Objective To study repair of osteochondral defects by using composite of autologous BMSCs and chitosan/HAP (CS/HAP) bilayered scaffold in rabbits and its feasibil ity as osteochondral tissue engineering scaffolds. Methods CS/HAP bilayered scaffolds were produced with CS and HAP using a lyophil ization and sintering method. The pore size of the scaffold was observed by scanning electron microscopy (SEM). Anhydrous ethanol substitution method determined its porosity. BMSCs were isolated from bone marrow and cultured by general bone marrow methods. Both CD44 and CD45 on the BMSCs surface were detected with immunocytochemistry to identify BMSCs. Cell-scaffold complex was made with BMSCs as seed cells and CS/HAP bilayered scaffold as carrier by fibrin glue planting technique. The distribution ofBMSCs in CS/HAP scaffold was tested by SEM. The osteochondral defect (4 mm in diameter and 3 mm in height) model was made in the right knee joint of 36 Japanese white rabbits, which were randomly divided into 3 groups. Defects were repaired with CS/HAP and BMSCs composite ( group A, n=12) and with CS/HAP implants (group B, n=12); defects were not treated as a control (group C, n=12). Histological evaluation and gross observation were carried out at 6 weeks (n=6 in each group) and 12 weeks (n=6 in each group) postoperatively. Semi-quantitative histomorphological analysis was done to evaluate the repair cartilage tissue according to the modified Wakitani grading scale. Results CS/HAP bilayered scaffold possessed a porosity of 76.00% ± 5.01% and pore size of 200-400 μm (mean 300 μm ) in CS layer, and 72.00% ± 4.23% and 200-500 μm (mean 350 μm) in HAP layer, respectively. BMSCs formed colonies within 10-14 days. Immunocytochemistry results showed BMSCs had positive CD44 expression and negative CD45 expression. At 6 and 12 weeks after operation, gross and histological observation showed that the cartilage defects were fully filled with regenerated tissue, but bone defects were partially repaired in group A; the cartilage and bone defects were partially filled with regenerated tissue in group B and group C. The modified Wakitani grading scale were 5.17 ± 1.17 and 3.20 ± 0.75 in group A, 9.00 ± 0.63 and 6.00 ± 0.89 in group B, and 10.00 ± 0.89 and 9.60 ± 0.82 in group C at 6 weeks and 12 weeks postoperatively, respectively; showing significant differences between group A and groups B, C (P lt; 0.05). Conclusion The novel CS/HAP bilayered scaffold possesses porous structure and will possibly become a newbiomaterial of osteochondral tissue engineering.
Objective To compare the effectiveness of cortical bone trajectory screw (CBTS) and conventional pedicle screw for posterior lumbar interbody fusion (PLIF) in the treatment of single segment lumbar degenerative disease. Methods Between May 2013 and May 2016, a total of 97 patients with single segment lumbar degenerative disease were treated with PLIF. Fifty-one patients were fixed with CBTS in PLIF (trajectory screw group) and 46 with pedicle screw (pedicle screw group). There was no significant difference in age, gender, body mass index, preoperative diagnosis, lesion segment, and preoperative visual analogue scale (VAS) score, Oswestry dysfunction index (ODI) between 2 groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, bed rest time, length of hospital stay, serum creatine kinase (CK) concentration, total amount of diclofenac sodium, perioperative complications, ODI, VAS score, and interbody fusion rate were recorded and compared between 2 groups. Results All patients were followed up 12 months. The patients in trajectory screw group had a significantly less operation time, intraoperative blood loss, postoperative drainage, and serum CK concentration when compared with the patients in pedicle screw group (P<0.05). Thirty-five patients (68.6%) in trajectory screw group and 46 patients (100%) in pedicle screw group were given diclofenac sodium within 48 hours after operation, showing significant difference between 2 groups (χ2=89.334, P=0.000). There was no significant difference in the incidence of perioperative complications between trajectory screw group and pedicle screw group (3.9% vs. 8.7%, P=0.418). There was no significant difference in the VAS score, ODI, and interbody fusion rate at 12 months after operation between 2 groups (P>0.05). Conclusion For the single segment degenerative lumbar disease, the use of CBTS or conventional pedicle screw for PLIF can obtain satisfactory clinical function and interbody fusion rate. But the former has the advantages of less blood loss, less intraoperative muscle damage, less perioperative pain, shorter length of hospital stay and bed rest time.
Objective To investigate the factors influencing the medication adherence among patients with diabetes signing family doctor service contract in Beijing urban areas, and provide the basis for improving the level of medication adherence. Methods A total of 320 patients with diabetes from four community health service centers in Beijing urban areas were selected to answer the questionnaires using convenient sampling from June to September 2015. Univariate analysis and binary logistic regression were used for the influencing factors analysis. Results A total of 320 questionnaires were distributed, and 317 valid questionnaires were recovered, in which the rate of high medication adherence was 54.6%. The results of logistic regression showed that the main impact factors on medication adherence were age [odds ratio (OR)=1.918, P=0.011)], degree of education (OR=2.462, P=0.008), knowledge related to diabetes (OR=1.773, P=0.027), adopting of family doctor service or not (OR=2.521, P=0.029) and social function status (P=0.003). Conclusions The family doctor service team should implement the practice of the family doctor service to ensure that the contracted residents can make full use of the family doctor services; and strengthen the follow-up and interventions for patients less aged or with low degree of education. For those with poor social function, more attention should be paid to their self-health management behavior to improve the level of patients’ compliance. As a result, the levels of blood glucose will be well controlled to reduce possibilities of complications and improve their health status and quality of life.
