BACKGROUND: Scaffolds are an important part in bone tissue engineering. However, no perfect scaffolds have been developed for bone tissue engineering yet.OBJECTIVE: To evaluate the repair of rabbit radial defects by poly (L-lactic acid)/tricalcium phosphate(PLLA/TCP) scaffolds prepared by rapid prototyping(RP) technology so as to find a new carrier for growth factors.DESIGN: A completely randomized controlled study was conducted. SETTING: Orthopaedic institute of a military medical university.MATERIALS: The study was conducted in the General Orthopedic Institute,Fourth Military Medical University of Chinese PLA, from May 2001 to February 2002. Twenty clean New Zealand rabbits with body mass of(2.5 ±0. 5) kg for this study were obtained from the Experiment Animal Center of Fourth Military Medical University of Chinese PLA. The animals were divided into experiment group and control group with 10 rabbits in each group.INTERVETIONS: PLLA/TCP scaffolds prepared by RP technology and loaded with or without bovine bone morphogenetic protein (BMP) were used to repair the rabbit radial defects of 15 mm.MAIN OUTCOME MEASURES: Main outcomes: ① microscopic observation results of transplanted materials of the two groups; ② degradation rate of scaffolds. Secondary outcomes: ① gross observation; ② radiographic results; ③ bone density.RESULTS: At week 12, bone defect healing in experiment group was good. X-ray examination showed continuous bone callus and partial molding of different degrees. Degradation rate of scaffolds was 39.6%, and bone density in the defected part reached 70% of the normal level. All the indexes of experiment group were superior to those of control group, and no healing was found in the defected area in control group.CONCLUSION: PLLA/TCP scaffolds prepared by RP technology and loaded with bovine BMP can repair radial defects of 15mm in rabbits.

Objective To investigate the short and longterm effect of the treatment on acute coronary syndrome(ACS) with percutaneous coronary angioplasty and stenting.Methods 65 patients suffering from ACS were treated with angiography to illuminate the features of lesions and proceeded with percutaneous coronary angioplasty and stenting when the angina was not completed controlled with internal medicine.All patients were treated with a new anti-thrombotic regimen,including aspirin,ticlopidine or clopidogrel, and low-molecular-weight heparin.Results The rates of success for patients and lesions were 96.9% and 82.7% respectively.One patient died without myocardial infarction or emergency bypass surgery.56 patients had no symptom of angina after procedure,and 5 patients had non-typical chest pain which disappeared within 2~3 days.During the 3~54 month follow-up,one patient died,one patient developed myocardial infarction and 4 patients underwent target vessel revascularization(repeated angioplasty 2 and bypass surgery 2).Conclusions With the widespread use of aspirin-ticlopidine-low molecular heparin regimen,ACS patients can undergo PTCA and stenting with high success rate,excellent immediate efficacy and long-term efficacy.

Objective To evaluate the feasibility and efficiency of transthoracic echocardiography(TTE) combined with real-time three dimensional echocardiography(RT-3DE)in guiding transcatheter closure of atrial septal defect(TCASD)without X-ray.Methods Eleven patients with atrial septal defects(ASD)underwent the procedure of TCASD guided by TTE combined with RT-3DE.The position of the catheter and transporting sheath,the location and deploying of ASD occluder(ASO)were monitored by muhisection echoscan.especially in RT-3DE.The results were compared with those guided by conventional method(TTE and X-ray).Results All the operations were held successfully.The complications of cardiac tamponade,shedding of occluder,residual shunt,atrioventricular valve regurgitation,embolism and arrhythmia were not observed.Compared with the conventional procedure of the control group,the operation time was significantly prolonged[(65.76±14.15)min versus(45.50±20.88)min,P＜0.000)].Conclusions TCASD was tested to be safe and efficient guided by TTE combined RT-3DE without X-ray,especially for children and pregnant women.It may be expected used widely in the future independently from X-ray.

Objective To investigate the change of connexin (Cx) in mesenteric artery (MA) and aorta of spontaneously hyper‐tensive rats (SHR) and normotensive rats .Methods Quantitative RT‐PCR and Werstern blot technique were used to compare the difference in the expression of Cx37 and Cx40 mRNA and protein in MA and aorta of SHR and normotensive rats .Results The level of Cx37 mRNA expression in MA from SHR was decreased compared with that of the normotensive rats (P<0 .05) ,and more significantly in aorta (P<0 .01) .Cx40 mRNA expression in MA from SHR was significantly decreased compared with that of the normotensive rats (P<0 .01) ,but no change in aorta (P>0 .05) .The expression of Cx37 protein in MA from SHR was decreased compared with that of the normotensive rats (P<0 .05) ,and more significantly in aorta (P<0 .01) .Cx40 protein expression in MA from SHR was significantly decreased compared with that of the normotensive rats (P<0 .05) ,but no change in aorta (P>0 .05) . Conclusion Hypertension may could decrease gap junctional communication in cells of MA and aorta from SHR by the downregu‐lation of the expression of Cx37 and/or Cx40 .

