Preparation and application of collagen scaffold-encapsulated silver nanoparticles and bone morphogenetic protein 2 for enhancing the repair of infected bone.

The healing of contaminated/infected bone defects is a significant clinical challenge. Here, a novel collagen scaffold composite encapsulating silver nanoparticles (AgNP) and bone morphogenetic protein 2 (BMP-2) was prepared to enhance the healing of infected bone defects. Collagen scaffolds conjugated with AgNP possessed strong antibacterial properties that were dependent on the release rate of Ag(+). After introducing BMP-2, the BMP-2/AgNP/collagen scaffold composites did not adversely affect the adherence or proliferation of bone marrow-derived mesenchymal stromal cells (BMSCs). Differentiation of BMSCs toward osteoblasts was induced by the upregulation of RUNX2, osteopontin and osteonectin expression. BMP-2/AgNP/collagen scaffold composites, therefore, possess the antibacterial activity of AgNP and the osteoinductivity of BMP-2, making these composites an ideal pharmaceutical for the regeneration of bone in infected wounds.

Strong halo-femoral traction with wide posterior spinal release and three dimensional spinal correction for the treatment of severe adolescent idiopathic scoliosis.

BACKGROUND: Many investigators advocate anterior release combined with halo-femoral traction and posterior fusion when treating stiff thoracic curves in patient with adolescent idiopathic scoliosis (AIS). But the anterior operations often induce severe complications. Some surgeons choose posterior-only surgery with halo-femoral traction, posterior wide release and correction. But to the best of our knowledge, there are only rare prospective studies on these posterior-only surgeries for AIS patients who have a rigid curve more than 80° and flexibility less than 35%. METHODS: Sixty-four AIS patients were recruited from September 2006 to June 2009. All patients had rigid curves and underwent spinal correction. They were randomly divided into group A (combined anteroposterior surgery) and group B (posterior-only surgery). Images and scoliosis research society-22 questionnaire (SRS-22) scores were performed pre- and post-operation and during follow-up visits. The operation time, blood loss, hospital days, and hospital charges were compared between the two groups. RESULTS: These patients were followed for an average of 37.5 months (range, 24 - 65 months). No serious complications were observed. There were no significant differences between the two groups in gender, age, preoperative radiographic data, or preoperative SRS-22 score. The average operation time, blood loss, hospital days and hospital charges in group B were less than those in group A. The SRS-22 score in group B was better than in group A at post-operation and at final follow-up. CONCLUSIONS: In AIS with a rigid curve more than 80° and flexibility less than 35%, strong halo-femoral traction with wide posterior spinal release and three dimensional spinal correction can provide better SRS-22 scores, comparable curve correction, shorter operation time, less blood loss, shorter hospital stays and lower charges when compared to combined anterior and posterior surgery.

Association of estrogen receptor beta gene polymorphisms with susceptibility to adolescent idiopathic scoliosis.

STUDY DESIGN: A case-control study is presented. OBJECTIVE: To investigate the association of estrogen receptor beta gene polymorphisms with susceptibility to adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Studies have shown that idiopathic scoliosis is related to genetic factors, such as XbaI site polymorphism of the estrogen receptor alpha gene. To our knowledge, however, the relationship of estrogen receptor beta gene polymorphisms and the individual susceptibility to idiopathic scoliosis has not been studied. METHODS: This study included 218 patients with AIS and 140 healthy controls. Height, menarche status, curve pattern, Cobb angle, and Risser sign in female patients were recorded. Blood samples were taken from each subject by venipuncture. Genomic DNA was extracted from peripheral blood leukocytes using standard phenol/chloroform extraction. PCR products from amplification of genomic DNA from all individuals were analyzed using denaturing high-performance liquid chromatography. Samples with aberrant HPLC profiles were sequenced in both the forward and the reverse directions on an ABI 3100 automated sequencer. The chi test was used to determine the significant difference in genotype distribution between patients with AIS and the controls. RESULTS: The frequency of CC genotype of the exon ØK (in reality 5' UTR OK-1)was significantly higher in patients than that in controls (P < 0.05). The C alleles appeared to be overrepresented in patients compared with controls (P < 0.05). Furthermore, the frequencies of CC genotypes in female patients whose height was > or =160 cm and Cobb angle was > or =30 degrees were higher than those whose height was <160 cm and Cobb angle was <30 degrees (P < 0.05). CONCLUSION.: The sites of the exon ØK polymorphisms of estrogen receptor beta gene may be associated with a susceptibility of AIS. Furthermore, the sites of the exon ØK polymorphism may be associated with the height and the curve severity of patients.