OBJECTIVES: To investigate the ethnic origin of Chuanqing people, one of the largest unidentified ethnic groups in Guizhou, China, and analyze its genetic relationships with surrounding populations. METHODS: Based on a self-developed microhaplotype system, we conducted genotyping and analyzed the genetic distribution of microhaplotype loci and their forensic applicability in Chuanqing population in Guizhou Province. Using the microhaplotype data from different intercontinental populations and previously reported data from Han population living in Guizhou Province, we systematically investigated the genetic background of Chuanqing people through population genetic approaches, including genetic distance estimation, principal component analysis, and phylogenetic tree construction. RESULTS: Among the studied population, the number of haplotype per microhaplotype ranged from 6 to 25. The average expected heterozygosity (He), observed heterozygosity (Ho), power of discrimination (PD), and probability of exclusion (PE) were 0.8291, 0.8301, 0.9387, and 0.6593, respectively. The cumulative power of discrimination (CPD) and cumulative probability of exclusion (CPE) for these 33 loci were 1-2.62×10^-41 and 1-7.64×10^-17, respectively. Population genetic analyses revealed that the Chuanqing population had close genetic relationships with the East Asian populations, especially the local Guizhou Han population, Beijing Han population and the Han populations living in southern China. CONCLUSIONS The 33 microhaplotypes exhibit high levels of genetic diversity in the Guizhou Chuanqing population, highlighting their potentials for both forensic identification and parentage testing. The Han populations might have contributed a significant amount of genetic material to the Chuanqing population during the formation and development of the latter.
Humans ; China/ethnology* ; Ethnicity/genetics* ; Forensic Genetics/methods* ; Genetics, Population ; Genotype ; Haplotypes ; Phylogeny ; East Asian People/genetics*

Objective:To investigate the impact of ubiquitin-specific protease 38 (USP38) on the proliferation and migration of gastric cancer cells.Methods:Between March and September 2023, tissue samples were collected from 18 patients who underwent radical gastrectomy in the Department of General Surgery, Beijing Friendship Hospital Affiliated to Capital Medical University, and had complete clinical data. The samples included tumor tissue, adjacent tumor tissue, and normal tissue. Among the patients, there were 12 males and 6 females, aged between 34 and 71 years, with an average age of 62.5 years. The expression levels of USP38 in different tissue samples were validated using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The functional significance of USP38 was verified through cell experiments and human tissue samples by knocking down or exogenously overexpressing USP38. Potential molecular mechanisms of USP38 were validated through qRT-PCR, MTT, Transwell, Western blot, mass spectrometry, clone formation assays, and immunoprecipitation. Measurement data with a normal distribution are expressed as the mean±standard deviation ( ± s). Comparisons between groups were performed using a t-test or one-way analysis of variance. Measurement data with a skewed distribution were described as [ M( Q1, Q3)], and comparisons between groups were performed using non-parametric tests. Comparisons between counting data were performed using the chi-squared test or Fisher′s exact probability method, with P<0.05 indicating a statistically significant difference. Results:qRT-PCR confirmed that USP38 was highly expressed in gastric cancer tissues compared to normal and paratumor tissues. Furthermore, mass spectrometry analysis identified FASN as a potential downstream target of USP38, and immunoprecipitation experiments demonstrated a positive correlation between its expression level and USP38. USP38 was highly expressed in the SGC7901, AGS, and HGC27 gastric cancer cell lines. Knockdown of USP38 reduced FASN expression, thereby inhibiting cell proliferation and migration abilities. While the ability of cell proliferation and migration was increased significantly.Conclusions:USP38 is highly expressed in gastric cancer cells and promotes their proliferation and migration, potentially through downstream FASN-mediated fatty acid synthesis.

