BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

OBJECTIVE To explore the effect of Zi Zhu Ointment combined with herbal fumigation on wound heal-ing,oxidative stress and microribonucleic acid(miR)-200b of the patients with diabetic foot infection.METHODS A total of 102 patients with diabetic foot infection who were treated in Heping Hospital Affiliated to Changzhi Medical College from Sep.2020 to Sep.2023 were enrolled in the study and were divided into the control group with 48 cases and the study group with 54 cases according to the treatment program.The control group was trea-ted with conventional therapy and herbal fumigation,the study group was given additional Zi Zhu Ointment on ba-sis of the treatment of the control group,and both groups were persistently treated for 1 month.The clinical cura-tive effect,wound healing status,hemodynamics indexes of dorsal foot,pain score,oxidative stress indexes and miR-200b expression levels were observed and compared between the two groups of patients.RESULTS The effec-tive rate of clinical treatment of the study group was higher than that of the control group after the treatment(Z=2.138,P=0.033).The wound area of the study group was(0.42±0.05)cm2 after the treatment,smaller than that of the control group;the cover area of neoplastic granulation tissue of the study group was(16.87±3.21)cm2,larger than that of the control group;the coverage fraction of the neoplastic granulation tissue of the study group was(55.23±6.17)％,greater than that of the control group;there were significant differences between the two groups(P＜0.05).The blood vessel diameter of dorsal foot of the study group was greater than that of the control group after the treatment,the blood flow velocity of the study group was greater than that of the control group,and the visual analogue scale(VAS)score of the study group was lower than that of the control group(P＜0.05).There were no significant differences in the expression levels of advanced oxidative protein product(AOPP),superoxide dismutase(SOD),malondialdehyde(MDA)and miR-200b between the two groups of pa-tients before the treatment;the expression levels of AOPP,MDA and miR-200b of the study group were lower than those of the control group after the treatment,while the SOD level of the study group was higher than that of the control group(P＜0.05).CONCLUSIONS Zi Zhu Ointment combined with herbal fumigation can remarkably improve the clinical curative effect on the patients with diabetic foot infection,promote the wound healing,im-prove the arterial hemodynamics of dorsal foot,and relieve the pain.The mechanism may be associated with the improvement of oxidative stress response and downregulated expression level of miR-200b.

OBJECTIVE To explore the effect of Zi Zhu Ointment combined with herbal fumigation on wound heal-ing,oxidative stress and microribonucleic acid(miR)-200b of the patients with diabetic foot infection.METHODS A total of 102 patients with diabetic foot infection who were treated in Heping Hospital Affiliated to Changzhi Medical College from Sep.2020 to Sep.2023 were enrolled in the study and were divided into the control group with 48 cases and the study group with 54 cases according to the treatment program.The control group was trea-ted with conventional therapy and herbal fumigation,the study group was given additional Zi Zhu Ointment on ba-sis of the treatment of the control group,and both groups were persistently treated for 1 month.The clinical cura-tive effect,wound healing status,hemodynamics indexes of dorsal foot,pain score,oxidative stress indexes and miR-200b expression levels were observed and compared between the two groups of patients.RESULTS The effec-tive rate of clinical treatment of the study group was higher than that of the control group after the treatment(Z=2.138,P=0.033).The wound area of the study group was(0.42±0.05)cm2 after the treatment,smaller than that of the control group;the cover area of neoplastic granulation tissue of the study group was(16.87±3.21)cm2,larger than that of the control group;the coverage fraction of the neoplastic granulation tissue of the study group was(55.23±6.17)％,greater than that of the control group;there were significant differences between the two groups(P＜0.05).The blood vessel diameter of dorsal foot of the study group was greater than that of the control group after the treatment,the blood flow velocity of the study group was greater than that of the control group,and the visual analogue scale(VAS)score of the study group was lower than that of the control group(P＜0.05).There were no significant differences in the expression levels of advanced oxidative protein product(AOPP),superoxide dismutase(SOD),malondialdehyde(MDA)and miR-200b between the two groups of pa-tients before the treatment;the expression levels of AOPP,MDA and miR-200b of the study group were lower than those of the control group after the treatment,while the SOD level of the study group was higher than that of the control group(P＜0.05).CONCLUSIONS Zi Zhu Ointment combined with herbal fumigation can remarkably improve the clinical curative effect on the patients with diabetic foot infection,promote the wound healing,im-prove the arterial hemodynamics of dorsal foot,and relieve the pain.The mechanism may be associated with the improvement of oxidative stress response and downregulated expression level of miR-200b.

