1.Enzyme-directed Immobilization Strategies for Biosensor Applications
Xing-Bao WANG ; Yao-Hong MA ; Yun-Long XUE ; Xiao-Zhen HUANG ; Yue SHAO ; Yi YU ; Bing-Lian WANG ; Qing-Ai LIU ; Li-He ZHANG ; Wei-Li GONG
Progress in Biochemistry and Biophysics 2025;52(2):374-394
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.
2.Inner Ear Delivery of Polyamino Acid Nanohydrogels Loaded with Dexamethasone
Pingping AI ; Lidong ZHAO ; Zhaohui TANG ; Chaoliang HE ; Xuesi CHEN ; Shiming YANG ; Nan WU
Medical Journal of Peking Union Medical College Hospital 2025;16(2):370-378
To develop a novel polyamino acid-based nanohydrogel drug delivery system for dexamethasone to enhance its delivery efficiency to the inner ear. A fluorescein-labeled polyglutamic acid-based polyamino acid dexamethasone nanohydrogel was synthesized, and its gelation time was measured. The hydrogel was surgically injected into the round window niche of guinea pigs to determine its degradation time in the middle ear cavity in vivo. The safety, pharmacokinetics, and distribution patterns of dexamethasone in the inner ear were evaluated. The hydrogel exhibited a gelation time of 80 seconds in a 37℃ water bath. In vivo, the hydrogel was almost completely degraded within 7 days in the middle ear cavity of guinea pigs. Transient hearing loss was observed one day after administration, but hearing gradually returned to normal over time. No significant cytotoxicity, vestibular stimulation signs, or pathological abnormalities in spiral ganglion cells were observed. Histopathological examination revealed no significant inflammatory reactions. Pharmacokinetic analysis demonstrated sustained drug release and prolonged dexamethasone activity. Immunofluorescence staining confirmed the distribution of dexamethasone in both the cochlea and vestibular organs. The polyamino acid nanohydrogel exhibits excellent injectability and biodegradability, representing a safe and effective drug delivery system for the inner ear.
3.Adhesion Mechanisms of Aquatic Fouling Organisms Mediated by Biomacromolecules
Dan HE ; Shi-Guo LI ; Ai-Bin ZHAN
Progress in Biochemistry and Biophysics 2025;52(7):1833-1852
Aquatic organisms can secrete biomacromolecules through specialized organs, tissues, or structures, enabling adhesion to underwater material surfaces and leading to severe biofouling issues. This phenomenon adversely impacts aquatic ecosystem health and human activities. Biofouling has emerged as an emerging global environmental challenge. Adhesion serves as the foundation of biofouling, representing a critical step toward a comprehensive understanding of the adhesion mechanisms of aquatic organisms. Biomacromolecules, including proteins, lipids, and carbohydrates, are the primary functional components in the adhesive substances of aquatic fouling organisms. Research indicates that these biomacromolecules exhibit diversity in types and characteristics across different aquatic organisms, yet their adhesion mechanisms show unifying features. Despite significant progress, there remains a lack of comprehensive reviews on the adhesion mechanisms mediated by biomacromolecules in aquatic fouling organisms, particularly on the roles of lipids and carbohydrates. Through a comprehensive analysis of existing literature, this review systematically summarizes the mechanistic roles of three classes of macromolecules in aquatic biofouling adhesion processes. Proteins demonstrate central functionality in interfacial adhesion and cohesion through specialized functional amino acids, conserved structural domains, and post-translational modifications. Lipids enhance structural stability via hydrophobic barrier formation and antioxidative protection mechanisms. Carbohydrates contribute to adhesion persistence through cohesive reinforcement and enzymatic resistance of adhesive matrices. Building upon these mechanisms, this review proposes four prospective research directions: optimization of protein-mediated adhesion functionality, elucidation of lipid participation in adhesion dynamics, systematic characterization of carbohydrate adhesion modalities, and investigation of macromolecular synergy in composite adhesive systems. The synthesized knowledge provides critical insights into underwater adhesion mechanisms of aquatic fouling organisms and establishes a theoretical foundation for developing mechanism-driven antifouling strategies. This work advances fundamental understanding of bioadhesion phenomena while offering practical guidance for next-generation antifouling technology development.
