ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Melatonin (Mel) has been shown to have cardioprotective effects, but its action on ion channels is unclear. In this experiment, we investigated the inhibitory effect of Mel on late sodium currents (I_Na.L) in mouse ventricular myocytes and the anti-arrhythmic effect at the organ level as well as its mechanism. The whole-cell patch clamp technique was applied to record the ionic currents and action potential (AP) in mouse ventricular myocytes while the electrocardiogram (ECG) and monophasic action potential (MAP) were recorded simultaneously in mouse hearts using a multichannel acquisition and analysis system. The results demonstrated that the half maximal inhibitory concentration (IC₅₀) values of Mel on transient sodium current (I_Na.T) and specific I_Na.L opener 2 nmol·L^-1 sea anemone toxins II (ATX II) increased I_Na.L were 686.615 and 7.37 μmol·L^-1, respectively. Mel did not affect L-type calcium current (I_Ca.L), transient outward current (I_to), and AP. In addition, 16 μmol·L^-1 Mel shortened ATX II-prolonged action potential duration (APD), suppressed ATX II-induced early afterdepolarizations (EADs), and significantly reduced the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) in Langendorff-perfused mouse hearts. In conclusion, Mel exerted its antiarrhythmic effects principally by blocking I_Na.L, thus providing a significant theoretical basis for new clinical applications of Mel. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Wuhan University of Science and Technology (2023130).

Objective To elucidate the effect of curcumol on hepatic stellate cell iron death and epithelial-mesenchymal transition(EMT),and to investigate the molecular mechanism of its anti-liver fibrosis effect.Methods A model of hepatic stellate cell activation was constructed using normal cultured hepatic stellate cells in vitro,and the cells were divided into blank group and experimental-L,-M,-H groups.The blank group was given DMEM complete culture solution for normal culture;the experimental-L,-M,-H groups were given DMEM complete culture solution containing 12.5,25.0 and 50.0 mg·L-1 curcumol for 48 h of intervention.The effects of curcumol on the proliferation of hepatic stellate cells was observed by CCK-8.The expression levels of glutathione peroxidase 4(GPX4)and solute carrier family 7 member 11(SLC7A11)were detected by Western blot.The expression levels of E-cadherin and N-cadherin were detected by immunofluorescence.Results The cell proliferation rates of the experimental-M,-H groups and blank group were(68.97±5.61)％,(61.91±4.40)％and(118.07±10.01)％;the relative expression levels of GPX4 were 0.37±0.04,0.28±0.03 and 0.58±0.05;the relative expression levels of SLC7A11 were 0.38±0.04,0.28±0.03 and 0.60±0.05;E-cadherin levels were 6.76±1.09,9.57±1.73 and 2.05±0.72;N-cadherin levels were 5.66±0.66,3.44±0.78 and 10.37±0.66.The differences of above indicators were statistically significant between the blank group and the experimental-M,-H groups(P＜0.05,P＜0.01).Conclusion Curcumol promotes iron death in hepatic stellate cells,thereby inhibiting hepatic stellate cell EMT,which may be its molecular mechanism to prevent and treat liver fibrosis.

Objective To study the bioequivalence of two glipizide tablets in healthy Chinese subjects.Methods Randomized,open,single-administration,two-period,self-cross-over trial design was used in the study.There were 28 Chinese healthy subjects in the fasted state and 28 in the fed state,complete repeat cross single dose oral glipizide tablets test preparation or reference preparation 5 mg.The plasma concentration of glipizide was determined by liquid chromatography/tandem mass spectrometry at different time points after administration.The non-compartmental model was used to calculate the pharmacokinetic parameters and evaluate the bioequivalence of the two formulations.Results The main pharmacokinetic parameters of glipizide in the fasted state were as follows:Cmax were(551.60±91.26)and(518.10±105.10)ng·mL-1;AUC0-t were(3 074.33±861.91)and(3 026.77±934.25)h·ng·mL-1;AUC0-∞ were(3 204.85±990.78)and(3 166.35±1 107.36)h ng·mL-1.The parameters of glipizide in the fed state were as follows:Cmax were(517.30±98.97)and(472.80±114.48)ng·mL-1;AUC0-t were(3 001.12±830.87)and(2 932.79±736.35)h·ng·mL-1;AUC0-∞ were(3 067.00±918.84)and(2 997.44±819.14)h·ng·mL-1.The 90％confidence interval of the Cmax,AUC0-t and AUC0-∞ of the test formulation and the reference formulation were from 80.00％to 125.00％.The incidence of adverse events in fasted group and fed group was no serious adverse events.Conclusion The two glipizide tablets were bioequivalent under fasted and fed conditions,and good security.

Objective To develop a two-dimensional liquid chromatographic method for rifapentine blood concentration determination.Methods The blood concentration of rifapentine was determined by a novel two-dimensional liquid chromatography(2D-LC)with a one-dimensional column:Aston SC2T(3.5 mm ×50.0 mm,5 μm);a two-dimensional column:Aston SCB(4.6 mm ×250.0 mm,5 μm);the temperature of the column was 40 ℃;the flow rate was 1.0 mL·min-1;the detection wavelength was 335 nm;the injection volume was 300 μL.The specificity,standard curve and lower limit of quantification,precision and recovery,and stability of the method were investigated.The method was used to determine the blood concentration of rifapentine in tuberculosis patients.Results Rifapentine showed good linearity within 0.33-18.62 μg·mL-1 with the standard curve equation of y=2.68 x 105x-5 850.36(r=0.997),the recoveries were 99.81％-105.08％,and the intra-and inter-day precision were ≤4.84％.The results of rifapentine blood concentration measurements in tuberculosis patients were in the range of 0.10-54.70μg·mL-1,and 64.74％were within the therapeutic window concentration range(8-30 μg·mL-1).Conclusion The method is easy to operate,has high sensitivity,low detection limit and high specificity,and is suitable for clinical blood concentration determination.Individual differences in the administration of rifapentine in tuberculosis patients are large,and blood concentration monitoring is required for individualized treatment.

