Objective To fabricate an anti?tuberculosis controlled drug release coating with Ti?PDA?PEG?PLGA?INH and to investigate its surface characteristics, in vivo and in vitro drug release behavior, and tissue biocompatibility. Methods 4?arm?polyethylene glycol (PEG) was synthesized first. Then cover the surface of titanium (Ti) with a layer of poly dopamine (PDA) by Michael addition reaction. Use porous starch and 4?arm?PEG as a carrier, load with isoniazid (INH), then attach to the surface of titanium by casting or sol?gel dip coating methods, and then cover with a layer of poly lactic?co?glycolic acid (PLGA) by the same method, to fabricate the Ti?PDA?PEG?PLGA?INH composite coating finally. The functional group of 4?arm?PEG was charac?terized by proton nuclear resonance spectroscopy (HNMR). The surface characteristics of Ti?PDA?PEG?PLGA?INH were evaluated by scanning electron microscope (SEM), while drug release behaviors were detected by high performance liquid chromatography (HPLC) and the cumulative release rate was calculated, and carry out the antibacterial performance in vitro. The animal model of femoral condyle bone defect was established in 25 New Zealand white rabbits. Titanium rods covered with PDA?PEG?PLGA?INH coating were implanted into defect area. INH concentrations were detected by HPLC in venous blood, muscle and bone tissue at each time point postoperatively. Another 12 rabbits were randomly divided into experimental group and control group, the experi?mental group was implanted with titanium tablets and titanium rods coated with PDA?PEG?PLGA?INH in the paraspinous muscle and left femoral condyles respectively, while the control group was implanted with a blank sheet of titanium tablets and titanium rods in the same place. Hematoxylin and Eosin Staining were used to observe the biocompatibility of the composite system in vivo at 28 and 56 days postoperatively. Results Ti?PDA?PEG?PLGA?INH controlled drug release coating uniformly distributed on the surface of plates and rods, with translucent form and smooth surface. In vitro INH release kinetics exhibited a short?burst release during the first 8h, and the cumulative release of the INH was about 65%. On the 9th day, the cumulative release of the INH was about 90%, and then the release tended to be flat, and the drug release behavior in vitro continued more than 20d. In vivo release test showed that the concentration of INH in vein blood, muscle and bone tissue around the composite system was increased steadi?ly postoperatively. On about the 28th day, the concentration reached the max. However, the INH concentrations in muscle and bone tissue around the composite system were still higher than the minimum inhibitory concentration (MIC) on the 56th day. The antibacterial test in vitro showed that the titanium tablets coated with PDA?PEG?PLGA?INH formed obvious bacterial inhibition zones. The pathological results indicated that mild inflammatory reaction was seen in the 4th week postoperatively, and the reac?tive capsule formed with loose connective tissue. In the 8th week postoperatively, there's no obvious inflammation occurred, and the reactive capsule became more dense and thicker. Conclusion The study successfully fabricated the Ti?PDA?PEG?PLGA?INH anti?tuberculosis controlled drug release coating, with reasonable release behavior both in vivo and in vitro, effective antibac?terial effect of Mycobacterium tuberculosis in vitro and good tissue biocompatibility, which is a potentially effective drug delivery system for spinal tuberculosis.

Objective To compare the effect of transplant islets between the subcutaneous inguinal white adipose tissues and renal capsule in the treatment of type 1 diabetes mellitus in mouse models. Methods The mice with type 1 diabetes mellitus undergoing islet transplantation were divided into the white adipose group (n=10) and renal capsule group (n=10). The islets were isolated, purified and transplanted to the subcutaneous white adipose tissues of inguinal region and renal capsule. The random blood glucose level and glucose tolerance function of the recipient mice in two groups were continuously monitored after operation. Islet grafts of the surviving recipient mice were harvested at postoperative 100 d for histopathological examination. Results In the white adipose group, the blood glucose levels of 6 recipient mice were restored to normal at 1 month after transplantation, whereas the blood glucose levels of the other 4 recipient mice were high, which died before the end of monitoring. In the renal capsule group, the blood glucose levels of 10 recipient mice returned to normal within 10 d after transplantation. Islet grafts of the recipient mice in two groups could lower the blood glucose levels, whereas the islet grafts in the white adipose group required a longer time to exert the effect. The glucose tolerance function of the mice in the renal capsule group was significantly better than that of those in white adipose group (P < 0.05). Histopathological examination demonstrated that the insulin of the islet grafts was normally expressed in two groups. Conclusions The islets transplanted into the subcutaneous white adipose tissues of inguinal region can play an effective role in regulating the changes of blood glucose level. Although the blood glucose-lowering function is slightly weaker than that of the islets graft in the renal capsule, it has multiple advantages resembling the ideal islet transplantation sites, which is a promising replacement site for islet transplantation.

Objective To investigate the clinical therapeutic effects of bone cement-augmented pedicle screw fixation for cement vertebrae refractures with lower limb neurological symptoms after percutaneous kyphoplasty (PKP) in elderly patients with osteoporotic thoracolumbar compression fractures.Methods A total of 123 elderly patients with osteoporotic thoracolumbar compression fractures underwent PKP from December 2013 to December 2016 were retrospectively analyzed by case series study.Twelve patients had vertebral refracture with compression of the spinal cord or cauda equina which resulted in lumbosacral and leg pain,numbness and disability of ambulation and there were five males and seven females,with age of (69.2 ± 7.1) years.Injured vertebrae was located at T12 in five cases,at L1 in five and at L2 in two.Bone cement-augmented pedicle screw fixation through a standard posterior approach was utilized to treat all the 12 patients.Visual analogue scale (VAS),Oswestry disability index (ODI),anterior vertebral height compression ratio,and kyphotic angle at the preoperative time,one week postoperatively and last follow-up were recorded and compared.Intraoperative and postoperative complications were also recorded.Results The mean duration of follow-up in all the patients was 26.7 months (range,12-36 months).Intraoperative nerve injury,dural tear,leakage of bone cement,bone cement toxicity reaction,and pulmonary embolism were not observed during the surgery.The postoperative radiographs for all the 12 patients showed that the bone cement was distributed in cancellous bone and around the screw appropriately where there was no cement leakage out of the vertebral body or pedicle.Compared with preoperative scores,the average low back pain VAS,leg pain VAS and ODI at postoperative one week were improved by (2.2 ± 0.7) points,(2.2 ± 0.4) points and (33.2 ± 8.9) points,respectively (P ＜ 0.01).Anterior vertebral height compression ratio was decreased from preoperative (71.5 ± 11.7) ％ to (18.7 ± 10.3) ％ at postoperative one week (P ＜ 0.01).The mean kyphotic angle was corrected from preoperative (28.3 ± 7.6) ° to (7.1 ± 2.3) ° at postoperative one week (P ＜ 0.01).The symptoms of lumbar pain,and numbness and weakness of lower limbs were improved significantly.There was no statistically significant difference of all the parameters between the last follow-up evaluation and one week post-operatively (P ＞ 0.05).Conclusion For elderly patients with spinal cord or cauda equina nerve compression symptoms after PKP for osteoporotic thoracolumbar compression fractures,the usage of posterior approach bone cement-augmented pedicle screw fixation can effectively correct kyphosis,relieve neurological symptoms and restore spinal stability.