Objective:To prepare novel targeted lipid nanobubbles（MEB-NBs）that can be loaded with exosomes（Exo），and test the property and explore the specific invitro target-seeking ability of MEB-NBs. Methods:The core lipid nanobubbles（NBs）were prepared using mechanical oscillation methods，and Exo was connected to the NBs through membrane fusion. The target antibody MYH6 was linked to the NBs using a phospholipid coupling covalent method，resulting in the preparation of targeted lipid nanobubbles MEB-NBs loaded with Exo. The morphology，particle size，and surface potential of the prepared lipid nanobubbles MEB-NBs were observed，and the co-loading of Exo and NBs was verified using laser confocal and fluorescence resonance energy transfer techniques. The in vitro imaging capability and biosafety of MEB-NBs were evaluated，and the loading rate and drug content of Exo carried by MEB-NBs were measured. The ability of MEB-NBs to specifically target hiPSC-CMs cells was observed using flow cytometry，small animal in vivo imaging systems，and laser confocal microscopy. Results:The average particle size of the prepared MEB-NBs was（597.10 ± 47.70）nm，the surface potential was（-11.70 ± 0.21）mV，and the concentration was（2.43 ± 0.06）×10 7/ml. Laser confocal microscopy and FRET results confirmed that the Exo was effectively connected with the NBs；When the Exo concentration was 250 μg/ml，the Exo loading rate and drug loading of MEB-NBs were both 73.8%，and the results of laser confocal microscopy showed that MEB-NBs could be effectively targeted to hiPSC-CMs cells. MEB-NBs were well developed in vitro and had good biological safety. Conclusions:This study constructs novel Exo-loaded targeted lipid nanobubbles（MEB-NBs）that demonstrate stable physicochemical properties and ultrasound imaging capabilities. The developed MEB-NBs precisely target hiPSC-CMs cells，providing an innovative drug delivery system with enhanced therapeutic efficacy for Exo-based therapies.

Objective To explore the correlation between serum vitamin D(VD3)level differences and immune inflammatory markers in elderly sepsis patients.Methods A total of 103 elderly patients with sepsis(aged 65-99 years)in the ICU of the First Affiliated Hospital of Kunming Medical University from January 2020 to December 2022 were collected and divided into two groups according to the diagnostic criteria for VD3 deficiency:VD3 deficiency group(n=32)and VD3 severe deficiency group(n=71).Correlation analysis was conducted by comparing the differences in serum 25-(OH)-D3(VD3)levels,immune function-related indicators upon admission(blood routine,infection-related proteins,combined detection of 12 cytokines,absolute count analysis of lymphocytes and subgroups,quantitative determination of infection-related immune cells,immunoglobulin,and complement),illness severity,and prognostic indicators(APACHE-II score,SOFA score,duration of ICU stay,and 28-day mortality rate).Result(1)Serum VD3 levels were lower in elderly patients with sepsis.No patient was in the VD3 normal or insufficient group.Patients with severe VD3 deficiency had higher APACHE-II scores,SOFA scores,and 28-day mortality rates than those with VD3 deficiency,and these scores were negatively correlated with serum VD3 levels(P<0.001),while the difference in ICU stay duration between the two groups was not statistically significant(P>0.05);(2)WBC,PCT,CRP,and CD4/CD8 in the VD3 deficiency group were all lower than those in the VD3 severe deficiency group(P<0.05),while IL-6,IL-10,CD45+,CD3+/CD45+,and CD19+Abs were all higher than those in the VD3 severe deficiency group(P<0.05);In the VD3 deficiency group,VD3 levels were positively correlated with CD45+(P<0.05 for all),while negatively correlated with IL-6,IL-10,PCT,and CRP(P<0.05 for all);In the VD3 severe deficiency group,there were fewer corre-lation indicators and the correlation strength was not as strong as that in the VD3 deficiency group.Conclusion(1)Elderly patients with sepsis generally have lower levels of VD3,with lower levels associated with more severe illness and poorer prognosis;(2)In elderly sepsis patients,compared to patients with severe VD3 deficiency,patients with VD3 deficiency have lower levels of inflammation,stronger cellular immune response,and stronger correlation,suggesting that the effects of different VD3 levels on immune inflammatory responses may vary in elderly sepsis patients.

