Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Biomolecular condensates are formed through phase separation of biomacromolecules such as proteins and RNAs. These condensates exhibit liquid-like properties that can futher transition into more stable material states. They form complex internal structures via multivalent weak interactions, enabling precise spatiotemporal regulations. However, the use of inconsistent and non-standardized terminology has become increasingly problematic, hindering academic exchange and the dissemination of scientific knowledge. Therefore, it is necessary to discuss the terminology related to biomolecular condensates in order to clarify concepts, promote interdisciplinary cooperation, enhance research efficiency, and support the healthy development of this field.

AIM To study the extraction process,enzymatic properties and practical application of glucuronic hydrolase in Scutellaria baicalensis stems and leaves(sbsl GUS).METHODS With granularity,water consumption,extraction time and extraction frequency as influencing factors,enzymatic activity as an evaluation index,the extraction process was optimized by orthogonal test on the basis of single factor test.The relationship between substrate(baicalin)concentration and enzymolysis rate,after which Vmax and Km were calculated,the effects of pH value,temperature and metal ion on enzymatic activity were investigated,pH stability and heat stability were evaluated.sbsl GUS was adotped in the enzymolysis of baicalin to prepare baicalein,then the effects of pH value,temperature,reaction time,initial substrate concentration and enzyme addition on transfer rate were investigated.RESULTS The optimal extraction process was determined to be 40 mesh for granularity,10 times for water consumption,15 min for extraction time,and 3 times for extraction frequency.The enzymolysis accorded with the kinetics of enzymatic reaction,Km was 0.006 3 mol/L,Vmax was 70.42 μmol/h,the strongest enzymatic activity was found at the pH value of 6.0,temperature of 45℃and metal ion of 100 mmol/L Cu2+,sbsl GUS demonstrated good stability at the ranges of 4.0-7.0 for pH value and 4-30℃for temperature.The optimal preparation process was determined to be 6.0 for pH value,45℃for temperature,more than 12 h for reaction time,67.2 mmol/L for initial substrate concentration,and 1 mL/0.269 mmol baicalin for enzyme addition,the transfer rate was 97.83%.CONCLUSION sbsl GUS enzymolysis exhibits high efficiency and mild condition,which can provide a simple preparation method for obtaining baicalein,and expand the application path of Scutellaria baicalensis stems and leaves.

AIM To establish a UPLC-MS/MS method for the simultaneous content determination of liquiritin apioside,alibiflorin,swertiamarin,methyl gallate,benzoylpaeoniflorin,sweroside,6′-O-β-D-glucosylgentiopicroside,isoliquiritigenin,loganic acid,liquiritigenin,gallic acid,paeoniflorin,oxypaeoniflorin,gentiopicroside,glycyrrhizic acid,isoliquiritoside and liquiritin in Yangxue Ruanjian Capsules.METHODS The analysis was performed on a 40℃thermostatic Waters BEH C18column(2.1 mm×100 mm,1.7 μm),with the mobile phase comprising of 2 mmol/L ammonium acetate(containing 0.1%formic acid)-acetonitrile flowing at 0.3 mL/min in a gradient elution manner,and electron spray ionization source was adopted in negative ion scanning with multiple reaction monitoring mode.RESULTS Seventeen constituents showed good linear relationships within their own ranges(r>0.999 6),whose average recoveries were 91.33%-104.03%with the RSDs of 1.58%-3.50%.CONCLUSION This rapid,accurate and stable method can be used for the quality control of Yangxue Ruanjian Capsules.

