1.DNMT1 promotes the proliferation and migration of colorectal cancer HCT8 cells by suppressing TRAF6-mediated ubiquitination of EZH2
PENG Xiaomei1 ; LUO Shunyuan2 ; SHI Xinpeng3 ; ZUO Haojian3 ; CAO Luyang1 ; CHEN Han3 ; ZHOU Haitao4 ; LUO Xiaoyong1,3
Chinese Journal of Cancer Biotherapy 2026;33(1):28-36
[摘 要] 目的:探讨DNA甲基转移酶1(DNMT1)通过稳定zeste基因增强子同源物2(EZH2)促进结直肠癌(CRC)HCT8细胞增殖与迁移的机制。方法:利用生物信息学方法分析DNMT1在CRC组织中的表达水平。WB法检测DNMT1在CRC细胞HCT8、SW620和正常结肠上皮细胞NCM460中的表达。通过siRNA或慢病毒载体转染HCT8细胞,分为siNC组、siDNMT1组、Vector组、DNMT1-OE组、siTRAF6组、siEZH2组、siEZH2 + DNMT1-OE组。采用克隆形成实验、CCK-8法、Transwell实验和划痕愈合实验检测敲低或过表达DNMT1对HCT8细胞增殖与迁移的影响,WB和qPCR法检测EZH2蛋白和mRNA水平,免疫沉淀(IP)法检测EZH2泛素化水平,免疫荧光双染检测肿瘤坏死因子受体相关因子6(TRAF6)与EZH2的细胞内共定位情况,克隆形成和划痕愈合实验验证EZH2对DNMT1功能的逆转作用。收集2022—2025年间郑州大学附属洛阳中心医院手术切除的12例CRC患者的癌及癌旁组织标本,采用免疫组化法检测CRC组织中DNMT1、TRAF6和EZH2的表达水平。结果:DNMT1在CRC组织中表达显著高于癌旁组织(P < 0.01),且在CRC细胞中表达上调(P < 0.05);DNMT1敲低显著抑制HCT8细胞增殖及迁移(均P < 0.01),过表达则相反(均P < 0.01)。DNMT1正向调控EZH2的蛋白水平(P < 0.01),而mRNA水平不变(P > 0.05)。MG132可恢复siDNMT1组的EZH2蛋白表达(P < 0.01),且siDNMT1组EZH2泛素化水平升高。DNMT1负向调控TRAF6的表达(P < 0.01),且TRAF6与EZH2在细胞质中共定位,IP证实两者直接结合。敲低TRAF6可减弱EZH2的泛素化水平,敲低EZH2可逆转DNMT1对HCT8细胞增殖、迁移的促进作用(均P < 0.01)。DNMT1和EZH2在CRC组织中呈高表达(P < 0.01),TRAF6在CRC组织中表达显著低于癌旁组织(P < 0.05)。结论:DNMT1通过抑制TRAF6稳定EZH2促进CRC细胞的增殖和迁移,DNMT1、TRAF6和EZH2可能是CRC治疗的潜在靶点。
2.Effects and mechanisms of combined exposure to noise and microwave on hippocampal structure and function in mice
Chunxue LU ; Lei SHI ; Yue WANG ; Yanhui HAO ; Xuelong ZHAO ; Yang LI ; Hongyan ZUO ; Liqian ZHU
Journal of Environmental and Occupational Medicine 2026;43(4):419-426
Background Co-exposure to noise and microwave radiation occurs frequently. The central nervous system has been identified as a sensitive target organ for both noise and microwave exposure individually, and the underlying mechanisms remain poorly understood. The specific biological effects resulting from co-exposure to these two factors have yet to be fully elucidated. Objective To clarify the effects of co-exposure to noise and microwave on neurobehavior and hippocampal tissue structure, and to explore the underlying mechanism through the assessment of serum cytokines. Methods C57BL/6N mice were selected and randomly assigned to a blank control group, a noise group, a microwave group, and a combined noise & microwave exposure group. To establish the exposure models, the noise group was subjected to broadband noise at 100 dB for 2 h, while the microwave group received radiation at a central frequency of 9.375 GHz with an average power density of 12 mW·cm−2 and a specific absorption rate of 2.58 W·kg−1 for 15 min. Open field and tail suspension tests assessed anxiety-like emotional behaviour; novel object recognition and Y-maze tests evaluated cognitive function. Histological changes in hippocampal tissue were examined using haematoxylin and eosin (HE) staining, and Nissl staining under light microscopy. Serum cytokine levels were measured using radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). Results After 3 d of exposure, the noise, microwave, and combined exposure groups showed significant reductions in exploration frequency, duration, and distance within the central zone of the open field test compared to the control group (P < 0.01); the combined exposure group exhibited increased ratios of peripheral-to-central exploration time and distance (P < 0.05). After 7 d of exposure, compared with the control group, the noise group maintained a decrease in central zone exploration time (P < 0.01), while the combined exposure group showed persistent decline across all central zone metrics (P < 0.05) and elevated peripheral-to-central ratios (P < 0.05); compared to the microwave group, the combined exposure group showed significant less time in the central zone (P < 0.05) and higher peripheral-to-central ratios (P < 0.05). Regarding behaviour and cognition, compared with the control group, the combined exposure group showed increased immobility time in the tail suspension test after 3 d of exposure (P < 0.01). At this interval, all exposure groups demonstrated reduced frequency and duration of novel object recognition (P < 0.05), with the combined exposure group showing a marked decrease