Organoid models are used to study kidney physiology, such as the assessment of nephrotoxicity and underlying disease processes. Personalized human pluripotent stem cell-derived kidney organoids are ideal models for compound toxicity studies, but there is a need to accelerate basic and translational research in the field. Here, we developed an automated continuous imaging setup with the "read-on-ski" law of control to maximize temporal resolution with minimum culture plate vibration. High-accuracy performance was achieved: organoid screening and imaging were performed at a spatial resolution of 1.1 μm for the entire multi-well plate under 3 min. We used the in-house developed multi-well spinning device and cisplatin-induced nephrotoxicity model to evaluate the toxicity in kidney organoids using this system. The acquired images were processed via machine learning-based classification and segmentation algorithms, and the toxicity in kidney organoids was determined with 95% accuracy. The results obtained by the automated "read-on-ski" imaging device, combined with label-free and non-invasive algorithms for detection, were verified using conventional biological procedures. Taking advantage of the close-to-in vivo-kidney organoid model, this new development opens the door for further application of scaled-up screening using organoids in basic research and drug discovery.
Humans ; Kidney ; Organoids ; Pluripotent Stem Cells

Erythromycin is a macrolide antibiotic produced by Saccharopolyspora erythraea. Its yield is greatly affected by the fermentation conditions and the bioreactor configurations. In this study, a novel scale-up method for erythromycin fermentation was developed based on computational fluid dynamics (CFD) and time constant analysis. Firstly, the dissolved oxygen (DO) was determined as a key parameter according to the physiological properties of S. erythraea cultivated in a 50 L bioreactor. It was found that the time constant of oxygen supply (t_mt) in a 500 m³ bioreactor should be less than 6.25 s in order to satisfy the organism's oxygen uptake rate (OUR). Subsequently, a 500 m³ bioreactor was designed using the time constant method combined with empirical correlations. The impeller combination with one BDT8 impeller at bottom and two MSX4 impellers at upper part was determined, and then validated by numerical simulation. The results indicated that the t_mt of the bioreactor (< 6.25 s) and the fluid properties, including gas hold-up, shear stress and fluid vector, met the requirements of erythromycin fermentation. Finally, the industrial production of erythromycin in the 500 m³ showed the design method was applicable in large scale fermentation.
Erythromycin ; Saccharopolyspora/genetics* ; Bioreactors ; Fermentation ; Anti-Bacterial Agents

Objective:To observe the ultrasonographic features of cervical lymph node metastasis and analyze their relationship with the expression of cell proliferation-associated nuclear antigen (Ki-67).Methods:The clinical data of 92 patients with cervical lymph node metastasis who received treatment in Zhejiang Quhua Hospital, China between June 2017 and July 2019 were retrospectively analyzed. The correlation between ultrasonographic features of cervical lymph node metastasis and Ki-67 expression was analyzed.Results:Among the 92 patients, 158 metastatic lymph nodes were confirmed by pathological examination. The main ultrasonic imaging features were the length ratio of long diameter to short diameter < 2 in 119 (75.32%) lymph nodes, disappearance of portal hyperechoic signal in 127 (80.38%) lymph nodes, punctate hyperechoic signal in 108 (68.35%) lymph nodes, cystic degeneration in 57 (36.08%) lymph nodes, mixed types of peripheral blood flow signal in 124 (78.48%) lymph nodes, microcalcification in 123 (77.85%) lymph nodes. The length ratio of long diameter to short diameter < 2, punctate hyperechoic signal and mixed types of peripheral blood flow signal were correlated with high expression of Ki-67 ( χ2 = 24.252, 15.732, 17.033, all P < 0.05). Conclusion:High expression of Ki-67 is correlated with the length ratio of long diameter to short diameter < 2, punctate hyperechoic signal and mixed types of peripheral blood flow signal in cervical lymph node metastasis.

