1.Strategic Optimization of CHO Cell Expression Platforms for Biopharmaceutical Manufacturing
Rui-Ming ZHANG ; Meng-Lin LI ; Hong-Wei ZHU ; Xing-Xiao ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):327-341
Chinese hamster ovary (CHO) cells are the most established and versatile mammalian expression system for the large-scale production of recombinant therapeutic proteins, owing to their genetic stability, adaptability to serum-free suspension culture, and ability to perform human-like post-translational modifications. More than 70% of biologics approved by the U.S. Food and Drug Administration rely on CHO-based production platforms, underscoring their central role in modern biopharmaceutical manufacturing. Despite these advantages, CHO systems continue to face three persistent bottlenecks that limit their potential for high-yield, reproducible, and cost-efficient production: excessive metabolic burden during high-density culture, heterogeneity of glycosylation patterns, and progressive loss of long-term expression stability. This review provides an integrated analysis of recent advances addressing these challenges and proposes a forward-looking framework for constructing intelligent and sustainable CHO cell factories. In terms of metabolic regulation, excessive lactate and ammonia accumulation disrupts energy balance and reduces recombinant protein synthesis efficiency. Optimization of culture parameters such as temperature, pH, dissolved oxygen, osmolarity, and glucose feeding can effectively alleviate metabolic stress, while supplementation with modulators including sodium butyrate, baicalein, and S-adenosylmethionine promotes specific productivity (qP) by modulating apoptosis and chromatin structure. Furthermore, genetic engineering strategies—such as overexpression of MPC1/2, HSP27, and SIRT6 or knockout of Bax, Apaf1, and IGF-1R—have demonstrated significant improvements in cell viability and product yield. The combination of multi-omics metabolic modeling with artificial intelligence (AI)-based prediction offers new opportunities for building self-regulating CHO systems capable of dynamic adaptation to environmental stress. Regarding glycosylation uniformity, which determines therapeutic efficacy and immunogenicity, gene editing-based glycoengineering (e.g., FUT8 knockdown or ST6Gal1 overexpression) has enabled the humanization of CHO glycan profiles, minimizing non-human sugar residues and enhancing drug stability. Process-level strategies such as galactose or manganese co-feeding and fine control of temperature or osmolarity further allow rational regulation of glycosyltransferase activity. Additionally, in vitro chemoenzymatic remodeling provides a complementary route to construct human-type glycans with defined structures, though industrial applications remain constrained by cost and scalability. The integration of model-driven process design and AI feedback control is expected to enable real-time prediction and correction of glycosylation deviations, ensuring batch-to-batch consistency in continuous biomanufacturing. Long-term expression stability, another critical challenge, is often impaired by promoter silencing, chromatin condensation, and random genomic integration. Molecular optimization—such as the use of improved promoters (CMV, EF-1α, or CHO endogenous promoters), Kozak and signal peptide refinement, and incorporation of chromatin-opening elements (UCOE, MAR, STAR)—helps maintain durable transcriptional activity, while site-specific integration systems including Cre/loxP, Flp/FRT, φC31, and CRISPR/Cas9 can enable single-copy, position-independent gene insertion at genomic safe-harbor loci, ensuring stable, predictable expression. Collectively, this review highlights a paradigm shift in CHO system optimization driven by the convergence of genome editing, synthetic biology, and artificial intelligence. The transition from empirical optimization to rational, data-driven design will facilitate the development of programmable CHO platforms capable of autonomous regulation of metabolic flux, glycosylation fidelity, and transcriptional activity. Such intelligent cell factories are expected to accelerate the transformation from laboratory-scale research to industrial-scale, high-consistency, and economically sustainable biopharmaceutical manufacturing, thereby supporting the next generation of efficient and customizable biologics manufacturing.