AIM To evaluate the quality of Beidougen Formula Granules.METHODS Fifteen batches of standard decoctions and three batches of formula granules were prepared,after which paste rate and contents,transfer rates of magnoflorine,daurisoline,dauricine were determined.HPLC specific chromatograms were established,and cluster analysis was adopted in chemical pattern recognition.RESULTS For three batches of formula granules,the paste rates were 15.1%-16.6%,the contents of magnoflorine,daurisoline,dauricine were 18.93-19.39,9.42-9.60,6.79-6.85 mg/g with the transfer rates of 34.42%-35.25%,43.81%-44.65%,27.27%-27.51%from decoction pieces to formula granules,respectively,and there were seven characteristic peaks in the specific chromatograms with the similarities of more than 0.95,which demonstrated good consistence with those of standard decoctions and accorded with related limit requirements.Fifteen batches of standard decoctions were clustered into two types,and the medicinal materials produced from Jilin,Hebei,Shangdong could be used for the preparation of formula granules.CONCLUSION This reasonable and reliable method can provide references for the quality control and clinical application of Beidougen Formula Granules.

Purpose To evaluate the image quality improvement of deep learning iterative reconstruction(DLIR)on pediatric head CT images of head injury and to evaluate the performance of DLIR and conventional adaptive statistical iterative reconstruction-veo(ASIR-V)of noise and image texture of CT image in children's head trauma.Materials and Methods A total of 80 cases in Beijing Children's Hospital,Capital Medical University from December 7th to 11th 2020 of children's head low-dose CT were retrospectively selected.Scan voltage was 120 kV.Scan current was 150-220 mA.The raw data were reconstructed into 5 mm thick slice and 0.625 mm thin slice brain window and bone window images.50%ASIR-V and high weight DLIR images(DL-H)were reconstructed,respectively.A 4-point system was used to subjectively evaluate the display of sulcus,brain matter and bone.The number of lesions in each group was counted.The CT value and image noise values of gray matter and white matter were measured,and the contrast to noise ratio was calculated,then measured the blur metric index was measured in the same slice.The differences between the two image reconstruction methods were compared.Results Compared to 50%ASIR-V images,DL-H significantly improved the display ability of the sulcus and ventricles,as well as the display ability of the brain parenchyma(W=5.5-22.2,all P<0.05)in both slice thickness.There was no statistically significant difference in the display ability of the sulcus and ventricles between 5 mm 50%ASIR-V and 0.625 mm DL-H images(W=0.9,2.0,P=0.32,0.05,respectively).In terms of bone display ability,all images could achieve a maximum score of 4.0.A total of 35 lesions were found in 80 patients via 5 mm 50%ASIR-V and DL-H images,including 12 hemorrhagic lesions,1 intracranial gas,9 fractures,and 13 soft tissue swelling.In terms of objective evaluation,the noise level of DL-H images was significantly lower than that of 50%ASIR-V images(t=21.4-35.7,all P<0.05),and there was no statistically significant difference in noise and contrast noise ratio between 5 mm 50%ASIR-V and 0.625 mm DL-H images(t=1.7-2.2,all P≥0.05).The blur metric index showed that DL-H was superior to 50%ASIR-V images(t=6.1,10.0,both P<0.05),and there was no statistically significant difference in blur metric index between 0.625 mm DL-H and 5 mm 50%ASIR-V images(t=2.6,P=0.28).Conclusion DLIR can improve the CT image quality and image texture of children's head trauma,0.625 mm DL-H image quality is close to 5 mm 50%ASIR-V image,which can meet the diagnostic requirements,and possible to further reduce the radiation dose.

The assessment of adverse drug events is an important basis for clinical safety evaluation and post-marketing risk control of drugs,and its causality assessment is gaining increasing attention.The existing methods for assessing the causal relationship between drugs and the occurrence of adverse reactions can be broadly classified into three categories:global introspective methods,standardized methods,and probabilistic methods.At present,there is no systematic introduction of the operational details of the various methods in the domestic literature.This paper compares representative causality assessment methods in terms of definition and concept,methodological steps,industry evaluation and advantages and disadvantages,clarifies the basic process of determining the causality of adverse drug reactions,and discusses how to further improve the adverse drug reaction monitoring and evaluation system,with a view to providing a reference for drug development and pharmacovigilance work in China.