4.Research progress of needle-free injection technology
He ZHANG ; Shuo LI ; Yi CHENG ; Zeng-ming WANG ; Nan LIU ; Meng LI ; Hui ZHANG ; Ai-ping ZHENG
Acta Pharmaceutica Sinica 2024;59(3):591-599
Needle-free injection technology (NFIT) refers to the drug delivery systems in which drugs are propelled as high-speed jet streams using any of the pressure source to penetrate the skin to the required depth. NFIT is a promising drug delivery system as it enables the injection of liquids, powders, and depot/projectiles, and has the advantages of preventing needle stick accidents, improving drug bioavailability, eliminating needle-phobia, increasing vaccine immunity, simplifying operations and is convenient for patients to use. NFIT and its research background, the structure and classification of needle-free jet injectors (NFJI), drugs that can be delivered using NFJI and the factors affecting the injection effect are comprehensively reviewed in this paper. The limitations and potential development directions are summarized to provide a theoretical basis for the application and development of NFIT.
5.Reduced Field of View APT Imaging of Rectum (RAPTOR) at 3T MRI Scanner
Xu-Bin CHAI ; Yi WANG ; Zi-Jun HE ; Ai-Hua LIU ; Rong XUE
Progress in Biochemistry and Biophysics 2024;51(6):1471-1478
ObjectiveThe chemical exchange saturation transfer (CEST) technique has become a valuable tool in diagnosing metabolic changes associated with cerebral and systemic diseases, leveraging the calculation of compounds with exchangeable protons in proximity to water molecules. Specifically, the amide proton transfer (APT) CEST technique has shown promise in diagnosing cerebral strokes and tumors by comparing altered endogenous proteins or peptides with normal tissues. Reduced field of view (rFOV) imaging technology has been widely used in the diagnosis of small organ lesions in the body. In this study, we aim to apply the rFOV imaging to identify CEST signals in the rectum, investigating the potential utility of rFOV technique in clinical diagnosis of rectal diseases and providing metabolic insights for chemoradiotherapy. MethodsMRI images of eleven healthy volunteers were acquired using transverse Full_FOV and rFOV CEST imaging on a 3T scanner. The resolution was set at 2.5×2.5×6 mm³ and 1.5×1.5×6 mm³ for Full_FOV or the rFOV method. Saturation powers of 0.7 μT and 2 μT were applied. For the 2 μT saturation, MTRasym at ±3.5 ppm was employed, while for 0.7 μT saturation, Lorentzian difference was used for CEST quantification of the contrast maps and curves. ResultsThe rFOV method has the advantage of halving the scan time while maintaining the same contrast as the Full_FOV method. When compared to Full_FOV methods, rFOV methods exhibited nearly identical Z_spec and very similar MTRasym curves. Additionally, rFOV with a 1.5 mm×1.5 mm in-plane resolution could be achieved in approximately 3 min. rFOV method displayed better structural details for the entire rectum, including CEST contrast maps and quantitative curves. ConclusionCEST MRI proves valuable in diagnosing rectal diseases, and employing the rFOV technique could provide higher spatial and temporal resolution. CEST MRI should be the preferred choice for offering improved diagnostic capabilities with its potential for rectal disease diagnosis.