2.Strategic Optimization of CHO Cell Expression Platforms for Biopharmaceutical Manufacturing
Rui-Ming ZHANG ; Meng-Lin LI ; Hong-Wei ZHU ; Xing-Xiao ZHANG
Progress in Biochemistry and Biophysics 2026;53(2):327-341
Chinese hamster ovary (CHO) cells are the most established and versatile mammalian expression system for the large-scale production of recombinant therapeutic proteins, owing to their genetic stability, adaptability to serum-free suspension culture, and ability to perform human-like post-translational modifications. More than 70% of biologics approved by the U.S. Food and Drug Administration rely on CHO-based production platforms, underscoring their central role in modern biopharmaceutical manufacturing. Despite these advantages, CHO systems continue to face three persistent bottlenecks that limit their potential for high-yield, reproducible, and cost-efficient production: excessive metabolic burden during high-density culture, heterogeneity of glycosylation patterns, and progressive loss of long-term expression stability. This review provides an integrated analysis of recent advances addressing these challenges and proposes a forward-looking framework for constructing intelligent and sustainable CHO cell factories. In terms of metabolic regulation, excessive lactate and ammonia accumulation disrupts energy balance and reduces recombinant protein synthesis efficiency. Optimization of culture parameters such as temperature, pH, dissolved oxygen, osmolarity, and glucose feeding can effectively alleviate metabolic stress, while supplementation with modulators including sodium butyrate, baicalein, and S-adenosylmethionine promotes specific productivity (qP) by modulating apoptosis and chromatin structure. Furthermore, genetic engineering strategies—such as overexpression of MPC1/2, HSP27, and SIRT6 or knockout of Bax, Apaf1, and IGF-1R—have demonstrated significant improvements in cell viability and product yield. The combination of multi-omics metabolic modeling with artificial intelligence (AI)-based prediction offers new opportunities for building self-regulating CHO systems capable of dynamic adaptation to environmental stress. Regarding glycosylation uniformity, which determines therapeutic efficacy and immunogenicity, gene editing-based glycoengineering (e.g., FUT8 knockdown or ST6Gal1 overexpression) has enabled the humanization of CHO glycan profiles, minimizing non-human sugar residues and enhancing drug stability. Process-level strategies such as galactose or manganese co-feeding and fine control of temperature or osmolarity further allow rational regulation of glycosyltransferase activity. Additionally, in vitro chemoenzymatic remodeling provides a complementary route to construct human-type glycans with defined structures, though industrial applications remain constrained by cost and scalability. The integration of model-driven process design and AI feedback control is expected to enable real-time prediction and correction of glycosylation deviations, ensuring batch-to-batch consistency in continuous biomanufacturing. Long-term expression stability, another critical challenge, is often impaired by promoter silencing, chromatin condensation, and random genomic integration. Molecular optimization—such as the use of improved promoters (CMV, EF-1α, or CHO endogenous promoters), Kozak and signal peptide refinement, and incorporation of chromatin-opening elements (UCOE, MAR, STAR)—helps maintain durable transcriptional activity, while site-specific integration systems including Cre/loxP, Flp/FRT, φC31, and CRISPR/Cas9 can enable single-copy, position-independent gene insertion at genomic safe-harbor loci, ensuring stable, predictable expression. Collectively, this review highlights a paradigm shift in CHO system optimization driven by the convergence of genome editing, synthetic biology, and artificial intelligence. The transition from empirical optimization to rational, data-driven design will facilitate the development of programmable CHO platforms capable of autonomous regulation of metabolic flux, glycosylation fidelity, and transcriptional activity. Such intelligent cell factories are expected to accelerate the transformation from laboratory-scale research to industrial-scale, high-consistency, and economically sustainable biopharmaceutical manufacturing, thereby supporting the next generation of efficient and customizable biologics manufacturing.
