ObjectiveThe disordered growth of nerve stumps after amputation leading to the formation of neuromas is an important cause of postoperative pain in amputees. This severely affects the patients' quality of life. Regenerative peripheral nerve interfaces (RPNIs) are an emerging method for neuroma prevention, but its postoperative nerve growth and pathological changes are yet to be studied.MethodsThe rat sciatic nerve transection model was used to study the effectiveness of RPNI in this experiment. The RPNI (experimental) group (n = 11) underwent RPNI implantation after sciatic nerve transection, while the control group (n = 11) only underwent sciatic nerve transection. Autotomy behavior, ultrasonography, and histopathology were observed for 2 months postoperatively.ResultsCompared to the control group, the incidence and size of the neuromas formed and the incidence and extent of autotomy were significantly reduced in the RPNI group. The axon density in the stump and degree of stump fibrosis were also significantly reduced in the RPNI group.ConclusionRPNI effectively prevented the formation of neuromas.

To investigate whether human umbilical cord mesenchymal stem cell‐derived exosomes combined with gelatin methacryloyl (GelMA) hydrogel are beneficial in promoting healing of laser‐injured skin wounds in mice. Supernatants of cultured human umbilical cord mesenchymal stem cells (HUC‐MSCs) were collected to obtain human umbilical cord MSC‐derived exosomes (HUC‐MSCs‐Exos), which were combined with GelMA hydrogel complex to treat a mouse fractional laser injury model. The study was divided into PBS group, EX (HUC‐MSCs‐Exos) group, GEL (GelMA hydrogel) group and EX+GEL (HUC‐MSCs‐Exos combined with GelMA hydrogel) group. The healing of laser‐injured skin in each group was observed by gross view and dermatoscopy, and changes in skin structure, angiogenesis and proliferation‐related indexes were observed during the healing process of laser‐injured skin in each group. The results of the animal experiments showed that the EX and GEL groups alone and the EL+EX group exhibited less inflammatory response compared to the PBS group. The EX and GEL groups showed marked tissue proliferation and favourable angiogenesis, which promoted the wound healing well. The GEL+EX group had the most significant promotion of wound healing compared to the PBS group. qPCR results showed that the expression levels of proliferation‐related factors, including KI67 and VEGF and angiogenesis‐related factor CD31, were significantly higher in the GEL+EX group than in the other groups, with a time‐dependent effect. The combination of HUC‐MSCs‐Exos and GelMA hydrogel is beneficial in reducing the early inflammatory response of laser‐injured skin in mice and promoting its proliferation and angiogenesis, which in turn promotes wound healing.

Background: Risk factors for nonhealing wounds after abdomino-perineal resection (APR) remain inconclusive. And the pelvic floor reconstruction after APR based on gracilis-myofascial flaps (GMFs) is still controversial. This study aims to evaluate the risk factors for nonhealing wounds and demonstrate the clinical application of GMF reconstruction after APR. Methods: APR patients at Peking University Third Hospital from December 2010 to January 2021 were analyzed retrospectively, including 81 with primary suture and 5 with GMF reconstruction. The data collected included general information, comorbidities, pre/postoperative laboratory tests, surgical data and pathological results. Univariate analysis and multifactor binary logistic regression analysis was used. Results: There were 62 (71.2%) patients in the healing group (HG) and 24 (27.9%) patients in the nonhealing group (nHG). Old age (p = 0.011), hyperlipidemia (p = 0.042) and higher pathological Broders Grading (p = 0.048) were risk factors for nonhealing wounds. The mean hospitalization time (p = 0.002) and expense (p = 0.017) of the nHG were greater than HG. Multifactor binary logistic regression analysis showed age and hyperlipidemia were independent risk factors for nonhealing wounds after APR. Five patients with GMF reconstruction recovered well without any postoperative complications. Conclusion: Old age, hyperlipidemia and high Broders Grading are risk factors for nonhealing perineal wounds after APR, and age and hyperlipidemia are independent risk factors. GMF has satisfactory outcomes for pelvic floor reconstruction and lower probability of nonhealing wounds. Our study may provide new insights for the prevention and treatment of nonhealing perineal wounds after APR.

To investigate the role of GLI1 on skin proliferation and neovascularization during skin expansion in mice. We constructed GLI1-cre/R26-Tdtomato and GLI1-cre/R26mtmg gene-tagged skin expansion mouse models. Using a two-photon in vivo imaging instrument to observe the changes in the number and distribution of GLI1(+) cells dur-How to cite this article: Zhang X, Chen Y, Ding P, et al. The SHH-GLI1 pathway is required in skin expansion and angiogenesis.

Midfacial hypoplasia is a common maxillofacial deformity in patients with cleft lip and palate, which requires surgical treatment. However, achieving noninvasiveness in trans-sutural distraction osteogenesis (TSDO) for midfacial hypoplasia has been difficult. This study aimed to introduce the application of an optical surgical navigation system (OSNS) developed by the authors in TSDO. Six consecutive patients with midfacial hypoplasia (five boys and one girl, with an average age of 10 years; five patients with postoperative cleft lip and palate, and one patient without combined cleft lip and palate) who required TSDO were included in the study. Preoperatively, head computed tomography was performed, and the data were imported into the computer's Mimics software (version 20.0) to design a three-dimensional simulation of the surgical approach. TSDO was performed with the use of the OSNS, and the accuracy and results of the procedure were initially evaluated by comparing the preoperative and postoperative periods. The surgical procedure was successful, with a postoperative follow-up of 4–5 months. All patients demonstrated good treatment results, without complications. Therefore, the OSNS can safely and effectively guide the TSDO technique, essentially correcting midfacial dysplasia, achieving non-invasiveness, improving surgical precision, reducing bleeding, and obtaining better clinical results.