Objective To observe the effect of dynamic mechanical loading on the proliferation, differentiation, and specific gene expression of MC3T3-E1 cells that on three-dimensional (3D) biomimetic composite scaffolds prepared by low temperature 3D printing technology combined with freeze-drying. Methods The silk fibroin, collagen type Ⅰ, and nano-hydroxyapatite (HA) were mixed at a mass ratio of 3∶9∶2 and were used to prepare the 3D biomimetic composite scaffolds via low temperature 3D printing technology combined with freeze-drying. General morphology of 3D biomimetic composite scaffold was observed. Micro-CT was used to observe the pore size and porosity of the scaffolds, and the water swelling rate, stress, strain, and elastic modulus were measured. Then, the MC3T3-E1 cells were seeded on the 3D biomimetic composite scaffolds and the cell-scaffold composites were randomly divided into 2 groups. The experimental group was subjected to dynamic mechanical loading (3 500 με, 1 Hz, 15 minutes per day); the control group was not subjected to loading treatment. After 7 days and 14 days, the cell-scaffold composites of 2 groups were harvested to observe the growth of cells on the scaffolds by HE staining and scanning electron microscope. And the gene and protein expressions of collagen type Ⅰ, BMP-2, and osteocalcin (OCN) were measured by real-time fluorescent quantitative PCR and Western blot. Results The 3D biomimetic composite scaffold was a white cubic grid. Micro-CT detection showed the pore network structure in the scaffold material with good pore connectivity. The diameters of large pore and micro-aperture were (506.37±18.63) μm and (62.14±17.35) μm, respectively. The porosity was 97.70%±1.37%, and the water absorption swelling rate was 1 341.97%±64.41%. Mechanical tests showed that the compression displacement of the scaffold was (0.376±0.004) mm, the compressive stress was (0.016±0.002) MPa, and the elastic modulus was (162.418±18.754) kPa when the scaffold was compressed to 10%. At 7 days and 14 days, HE staining and scanning electron microscope observation showed that the cells grew inside the scaffold, mainly distributed around the scaffold pore wall. The cells in experimental group were more than control group, and the cells morphology changed from shuttle to flat. There was no significant difference in the cell counting between 2 groups at 14 days after 200-fold microscopy (t=–2.024, P=0.080), but significant differences were found between 2 groups at different time points under different magnifications (P<0.05). Real-time fluorescent quantitative PCR showed that the mRNA relative expressions of collagen type Ⅰ and OCN in experimental group were significantly higher than those in control group at 7 and 14 days (P<0.05). However, the mRNA relative expression of BMP-2 showing no significant difference between 2 groups (P>0.05). The protein relative expressions of collagen type Ⅰ, BMP-2, and OCN in experimental group were significantly higher than those in control group at 7 and 14 days (P<0.05). Conclusion After dynamic mechanical loading, the expressions of BMP-2, collagen type Ⅰ, and OCN in MC3T3-E1 cells inoculated into 3D biomimetic composite scaffolds are significantly up-regulated, indicating that appropriate mechanical loads favor osteoblast differentiation of MC3T3-E1 cells.
ObjectiveTo investigate the effect of saikosaponin a (SSa) on the levels of immune inflammation in rats with acute spinal cord injury and its possible mechanism.MethodsSeventy-two Sprague Dawley rats (weighing, 220-250 g) were randomly divided into sham operation group (group A), spinal cord injury group (group B), and SSa treatment group (group C) respectively, 24 rats in each group. The spinal cord injury model was induced by using the Allen’s method in groups B and C; the spinous process and vertebral plate at both sides were cut off by lamina excision to expose the spinal cord in group A. The rats were given intraperitoneal injection of 10 mg/kg SSa in group C and equal volume of normal saline in group B at immediate after injury. The spinal cord tissue was harvested from 18 rats of each group at 24 hours after operation to measure the levels of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) by ELISA, to detect the expressions of nuclear factor κB (NF-κB) P65, NF-κB P-P65, and aquaporin 4 (AQP4) by Western blot and to observe the morphology of spinal cord by HE staining. The motor function of the lower limbs was evaluated by BBB score and tiltboard experiment in 6 rats at 1, 3, 7, 14, 21, and 28 days after injury.ResultsThe BBB score and tiltboard experiment maximum angle were significantly higher in group A than groups B and C at each time point (P<0.05) and in group C than group B at 14, 21, and 28 days after operation (P<0.05). ELISA test showed that the concentrations of TNF-α and IL-6 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). Western blot results showed that the protein expression levels of NF-κB P65, NF-κB P-P65, and AQP4 were significantly lower in group A than groups B and C, and in group C than group B (P<0.05). HE staining demonstrated normal neurons of the spinal cord and no obvious lesion in group A; neuronal cells were observed in the injured area of group B, with hemorrhage, neutrophil infiltration, and nerve cell edema in the injured area; the neuronal cells were visible in the spinal cord of group C, with microglia mild hyperplasia, and the pathological changes were improved when compared with group B.ConclusionSSa has neuroprotective effects on acute spinal cord injury in rats by inhibiting NF-κB signaling pathway and AQP4 protein expression and reducing inflammation response and edema.