Objective:To investigate the perioperative safety, short-term and long-term efficacy, and surgical strategy of laparoscopic partial gastrectomy for gastrointestinal stromal tumors at the esophagogastric junction.Methods:Seventy-eight patients with mesenchymal tumors in the esophagogastric junction were retrospectively enrolled from September 2018 to August 2023 in which the upper edge of the tumor is less than 2 cm from the Z-line or has invaded the Z-line <1/2 circumference. There were 31 males (39.7%) and 47 females (60.3%), with an average age of (57.2±11.8) years and an average body mass index of (24.5±3.5) kg/m 2. All cases were divided into the wedge resection (WR) group ( n=51) and the resection by opening all of the layers of the stomach wall (RASW) group ( n=27) according to the surgical methods. Surgical outcomes, complications, recover and postoperative gastroesophageal reflux of both groups were compared. The measurement data with a normal distribution were represented by mean±standard deviation ( ± s), and values were compared using the independent sample t-test. The measurement data with a skewed distribution were represented by median (interquartile range) [ M( Q1, Q3)], and values were compared using the Mann-Whitney U test. Count data were expressed as examples (percentages) [ n(%)], and the χ2 test was used to compare countable data. A non-parametric test was used to compare the grade data. Results:The WR group had shorter operation time [(97.1±32.6) min vs (149.9±54.9) min, t=-5.33, P<0.001], less intraoperative blood loss [15(10, 20) mL vs 20(10, 50) mL, z=-2.47, P=0.014], shorter postoperative exhaust time [2(1, 3) d vs 3(2, 3) d, z=-2.49, P=0.013], shorter postoperative oral intake time [2(2, 3) d vs 4(2, 5) d, t=-3.70, P<0.001], shorter postoperative semi-liquid diet time[5(4, 6) d vs 7(5, 8) d, z=-3.57, P<0.001], and shorter postoperative hospital stay [5(4, 6) d vs 7(6, 8) d, z=-4.16, P<0.001] than the RASW group, with statistically significant differences. There was no significant difference in short-term (≤30 days) complications between the two groups (2.0% vs 3.7%, z=-0.46, P=0.648). No cases of cardia stenosis occurred in either group. In the WR group, 3 patients developed gastroesophageal reflux at 6 months postoperatively, with 2 patients relieved after taking acid-suppressing drugs and 1 patient not completely relieved. In the RASW group, 1 patient developed gastroesophageal reflux at 6 months postoperatively and was not completely relieved after taking acid-suppressing drugs. No other patients had gastroesophageal reflux. No other patients have gastroesophageal reflux. Conclusions:WR and RASW are safe and feasible for mesenchymal tumors at the esophagogastric junction in which the upper edge of the tumor is less than 2 cm from the Z-line or has invaded the Z-line <1/2 circumference, and has achieved an excellent short-term effect. The choice of surgical approach can be determined based on varions factors such as the location of the tumor, the relationship of the position between the tumor and the cardia, and whether the tumor is exophytic growth.