6.The effects of exercise preconditioning on angiogenesis and protein expression after cerebral ischemia and reperfusion
Lu ZHOU ; Liya TANG ; Qiong JIANG ; Meiyan HE ; Xiaoying SUN ; Qirui QU ; Xiqin YI ; Kun AI
Chinese Journal of Physical Medicine and Rehabilitation 2024;46(1):1-6
Objective:To observe any effect of exercise preconditioning on the levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in the brain tissue of rats after induced cerebral ischemia and reperfusion, and how it might promote angiogenesis.Methods:Thirty-six male Sprague-Dawley rats were randomly divided into a sham-operation group, a model group and an exercise preconditioning group, each of 12. After adaptive running training for 3 days, the exercise preconditioning group ran daily for 30 minutes at 15m/min for 14 days, while the other two groups did not exercise. Middle cerebral artery occlusion and reperfusion were then induced in the model and exercise preconditioning groups using the modified Zea-Longa suture method. Rats in the sham-operation group were only cut open to expose the right carotid artery. Right after the modeling, and again 24 hours later neurological deficit was evaluated using the Zea-Longa score and modified neurological severity scoring (mNSS). Infarct sizes were measured using 2, 3, 5-triphenyl tetrazolium chloride staining. Any morphological changes were noted using hematoxylin and eosin (HE) staining, and the expression of CD31 protein, hypoxia-inducible factor-1α and vascular endothelial growth factor in the ischemic cerebral cortex were quantified immunohistochemically.Results:Right after the modelling, compared with the sham-operation group, the average Zea-Longa scores of the model and exercise groups had increased significantly, but were not significantly different from each other. Twenty-four hours later the average Zea-Longa score, mNSS score and relative cerebral infarction area of the model group had increased significantly compared with the sham-operation group, while the exercise preconditioning group′s averages had decreased significantly. The HE staining showed that compared with the sham-operation group, pathological changes such as loose tissue, reduced number of nerve cells, nucleolysis, and vacuolization of the cerebral cortex on the ischemic side were found in the model group. Compared with the model group, the pathological changes in the exercise preconditioning group were less serious. The levels of CD31 protein, HIF-1α and VEGF in the ischemic cerebral cortexes of the model group had by then increased significantly. But compared with the model group, those levels had increased more in the exercise preconditioning group.Conclusion:Exercise preconditioning can effectively promote angiogenesis after cerebral ischemia and reduce chronic injury. That may be related to the activation of the HIF-1α and/or VEGF signaling pathways.
7.Analysis of the Spot vision screener for abnormal refractive outcomes in infants aged 6 to 48 months
Yongqiang ZHANG ; Yonggui AI ; Xiaohui LIU ; Xiaoying YANG ; Jiao HE
International Eye Science 2024;24(7):1162-1164
AIM: To analyze the abnormal refractive status of infants and young children aged 6 to 48 months, and to provide basis for the correction of ametropia and the early prevention and treatment of amblyopia.METHODS: Infants and young children aged 6 to 48 months were examined for refraction by Spot vision screener for natural optometry. Clinical data of infants and young children with refractive abnormalities were collected, Ciliary muscle paralysis agent was used for retinoscopy and optometry, and the results were statistically analyzed.RESULTS: A total of 168 cases(336 eyes)with abnormal Spot refractive outcomes were collected, with a high proportion of hyperopia and astigmatism abnormalities, 38.4% and 28.6%, respectively, while the proportion of myopia was low(12.2%). There were 90 cases of anisometropia(≥1.00 D), among which 41 cases(45.6%)were astigmatic anisometropia, 33 cases(36.7%)were hyperopic anisometropia, and 16 cases(17.8%)were myopic anisometropia, accounting for the least proportion. A total of 109 infants and young children with Spot refractive abnormalities completed ciliary muscle paralysis retinal optometry. The analysis of the difference and correlation between Spot diopter and post ciliary muscle paralysis optometry results showed that the difference in astigmatism was 0.34±0.64 D(P<0.001), the difference in hyperopia was -2.10±1.27 D(P<0.001), and the difference in myopia was -0.43±0.91 D(P=0.023). Although there was a statistical difference between the two results, astigmatism, hyperopia, and myopia were highly positively correlated, respectively(r=0.694, 0.762, 0.909).CONCLUSION: The main refractive abnormalities in infants and young children aged 6 to 48 months are astigmatism, hyperopia, and anisometropia, with fewer abnormalities in myopia. For screening abnormalities, further ciliary muscle paralysis agent retinoscopy and optometry should be performed, and glasses correction should be given to effectively prevent refractive amblyopia in infants and young children.