Purpose To construct an ultrasound molecular probe carrying miRNA-452/Let-7i and analyze its targeting effect on human induced pluripotent stem cell derived cardiomyocytes(hiPSCs-CMs)in vitro.Materials and Methods The biotinylated core lipid microbubbles(NBs),lipid microbubbles carrying adenovirus overexpressing miRNA-452/Let-7i(Ad-miR-452/Let-7i)and ultrasound molecular probes carrying adenovirus overexpressing miRNA-452/Let-7i and targeting protein MYH6(Ad-miR-452/Let7i-MYH6)were synthesized,and the expression rates of fluorescent proteins to verify their binding were compared.The physical and chemical properties,stability,and in vitro imaging of those abovementioned parameters were measured,respectively,and theirs biological safety was evaluated.hiPSCs-CMs was divided into Ad-miR-452/Let-7i group and Ad-miR-452/Let7i-MYH6 group,then theirs cell binding status were compared.Results The constructed NBs,Ad-miR-452/Let-7i and Ad-miR-452/Let7i-MYH6 had regular morphology and good stability.Detection data showed that theirs concentrations were(1.62±0.40)×108 particles/ml,(1.83±0.20)×108 particles/ml and(1.35±0.33)×108 particles/ml,respectively.The average particle sizes were(605.94±17.46)nm,(726.53±14.95)nm and(729.31±16.62)nm,respectively.The zeta potentials were(2.61±0.30)mV,(-11.21±0.71)mV and(-12.28±0.52)mV,respectively.The polydispersity indices were 0.24±0.07,0.26±0.14 and 0.25±0.13,respectively.With a concentration of 107 particles/ml,the imaging strengths of the three samples were 99.24±5.04,102.18±3.61 and 99.07±3.87,respectively.The miRNA-loaded ultrasound molecular probes exhibited no significant toxicity to the cells,with in vitro imaging lasting over 15 minutes,and they could specifically bind to hiPSC-CMs.Conclusion The constructed ultrasound molecular probe has stability and in vitro targeting,effectively improving virus transfection efficiency.

Purpose To construct an ultrasound molecular probe carrying miRNA-452/Let-7i and analyze its targeting effect on human induced pluripotent stem cell derived cardiomyocytes(hiPSCs-CMs)in vitro.Materials and Methods The biotinylated core lipid microbubbles(NBs),lipid microbubbles carrying adenovirus overexpressing miRNA-452/Let-7i(Ad-miR-452/Let-7i)and ultrasound molecular probes carrying adenovirus overexpressing miRNA-452/Let-7i and targeting protein MYH6(Ad-miR-452/Let7i-MYH6)were synthesized,and the expression rates of fluorescent proteins to verify their binding were compared.The physical and chemical properties,stability,and in vitro imaging of those abovementioned parameters were measured,respectively,and theirs biological safety was evaluated.hiPSCs-CMs was divided into Ad-miR-452/Let-7i group and Ad-miR-452/Let7i-MYH6 group,then theirs cell binding status were compared.Results The constructed NBs,Ad-miR-452/Let-7i and Ad-miR-452/Let7i-MYH6 had regular morphology and good stability.Detection data showed that theirs concentrations were(1.62±0.40)×108 particles/ml,(1.83±0.20)×108 particles/ml and(1.35±0.33)×108 particles/ml,respectively.The average particle sizes were(605.94±17.46)nm,(726.53±14.95)nm and(729.31±16.62)nm,respectively.The zeta potentials were(2.61±0.30)mV,(-11.21±0.71)mV and(-12.28±0.52)mV,respectively.The polydispersity indices were 0.24±0.07,0.26±0.14 and 0.25±0.13,respectively.With a concentration of 107 particles/ml,the imaging strengths of the three samples were 99.24±5.04,102.18±3.61 and 99.07±3.87,respectively.The miRNA-loaded ultrasound molecular probes exhibited no significant toxicity to the cells,with in vitro imaging lasting over 15 minutes,and they could specifically bind to hiPSC-CMs.Conclusion The constructed ultrasound molecular probe has stability and in vitro targeting,effectively improving virus transfection efficiency.

