyric acid,butyric acid,isovaleric acid,and valeric acid.Their levels were lower in the COPD group than in the Control group,but the levels in the SXT group were higher than those in the COPD group.Western blotting results showed that the expressions of p-PI3K,PI3K,p-AKT,AKT,p-NF-κB,and NF-κB proteins were significantly reduced in the SXT group compared to the COPD group(P＜0.05).ELISA results showed that the SXT group had significantly downregulated expression levels of IL-1β and IL-10 compared to the COPD group(P＜0.05).Conclusion Modified Shengxian Decoction can alleviate COPD inflammation.It may mediate the inflammatory response in COPD by inhibiting iILC2 cell activity and expressions of related proteins in the PI3K/AKT signaling pathway through gut microbiota metabolism.