Osteosarcoma (OS) is the most common primary malignant bone sarcoma mainly affecting adolescents and young adults, which often progresses to pulmonary metastasis and leads to the death of OS patients. OS is characterized as a highly heterogeneous cancer type and the underlying pathologic mechanisms triggering tumor progress and metastasis are incompletely recognized. Surgery combined with neoadjuvant and postoperative chemotherapy has elevated 5-year survival to over 70% for patients with localized OS tumors, as opposed to only 20% of patients with recurrence and/or metastasis. Therefore, novel therapeutic strategies are needed to overcome the drawbacks of conventional treatments. Immunotherapy is gaining momentum for the treatment of OS with an increasing number of FDA-approved therapies for malignancies resistant to conventional therapies. Here, we review the OS tumor microenvironment and appraise the promising immunotherapies available in the management of OS.

No abstract

ObjectiveA systematic review of the role of stem cell-derived exosomes in repairing spinal cord injury (SCI) and the existing problems in animal experiments to provide a reference for better animal experiments and clinical studies in the future.MethodThree electronic databases, namely PubMed, Web of Science, and Ovid-Embase were searched. The studies were retrieved from inception to October 2021. Two researchers independently screened the literature, extracted data, and evaluated the methodological quality based on the inclusion criteria.Results and DiscussionThirty-two studies were incorporated into the final analyses. Exosomes derived from stem cells could not only significantly improve the motor function of animals with SCI, but also significantly increase the expression of anti-inflammatory factors IL-4 and IL-10 and anti-apoptotic protein Bcl-2, while significantly lowering the pro-inflammatory factor IL-1β and TNF-α and the expression of the apoptotic protein BAX. However, the mechanism of exosome-mediated SCI repair, as well as the best source and dosage remain unknown. In addition, there are still some issues with the design, implementation, and reporting of animal experiments in the included studies. Therefore, future research should further standardize the implementation and reporting of animal studies and fully explore the best strategies for exosomes to repair SCI so as to promote the translation of preclinical research results to clinical research better and faster.

No abstract

No abstract

Background As an alternative of bone grafts for defect repair, tissue engineering is much promising for clinical application. In previous studies, we have succeeded in repair of long bone defect with homemade tissue-engineered periosteum (TEP), of which is fabraicated by incorporating osteogenically induced mesenchymal stem cells (MSCs) of rabbits with a scaffold of small intestinal submucosa (SIS).Methods In this study, we are aimed to discuss the feasibility of allogenic irregular bone defect repair with the TEP. Thirty-six rabbits whose scapulas were subtotally resected to establish large irregular bone defects model in allogenic rabbits. The defects were treat respectively with TEP (Group 1, n=12), allogenic deproteinized bone (DPB) (Group 2, n=12) and hybrid of TEP and DPB (Group 3, n=12). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed.ResultsThe findings suggested that the radiographic score in TEP-DPB hybrided implantation (Group 3) was higher than TEP or DPB grafting only (p<0.05).But that was inconsistent with histological findings, which Group1 appeared to possess significantly higher bone formation than Group 2 (p<0.05) and Group3 has higher new bone volume than that of Group 2 (p<0.05).Conclusion We conclude that TEP is a promising alternative in repair of large irregular bone defect.DPB served as a 3D scaffold in combining TEP could provide mechanical support and shaping guide, but hinder new bone formation via TEP approach due to retard degradation.

Background One-stage posterior hemivertebrectomy is widely used for the treatment of hemivertebral-induced scoliosis. However, reports on posterior hemivertebrectomy evaluating hemivertebral-induced spinal imbalance and shoulder balance remain scarce. This study aimed to retrospectively analyze the effects of one-stage posterior hemivertebrectomy on spinal imbalance and shoulder balance. Methods Clinical data of 49 patients with scoliosis caused by congenitally imbalanced hemivertebra who underwent posterior hemivertebrectomy between January 2018 and March 2021 were evaluated. Radiographic parameters included sagittal Cobb angle, total main Cobb angle, coronal balance, T1 tilt angle, clavicle angle (CA), shoulder lengthdifference (RSH), T1–S1 length, sagittal kyphosis, thoracic kyphosis, lumbar lordosis, sagittal vertical alignment, L1 pelvic incidence angle, sacral inclination angle, and pelvic incidence angle. After descriptive analysis, the demographic and radiological data were compared. Results The preoperative RSH, CA, and T1 tilt angles of the shoulder imbalance group were significantly different from those of the shoulder balance group (P < 0.001). After surgical treatment, shoulder imbalance was significantly improved at the last follow-up than before surgery (P < 0.05). At the last follow-up, a significant difference in the T1 tilt angle was observed between the shoulder imbalance group and shoulder balance group (P < 0.05); however, no significant differences in the RSH and CA were observed between the two groups. Surgical treatment may significantly improve shoulder imbalance caused by imbalanced hemivertebral. Additionally, thoracic and lumbar hemivertebrectomy had a greater impact on shoulder balance, and lumbar hemivertebrectomy was more likely to cause coronal and sagittal imbalances. Conclusion In patients with congenital scoliosis caused by imbalanced hemivertebra, posterior hemivertebrectomy combined with short-segment pedicle screw fixation can provide good correction of scoliotic curve, coronal and sagittal plane imbalances, and shoulder imbalance. No serious complications were observed.