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.

Hepatocellular carcinoma(HCC)is difficult to detect in its early stages and current treatment methods are associated with significant side effects and a high risk of developing drug resistance.This study aims to investigate the effect of phycocyanin(PC)on the apoptosis of human HCC HepG2 cells and its potential mechanism.HepG2 cells were treated with PC at concentrations of 0.1,0.25,0.5,1,2.5,5,and 10 μg/mL for 12 h,and with 10 μg/mL PC and 2.5 μmol/L Wip1 inhibitor(Wip1i)alone or in combination for 12 and 24 h,respectively.Cell proliferation levels were assessed using the CCK-8 cell proliferation-toxicity assay kit.Apoptosis levels were measured by Annexin V-FITC/Propidium Iodide double staining combined with flow cytometry.TMT(Tandem Mass Tag)proteomics quantitative technol-ogy was applied to analyze differential protein expression.Western blotting was used to detect the expres-sion levels of Wip1,p53,and phosphorylated-p53(Ser15)proteins.The CCK-8 assay revealed that PC effectively inhibited HepG2 cell proliferation in a concentration-dependent manner,with a half-maximal inhibitory concentration(IC50)of 19.37 μg/mL.Flow cytometry results showed that PC significantly in-duced apoptosis,with an apoptosis rate of 30.40％.Quantitative proteomics analysis indicated that PC induced activation of the p53 pathway.The CCK-8 assay showed that Wip1i enhanced the cytotoxic effect of PC on HepG2 cells.Western blotting confirmed that PC inhibited Wip1 expression,induced p53 pro-tein phosphorylation,and promoted the expression of total p53 protein.Additionally,Wip1i further en-hanced PC-mediated activation of the p53 pathway,increasing the expression of p53 and pP53(S15).In conclusion,PC may induce apoptosis by inhibiting the activity of the p53 negative regulator Wip1,thereby promoting apoptosis through the Wip1/p53 pathway.

Objective To observe the characteristic symptoms in breast cancer-bearing mice and the beneficial effect of ginger-processed Jiangxiangru polysaccharides on traditional Chinese medical symptoms.Methods Thirty-eight mice were used for modeling and divided into normal,model,positive,and low-,medium-,and high-dose ginger-processed Jiangxiangru polysaccharide groups.Mice in the normal group were not inoculated with tumors and mice in the normal and model groups received physiological saline intragastrically.Mice in the positive group received celecoxib solution intragastrically,and mice in the low-,medium-,and high-dose groups received the same dose but different concentrations of ginger-processed Jiangxiangru polysaccharide solution intragastrically.Changes in body weight and tumor size were recorded after 4 weeks of continuous administration.Symptoms were observed at the end of the experiment.RGB values in photographs of the tongues,tails,and claws from mice in each group were analyzed and recorded.The degrees of blood deficiency,yin deficiency,and tumor phlegm stasis were calculated based on the method of quantitative dialectical diagnosis.The tumors were isolated and weighed,and the tumor volume and inhibition rate were calculated to determine the beneficial effect of ginger-processed Jiangxiangru polysaccharides on traditional Chinese medical symptoms.Results Mice in the breast cancer model group showed signs of blood deficiency,yin deficiency,and phlegm stasis.Tumor size was significantly reduced in mice in the ginger-processed Jiangxiangru polysaccharide groups.Ginger-processed Jiangxiangru polysaccharides inhibited tumor growth and improved blood deficiency,yin deficiency,and tumor phlegm stasis in breast cancer-bearing mice,with the best result in the high-dose group.Conclusions Ginger-processed Jiangxiangru polysaccharides can improve the symptoms of blood deficiency,yin deficiency,and tumor phlegm stasis in breast cancer-bearing mice,especially at high doses.