3.Clinical Observation on Prevention of Recurrence of Common Bile Duct Stones After ERCP with Yuyin Lidan Granules
Xiao WANG ; Yong FANG ; Cong HE ; Jiali ZHANG ; Meng YU ; Jing KONG ; Yi JIANG ; Chuanqi CHENG ; Xiaosu WANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(4):159-166
ObjectiveTo observe the clinical efficacy and safety of Yuyin Lidan granules (YYLD) in preventing the recurrence of common bile duct stones (CBDS) in patients with liver and gallbladder dampness-heat syndrome following endoscopic retrograde cholangiopancreatography (ERCP). MethodsThis randomized, parallel, controlled trial enrolled postoperative CBDS-ERCP patients who met the inclusion and exclusion criteria. Sixty-four patients were randomly assigned to an observation group or a control group, with 32 cases in each. Both groups received conventional Western medical treatment after ERCP, while the observation group additionally received YYLD for 8 weeks. The follow-up period lasted for 1 year. The efficacy indicators included bile bilirubin levels, traditional Chinese medicine (TCM) syndrome scores, clinical efficacy rate, pancreatitis and inflammation markers, postoperative liver function, and CBDS recurrence rate at 1-year follow-up, which were used to jointly evaluate the clinical efficacy and safety of both groups. ResultsA total of 56 patients completed the study and were included in the final analysis, i.e., 29 in the observation group and 27 in the control group. Baseline characteristics were comparable between the two groups. Compared with pre-treatment and with the control group after treatment, the bile bilirubin level in the observation group significantly decreased (P<0.05). After treatment, the clinical cure and marked improvement rates were higher in the observation group than in the control group, showing a statistically significant difference in overall clinical efficacy (P<0.05). Compared with pre-treatment, the primary and secondary symptoms in the observation group, as well as the primary symptom and the secondary symptom of nausea and vomiting in the control group (weeks 4 and 8), were significantly reduced (P<0.05). Compared with the control group after treatment, the observation group showed significant reductions in the primary symptom of loose stools/constipation (day 5 and week 4) and in three secondary symptoms, i.e., bitter taste and sticky dry mouth, abdominal distension and poor appetite (throughout the treatment period), and general heaviness and fatigue (day 5 and week 4), with statistical differences (P<0.05). Compared with pre-treatment, both groups showed decreased lipase and urinary amylase levels (P<0.05). However, no significant between-group differences were observed in pancreatitis or inflammation-related indices after treatment. Compared with pre-treatment, all liver function indicators in the observation group and alanine aminotransferase ( ALT ), γ-glutamyl transferase ( γ-GT ), alkaline phosphatase (ALP), and conjugated bilirubin in the control group significantly decreased at weeks 4 and 8 (P<0.05). Compared with the control group after treatment, only serum total bilirubin and unconjugated bilirubin were significantly reduced in the observation group during the treatment period (P<0.05). ConclusionYYLD combined with conventional Western medical treatment can effectively regulate bilirubin metabolism (in bile and serum), improve TCM clinical symptoms, and prevent CBDS recurrence after ERCP in patients with liver and gallbladder dampness-heat syndrome. This regimen is safe and effective and is worthy of further clinical research and promotion.
4.The first record of Anopheles messeae (Diptera: Culicidae) parasitized by water mites in China
Xue-ru CHEN ; Wen-zhen YAO ; Yu-hao LI ; Gui-chang LI ; Tao MENG ; Qun-ling FENG ; Xin-hui LIU ; Li-hong QIAO ; Xiang-ting WU ; Xue-feng ZHANG ; Cheng-lin LI ; Xue-cheng DONG ; Da-wei WANG ; Xiao-yan SI ; Yu-hong GUO
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):53-57
Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China. Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level. Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex(Cx. modestus, Cx. pipiens pallens), Aedes(Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens,3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2,4,27 mites separately. Morphological and molecular identification reached the same result as water mites(Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus. Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.
5.In vitro studies of the anti-inflammatory activity of micheliolide on myeloproliferative neoplasm cell lines
Meng CHEN ; Jinqin LIU ; Ying ZHANG ; Zhexin SHI ; Zhijian XIAO
Journal of Beijing University of Traditional Chinese Medicine 2025;48(1):68-79
Objective:
The effects and molecular mechanisms of micheliolide on cytokine expression in myeloproliferative neoplasm cell lines were explored based on the signal transducer and activator of transcription 3 (STAT3)/nuclear factor-kappa B (NF-κB) signaling pathways.