Objective:To prepare novel targeted lipid nanobubbles（MEB-NBs）that can be loaded with exosomes（Exo），and test the property and explore the specific invitro target-seeking ability of MEB-NBs. Methods:The core lipid nanobubbles（NBs）were prepared using mechanical oscillation methods，and Exo was connected to the NBs through membrane fusion. The target antibody MYH6 was linked to the NBs using a phospholipid coupling covalent method，resulting in the preparation of targeted lipid nanobubbles MEB-NBs loaded with Exo. The morphology，particle size，and surface potential of the prepared lipid nanobubbles MEB-NBs were observed，and the co-loading of Exo and NBs was verified using laser confocal and fluorescence resonance energy transfer techniques. The in vitro imaging capability and biosafety of MEB-NBs were evaluated，and the loading rate and drug content of Exo carried by MEB-NBs were measured. The ability of MEB-NBs to specifically target hiPSC-CMs cells was observed using flow cytometry，small animal in vivo imaging systems，and laser confocal microscopy. Results:The average particle size of the prepared MEB-NBs was（597.10 ± 47.70）nm，the surface potential was（-11.70 ± 0.21）mV，and the concentration was（2.43 ± 0.06）×10 7/ml. Laser confocal microscopy and FRET results confirmed that the Exo was effectively connected with the NBs；When the Exo concentration was 250 μg/ml，the Exo loading rate and drug loading of MEB-NBs were both 73.8%，and the results of laser confocal microscopy showed that MEB-NBs could be effectively targeted to hiPSC-CMs cells. MEB-NBs were well developed in vitro and had good biological safety. Conclusions:This study constructs novel Exo-loaded targeted lipid nanobubbles（MEB-NBs）that demonstrate stable physicochemical properties and ultrasound imaging capabilities. The developed MEB-NBs precisely target hiPSC-CMs cells，providing an innovative drug delivery system with enhanced therapeutic efficacy for Exo-based therapies.

Objective:To prepare urokinase targeted thrombus microbubbles combined with low frequency ultrasound to dissolve thrombus in rabbit femoral artery, and to explore the mechanism of thrombolysis through the change of urokinase concentration.Methods:Twenty-four rabbits with thrombosed femoral artery were randomly divided into four treatment groups: urokinase alone (UK) group, ultrasound with non-targeted microbubble and urokinase (US+ M+ UK) group, platelet-targeted microbubble with urokinase (R+ UK) group, ultrasound with platelet-targeted microbubble and urokinase (US+ R+ UK) group. Thrombus-targeted microbubbles were injected through the ear vein and irradiated by ultrasound for 30 minutes, and the pulsed Doppler blood flow meter was used to continuously monitor the blood flow at 0 min, 10 min, 20 min, 30 min, 60 min, 90 min and 120 min after injection. At the same time, the changes in urokinase concentration were monitored, and the characteristics of blood flow and urokinase concentration changes were analyzed.Results:UK and US+ M+ UK groups failed to show recanalization at 120 minutes after treatment.In contrast, the US+ R+ UK and R+ UK groups both achieved persistent recanalization( P<0.001). Compared with the basal state. Both the R+ UK group and R+ UK+ US group showed a decrease at 60 minutes, and the difference was statistically significant( P<0.05). Conclusions:In the thrombolysis process of low-frequency ultrasound combined with a targeted contrast agent carrying urokinase, the targeting can make the local urokinase concentration of thrombus reach the highest level. At the same time, ultrasound and targeted microbubbles promote urokinase to enter the thrombus, and finally achieve the strongest thrombolytic effect.

Objective To construct the uItrasound microbubbIes co-carrying recombinant adenovirus containing stromal cell derived factor 1 (SDF-1α) and bone morphogenetic protein 2 (BMP2),and to study the maximum efficiency of carrying adenovirus and the optimum proportion of double gene combined with ultrasound contrast agents.Methods Microbubbles were combined separately with recombinant adenovirus co-expression of enhanced green fluorescent protein and SDF-1α(pAd-EGFP/SDF-1α) as well as red fluorescence protein and BMP2 (pAd-RFP/BMP2) via biotin-streptavidin method,and the maximum efficiency of carrying DNA in microbubbles was detected.Three microbubbles with binary vectors were prepared by blending the two above-mentioned pAd at different ratio (1 ∶1,1 ∶ 2,2 ∶ 1) into the microbubbles.The microbubbles with binary vectors were evaluated though physiochemical properties,fluorescence microscope and flow cytometry to test the carrying rate of DNA in microbubbles.Results There was no significant difference in PH,average diameter and concentrations between targeted microbubbles and control group (P ＞0.05).The carrying efficiency of DNA increased with virus loads in microbubbles,but lowered if further increasing virus amount after reaching saturation.When the proportion of binary vectors and microbubbles was 1 ∶ 1,its efficiency of carrying SDF-1α gene and BMP-2 was approximately equal,and flow cytometry demonstrated that the positive rate of microbubbles labeled by both fluorescein isothiocyanate(FITC) and rhodamine was (65.6 ± 0.5)％.However,it was (59.0 ± 2.3)％ when their proportion was the 2 ∶ 1,which was significantly lower than those when other two proportions (1 ∶ 1 and 1 ∶ 2).Under the fluorescence microscope,the targeted microbubbles were equally surrounded by bright green or red fluorescence.Conclusions Ultrasound microbubbles of double genes carrying EGFP/SDF-1a and RFP/BMP2 is made successfully via biotin-streptavidin method.The optimal proportion of combining microbubbles with double gene is 1 ∶1,which can reveal the optimum load rate and stable combination.