in novel arm exploration time (P < 0.01). After 7 d of exposure, compared with the control group, the noise group showed reduced novel object recognition frequency (P < 0.05), and both the noise and microwave groups exhibited decreased novel arm exploration time (P < 0.05). Pathological alterations including an increased number of hyperchromatic nuclei and depleted Nissl bodies were observed in the CA3 and DG regions across all exposure groups with the most severe lesions observed in the combined exposure group. Serum levels of central nervous system-specific protein β (S-100β), glial fibrillary acidic protein (GFAP), and corticosterone (CORT) were significantly elevated in all exposure groups compared with the control group (P < 0.05). Aquaporin-4 (AQP4) levels increased in the combined exposure group (P < 0.05), while CXC chemokine ligand 10 (CXCL10) levels rose in both the noise and combined groups compared with the control group (P < 0.05). Specifically, S-100β and CXCL10 levels in the combined exposure group were higher than those in the microwave group (P < 0.05); moreover, levels of S-100β, GFAP, CORT, AQP4, and CXCL10 in the combined exposure group were significantly higher than those in the noise group (P < 0.05). Conclusion Combined exposure to noise and microwave radiation induces pathological changes in the hippocampus of mice, increases levels of serum stress hormones and neuro-specific biomarkers. These impairments are more severe than those observed following single-factor exposure. The underlaying mechanism may be related to systemic stress response, neuronal damage, astrocyte activation, and changes in blood-brain barrier permeability, leading to emotional behavioral abnormalities and cognitive decline.
3.Review and reflection on the practice of pre-ethical review for drug clinical trials
Min HOU ; Xiaoyuan SHI ; Rongguo SUN ; Fang LIU ; Lei CHEN ; Zejin ZUO
Chinese Medical Ethics 2026;39(5):594-600
ObjectiveTo sort out the pre-ethical review status of drug clinical trials in a tertiary A hospital, summarize practical experience, and provide references for pre-ethical review. MethodA retrospective analysis was conducted on the ethical review of pre-ethical projects in a tertiary A hospital from 2018 to 2023. ResultsFrom 2018 to 2023, a total of 285 pre-ethical projects were reviewed in this tertiary hospital, including 79 projects where it served as the leading unit. Among these, 279 clinical trials ultimately received approval of the ethical review committee, while 6 projects were not approved due to sponsors’ refusal to modify study protocols. In terms of trial phases, phase III clinical trials constituted the largest proportion, and the oncology center was the department with the highest number of projects. In 2023, the average time for pre-ethical review projects from submission to approval was 43 calendar days, 3 days longer than for other project types. In 2023, this hospital reviewed 75 pre-ethical review projects, including 58 where it served as a participating unit. Among these, 42 projects received approval later than the leading unit, while 9 projects were approved earlier than the leading unit’s ethical approval date. Among the pre-ethical review projects applied in 2023, 70 projects obtained drug clinical trial notifications from the National Medical Products Administration, while 5 projects had unknown notification status due to the lack of ethical approval or discontinuation. Of the projects receiving approval notifications, 16 were annotated with matters requiring enhanced attention during clinical trials, and 7 necessitated protocol improvements. ConclusionThis tertiary A hospital has implemented multiple measures to optimize the management of pre-ethical review. This ethical review model does not compromise the quality of ethical review and contributes to accelerating the initiation of clinical trials. Notably, it is crucial to construct a patient-centered drug development system. Clinical trials guided by this concept align with ethical values, laying the foundation for the smooth conduct of clinical trials, assisting in the drug development process, and safeguarding patients’ medication needs.