Objective:To explore the short-term clinical effects of deep cervical lymph node-venous anastomosis in the treatment of Alzheimer’s disease (AD).Methods:A prospective exploratory study was conducted on the treatment of AD patients using the cervical deep lymph node-venous anastomosis technique in Scar and Wound Treatment Department, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, from September to October 2024. The patients underwent high-frequency ultrasound to locate deep cervical lymph nodes and the external jugular vein. Under general anesthesia, bilateral deep cervical lymph node-venous anastomoses were performed. Indocyanine green (ICG) lymphography was conducted via subcutaneous injection behind the ear to visualize lymph nodes in levels Ⅱ and Ⅲ. After making a skin incision along the posterior margin of the sternocleidomastoid muscle, the external jugular vein, internal jugular veins, and associated lymph nodes were exposed. Adjacent veins were selected for anastomosis of lymph node. Using microsurgical techniques, end-to-side or end-to-end anastomosis was completed for lymph nodes in levels Ⅱ and Ⅲ. Preoperative assessments included the mini-mental state examination (MMSE, a higher score indicates better cognitive function), Alzheimer’s disease assessment scale-cognitive subscale (ADAS-Cog, a higher score indicates greater impairment of cognitive function), Alzheimer’s disease cooperative study scale for activities of daily living (ADCS-ADL, a higher score indicates better ability to perform daily activity), and neuropsychiatric inventory (NPI, a higher score indicates more severe behavioral and emotional symptom). Postoperative follow-up included the same scales to observe changes in cognitive function, activities of daily living, and emotional communication.Results:Four patients (1 male, 3 females, aged 58-79 years) with AD were included. All were diagnosed based on cerebrospinal fluid biomarkers. All patients successfully underwent bilateral deep cervical lymph node-venous anastomoses. On average, 4.3 (2-7 per person) anastomoses were performed per patient. Surgical procedures lasted an average of 6.5 h (5.5-8.5 h) with minimal blood loss (less than 50 ml). Patients resumed normal activity within 6 hours postoperatively and were discharged after an average of 4.1 d (3.5-5.0 d). Postoperative complications included one case each of aspiration pneumonia, lower limb venous thrombosis, and transient delirium, all of whom resolved without long-term effects. Clinical symptoms, including memory decline, mood swings, and anxiety, showed varying degrees of improvement. Patients reported enhanced quality of life, emotional stability, and social engagement, confirming the procedure’s safety and potential cognitive benefits. At one month postoperatively, the MMSE scores of the four patients increased by an average of 0.8 points compared to preoperative levels. Additionally, the two patients who completed the ADAS-Cog assessments showed a decrease in their scores (reduced by 1.0 points and 11.3 points, respectively, compared to preoperative scores), indicating a certain degree of improvement in cognitive function during this period. The ADCS-ADL and NPI scores of four patients varied significantly, without showing any clear pattern.Conclusion:Lymphovenous anastomosis of the deep cervical lymph node-venous anastomosis may provide a new surgical intervention approach for AD, but further large-scale studies and long-term follow-up are needed to validate its safety and effectiveness.

Objective:To evaluate the short-term efficacy of endoscopic-laparoscopic regional gastric resection combined with sentinel lymph node basin dissection in patients with early-stage gastric cancer.Methods:This is a retrospective case series study. Data of 17 consecutive early gastric cancer patients from a prospective cohort at Beijing Friendship Hospital,Capital Medical University were analyzed between August 2023 and August 2024. Sixteen cases were from the department of general surgery and 1 from the department of gastroenterology. The cohort included 9 males and 8 females,with a mean age of 61.4 years (range: 46 to 79 years). Clinical data,including demographics,pathological features,surgical procedures,and follow-up outcomes,were collected through medical records and databases. All patients were followed for over 3 months,with follow-up ending on December 5,2024.Results:A total of 17 patients were involved. Among them, 5 patients underwent endoscopic submucosal dissection (ESD) combined with laparoscopic sentinel lymph node dissection (LSBD),and another 3 patients who underwent complete ESD resection received LSBD due to pathological stage meeting the expanded indications. 6 patients who underwent non-curative ESD resection received laparoscopic gastric regional resection (LRG) combined with LSBD,and another 3 patients directly received LRG combined with LSBD. The average number of sentinel lymph nodes dissected before surgery ( M(IQR)) was 8.9 (4.5) (range: 4 to 21),and the detection rate and accuracy rate were both 100%. Postoperative pathology confirmed that there was no metastasis in the sentinel lymph nodes of 5 patients who underwent ESD combined with LSBD and 3 patients who underwent LSBD after complete ESD resection. The vertical and horizontal margins of ESD were all negative. One patient was an absolute indication for ESD. For the 6 patients who underwent non-curative ESD resection combined with LRG and LSBD,the horizontal margins were all negative. Two patients showed 1 metastasis in each of the 21 and 9 sentinel lymph nodes during the operation,and additional distal gastrectomy was performed during the operation. Postoperatively,73 and 39 lymph nodes were retrieved respectively. The former had 1 additional metastasis,while the latter had no metastasis. Among the 3 patients who underwent direct LRG combined with LSBD,the horizontal margins were negative. One patient was confirmed as an absolute indication for ESD by postoperative pathology,and one patient had 1 metastasis in 8 sentinel lymph nodes during the operation,and additional distal gastrectomy was performed. Postoperatively,there was no metastasis in 54 lymph nodes. All patients had no complications such as infection,bleeding,perforation,or death after surgery. Among the 14 patients who did not receive additional radical surgery,they were able to pass gas and defecate within 3 days after surgery,with an average hospital stay of 6 days. The nutritional indicators and gastric radionuclide emptying imaging half-emptying time were similar to those before surgery at 3 months after surgery. Conclusions:Laparoscopic and endoscopic cooperative regional gastrectomy with sentinel lymph node basin dissection has the advantages of minimal invasiveness,preservation of gastric function,and precise treatment. It maybe suitable for patients with early-stage gastric cancer at high risk of lymph node metastasis and has good short-term efficacy.