8.Clinical Study on Yiqi Huatan Tongluo Prescription Combined with Drug-Coated Balloon in the Treatment of Coronary Heart Disease of Qi Deficiency and Phlegm Stasis Obstructing Collateral Type
Mei-Chun HUANG ; Yu-Peng LIANG ; Pei-Zhong LIU ; Sheng-Yun ZHANG ; Se PENG ; Chuang-Peng LI ; He-Zhen ZHANG ; Tian-Wei LAI ; Chang-Jiang AI ; Qing LIU ; Ai-Meng ZHANG ; Shao-Hui LI
Journal of Guangzhou University of Traditional Chinese Medicine 2024;41(10):2656-2662
Objective To investigate the clinical efficacy and safety of Yiqi Huatan Tongluo Prescription(mainly composed of Fici Simplicissimae Radix,Notoginseng Radix et Rhizoma,Pinelliae Rhizoma Praeparatum,Poria,Nelumbinis Folium,and Glycyrrhizae Radix et Rhizoma,etc.)combined with drug-coated balloon(DCB)in the treatment of coronary heart disease(CHD)and to observe its effect on low-shear related serological indicators.Methods A total of 106 patients with CHD of qi deficiency and phlegm stasis obstructing collateral type who were scheduled to undergo percutaneous coronary intervention were randomly divided into a treatment group and a control group,with 53 cases in each group.The control group was treated with drug-eluting stent implantation,and the treatment group was treated with DCB.After the operation,the control group was given conventional antiplatelet aggregation drugs,and the treatment group was given oral administration of Yiqi Huatan Tongluo Prescription.The medication for the two groups lasted for 12 weeks.The changes in the serum levels of monocyte chemoattractant protein 1(MCP-1),interleukin 1 β(IL-1β)and vascular endothelial growth factor(VEGF)in the two groups were observed before and after treatment.Moreover,the traditional Chinese medicine(TCM)syndrome efficacy after treatment and the incidence of adverse events one year after operation were compared between the two groups.Results(1)After 12 weeks of treatment,the total effective rate for TCM syndrome efficacy of the treatment group was 88.68%(47/53),and that of the control group was 75.47%(40/53).The intergroup comparison(tested by chi-square test)showed that the TCM syndrome efficacy in the treatment group was significantly superior to that in the control group(P<0.05).(2)The analysis of indicators related to endothelial dysfunction in the blood flow with low shear stress showed that after treatment,the levels of serum MCP-1,IL-1βand VEGF in the control group presented no obvious changes(P>0.05),but the serum levels of MCP-1 and IL-1β in the treatment group were significantly lowered compared with those before treatment(P<0.05).The intergroup comparison showed that the decrease of serum MCP-1,IL-1β and VEGF levels in the treatment group was significantly superior to that in the control group(P<0.05).(3)The one-year follow-up after the operation showed that the total incidence of adverse events in the treatment group was 18.87%(10/53),and that in the control group was 20.75%(11/53).There was no significant difference between the two groups(P>0.05).Conclusion Yiqi Huatan Tongluo Prescription combined with DCB has definite action on the targets related to endothelial dysfunction in coronary blood flow with low shear stress,which is conducive to reducing inflammatory response,improving the symptoms of angina pectoris and enhancing clinical efficacy.The incidence of adverse events did not increase one year after operation,indicating good safety and effectiveness.