Objective To evaluate the efficacy and safety of brexpiprazole in treating acute schizophrenia.Methods Patients with schizophrenia were randomly divided into treatment group and control group.The treatment group was given brexpiprozole 2-4 mg·d-1 orally and the control group was given aripiprazole 10-20 mg·d-1orally,both were treated for 6 weeks.Clinical efficacy of the two groups,the response rate at endpoint,the changes from baseline to endpoint of Positive and Negative Syndrome Scale(PANSS),Clinical Global Impression-Improvement(CGI-S),Personal and Social Performance scale(PSP),PANSS Positive syndrome subscale,PANSS negative syndrome subscale were compared.The incidence of treatment-related adverse events in two groups were compared.Results There were 184 patients in treatment group and 186 patients in control group.After treatment,the response rates of treatment group and control group were 79.50％(140 cases/184 cases)and 82.40％(150 cases/186 cases),the scores of CGI-I of treatment group and control group were(2.00±1.20)and(1.90±1.01),with no significant difference(all P＞0.05).From baseline to Week 6,the mean change of PANSS total score wese(-30.70±16.96)points in treatment group and(-32.20±17.00)points in control group,with no significant difference(P＞0.05).The changes of CGI-S scores in treatment group and control group were(-2.00±1.27)and(-1.90±1.22)points,PSP scores were(18.80±14.77)and(19.20±14.55)points,PANSS positive syndrome scores were(-10.30±5.93)and(-10.80±5.81)points,PANSS negative syndrome scores were(-6.80±5.98)and(-7.30±5.15)points,with no significant difference(P＞0.05).There was no significant difference in the incidence of treatment-related adverse events between the two group(69.00％vs.64.50％,P＞0.05).Conclusion The non-inferiority of Brexpiprazole to aripiprazole was established,with comparable efficacy and acceptability.

Objective To investigate the effects of palmatine on migration,invasion and epithelial mesenchymal transformation(EMT)in human oral cancer KB cells.Methods KB cells were divided into control group and palmatine-L,-M,-H groups,cultured with 0,4,8 and 16 μmol·L-1 palmatine.After incubation for 48 h,scratch assay was used to detect migration;Traswell assay was used to detect invasion;matrix metalloproteinase 2(MMP-2),MMP-9 and fibronectin(FN)contents were detected by enzyme-linked immunosorbent assay;the expression of Vimentin,N-cadherin and E-cadherin mRNA were detected by real-time quantitative polymerase chain reaction;the expression of Vimentin,N-cadherin,E-cadherin,Wnt3 and β-catenin protein were detected by Western blot.Results Cell mobility in control group and palmatine-L,-M,-H groups were(69.27±8.62)％,(52.94±4.49)％,(45.22±5.05)％and(37.63±4.88)％;the number of transmembrane cells were 197.33±20.26,125.33±12.01,97.00±9.17 and 62.67±7.51;the content of MMP-2 were(2.93±0.21),(1.49±0.13),(1.16±0.15)and(0.95±0.09)ng·mL-1;the content of MMP-9 were(3.51±0.36),(2.37±0.23),(2.06±0.35)and(1.72±0.16)ng·mL-1;the content of FN were(41.28±4.02),(24.03±3.17),(20.67±2.63)and(13.82±2.19)ng·mL-1;the above indexes in palmatine-L,-M,-H groups were compared with the control group,and the differences were statistically significant(P＜0.05,P＜0.01).The mRNA and protein expressions of Vimentin,N-cadherin and E-cadherin,and the expressions of Wnt3 and β-catenin protein in palmatine-L,-M,-H groups were statistically significant compared with those in control group(P＜0.05,P＜0.01).Conclusion Palmatine can inhibit the migration,invasion and EMT of human oral cancer KB cells,and its mechanism is related to the regulation of Wnt/β-catenin signaling pathway.