Objective:To explore the short-term clinical effects of deep cervical lymph node-venous anastomosis in the treatment of Alzheimer’s disease (AD).Methods:A prospective exploratory study was conducted on the treatment of AD patients using the cervical deep lymph node-venous anastomosis technique in Scar and Wound Treatment Department, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, from September to October 2024. The patients underwent high-frequency ultrasound to locate deep cervical lymph nodes and the external jugular vein. Under general anesthesia, bilateral deep cervical lymph node-venous anastomoses were performed. Indocyanine green (ICG) lymphography was conducted via subcutaneous injection behind the ear to visualize lymph nodes in levels Ⅱ and Ⅲ. After making a skin incision along the posterior margin of the sternocleidomastoid muscle, the external jugular vein, internal jugular veins, and associated lymph nodes were exposed. Adjacent veins were selected for anastomosis of lymph node. Using microsurgical techniques, end-to-side or end-to-end anastomosis was completed for lymph nodes in levels Ⅱ and Ⅲ. Preoperative assessments included the mini-mental state examination (MMSE, a higher score indicates better cognitive function), Alzheimer’s disease assessment scale-cognitive subscale (ADAS-Cog, a higher score indicates greater impairment of cognitive function), Alzheimer’s disease cooperative study scale for activities of daily living (ADCS-ADL, a higher score indicates better ability to perform daily activity), and neuropsychiatric inventory (NPI, a higher score indicates more severe behavioral and emotional symptom). Postoperative follow-up included the same scales to observe changes in cognitive function, activities of daily living, and emotional communication.Results:Four patients (1 male, 3 females, aged 58-79 years) with AD were included. All were diagnosed based on cerebrospinal fluid biomarkers. All patients successfully underwent bilateral deep cervical lymph node-venous anastomoses. On average, 4.3 (2-7 per person) anastomoses were performed per patient. Surgical procedures lasted an average of 6.5 h (5.5-8.5 h) with minimal blood loss (less than 50 ml). Patients resumed normal activity within 6 hours postoperatively and were discharged after an average of 4.1 d (3.5-5.0 d). Postoperative complications included one case each of aspiration pneumonia, lower limb venous thrombosis, and transient delirium, all of whom resolved without long-term effects. Clinical symptoms, including memory decline, mood swings, and anxiety, showed varying degrees of improvement. Patients reported enhanced quality of life, emotional stability, and social engagement, confirming the procedure’s safety and potential cognitive benefits. At one month postoperatively, the MMSE scores of the four patients increased by an average of 0.8 points compared to preoperative levels. Additionally, the two patients who completed the ADAS-Cog assessments showed a decrease in their scores (reduced by 1.0 points and 11.3 points, respectively, compared to preoperative scores), indicating a certain degree of improvement in cognitive function during this period. The ADCS-ADL and NPI scores of four patients varied significantly, without showing any clear pattern.Conclusion:Lymphovenous anastomosis of the deep cervical lymph node-venous anastomosis may provide a new surgical intervention approach for AD, but further large-scale studies and long-term follow-up are needed to validate its safety and effectiveness.