9.Correlation analysis between eNOS gene single nucleotide polymorphism and systemic lupus erythematosus in Hainan
Xuan ZHANG ; Hui-Tao WU ; Qi ZHANG ; Gui-Ling LIN ; Xi-Yu YIN ; Wen-Lu XU ; Zhe WANG ; Zi-Man HE ; Ying LIU ; Long MI ; Yan-Ping ZHUANG ; Ai-Min GONG
Medical Journal of Chinese People's Liberation Army 2024;49(9):986-991
Objective To investigate the relationship between single nucleotide polymorphisms(SNPs)in the eNOS gene and genetic susceptibility to systemic lupus erythematosus(SLE)in Hainan.Methods Blood samples were collected from SLE patients(SLE group,n=214)and healthy controls(control group,n=214)from January 2020 to December 2022 at the First Affiliated Hospital of Hainan Medical College and Hainan Provincial People's Hospital.The bases of eNOS gene rs3918188,rs1799983 and rs1007311 loci in each group were detected by SNaPshot sequencing technology.Logistic regression was used to analyze the correlation between genotypes,alleles and gene models(dominant model,recessive model,and overdominant model)of the above 3 target loci of the eNOS gene and genetic susceptibility to SLE.Haplotype analysis was conducted using HaploView 4.2 software to investigate the relationship between haploid and genetic susceptibility to SLE at each site.Results The results of logistic regression analysis revealed that the CC genotype and the C allele at rs3918188 locus were risk factors for genetic susceptibility to SLE(CC vs.AA:OR=2.449,P<0.05;C vs.A:OR=2.133,P<0.001).In recessive model at rs3918188 locus,CC genotype carriers had an increased risk of SLE development compared with AA+AC genotype carriers(OR=2.774,P<0.001).In contrast,in overdominant model at this locus,AC genotype carriers had a decreased risk of SLE occurrence compared with AA+CC genotype carriers(OR=0.385,P<0.001).In addition,polymorphisms of rs1799983 and rs1007311 were not associated with susceptibility to SLE in genotype,allele type and the 3 genetic models(P>0.05).Haplotype analysis revealed a strong linkage disequilibrium between the rs1007311 and rs1799983 loci of the eNOS gene,but no significant correlation was found between haplotype and genetic susceptibility to SLE(P>0.05).Conclusion The CC genotype and C allele at rs3918188 locus of eNOS gene may be risk factors for SLE in Hainan,while the risk of SLE occurrence is reduced in carriers of AC genotype under the overdominant model.
10.Feasibility of radiomics combined with machine learning in predicting lymphovascular and perineural invasion of gastric cancer
Shuangquan AI ; Miao YANG ; Zilong YUAN ; Yaoyao HE ; Tingting NIE ; Yulin LIU
Journal of Practical Radiology 2024;40(5):746-751
Objective To explore the feasibility of radiomics features combined with different machine learning methods based on CT scans to predict lymphovascular and perineural invasion in patient with gastric cancer.Methods A total of 142 patients with gas-tric cancer lymphovascular confirmed by operative pathological examination were retrospectively selected.Among all patients,there were 96 positive cases and 46 negative cases.Among 137 patients with perineural invasion,there were 76 positive cases and 61 nega-tive cases.The 3D-Slicer package was used for delineation,and the Pyradiomics package was used to extract radiomics features.All data were randomly divided into training set and test set in an 8∶2 ratio.Intraclass correlation coefficient(ICC),Pearson correla-tion analysis,least absolute shrinkage and selection operator(LASSO)algorithm were used for feature selection.Support vector machine(SVM),K-nearest neighbor(KNN),decision tree(DT),random forest(RF),extreme tree(ET),extreme gradient boosting(XGBoost),and LightGBM were used to compare the models of lymphovascular and perineural invasion,respectively.Receiver operating characteris-tic(ROC)curve and area under the curve(AUC)were used to evaluate the predictive performance of these models.Results The lymphovascular group AUC of SVM,KNN,DT,RF,ET,XGBoost,and LightGBM in the training set were 0.926,0.753,1.000,0.999,1.000,1.000,and 0.917,and the AUC in the test set were 0.894,0.692,0.456,0.678,0.753,0.650,and 0.650,respectively.The perineural invasion group AUC of SVM,KNN,DT,RF,ET,XGBoost,and LightGBM in the training set were 0.864,0.794,1.000,1.000,1.000,1.000,and 0.866,and the AUC in the test set were 0.861,0.706,0.700,0.672,0.731,0.667,and 0.678,respectively.Conclusion Based on venous phase CT radiomics features combined with machine learning methods,it is feasible to predict lymphovascu-lar and perineural invasion of gastric cancer preoperatively.Among the variousmachine learning methods,SVM shows the best predictive performance for lymphovascular and perineural invasion in patient with gastric cancer.

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