Objective:To explore the application of scenario simulation and rapid film reading training in the standardization of cervical vertebra DR examination in radiology department.Methods:Using the method of scene simulation in the examination room to take DR films of cervical vertebra, two senior technicians in charge evaluated and guided the deficiencies of junior technicians from the aspects of patient check, exposure conditions, body position placement, film printing, inspection safety and radiation protection. Every morning, DR images of cervical vertebra were randomly selected and read quickly, and the junior technicians should quickly browse the images within one minute and make quality control evaluation. Then the senior technician in charge pointed out the shortcomings of the evaluation and related improvement methods. After that, the technical specification manual of cervical vertebra DR was compiled based on the deficiencies and problems found by each technician, and 200 patients aged 18-55 years, without abnormal movement and no internal fixation before and after the establishment of standardization were randomly selected in group A (before standardization) and group B (after standardization). The image quality and repetition projection rate of group A and group B before and after the standardization were compared. SPSS 25.0 was used to analyze the data.Results:The image quality score of group B (8.83±0.33) was higher than that of group A (8.45±0.30), and the repetition projection rate of group B (2%) was lower than that of group A (9%), with statistical significance ( P<0.05). Conclusion:Through the training mode of rapid film reading and scenario simulation, the standardization of cervical vertebra DR examination technology suitable for the situation of the department has been established, which effectively solves the problem of abstraction in the technical teaching of radiology department. The standardization establishment plays an important role in standardized training, for which, the technicians can quickly grasp the work process of the department and the corresponding examination technology during participating in the standardization establishment and training process.

Bioreactors have been central in monoclonal antibodies and vaccines manufacturing by mammalian cells in suspension culture. Numerical simulation of five impeller combinations in a stirred bioreactor was conducted, and characteristics of velocity vectors, distributions of gas hold-up, distributions of shear rate in the bioreactor using 5 impeller combinations were numerically elucidated. In addition, genetically engineered CHO cells were cultivated in bioreactor installed with 5 different impeller combinations in fed-batch culture mode. The cell growth and antibody level were directly related to the maximum shear rate in the bioreactor, and the highest viable cell density and the peak antibody level were achieved in FBMI3 impeller combination, indicating that CHO cells are sensitive to shear force produced by impeller movement when cells were cultivated in bioreactor at large scale, and the maximum shear rate would play key roles in scaling-up of bioreactor at industrial scale.
Animals ; Batch Cell Culture Techniques ; Bioreactors ; standards ; CHO Cells ; Cell Count ; Computer Simulation ; Cricetinae ; Cricetulus ; Industrial Microbiology ; instrumentation ; methods

A rapid quantitative evaluation method for Siraitia grosvenorii cells was successfully developed based on plant cells' capacitance value detected by a viable cell mass monitor and the cryopreservation of S. grosvenorii suspension cells was optimized. The survival rate of S. grosvenorii cells was quantitatively measured by viable cell mass monitor and 2, 3, 5-triphenyltetrazolium chloride (TTC). An optimum cryoprotectant recipe is that the growth medium contained 10% sucrose and 10% DMSO. The experimental results also showed higher cell survival rates and cell viabilities were achieved when suspension cells were treated with pretreatment of 0.2 mol/L sucrose. With the increase of concentration of sucrose, however, the cell survival rate was decreased. And the cell survival rate represented a bell shape with the increase of pretreatment time. The highest cell survival rate and cell viability were obtained with the 9 h' s pretreatment. In addition, there was a good correlation between the cell survival rate measured by cell recovery test and that measured by viable cell mass monitor, while there were no significant differences in the cell morphology and the ability of mogrosides V production by S. grosvenorii cells cultured in suspension after cryopreservation. Therefore, the evaluation method developed based on the viable cell mass monitor has good feasibility and reliability.