Objective:To evaluate the short-term efficacy of endoscopic-laparoscopic regional gastric resection combined with sentinel lymph node basin dissection in patients with early-stage gastric cancer.Methods:This is a retrospective case series study. Data of 17 consecutive early gastric cancer patients from a prospective cohort at Beijing Friendship Hospital,Capital Medical University were analyzed between August 2023 and August 2024. Sixteen cases were from the department of general surgery and 1 from the department of gastroenterology. The cohort included 9 males and 8 females,with a mean age of 61.4 years (range: 46 to 79 years). Clinical data,including demographics,pathological features,surgical procedures,and follow-up outcomes,were collected through medical records and databases. All patients were followed for over 3 months,with follow-up ending on December 5,2024.Results:A total of 17 patients were involved. Among them, 5 patients underwent endoscopic submucosal dissection (ESD) combined with laparoscopic sentinel lymph node dissection (LSBD),and another 3 patients who underwent complete ESD resection received LSBD due to pathological stage meeting the expanded indications. 6 patients who underwent non-curative ESD resection received laparoscopic gastric regional resection (LRG) combined with LSBD,and another 3 patients directly received LRG combined with LSBD. The average number of sentinel lymph nodes dissected before surgery ( M(IQR)) was 8.9 (4.5) (range: 4 to 21),and the detection rate and accuracy rate were both 100%. Postoperative pathology confirmed that there was no metastasis in the sentinel lymph nodes of 5 patients who underwent ESD combined with LSBD and 3 patients who underwent LSBD after complete ESD resection. The vertical and horizontal margins of ESD were all negative. One patient was an absolute indication for ESD. For the 6 patients who underwent non-curative ESD resection combined with LRG and LSBD,the horizontal margins were all negative. Two patients showed 1 metastasis in each of the 21 and 9 sentinel lymph nodes during the operation,and additional distal gastrectomy was performed during the operation. Postoperatively,73 and 39 lymph nodes were retrieved respectively. The former had 1 additional metastasis,while the latter had no metastasis. Among the 3 patients who underwent direct LRG combined with LSBD,the horizontal margins were negative. One patient was confirmed as an absolute indication for ESD by postoperative pathology,and one patient had 1 metastasis in 8 sentinel lymph nodes during the operation,and additional distal gastrectomy was performed. Postoperatively,there was no metastasis in 54 lymph nodes. All patients had no complications such as infection,bleeding,perforation,or death after surgery. Among the 14 patients who did not receive additional radical surgery,they were able to pass gas and defecate within 3 days after surgery,with an average hospital stay of 6 days. The nutritional indicators and gastric radionuclide emptying imaging half-emptying time were similar to those before surgery at 3 months after surgery. Conclusions:Laparoscopic and endoscopic cooperative regional gastrectomy with sentinel lymph node basin dissection has the advantages of minimal invasiveness,preservation of gastric function,and precise treatment. It maybe suitable for patients with early-stage gastric cancer at high risk of lymph node metastasis and has good short-term efficacy.

Existing epidemiologic and clinical studies have demonstrated that obesity is associated with the risk of a variety of cancers. In recent years, an increasing number of experimental and clinical studies have unraveled the complex relationship between obesity and cancer risk and the underlying mechanisms. Obesity-induced abnormalities in immunity and biochemical metabolism, including chronic inflammation, hormonal disorders, dysregulation of adipokines, and microbial dysbiosis, may be important contributors to cancer development and progression. These contributors play different roles in cancer development and progression at different sites. Lifestyle changes, weight loss medications, and bariatric surgery are key approaches for weight-centered, obesity-related cancer prevention. Treatment of obesity-related inflammation and hormonal or metabolic dysregulation with medications has also shown promise in preventing obesity-related cancers. In this review, we summarize the mechanisms through which obesity affects the risk of cancer at different sites and explore intervention strategies for the prevention of obesity-associated cancers, concluding with unresolved questions and future directions regarding the link between obesity and cancer. The aim is to provide valuable theoretical foundations and insights for the in-depth exploration of the complex relationship between obesity and cancer risk and its clinical applications.