As a new transdermal drug delivery system, microneedles can significantly improve skin permeability, enhance drug transdermal delivery, and demonstrate unique advantages in breaking stratum corneum barrier of skin. This feature enables microneedles to demonstrate enormous potential in delivering biotechnology drugs. The traditional delivery method for biotechnology drugs is mainly injection, which brings problems such as pain and skin redness to patients, leading to poor patient compliance. In addition, the production, transportation, and storage of biotechnology drugs require strict low-temperature conditions to maintain their activity and increase cost output. Microneedles, by contrast, have many benefits, providing new avenues and solutions for biomolecular delivery. Accordingly, this review introduced the microneedle drug delivery system for delivery biotechnology drugs, and summarized the research progress of microneedle systems in biotechnology drugs.

Traditional decoction pieces have low efficiency, poor batch-to-batch consistency, and irregular physical form, making it difficult to meet the demands of modern automated production and precise and rapid clinical blending. Therefore, this study aims to develop a new type of granular drinking tablet to meet the demand for high-quality development in the traditional Chinese medicine industry. In the current study, the differences and similarities between the new Lonicerae Japonicae Flos (LJF) granular drinking tablets and the traditional ones were evaluated based on the flowability, the paste rate of the standard soup, the characterization fingerprint, the degree of pasting, the content of active ingredients, the transfer rate, and its traditional antipyretic and anti-inflammatory efficacy, using the traditional LJF decoction piece as a reference. The flowability experiments showed that the flowability of medium-sized granules (10-24 mesh) was significantly better than that of traditional drinking tablets (P < 0.01); the results of the paste rate showed that there was no significant difference between the different particle sizes and the original decoction pieces (P > 0.05), but the small particle sizes (24-65 mesh) had poor decoction clarity and gelatinization; the transfer rate was calculated as chlorogenic acid and luteoloside, and there was no significant difference in the transfer rate between traditional slices and different particle sizes (P > 0.05); the pharmacological results showed that the contents of rat tumor necrosis factor-α (TNF-α), rat interleukin-1β (IL-1β) and rat prostaglandin E₂ (PGE₂), xylene ear swelling inhibition rate and granuloma inhibition rate showed that there was no significant difference between the traditional and new granule decoction pieces (P > 0.05). In this study, by examining the fluidity, paste rate, paste degree, and antipyretic and anti-inflammatory effects of the new granular decoction piece of LJF, it was initially revealed that the new granular drinking tablets of LJF were consistent with the basic properties and pharmacological effects of the commercially available traditional drinking tablets. Still, the new granular tablets were characterized by high utilization rate, homogeneous quality, and ease of clinical transfer, which had a good prospect for application. The animal experiment was approved by the Ethics Committee of the China Academy of Chinese Medical Sciences (approval number. 2022B214).

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

Objective To observe the effects of total saponins of Trillium tschonoskii Maxim(TST)on vascular cognitive impairment(VCI),neurovascular units(NVUs),and neural circuit integrity in rats.Methods Forty-eight male Sprague-Dawley(SD)rats were randomly divided into sham-operated group,model group,TST group(intragastric administration,100 mg/kg),and donepezil group(intragastric administration,0.45 mg/kg),and then subjected to ischemic stroke by 2-VO method(bilateral common carotid artery ligation)or sham surgery.After 28 days of intragastric administration,Mirros water maze test was performed to evaluate the spatial learning and memory abilities of rats in each group.HE and Nissl staining were used to observe the pathological changes of brain tissue in rats.The expression of synuclein(SYN)in rat hippocampus was observed by immunohistochemical staining.Changes in dendritic spines in rat's hippocampal neurons were observed by Golgi staining.Western blotting was used to detect the expression levels of IL-1β,IL-10,vascular endothelial growth factor A(VEGFA),postsynaptic density protein 95(PSD95),and growth associated protein 43(GAP43)in rat's hippocampus in each group.Results In Mirros water maze test,rats in model group showed significant prolonged escape latency(P＜0.05),and a significant reduction in the number of crossing platforms and the percentage of activity time in the target quadrant(P＜0.05)than those in sham-operated group;while rats in TST group and donepezil group showed significant shortened escape latency(P＜0.01),and significant increase of the number of times of crossing platforms and the percentage of activity time in the target quadrant(P＜0.05)than those in model group.Compared of sham-operated group,model group showed a decrease in the expression of SYN and the number of neurons,Nissl bodies,and dendritic spines in the CA1 region of the hippocampus(P＜0.05).Compared with model group,TST group and donepezil group showed an increase in the expression of SYN and the number of neurons,Nissl bodies,and dendritic spines in the CA1 region of the hippocampus(P＜0.05).Western blotting showed a significant increase in the expression of IL-1β and VEGF(P＜0.05),and a decrease in the expression of IL-10,PSD95,and GAP43(P＜0.01)in rat's hippocampus of model group than those in sham-operated group.Compared with model group,TST group and donepezil group showed a significant decrease in the expression of IL-1β(P＜0.05),and an increase in the expression of VEGFA,IL-10,and GAP43(P＜0.05).Conclusions TST could alleviate cognitive impairment through promoting synaptic plasticity and neurovascular unit remodeling in 2-VO model rats,suggesting its significance as a potential drug for apoplexy.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.