Methods:
The UKE-1 and SET-2 cell lines were investigated, and micheliolide concentrations were screened using the CCK-8 assay. The UKE-1 and SET-2 cells were divided into the control and micheliolide-treated groups at concentrations of 2.5, 5.0, and 10.0 μmol/L. Each group received 1 mL of micheliolide solution at final concentrations of 2.5, 5.0, and 10.0 μmol/L, respectively, whereas the control group only received an equal volume of culture medium. The inhibition rates of interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α), and chemokine ligand 2 (CCL2) mRNA expression in cells from each group were detected using real-time fluorescent PCR (RT-PCR). Western blotting was used to measure STAT3 and phosphorylated STAT3 (p-STAT3) protein expression levels in cells from each group. Reversal experiments with reduced glutathione and dithiothreitol were performed using UKE-1 cells, which were divided into the control group, micheliolide, micheliolide + glutathione, micheliolide + dithiothreitol, and glutathione + dithiothreitol groups. Western blotting was used to detect the STAT3 and p-STAT3 protein expression levels in the cells of each group. UKE-1 cells were stimulated with TNF-α (5 μg/L) to replicate a pathological model of excessive cytokine secretion. Subsequently, UKE-1 cells were divided into the control, model, and three micheliolide-treated groups at concentrations of 2.5, 5.0, and 10.0 μmol/L. RT-PCR was used to measure the indicators above. An enzyme-linked immunosorbent assay (ELISA) was used to detect the CCL2 content in the cell culture media of each group. Western blotting was performed to assess the protein expression levels of STAT3, p-STAT3, and proteins related to the NF-κB signaling pathway.
Results:
Compared with the control group, the proliferation inhibition rates of UKE-1 cells at 24, 48, and 72 h increased in the micheliolide-treated groups at concentrations of 2.5, 5.0, 10.0, and 20.0 μmol/L. Similarly, the proliferation inhibition rates of SET-2 at 48 and 72 h increased in the micheliolide-treated groups at concentrations of 5.0, 10.0, and 20.0 μmol/L (P<0.05). Concentrations of 2.5, 5.0, and 10.0 μmol/L were selected for further studies to exclude the potential influence of high micheliolide concentrations on subsequent result owing to reduced cell numbers. Compared with the control group, the inhibition rates of TNF-α mRNA expression in UKE-1 and SET-2 cells increased in the micheliolide-treated groups at concentrations of 2.5, 5.0, and 10.0 μmol/L. Similarly, the inhibition rates of IL-1β mRNA expression in UKE-1 and SET-2 cells also increased in the micheliolide-treated groups at concentrations of 5.0 and 10.0 μmol/L. Additionally, the inhibition rate of CCL2 mRNA expression in UKE-1 and SET-2 cells increased in the micheliolide-treated group at a concentration of 10 μmol/L (P<0.05). Compared with the model group, the inhibition rates of TNF-α, IL-1β, and CCL2 mRNA expression in UKE-1 cells increased in the micheliolide-treated groups at concentrations of 2.5, 5.0, and 10.0 μmol/L after stimulation with TNF-α (P<0.05). ELISA showed that compared with the control group, the CCL2 content in UKE-1 cells increased in the model group. Compared with the model group, the CCL2 content in UKE-1 cells decreased in the micheliolide-treated groups at concentrations of 2.5, 5.0, and 10.0 μmol/L (P<0.05). Western blotting showed that compared with the control group, the p-STAT3 protein expression levels in UKE-1 and SET-2 cells were downregulated in the micheliolide-treated groups at concentrations of 5.0 and 10.0 μmol/L, and the protein expression level of STAT3 in SET-2 was also downregulated (P<0.05). Compared with the control group, the p-STAT3 expression level in UKE-1 cells decreased in the micheliolide group in the reductive glutathione and dithiothreitol reversal experiments. Compared with the micheliolide group, the p-STAT3 protein expression levels in UKE-1 cells increased in the micheliolide + dithiothreitol and micheliolide + glutathione groups (P<0.05). Compared with the control group, the model group showed increased p-STAT3, p-IκKα/β, p-IκBα, and p-NF-κB p65 protein expression and decreased IκBα protein expression after stimulation with TNF-α. Compared with the model group, the micheliolide-treated groups showed decreased p-IκKα/β, p-IκBα, p-STAT3, and p-NF-κB p65 protein expression at concentrations of 2.5, 5.0, and 10.0 μmol/L, whereas the micheliolide-treated groups showed increased IκBα protein expression at concentrations of 5.0 and 10.0 μmol/L (P<0.05).