4.Epidemiological characteristics of pertussis in Taizhou City, Zhejiang Province, 2024
Zuo LI ; Lu SHI ; Jingxing WU ; Hua LIN
Shanghai Journal of Preventive Medicine 2026;38(5):350-354
ObjectiveTo analyze the epidemiological and clinical characteristics of pertussis in Taizhou City, Zhejiang Province, 2024, and to provide a scientific basis for formulating local prevention and control strategies. MethodsCase data and population data were obtained from the China Disease Prevention and Control Information System. Epidemiological case investigation data were collected from the Zhejiang Vaccine Clinical Research and Application Effectiveness Evaluation System and the Immunization Service Information System. Descriptive epidemiological methods were used to analyze the temporal, spatial and demographic distributions, and SaTScan 9.7 software was applied for spatiotemporal cluster scanning. ResultsIn 2024, a total of 3 090 pertussis cases were reported in Taizhou City, with no deaths. The number of reported cases increased significantly compared with those in previous years, and the peak occurred in April. Spatiotemporal scanning identified three clusters: a most likely cluster centered around Tantou Town in Tiantai County, covering 16 streets/towns, a second most likely cluster centered around Taiping Subdistrict in Wenling City, covering 11 streets/towns, and a third most likely cluster centered around Ganjiang Town in Yuhuan City, covering 6 streets/towns. The three clusters together accounted for 31.04% of the total scanned cases.The majority of cases were in the 6‒10 years age group (55.02%), and students accounted for the highest proportion by occupation (44.17%). Among 2 929 epidemiological investigation cases, the most common clinical manifestations were cough (97.58%) and aggravated nocturnal cough (52.10%), while typical symptoms (including paroxysmal spasmodic cough and post-tussive vomiting, etc.) were less frequent. Among the cases, 82.49% had completed the full 4-dose vaccination schedule, and their complication rate (10.47%) was lower than that of the unvaccinated group (20.56%). ConclusionThe number of reported pertussis cases surged in Taizhou City in 2024, showing significant spatiotemporal clustering, with school‑aged children being the high‑risk group. Vaccination could reduce the risk of complications. It is recommended to further enhance surveillance sensitivity, with a focus on strengthening immunization strategies for high-risk groups such as school-aged children aged 6‒10 years, and to reinforce targeted protection for infants under 1 year old who have not completed primary vaccination, along with their families. In addition, prevention and control resources should be deployed in advance for the cluster areas identified through spatiotemporal analysis and for the spring peak season,to interrupt local transmission chains.
5.A survey on Chinese physicians’cognition,attitudes,and practices regarding biosimilars and their clinical switching
Liyang GAO ; Lijuan ZUO ; Huiting PENG ; Weixin XU ; Li ZHANG ; Haisheng CHEN ; Jing SHI
China Pharmacy 2026;37(18):2363-2368
OBJECTIVE To investigate the cognition, attitudes, and current practices of Chinese physicians regarding biosimilars and their clinical switching, so as to provide a basis for the rational clinical application of biosimilars in China and the improvement of related policies.METHODS A national cross-sectional online questionnaire survey was conducted in 2025. Quota sampling was adopted, with quotas based on physicians’ sex, city tier, and specialty. Questionnaire invitations were distributed to licensed physicians, and physicians who had prescribed monoclonal antibody biosimilars were included for analysis. The questionnaire covered their familiarity with biosimilars, attitudes, clinical switching practices, and reasons. Data were processed using reliability and validity tests, dispersion analysis, and cross-tabulation analysis.RESULTS The questionnaire scale showed good reliability and validity, with Cronbach’s α coefficient >0.7 and KMO value >0.6. A total of 2 071 survey invitations were distributed, and 300 valid questionnaires were returned, with an effective response rate of 14.5%. Among the respondents, 75.3% had prescribed 3-5 types of monoclonal antibody biosimilars; only 35.3% were aware that China currently has no clear regulatory provisions on biosimilar switching; 46.3% and 47.3% of respondents believed that there was no difference in safety and efficacy, respectively, between biosimilars and originator products; 63.0% of respondents were concerned about the immunogenicity risk of long-term switching between originator drugs and biosimilars. A total of 92.3% of respondents had experience with biosimilar switching, 87.7% of which involved switching from originator products to biosimilars, and 28.2% of respondents had completed three or more switches in the same patient. Among the primary reasons for switching, non-medical factors accounted for 57.4%, higher than medical factors at 42.6%; “lower treatment cost after switching” was the most important reason for switching; 95.3% of respondents believed that informed consent should be obtained from patients before switching.CONCLUSIONS The surveyed physicians had basic knowledge of biosimilars, but their understanding of the relevant regulations of the national drug regulatory authority was insufficient. Although most physicians were concerned about the risks of non-medical switching, clinical switching was mostly driven by non-medical factors. It is recommended to strengthen policy education for medical professionals and standardize clinical switching behavior. The National Medical Products Administration should also promptly improve the interchangeability review standards and post-marketing surveillance system for biosimilars, so as to promote the rational use of biosimilars.