Humans ; Adipokines/metabolism* ; Bariatric Surgery ; Inflammation/therapy* ; Neoplasms/prevention & control* ; Obesity/therapy* ; Risk Factors

Objective:To evaluate the impact of self-crosslinked hyaluronic acid (SCH) gel on endometrium recovery after artificial abortion.Methods:A multicenter, prospective randomized controlled trial was conducted across 18 hospitals from December 2021 to February 2023, involving 382 women who underwent artificial abortion. Participants were randomly allocated to receive either treatment with SCH gel (SCH group) or no treatment (control group) in a 1∶1 ratio. The primary outcome was endometrium thickness in 14 to 18 days after the first postoperative menstruation. Secondary outcomes included changes in menstrual volume during the first postoperative menstruation, menstruation resumption within 6 postoperative weeks, time to menstruation resumption, duration of the first postoperative menstruation, and incidence of dysmenorrhea.Results:Baseline characteristics of participants were comparable between the two groups (all P>0.05), with 95.3% (182/191) in SCH group and 92.7% (177/191) in the control group completed the study. The postoperative endometrial thickness in SCH group was significantly greater than that in the control group [(9.78±3.15) vs (8.95±2.32) mm; P=0.005]. SCH group also had significantly fewer participants with reduced menstrual volume [23 cases (12.6%, 23/182) vs 31 cases (17.5%, 31/177); P=0.038]. Although SCH group experienced less dysmenorrhea during the first postoperative menstrual period, this difference was not statistically significant [28.5% (51/179) vs 37.1% (65/175); P=0.083]. Outcomes were similar between SCH group and the control group regarding the proportion of participants who resumed menstruation within 6 weeks postoperatively, time to menstruation resumption, and duration of the first postoperative menstruation ( P=0.792, 0.485, and 0.254, respectively). No serious adverse events were observed during the study period, and no adverse events were attributed to SCH gel treatment. Conclusion:The application of SCH gel after artificial abortion is safe and might aid in the recovery of the endometrium.

Objective:To investigate the effects of gelatin methacrylate anhydride (GelMA) hydrogel loaded with small extracellular vesicles derived from human umbilical cord mesenchymal stem cells (hUCMSCs-sEVs) in the treatment of full-thickness skin defect wounds in mice.Methods:This study was an experimental study. hUCMSCs-sEVs were extracted by ultracentrifugation, their morphology was observed through transmission electron microscope, and the expression of CD9, CD63, tumor susceptibility gene 101 (TSG101), and calnexin was detected by Western blotting. The human umbilical vein endothelial cells (HUVECs), the 3 rd and 4 th passages of human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs) were all divided into blank control group (routinely cultured) and hUCMSC-sEV group (cultured with the cell supernatant containing hUCMSCs-sEVs). The cell scratch test was performed and the cell migration rates at 6, 12, and 24 h after scratching were calculated, the cell Transwell assay was performed and the number of migration cells at 12 h after culture was calculated, and the proportion of proliferating cells was detected by 5-acetylidene-2'-deoxyuridine and Hoechst staining at 24 h after culture, with sample numbers being all 3. The simple GelMA hydrogel and the GelMA hydrogel loaded with hUCMSCs-sEVs (hereinafter referred to as hUCMSC-sEV/GelMA hydrogel) were prepared. Then the micromorphology of 2 kinds of hydrogels was observed under scanning electron microscope, the distribution of hUCMSCs-sEVs was observed