Background and Objectives: The goal of this study was to investigate the mechanism of mesenchymal stem cell (MSC)-derived microRNA (miR)-150-5p-expressing exosomes in promoting skin wound healing through activating PI3K/AKT pathway by PTEN. Methods: and Results: Human umbilical cord (HUC)-MSCs were infected with miR-150-5p overexpression and its con-trol lentivirus, and HUC-MSCs-derived exosomes (MSCs-Exos) with stable expression of miR-150-5p were obtained. HaCaT cells were induced by H2O2 to establish a cellular model of skin injury, in which the expression of miR-150-5p and PTEN and the phosphorylation of PI3K and AKT were evaluated. HaCaT cells were transfected with pcDNA3.1-PTEN or pcDNA3.1 and then cultured with normal exosomes or exosomes stably expressing miR-150-5p. Cell proliferation was inspected by CCK-8. Cell migration was detected by scratch test and cell apoptosis by flow cytometry. The starBase tool was used to predict the binding site of miR-150-5p to PTEN. Dual-luciferase reporter assay and RIP assay were applied to assess the interaction between miR-150-5p and PTEN. In H2O2 -induced HaCaT cells, the miR-150-5p expression decreased, and PTEN expression increased in a concentration-dependent manner. MSCs-Exos promoted the growth and migration of H2O2 -induced HaCaT cells and inhibited their apoptosis. In addition, overexpression of exosomal miR-150-5p enhanced the protective effect of MSCs-Exos on H2O2 -induced HaCaT cells; PTEN overexpression in HaCaT cells partially restrained miR-150-5p-mediated inhibition on H2O2 -induced injury in HaCaT cells. PTEN was a target gene of miR-150-5p. MiR-150-5p regulated PI3K/AKT pathway through PTEN. Conclusions MSCs-derived miR-150-5p-expressing exosomes promote skin wound healing by activating PI3K/AKTpathway through PTEN.

Objective:To investigate the application effect of reverse abdominal wall advancement flap in repairing chest wall soft tissue defect after breast tumor resection.Methods:From October 2020 to April 2021, the Department of Plastic Surgery and Breast Surgery of Hainan Cancer Hospital cooperated to repair the chest wall wounds of 4 female patients with unilateral giant breast tumors after primary lesion resection. Patients aged 40-63 years old, with an average of 51.5 years old. The size of the tumor estimated by physical examination was 7 cm × 6 cm-15 cm × 20 cm. The flaps were closely monitored after surgery, and complications were recorded. Local recurrence was followed-up.Results:The wound size of 4 patients after mastectomy was 16 cm×14 cm-20 cm×18 cm. Abdomen separation range reached anterior axillary line laterally and contralateral clavicle midline medially. Inferiorly, 1 case reached umbilical level, 1 case reached 2 cm below the umbilicus, and 2 cases reached 3 cm below the umbilicus. Three cases were diagnosed as breast lobulated tumors, and 1 case invasive lobular carcinoma. Among the 4 cases, 3 flaps survived completely and healed by first intention, while another flap healed under blister scab. There was no necrosis, infection, hematoma, seroma, or vascular crisis of the flap. All patients were satisfied. Three patients received radiotherapy and one received radiotherapy combined with oral chemotherapy. All patients were followed up for 3-6 months. No local recurrence was discovered. The abdomen was tighter than before operation, but no stiffness was found. There was no abdominal pain, abdominal wall bulging or abdominal hernia.Conclusions:Reverse abdominal wall advancedment flap was used to repair soft tissue defect of the chest wall after breast tumor resection. The operation was simple and fast, with no need for additional donor site incision. Quick recovery allowed shorter interval between surgery and next scheduled treatments.

Objective:To investigate the application effect of reverse abdominal wall advancement flap in repairing chest wall soft tissue defect after breast tumor resection.Methods:From October 2020 to April 2021, the Department of Plastic Surgery and Breast Surgery of Hainan Cancer Hospital cooperated to repair the chest wall wounds of 4 female patients with unilateral giant breast tumors after primary lesion resection. Patients aged 40-63 years old, with an average of 51.5 years old. The size of the tumor estimated by physical examination was 7 cm × 6 cm-15 cm × 20 cm. The flaps were closely monitored after surgery, and complications were recorded. Local recurrence was followed-up.Results:The wound size of 4 patients after mastectomy was 16 cm×14 cm-20 cm×18 cm. Abdomen separation range reached anterior axillary line laterally and contralateral clavicle midline medially. Inferiorly, 1 case reached umbilical level, 1 case reached 2 cm below the umbilicus, and 2 cases reached 3 cm below the umbilicus. Three cases were diagnosed as breast lobulated tumors, and 1 case invasive lobular carcinoma. Among the 4 cases, 3 flaps survived completely and healed by first intention, while another flap healed under blister scab. There was no necrosis, infection, hematoma, seroma, or vascular crisis of the flap. All patients were satisfied. Three patients received radiotherapy and one received radiotherapy combined with oral chemotherapy. All patients were followed up for 3-6 months. No local recurrence was discovered. The abdomen was tighter than before operation, but no stiffness was found. There was no abdominal pain, abdominal wall bulging or abdominal hernia.Conclusions:Reverse abdominal wall advancedment flap was used to repair soft tissue defect of the chest wall after breast tumor resection. The operation was simple and fast, with no need for additional donor site incision. Quick recovery allowed shorter interval between surgery and next scheduled treatments.