A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.

Objective To assess the clinical effect of oblique lumbar interbody fusion (OLIF) combined with percutaneous pedicle screw fixation on computer navigation for lumbar spondylolisthesis.Methods Total 20 patients (8 males and 12 females with average age of 54.1± 12.3 years) with lumbar spondylolisthesis were enrolled in our study during Oct.2014 and May.2016.All patients were treated with OLIF combined with percutaneous pedicle screw fixation on computer navigation.Operation time,blood loss and complications were all recorded.Clinical and Radiographic evaluation were investigated on 1 week,3 months,6 months,12 months postoperatively and final follow-up.Visual analogue scale (VAS) for low back pain and leg pain,Oswestry disability index (ODI) for low back pain and the MOS item short form health survey (SF-36) were used to evaluate the clinical efficacy of surgery.Disc height,disc angle,lumbar lordosis and degree of upper vertebral slip of patients were investigated with X-ray.Cross-sectional area of intervertebral foramina was measured with three-dimensional CT and MRI.The cross-sectional area and sagittal diameter of the thecal sac were measured on T2-weighted axial and sagittal magnetic resonance images.Accuracy of pedicle screw placement was investigated with three-dimensional CT.Fusion rate was investigated with three-dimensional CT and Xray.Results All patients were followed for 12-30 months (22.9±4.8 months).The mean operation time was (119.0±23.8) min,the mean blood loss was (57.8±20.6) ml.VAS for low back pain,VAS for leg pain,and ODI were significantly improved from (6.7± 2.6),(6.3±2.7) and 50.5％±18.2％ preoperatively to (1.3±1.0),(0.8±1.0) and 14.0％±9.6％ at the latest follow-up.The SF-36 PCS and MCS scores were improved from (27.1 ± 13.9) and (51.0±22.7) preoperatively to (67.3± 18.9) and (81.2±14.1) at the latest follow-up.Disc height,disc angle,lumbar lordosis were significantly increased from (6.0±3.6) mm,1.8°±6.2° and 39.2°±8.4° preoperatively to (10.8± 1.7) mm,6.2°±3.5° and 45.0°±7.8° at the latest follow-up.Degree of upper vertebral slip of patients was reduced from 23.5％±7.4％ preoperatively to 4.2％±3.1％ at the latest follow-up.Cross-sectional area of intervertebral foramina in CT and MRI were significantly increased from (140.6±36.0) mm2 and (78.1±31.2) mm2 before surgery to (179.8±35.6) mm2 and (141.7±29.5) mm2 at 6 months after surgery.Cross-sectional area and sagittal diameter of thecal sac were significantly increased from (73.4±29.3) mm2 and (5.2±3.2) mm before surgery to (124.5±26.6) mm2 and (9.5±2.0) mm at 6 months after surgery.Accuracy of pedicle screw placement was 95％,and fusion rate was 100％ at 6 months after surgery.There were no severe vascular and nerve injuries.Conclusion OLIF combined with percutaneous pedicle screw fixation on computer navigation has good indirect decompression effect on lumbar spondylolisthesis,and was associated with high fusion rate.It can also effectively decrease the surgical trauma,improve the accuracy of pedicle screw placement,and increase disc height,disc angle and lumbar lordosis.

A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.
Bone Morphogenetic Protein 2 ; chemistry ; pharmacology ; Bone Regeneration ; drug effects ; Humans ; Lactic Acid ; chemistry ; pharmacology ; Phosphatidylinositol Phosphates ; chemistry ; pharmacology ; Polyglycolic Acid ; chemistry ; pharmacology ; Tissue Scaffolds

ObjectiveTo analyze the causes of occupational acute 1,2-dichloroethane (1,2-DCE) poisoning accident during the use of polyurethane grouting materials for waterproof plugging operation in the construction industry. Methods By combining the clinical symptoms of the patient, worksite survey of occupational health and workplace occupational hazards monitoring method, the cause of an occupational acute 1,2-DCE poisoning accident was investigated at a construction site during the use of polyurethane grouting material for waterproofing and plugging operations. Results The patient was engaged in waterproof grouting work using polyurethane grouting material. The main volatile organic components in the raw materials were 1,2-DCE, with traces of dichloromethane, methyl acetate and others. The result of post-incident on-site investigation showed that the short-term exposure concentration of 1,2-DCE in the workplace air was 578.70 mg/m³, which was more than 30 times higher than the national occupational health standard limit. The mass concentration of 1,2-DCE in the patient's blood was 230 μg/L. Combined with the patient's occupational hazard exposure history, clinical manifestations, worksite survey of occupational health, and laboratory test results, according to GBZ 39-2016 Diagnosis of Occupational Acute 1,2-Dichloroethane Poisoning, this incident was diagnosed as a severe occupational acute 1,2-DCE poisoning event caused by the use of inferior polyurethane grouting material. Conclusion The excessive concentration of 1,2-DCE in the workplace air is the main cause of this poisoning accident. Construction sites with confined space operations should improve various occupational health management systems, occupational health engineering protective facilities, and personal protective equipment must be provided for workers.