by laser scanning confocal microscope, and the cumulative release rates of hUCMSCs-sEVs at 0 (immediately), 2, 4, 6, 8, 10, and 12 d after soaking hUCMSC-sEV/GelMA hydrogel in phosphate buffer solution (PBS) were measured and calculated by protein colorimetric quantification ( n=3). Twenty-four 6-week-old male C57BL/6J mice were divided into PBS group, hUCMSC-sEV alone group, GelMA hydrogel alone group, and hUCMSC-sEV/GelMA hydrogel group according to the random number table, with 6 mice in each group, and after the full-thickness skin defect wounds on the back of mice in each group were produced, the wounds were performed with PBS injection, hUCMSC-sEV suspenson injection, simple GelMA coverage, and hUCMSC-sEV/GelMA hydrogel coverage, respectively. Wound healing was observed on post injury day (PID) 0 (immediately), 4, 8, and 12, and the wound healing rates on PID 4, 8, and 12 were calculated, and the wound tissue was collected on PID 12 for hematoxylin-eosin staining to observe the structure of new tissue, with sample numbers being both 6. Results:The extracted hUCMSCs-sEVs showed a cup-shaped structure and expressed CD9, CD63, and TSG101, but barely expressed calnexin. At 6, 12, and 24 h after scratching, the migration rates of HEKs (with t values of 25.94, 20.98, and 20.04, respectively), HDFs (with t values of 3.18, 5.68, and 4.28, respectively), and HUVECs (with t values of 4.32, 19.33, and 4.00, respectively) in hUCMSC-sEV group were significantly higher than those in blank control group ( P<0.05). At 12 h after culture, the numbers of migrated HEKs, HDFs, and HUVECs in hUCMSC-sEV group were 550 ±23, 235 ±9, and 856 ±35, respectively, which were significantly higher than 188 ±14, 97 ±6, and 370 ±32 in blank control group (with t values of 22.95, 23.13, and 17.84, respectively , P<0.05). At 24 h after culture, the proportions of proliferating cells of HEKs, HDFs, and HUVECs in hUCMSC-sEV group were significantly higher than those in blank control group (with t values of 22.00, 13.82, and 32.32, respectively, P<0.05). The inside of simple GelMA hydrogel showed a loose and porous sponge-like structure, and hUCMSCs-sEVs was not observed in it. The hUCMSC-sEV/GelMA hydrogel had the same sponge-like structure, and hUCMSCs-sEVs were uniformly distributed in clumps. The cumulative release rate curve of hUCMSCs-sEVs from hUCMSC-sEV/GelMA hydrogel tended to plateau at 2 d after soaking, and the cumulative release rate of hUCMSCs-sEVs was (59.2±1.8)% at 12 d after soaking. From PID 0 to 12, the wound areas of mice in the 4 groups gradually decreased. On PID 4, 8, and 12, the wound healing rates of mice in hUCMSC-sEV/GelMA hydrogel group were significantly higher than those in the other 3 groups ( P<0.05); the wound healing rates of mice in GelMA hydrogel alone group and hUCMSC-sEV alone group were significantly higher than those in PBS group ( P<0.05). On PID 8 and 12, the wound healing rates of mice in hUCMSC-sEV alone group were significantly higher than those in GelMA hydrogel alone group ( P<0.05). On PID 12, the wounds of mice in hUCMSC-sEV/GelMA hydrogel group showed the best wound epithelization, loose and orderly arrangement of dermal collagen, and the least number of inflammatory cells, while the dense arrangement of dermal collagen and varying degrees of inflammatory cell infiltration were observed in the wounds of mice in the other 3 groups. Conclusions:hUCMSCs-sEVs can promote the migration and proliferation of HEKs, HDFs, and HUVECs which are related to skin wound healing, and slowly release in GelMA hydrogel. The hUCMSC-sEV/GelMA hydrogel as a wound dressing can significantly improve the healing speed of full-thickness skin defect wounds in mice.