Aim To identify the underlying target of bullatine A(BA)against rheumatoid arthritis(RA)u-sing limited proteolysis-small molecule mapping(LiP-SMap)drug target proteomics and to provide a scientif-ic basis for clinical application of Aconiti brachypodi Radix in the treatment of RA.Methods LiP-SMap drug target proteomics was employed to perform bioin-formatics analysis for comparing and validating the dif-ferential protein expression after BA intervention.A collagen-induced arthritis(CIA)model was estab-lished in DBA/1 mice using bovine type Ⅱ collagen.The mice were then divided into the CIA model group,methotrexate-positive control group(MTX group),and BA groups(10 mg·kg-1 and 20 mg·kg-1)based on their clinical scores.After drug intervention,the thera-peutic efficacy against RA was assessed by joint index scores and foot thickness measurements.Histopatholog-ical changes in the arthritic joints of CIA mice were e-valuated using hematoxylin and eosin(HE)staining.Enzyme-linked immunosorbent assay(ELISA)was employed to detect inflammatory cytokines interleukin-17(IL-17)and total IgG and IgG3 anti-collagen-spe-cific antibodies levels from the serum of CIA mice.Flow cytometry was used to detect the expression levels of intracellular Th17 cells(IL-17+CD4+T cells)and Th1 cells(IFN-γ+CD4+T cells).Fluorescent quanti-tative PCR was performed to detect the expression of genes related to differential proteins.Results The proteomic analysis identified Serpinb1a as a protein with strong binding affinity to BA,and KEGG enrich-ment analysis indicated IL-17 signaling pathway was a crucial pathway of BA in against RA.BA treatment significantly reduced clinical scores and foot thickness,improved local arthritis symptoms in CIA mice,and al-leviated inflammatory cell infiltration into arthritic joints(P＜0.05).Differential protein validation re-sults showed that BA had strong affinity with Serpinb1a(-5.92 kJ·mol-1)and downregulated the expres-sion of Serpinb1a mRNA.Furthermore,the administra-tion of BA markedly reduced serum IL-17 A levels from CIA mice,inhibited the expression of intracellular IL-17 A and IFN-γ cytokines in splenic CD4+T cells(P＜0.05),and significantly downregulated the transcrip-tional expression of IL-17F(P＜0.05).Conclusion BA exhibits therapeutic effects on collagen-induced arthritis,and its mechanism of action may involve the regulation of Serpinb1a and the IL-17 signaling path-way.

Aim To investigate the therapeutic effect of newly formulated Tadalafil tablets on liver fibrosis in mice induced by carbon tetrachloride(CCl4)and its impact on the activation of hepatic stellate cells(HSCs).Methods Liver fibrosis model was estab-lished by intraperitoneally injecting 20％CCl4 corn oil solution twice a week for eight weeks.After four weeks of modeling,the treatment group was administered ei-ther the newly formulated Tadalafil tablets(1.0 mg·kg-1)or the Cialis(2.5 mg·kg-1)via gavage for the remaining four weeks.We assessed the effects of Tadalafil on collagen deposition,tissue structural dam-age,and HSCs activation markers in the fibrotic liver of mice using serum biochemical analysis,histopathologi-cal staining,and Western blotting following the treat-ment period.LX-2 cells were cultured and treated with tadalafil after TGF β1 stimulation,and the effects of tadalafil on LX-2 cell activation were assessed via Western blot.Results Compared to the normal mice,the model group mice exhibited a significantly higher liver-specific index,increased liver function indicators,and notable hepatocyte necrosis.Additionally,liver lobules were damaged,accompanied by severe infiltra-tion of inflammatory cells.Both smooth muscle actin(α-SMA)and fibronectin(Fn)were elevated,serving as markers of HSCs activation.As a result of treatment with the newly formulated Tadalafil tablets,liver tissue damage was significantly reduced,transaminase levels decreased,necrosis and inflammatory cell infiltration were reduced,and collagen fiber deposition was allevia-ted,and α-SMA and Fn expression was reduced.It was worth noting that low-dose newly formulated Tadalafil tablets were found to be as effective as high-dose Cia-lis.In a cellular model,Tadalafil significantly inhibited the activation of LX-2 cells and reduced the expression of proteins related to cell activation.Conclusions The newly formulated Tadalafil tablets can significantly inhibit HSCs activation,reduce extracellular matrix(ECM)deposition,improve liver fibrosis and liver function damage caused by CCl4.This new formulation offers a significant advantage over Cialis in terms of ef-fectiveness,with a lower effective dose.

Objective:To evaluate the efficacy of multimodal prehabilitation in patients with refractory functional constipation undergoing Jinling procedure(modified Duhamel surgery).Methods:In this prospective randomized controlled trial,80 patients with refractory functional constipation scheduled for Jinling procedure at the Department of General Surgery,the General Hospital of Eastern Theater Command between January 2020 and December 2021 were enrolled.Participants were randomly assigned to either the observation group(n=40,multimodal prehabilitation)or control group(n=40,routine nursing care).Outcome measures included:time to first flatus,time to first ambulation,defecation volume on postoperative day 5,length of hospitalization,nutritional markers(hemoglobin,albumin,total protein at postoperative day 7),anxiety/depression scores(Hospital Anxiety and Depression Scale,HADS),and total complication rates.Results:Compared to controls,the first ventilation time(48.02±6.15)h,first ambulation time(49.92±5.58)h,defecation volume on the fifth day(234.50±51.03)mL,hospital stay(13.15±2.64)d,anxiety score(43.68±3.45)points,depression score(43.81±1.58)points,and the total incidence of postoperative complications(15%)were significantly lower in the observation group(all p values<0.05).By contrast,the serum levels of hemoglobin(115.60±11.60)g/l,albumin(41.19±5.79)g/L and total protein(61.64±4.94)g/L on day 7 post-operatively were significantly higher in the observation group than those in the control group(P<0.05).Conclusions:Multimodal prehabilitation enhances postoperative intestinal recovery,reduces complications,improves nutritional status,and shortens hospital stays in refractory functional constipation patients undergoing Jinling procedure,supporting its clinical adoption.

Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.

Objective:To investigate the dynamic characteristics of human papillomavirus (HPV) genomic integration during cervical lesion progression and the clinical value of HPV integration detection in stratify HPV-positive women, and to explore its molecular mechanisms in cervical carcinogenesis.Methods:A prospective cohort study was designed to enroll high-risk HPV (HR-HPV) positive women who underwent cervical cancer screening in Drum Tower Hospital Affiliated to Nanjing University Medical School and Nanjing Maternity and Child Health Care Hospital from July 2022 to July 2024. Cervical exfoliated cells samples were collected, and HPV whole genome targeted capture and high-throughput sequencing technology were used. The HPV integration patterns, host gene functional region distribution and pathway enrichment characteristics of 157 samples with different cervical lesions grades were analyzed, including 31 cases of normal cervix, 40 cases of cervical intraepithelial neoplasia (CIN) Ⅰ, 32 cases of CIN Ⅱ, 42 cases of CIN Ⅲ, and 12 cases of cervical cancer.Results:HR-HPV integration was detected in 80.2% (126/157) of the 157 HR-HPV positive samples. The incidence of HR-HPV integration in cervical cancer patients was 12/12, which was higher than that in normal women (77%, 24/31). The incidence of HPV16 integration was significantly higher in high-grade lesions, and the incidence of HPV16 integration was 43% (18/42) in CIN Ⅲ patients and 8/12 in cervical cancer patients ( P<0.001). A total of 14 438 integration events were detected in 126 samples with HPV integration. The integration sites were mainly distributed in the host intergenic region (51.0%, 7 359/14 438) and intronic region (38.1%, 5 494/14 438), and the integration frequency of viral L1 gene was the highest (28.4%, 4 498/16 781). Functional enrichment analysis showed that HPV integration-related host genes were significantly enriched in transport of small molecules,cyclic guanosine monophosphate (cGMP)-protein kinase G (PKG) signaling pathway, and purine ribonucleotide biosynthetic process, which synergistically drove carcinogenesis through multiple mechanisms. Conclusions:HPV integration events are significantly associated with the progression of cervical lesions. HPV integrated detection based on cervical exfoliated cells is expected to optimize the current screening strategy, reduce excessive intervention of HPV positive women and facilitate their accurate triage management.

Objective:To evaluate the safety and clinical efficacy of enteral nutrition (EN) initiated within 24 h after heart transplantation in pediatric patients.Methods:A retrospective cohort study was conducted. Clinical data from 16 pediatric heart transplant recipients at the Seventh Medical Center of the Chinese People′s Liberation Army General Hospital between October 2022 and October 2024 were collected, including demographics, anthropometric measurements, biochemical markers, cytokine levels, and clinical outcomes. Based on the timing of EN initiation, the patients were divided into EN-initiated within 24 h and EN-initiated after 24 h 2 groups. Demographic data, preoperative extracorporeal membrane oxygenation (ECMO) support, physical examination indicators, laboratory parameters, and cytokine levels were compared between groups using independent samples t-test, Mann-Whitney U test, Fisher′s exact probability test. Results:The cohort comprised 16 patients (10 males and 6 females) with an age of (12.5±1.9) years. The EN-initiated within 24 h group comprised 6 cases, and the EN-initiated after 24 h group comprised 10 cases. No significant difference was observed between the two groups in age, preoperative body mass index Z-score, preoperative ECMO support, physical examination indicators, laboratory parameters (total protein, albumin, hemoglobin), or cytokine levels (all P>0.05). Compared to the EN-initiated after 24 h group, the EN-initiated within 24 h group exhibited a shorter intensive care unit stay ( t=2.65, P<0.05) and shorter mechanical ventilation duration ( t=2.23, P<0.05) than EN-initiated after 24 h group. Total hospitalization length had no significant difference ( P>0.05). At 72 h post-transplant, the EN-initiated within 24 h group had a lower interleukin-12 P70 ( t=2.46, P<0.05) and interferon-γ levels ( t=2.55, P<0.05) than EN-initiated after 24 h group. Prior to discharge, the EN-initiated within 24 h group has a lower mean skinfold thickness ( t=2.49, P<0.05) and lower mid-upper arm circumference ( t=2.36, P<0.05) compared with the EN-initiated after 24 h group. Conclusions:Initiating EN within 24 h postoperatively is safe and feasible in pediatric heart transplant recipients. Early EN may shorten the length of intensive care unit stay and mechanical ventilation while attenuating postoperative release of inflammatory cytokine.