Synergistic effects of 3D chitosan-based hybrid scaffolds and mesenchymal stem cells in orthopaedic tissue engineering.

Restoration of damaged bone and cartilage tissue with biomaterial scaffolds is an area of interest in orthopaedics. Chitosan is among the low-cost biomaterials used as scaffolds with considerable biocompability to almost every human tissue. Considerable osteoconductivity, porosity, and appropriate pore size distribution have made chitosan an appropriate scaffold for loading of stem cells and a good homing place for differentiation of stem cells to bone tissue. Moreover, the similarity of chitosan to glycosaminoglycans and its potential to be used as soft gels, which could be lasting more than 1 week in mobile chondral defects, has made chitosan a polymer of interest in repairing bone and cartilage defects. Different types of scaffolds using chitosan in combination with mesenchymal stem cells (MSCs) are discussed. MSCs are widely used in regenerative medicine because of their regenerative ability, and recent line evidence reviewed demonstrated that the combination of MSCs with a combination of chitosan with different materials, including collagen type 1, hyaluronic acid, Poly(L-lacticacid)/gelatin/ß-tricalcium phosphate, gamma-poly[glutamic acid] polyelectrolyte/titanium alloy, modified Poly(L-Lactide-co-Epsilon-Caprolactone), calcium phosphate, ß-glycerophosphate hydrogel/calcium phosphate cement (CPC), and CPC-Chitosan-RGD, can increase the efficacy of using MSCs, and chitosan-based stem cell delivery can be a promising method in restoration of damaged bone and cartilage tissue.

Evaluation of clinical efficacy of Chemotherapy for Rhabdomyosarcoma in children.

OBJECTIVE: To investigate the clinical characteristics and treatment methods of rhabdomyosarcoma in children and the efficacy of the methods. METHODS: The clinical data of 30 children with rhabdomyosarcoma who were admitted to our hospital from August 2013 to August 2017 were retrospectively analyzed. The clinical characteristics were summarized, and the curative effect and prognosis were evaluated. RESULTS: Among all the children (N=30), there were 20 males and 10 females, with a median age of 3.5 years. As to the primary site, there were 13 cases of head and neck, 11 cases of trunk, three cases of urogenital system and three cases of limbs. There were 25 cases of embryonic type, 4 cases of alveolar type and one case of polymorphic type. As regards clinical stage, there were one case of stage I, 9 cases of stage II, 13 cases of stage III and 7 cases of stage IV. There were one case of low risk, 19 cases of medium risk and 10 cases of high risk. Eight cases received surgery alone, 22 cases received combined treatment of surgery and chemotherapy (the chemotherapeutics followed three schemes, low-risk group (VAC+VA), moderate risk group (VAC) and high risk group (alternating use of VDC and IE). Among all the cases (N=30), there were 14 cases of complete remission (CR), five cases of partial remission (PR), four cases of stable disease (SD), and 7 cases of progressive disease (PD). The CR rate was (N=14, 46.7%). The three-year overall survival (OS) rate was (N=19, 63.3%). The clinical efficacy and prognosis of children receiving surgery and chemotherapy were better than those of children receiving surgery alone, and the difference was statistically significant (P<0.05). CONCLUSION: Rhabdomyosarcoma in children frequently happens in the head, neck and trunk. Embryonic type is the main pathological type of rhabdomyosarcoma. Comprehensive and standardized treatment based on surgery and chemotherapy is an important way to improve the curative effect in the treatment of rhabdomyosarcoma in children.