Conclusion
Micheliolide potently suppresses IL-1β, TNF-α, and CCL2 mRNA expression in UKE-1 and SET-2 cells, as well as CCL2 secretion by UKE-1 cells, which may be associated with STAT3 phosphorylation suppression and NF-κB signaling pathway activation.
6.Reliability and validity of the diagnostic scale for toxic pathogen syndrome in heart failure
Di XIAO ; Meng LI ; Zhuoran WU ; Ce WANG ; Jiashang LIU ; Lijing ZHANG
Journal of Beijing University of Traditional Chinese Medicine 2025;48(10):1404-1412
Objective To evaluate the reliability,validity,and feasibility of the diagnostic scale for toxic pathogen syndrome in heart failure(HF),and to verify its reliability and effectiveness in clinical diagnosis.Methods A cross-sectional study was conducted.Patients with HF who visited four hospitals,including Dongzhimen Hospital,Beijing University of Chinese Medicine,from March 1st to September 30th,2024 were selected.General information of the patients,including gender,age,smoking history,drinking history,and comorbidities,was collected.Cronbach's α coefficient,split-half reliability,and test-retest reliability were used to evaluate the reliability of the scale.Surface validity,discriminant validity,and structural validity were used to assess the validity of the scale.Acceptance rate,completion rate,and completion time were used to evaluate the feasibility.Results A total of 600 patients with HF meeting the research criteria were included,including 290 males and 310 females,with a median(IQR)age of 66.50(58.00,70.00)years.Internal consistency reliability:the Cronbach's α coefficients of the total scale and the four dimensions were all greater than 0.6,indicating a good consistency among the items of the scale.The Spearman-Brown coefficients of the total scale and the four dimensions were all greater than 0.7,indicating good stability and homogeneity within the scale.External consistency reliability:the Kappa coefficients of the total scale and the four dimensions were all greater than 0.7,indicating good external consistency of the scale.Discriminant validity evaluation:patients were divided into the toxic pathogen syndrome group(n=180)and the non-toxic pathogen syndrome group(n=420).There were no statistically significant differences in gender,age,smoking history,drinking history,and comorbidities between the two groups(P>0.05).The scores of the two groups were evaluated using the diagnostic scale for the toxic pathogen syndrome in HF.The toxic pathogen syndrome group had higher scores in all four dimensions and the total scale than the non-toxic pathogen syndrome group(P<0.01),indicating good discriminant validity of the scale.Structural validity assessment:principal component analysis was used to extract 28 factors,and a total of 7 common factors were extracted,with a total variance contribution rate of 60.554%.The absolute values of the loadings of each item were basically greater than 0.5,and the commonalities of the corresponding dimensions ranged from 52.1%to 96.5%,indicating good structural validity of the scale.The acceptance rate of the scale in this evaluation was 100%,the completion rate was 100%,and the average completion time was between 6 and 8 minutes,indicating good feasibility of the scale.Conclusion The diagnostic scale for the toxic pathogen syndrome in HF has good reliability,validity,and feasibility.
7.Resveratrol attenuates hepatic inflammation and oxidative stress in rheumatoid arthritis via Nrf2/Keap1 pathway
Xue-fei FAN ; Jian ZHOU ; Su-huan CHEN ; Meng-yan ZHANG ; Hao-miao LIU ; Rui SU ; Guang-yi CHEN ; Yu-bao SHAO ; Tao YAO ; Xiao-yu CHEN
Chinese Pharmacological Bulletin 2025;41(5):861-867
Aim To explore the therapeutic effects of resveratrol(Res)on hepatic inflammation and oxida-tive stress in rheumatoid arthritis(RA),and to eluci-date the relationship of the regulatory mechanism of the Nrf2/Keap1 signaling pathway in it.Methods A mouse model of arthritis was induced using chicken type Ⅱ collagen in combination with complete Freund's adjuvant,and Res was administered by tube feeding for treatment.Serum liver function indices and levels of hepatic inflammation and oxidative stress were detected in mice.An in vitro cellular model of hepatic inflam-mation and oxidative stress was established by treating mouse primary hepatocytes(MPHs)with TNF-α(5μg·L-1),cell proliferation inhibition was detected by CCK-8,and inflammation and oxidative stress-relat-ed indices were detected by protein blotting.The in-trinsic mechanisms by which Res attenuated hepatic in-flammation and oxidative stress in rheumatoid arthritis were explored by treating MPHs with Nrf2 inhibitor and Keap1 overexpression plasmid.Results Res signifi-cantly reduced the levels of inflammation and oxidative stress in hepatic tissues of collagen-induced arthritis mice as well as TNF-α-treated MPHs,and activated the Nrf2/Keap1 signaling pathway.Inflammation and oxidative stress levels in MPHs were exacerbated by the use of Nrf2 inhibitors and Keap1 overexpression,which promoted apoptosis.Conclusion Res attenuates he-patic inflammation and oxidative stress in rheumatoid arthritis via the Nrf2/Keap1 pathway.