6.Guideline for the workflow of clinical comprehensive evaluation of drugs
Zhengxiang LI ; Rong DUAN ; Luwen SHI ; Jinhui TIAN ; Xiaocong ZUO ; Yu ZHANG ; Lingli ZHANG ; Junhua ZHANG ; Hualin ZHENG ; Rongsheng ZHAO ; Wudong GUO ; Liyan MIAO ; Suodi ZHAI
China Pharmacy 2025;36(19):2353-2365
OBJECTIVE To standardize the main processes and related technical links of the clinical comprehensive evaluation of drugs, and provide guidance and reference for improving the quality of comprehensive evaluation evidence and its transformation and application value. METHODS The construction of Guideline for the Workflow of Clinical Comprehensive Evaluation of Drugs was based on the standard guideline formulation method of the World Health Organization (WHO), strictly followed the latest definition of guidelines by the Institute of Medicine of the National Academy of Sciences of the United States, and conformed to the six major areas of the Guideline Research and Evaluation Tool Ⅱ. Delphi method was adopted to construct the research questions; research evidence was established by applying the research methods of evidence-based medicine. The evidence quality classification system of the Chinese Evidence-Based Medicine Center was adopted for evidence classification and evaluation. The recommendation strength was determined by the recommendation strength classification standard formulated by the Oxford University Evidence-Based Medicine Center, and the recommendation opinions were formed through the expert consensus method. RESULTS & CONCLUSIONS The Guideline for the Workflow of Clinical Comprehensive Evaluation of Drugs covers 4 major categories of research questions, including topic selection, evaluation implementation, evidence evaluation, and application and transformation of results. The formulation of this guideline has standardized the technical links of the entire process of clinical comprehensive evaluation of drugs, which can effectively guide the high-quality and high-efficient development of this work, enhance the standardized output and transformation application value of evaluation evidence, and provide high-quality evidence support for the scientific decision-making of health and the rationalization of clinical medication.
7.Decoding the immune microenvironment of secondary chronic myelomonocytic leukemia due to diffuse large B-cell lymphoma with CD19 CAR-T failure by single-cell RNA-sequencing.
Xudong LI ; Hong HUANG ; Fang WANG ; Mengjia LI ; Binglei ZHANG ; Jianxiang SHI ; Yuke LIU ; Mengya GAO ; Mingxia SUN ; Haixia CAO ; Danfeng ZHANG ; Na SHEN ; Weijie CAO ; Zhilei BIAN ; Haizhou XING ; Wei LI ; Linping XU ; Shiyu ZUO ; Yongping SONG
Chinese Medical Journal 2025;138(15):1866-1881
BACKGROUND:
Several studies have demonstrated the occurrence of secondary tumors as a rare but significant complication of chimeric antigen receptor T (CAR-T) cell therapy, underscoring the need for a detailed investigation. Given the limited variety of secondary tumor types reported to date, a comprehensive characterization of the various secondary tumors arising after CAR-T therapy is essential to understand the associated risks and to define the role of the immune microenvironment in malignant transformation. This study aims to characterize the immune microenvironment of a newly identified secondary tumor post-CAR-T therapy, to clarify its pathogenesis and potential therapeutic targets.
METHODS:
In this study, the bone marrow (BM) samples were collected by aspiration from the primary and secondary tumors before and after CD19 CAR-T treatment. The CD45 + BM cells were enriched with human CD45 microbeads. The CD45 + cells were then sent for 10× genomics single-cell RNA sequencing (scRNA-seq) to identify cell populations. The Cell Ranger pipeline and CellChat were used for detailed analysis.
RESULTS:
In this study, a rare type of secondary chronic myelomonocytic leukemia (CMML) were reported in a patient with diffuse large B-cell lymphoma (DLBCL) who had previously received CD19 CAR-T therapy. The scRNA-seq analysis revealed increased inflammatory cytokines, chemokines, and an immunosuppressive state of monocytes/macrophages, which may impair cytotoxic activity in both T and natural killer (NK) cells in secondary CMML before treatment. In contrast, their cytotoxicity was restored in secondary CMML after treatment.