8.Dynamic changes of serum exosome miR-552 and miR-653 levels be-fore and after chemotherapy in gastric cancer and their relationship with clinical benefit
Xiao-rui ZHAO ; Run-chun HAO ; Meng-jing HE ; Shan-shan SU ; Bing-xin YANG ; Wen-zhong ZHANG
Chinese Journal of Current Advances in General Surgery 2025;28(3):208-212
Objective:To analyze the dynamic changes of serum exosome miR-552 and miR-653 levels in pa-tients with gastric cancer before and after chemotherapy and their relationship with clinical benefit.Methods:IA total of 128 patients with gastric cancer received chemotherapy from January 2022 to January 2024.According to the chemo-therapy effect,the two groups were divided into disease progression group and disease remission group.The levels of serum exosome miR-552 and miR-653 before and after chemotherapy were detected in the two groups,the risk fac-tors affecting the chemotherapy effect of gastric cancer patients were screened,the risk nomogram model was con-structed,and the efficacy was evaluated.Results:The proportion of TNM stage(Ⅲ+Ⅳ),lymph node metastasis,dis-tant metastasis,tumor size(>5 cm),invasion depth(T3/T4)and tumor growth pattern(invasive type)in disease progres-sion group was higher than that in disease remission group(P<0.05).The levels of serum exosomes miR-552 and miR-653 in disease progression group were higher than those in remission group before and after chemotherapy(P<0.05).Compared with before chemotherapy,miR-552 and miR-653 levels in both groups decreased(P<0.05).Logistic regres-sion analysis showed that TNM stage,lymph node metastasis,distant metastasis,tumor size,invasion depth,miR-552 and miR-653 were all risk factors affecting the chemotherapy efficacy of gastric cancer(P<0.05).ROC curve results showed that the AUC,95%CI,sensitivity and specificity of risk nomogram model to predict chemotherapy efficacy of gastric cancer were 0.867,0.672~0.991,92.80%and 80.40%,respectively(P<0.001).Calibration curve results showed that both predicted and actual predicted values were near the ideal curve,and the Hosmer-Lemeshow goodness of fit curve test χ2=1.869,P=0.782.Conclusion:The levels of serum exosomes miR-552 and miR-653 are closely related to the chemotherapy efficacy of gastric cancer,and dynamic monitoring of the above indexes is helpful for the evaluation of the disease and prognosis of gastric cancer.In this study,the risk nomogram model constructed based on the above indexes and other risk factors has high predictive value and clinical practicability for chemotherapy efficacy in patients with gastric cancer.
9.Experimental study on alternative method of local lymph node assay using bromodeoxyuridine with flow cytometry(LLNA:BrdU-FCM)for skin sensitization evaluation of cosmetics
Xiao-jun LYU ; Ju ZHANG ; Sen WU ; Xiao-ling XU ; Meng-ting SHI ; Jin-jing XU ; Wang-ping PAN ; Jia-te SHEN ; Kai-yong HE
Chinese Pharmacological Bulletin 2025;41(4):793-799
Aim To establish and evaluate an alternative meth-od for detecting skin sensitization of cosmetics based on local lymph node assay using bromodeoxyuridine(BrdU)with flow cytometry(FCM).Methods(1)25%hexyl cinnamic alde-hyde(HCA)was chosen as a positive control with an acetone:olive oil(4∶1,V/V,AOO)mixture as a vehicle control for the experiment.The dorsal sides of both ears of mice were treated with test solutions on day 1,day 2,and day 3.Brdu solution was injected inter-peritoneally on day 5.On day 6,the bilateral ears and mandibular lymph nodes were excised,and the number of Brdu positive cells was measured by flow cytometry.The stim-ulation index(SI)was calculated to identify whether it was ≥3,in order to establish the method of LLNA:Brdu-FCM.(2)BrdU-FCM test was conducted using a blind method with the fif-teen reference substances listed in OECD TG429 whose skin sensitization potentials were known.The test substances were dissolved in AOO,N,N-dimethylformamide(DMF)or dimeth-yl sulfoxide(DMSO)at three different concentrations.Tests were performed the same as above.SI and EC2.7 were calculat-ed to evaluate whether the test substance was categorized as a skin sensitizer.The reliability and accuracy of the method were validated by comparing the classification of test substances with that in OECD TG429.Results The SI for 25%HCA was 3.9,showing positive in the skin sensitization test.It demonstrated that the LLNA:Brdu-FCM test method was properly implemen-ted.Nine test substances(2,4-dinitrochlorobenzene,4-pheny-lenediamine,cobalt chloride,2-mercaptobenzothiazole,hexyl-cinnamaldehyde,eugenol,phenyl benzoate,cinnamic alcohol,imidazolidinyl urea)were positive,and six test substances(methyl methacrylate,chlorobenzene,isopropanol,lactic acid,methyl salicylate,salicylic acid)were negative.The method was evaluated with sensitivity of 90%,specificity of 100%,positive prediction rate of 100%,negative prediction rate of 83%,false positive rate of 0%,false negative rate of 17%and accuracy of 93%.The LLNA:BrdU-FCM assay could correctly categorize the test substances that were skin sensitizers or non-sensitizers.Conclusion The LLNA:BrdU-FCM assay appears to be a relia-ble predictor of skin sensitization protential of chemicals,and it is expected to an alternative method for identifying skin sensitization as a supplementary in safety evaluation of cosmetic ingredient.
10.Assay for detection of toxigenic Clostridioides difficile with combined microfluidic chip and immunochromatography technology
Hong-rui CHENG ; Xiao-jun SONG ; Yu CHEN ; Meng ZHANG ; Meng-ting CAI ; Kun ZHU ; Yu-lei TAI ; Shi-bo YING ; Da-zhi JIN
Chinese Journal of Zoonoses 2025;41(2):142-149
An assay was established for detection of toxigenic Clostridioides difficile by combining microfluidic chip analysis with immunochromatography,and its performance was evaluated and compared with those of the Xpert C.difficile/Epi and VIDAS CD AB tests.Primer pairs were designed according to the tcdB and tpi genes in C.difficile.The specificity,limit of detection,reproducibility,and stability were evaluated.A total of 215 stool samples from patients with diarrhea were collected and tested in parallel with the Xpert C.difficile/Epi,VIDAS CDAB,and our assay.C.difficile was isolated from samples,and the tcdB gene was identified when discrepant results were obtained from the three above assays.Our assay showed no cross-reaction with other diarrhea-associated pathogens.Its reproducibility was 100%in testing of two standard plasmids containing tcdB and tpi genes at two concentrations(105 and 102 copies/μL).Two standard plasmids were detected after the PCR and immunochromatography reagents had been stored for 3,6,9,and 12 months,and all the results were posi-tive.The limit of detection was 10 copies/μL for toxigenic C.difficile.Testing of 33 samples positive for C.difficile with our assay(33/215,15.3%)yielded findings statistically coherent with those of the Xpert C.difficile/Epi test(kappa value=0.965).The sensitivity,specificity,positive predictive value,and negative predictive value of our assay,with respect to Xpert C.difficile/Epi as the standard,were 94.3%,100.0%,100.0%,and 98.9%;these values were significantly higher than those of VIDAS CDAB(60.0%,98.9%,91.3%,and 92.7%)(Kappa=0.714,OR=157.50,95%CI:62.03-847.28,P=0.013).In conclusion,our newly developed assay is specific,stable,and reproducible,and may be used for rapid and accu-rate detection of toxigenic C.difficile.The assay could be used for C.difficile infection screening in outpatient and emergen-cy,community medical service center,and epidemiological settings.


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