CONCLUSIONS
This finding delineates a previously unrecognized type of secondary tumor, CMML, after CAR-T therapy and provide a framework for defining the immune microenvironment of secondary tumor occurrence after CAR-T therapy. In addition, the results provide a rationale for targeting macrophages to improve treatment strategies for CMML treatment.
Humans
;
Lymphoma, Large B-Cell, Diffuse/therapy*
;
Tumor Microenvironment/genetics*
;
Antigens, CD19/metabolism*
;
Leukemia, Myelomonocytic, Chronic/genetics*
;
Immunotherapy, Adoptive/adverse effects*
;
Male
;
Single-Cell Analysis/methods*
;
Female
;
Sequence Analysis, RNA/methods*
;
Receptors, Chimeric Antigen
;
Middle Aged
8.Relationship between the geriatric nutritional risk index and cognitive function: a cross-sectional study based on the NHANES database.
Long WANG ; Na WANG ; Weihua LI ; Huanbing LIU ; Lizhong NIE ; Menglian SHI ; Wei XU ; Shuai ZUO ; Xinqun XU
Chinese Critical Care Medicine 2025;37(5):465-471
OBJECTIVE:
To explore the relationship between the geriatric nutritional risk index (GNRI) and cognitive function.
METHODS:
A cross-sectional study method was conducted. People aged ≥ 60 years from the National Health and Nutrition Examination Survey (NHANES) databases from 1999 to 2002 and 2011 to 2014 were included as study subjects. The participants were divided into three groups based on their GNRI scores: a medium-high risk group (82 ≤ GNRI < 92), a low risk group (92 ≤ GNRI < 98), and a no-risk group (GNRI ≥ 98). Demographic characteristics (gender, age, race, education), chronic diseases [chronic bronchitis, emphysema, thyroid problems, coronary heart disease, angina pectoris, stroke, hypertension, diabetes mellitus, and depression score on the patient health questionnaire (PHQ-9)], lifestyle habits (history of smoking, hours of sleep), etc., were collected. Cognitive function was assessed using the consortium to establish a registry for Alzheimer's disease word learning subtest (CERAD-WL), animal fluency test (AFT), and digit symbol substitution test (DSST) for the 2011-2014 data, while only the DSST was used for the 1999-2002 data. Differences in the above information among the GNRI cohorts were compared. Factors affecting cognitive function in the population were analyzed using multifactorial Logistic regression.
RESULTS:
2 653 participants from 2011 to 2014 and 2 380 participants from 1999 to 2002 were enrolled, with a total of 5 033 participants in the study. There were statistically significant differences in age, stroke, diabetes mellitus, DSST score, AFT score, CERAD score test 1 recall (Cst1), and CERAD score test 2 recall (Cst2) among the GNRI groups. Multifactorial Logistic regression analysis of data from 2011 to 2014 showed that in model 3 (DSST score, age, gender, race, marriage, education, hours of sleep, history of smoking, emphysema, thyroid problems, chronic bronchitis, coronary heart disease, angina pectoris, hypertension, diabetes mellitus, depression score on the PHQ-9, and stroke) adjusted for all covariates, GNRI was a protective factor for DSST [odds ratio (OR) = 1.03, 95% confidence interval (95%CI) was 1.00 to 1.05, P = 0.03]; Logistic regression analyse for 1999 to 2002 and 2011 to 2014 showed a significant association even after adjustment for covariates (OR = 1.02, 95%CI was 1.00 to 1.03, P = 0.02). Subgroup Logistic regression analyses of the total population from 2011 to 2014 showed a significant association between GNRI and DSST scores (OR = 1.02, 95%CI was 1.01 to 1.03, P < 0.001), with significant associations in the age subgroups of 60 to 64 years old, across gender, non-Hispanic Whites and Blacks, by education, and by marital status associations were significant (all P < 0.05). Subgroup Logistic regression analyse of the total populations from 1999 to 2002 and 2011 to 2014 showed a significant association between the GNRI and DSST score (OR = 1.01, 95%CI was 1.01 to 1.02, P < 0.001), but did not show a significant year difference (interaction P = 0.503), and the newly found in the smoking population the association was also more significant (P < 0.01).
CONCLUSION
The GNRI correlates with the presence of cognitive functions related to processing speed, sustained attention, and executive function, and may be able to serve as an indicator for the assessment or prediction of related cognitive functions.
Humans
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Cross-Sectional Studies
;
Aged
;
Middle Aged
;
Nutrition Surveys
;
Cognition
;
Female
;
Male
;
Nutritional Status
;
Risk Factors
;
Geriatric Assessment
9.Engineering of CmpLs enhances L-glutamate production of Corynebacterium glutamicum.
Xingtao ZUO ; Shasha ZHONG ; Ningyun CAI ; Tuo SHI ; Zhidan ZHANG ; Yuantao LIU ; Jiao LIU ; Depei WANG ; Jiuzhou CHEN ; Ping ZHENG
Chinese Journal of Biotechnology 2025;41(1):271-287
The efficient production of L-glutamate is dependent on the product's rapid efflux, hence researchers have recently concentrated on artificially modifying its transport system and cell membrane wall structure. Considering the unique composition and structure of the cell wall of Corynebacterium glutamicum, we investigated the effects of CmpLs on L-glutamate synthesis and transport in SCgGC7, a constitutive L-glutamate efflux strain. First, the knockout strains of CmpLs were constructed, and it was confirmed that the deletion of CmpL1 and CmpL4 significantly improved the performance of L-glutamate producers. Next, temperature-sensitive L-glutamate fermentation with the CmpL1 and CmpL4 knockout strains were carried out in 5 L bioreactors, where the knockout strains showcased temperature-sensitive characteristics and enhanced capacities for L-glutamate production under high temperatures. Notably, the CmpL1 knockout strain outperformed the control strain in terms of L-glutamate production, showing production and yield increases of 69.2% and 55.3%, respectively. Finally, the intracellular and extracellular metabolites collected at the end of the fermentation process were analyzed. The modification of CmpLs greatly improved the L-glutamate excretion and metabolic flux for both L-glutamate production and transport. Additionally, the CmpL1 knockout strain showed decreased accumulation of downstream metabolites of L-glutamate and intermediate metabolites of tricarboxylic acid (TCA) cycle, which were consistent with its high L-glutamate biosynthesis capacity. In addition to offering an ideal target for improving the stability and performance of the industrial strains for L-glutamate production, the functional complementarity and redundancy of CmpLs provide a novel target and method for improving the transport of other metabolites by modification of the cell membrane and cell wall structures in C. glutamicum.
Corynebacterium glutamicum/genetics*
;
Glutamic Acid/biosynthesis*
;
Fermentation
;
Metabolic Engineering
;
Bacterial Proteins/metabolism*
;
Bioreactors/microbiology*
;
Gene Knockout Techniques
10.Preparation and In Vitro Degradation Characteristics Analysis of Poly(lactic-co-glycolide)Microspheres Based on Microfluidic Process
Bao-Cheng WANG ; Cong-Yu MA ; Ke WANG ; Si-Tong ZHENG ; Xiao-Yan ZHANG ; Yue-Mei ZHAO ; Xun ZHAO ; Jian-Bin PAN ; Zheng-Song GAO ; Hai-Wei SHI ; Yao-Zuo YUAN ; Hong-Yuan CHEN
Chinese Journal of Analytical Chemistry 2025;53(4):621-630
Poly(lactic-co-glycolide)(PLGA)is a key excipient in long-acting sustained-release preparations,and its degradation properties directly affect the drug release behavior.In this study,PLGA microspheres were prepared by microfluidic techniques,and the morphology changes of the microspheres were observed by scanning electron microscopy(SEM).In alkaline environment,due to the accelerated hydrolysis of ester bonds,the surface of the microspheres was rapidly dissolved and eroded,and the degradation rate was significantly higher than that in acidic environment.High temperature accelerated the degradation of PLGA microspheres.Under neutral and alkaline conditions,the microspheres showed aggregation and adhesion.Under acidic conditions,the microspheres gradually decomposed into irregular fragments.The high ionic strength further promoted the surface corrosion of the microspheres,especially under extreme pH conditions.Simultaneously,PLGA microspheres encapsulating coumarin were prepared to simulate the microsphere formulation.The release rate of coumarin after degradation of the microspheres under different conditions was observed by measuring the absorbance with ultraviolet-visible spectrophotometry.The results were consistent with those of the blank microspheres.This study revealed that the degradation of PLGA microspheres was significantly pH-dependent,temperature sensitive and ion strength responsive.These findings not only helped to understand and optimize the long-term stability and controlled release performance of drug-carrying microspheres,but also provided a theoretical basis for further improvement of PLGA-based drug carrier design.

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