Objective To evaluate the efficiency of transcatheter closure of PDA using domestic occluder device.Methods Thirteen two patients(male 11,female 21) with PDA were treated by transcatheter closure of PDA with domestic occluder device. The mean age of patients was 14.4?9.8 years (ranged from 1.8 to 39 years old). PDA were shown by transethroracic echocardiography (TTE) before interventions. Each case was treated with domestic occluder device through the percutaneous procedure under fluoroscopy and TTE. After the procedure,TTE were performed immediately to find whether there any residual shunt remained. Transthoracic echocardiography (TTE) and X-ray examination were done 24-hour, 1-month, 3-month and 6-month after the procedure to evaluate the efficiency.Results The success rate of placement of domestic occluder was 100%. Thoracic angiography showed that 18 patients had complete immediate closure and one had a small residual shunt after the operation. Residual shunt was found in four case after the operation. X-ray examination and TTE showed that both pulmonary vascularity and heart size were improved.Conclusions Transcatheter closure of PDA using domestic occluder device is an efficient nonsurgical method for patients of any age group. The operation is simple and safe with a high success rate of placement and a good occlusion effect. The long-term follow-up remains to be studied.

OBJECTIVETo evaluate the effects of repairing rabbit radial defects with polyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with bovine bone morphogenetic protein (bBMP), and find new carriers for growth factors.

METHODSPolyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with and without bovine BMP were used to repair the 15 mm radial defect in rabbit. Then the results of radiography, histology, scaffolds degrade rates and bone mineral density (BMD) were appraised to examine the effects at the 12th week.

RESULTSAt the 12th week postoperatively, all defects treated with bBMP were radiographically repaired. No radius implanted polyester/tricalcium phosphate scaffolds without bBMP showed radiographic and histological union. At experimental groups, longitudinal alignment of lamellar structure was observed histologically at the 12th week, indicating that remodeling of regenerated bone was complete in different degree. Of the three experimental groups, the bony regeneration and remodeling of callus in poly lactide-co-glycolide/tricalcium phosphate (PLGA/TCP) group was the best. The BMD values were beyond 70% of normal value at the 12th week while the PLGA/TCP scaffolds group was the highest, and no abnormalities were observed in the surrounding soft tissue in all groups.

CONCLUSIONSPolyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with bovine BMP can repair a 15 mm radial defect of rabbit. As for the results, the PLGA/TCP scaffold is ideal and better than poly L-lactide-co-D, L-lactide (PDLLA/TCP) scaffold, but the ploy L-lactic acid (PLLA/TCP) is not so good for its low degradation rates.

Animals ; Bone Density ; Bone Morphogenetic Proteins ; Bone Regeneration ; Bone Substitutes ; therapeutic use ; Calcium Phosphates ; therapeutic use ; Polyesters ; therapeutic use ; Rabbits ; Radiography ; Radius ; diagnostic imaging ; pathology ; surgery

Polyethylene glycol-polybenzyl-L-glutamate copolymer (PEG-PBLG) was synthesized and paclitaxel-loaded core-shell type nano-micelles with amphiphilic copolymer PEG-PBLG was prepared by the dialysis method. The drug loading content and entrapment efficiency were determined by HPLC. The average size and its distribution were determined by dynamic light scattering method. The paclitaxel release rate in vitro from micelles was measured by HPLC. The cell cytotoxicity in vitro was observed with MTT assay. The anti-tumor activity of paclitaxel-loaded micelles were evaluated in tumor-inhibiting test of nude mice using human liver cancer HepG-2. The results indicated that paclitaxel could be entrapped in PEG-PBLG copolymer micelles and its size was in the range of 80-265 nm which increased with an increase in molecular weight of PBLG in copolymer; in vitro the paclitaxel could be released sustainably from the micelles. In high concentration of paclitaxel (>20 microg x mL(-1)) the paclitaxel-loaded PEG-PBLG micelles displayed much less cell cytotoxicity than paclitaxel injections with Cremophor EL (P<0.05); the tumor inhibiting activity of paclitaxel-loaded PEG-PBLG micelles was similar to that of paclitaxel injections with Cremophor EL in the same paclitaxel concentration. It was concluded that the paclitaxel-loaded PEG-PBLG micelles had more uniform size and size distribution, excellent drug sustainable-release behavior, less cytotoxicity, good anti-tumor activity similar to paclitaxel injections with Cremophor EL. So paclitaxel-loaded PEG-PBLG micelles would be a novel paclitaxel preparation in clinic for the treatment of tumor.
Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Line, Tumor ; Delayed-Action Preparations ; Drug Delivery Systems ; Humans ; Liver Neoplasms, Experimental ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Micelles ; Nanoparticles ; Neoplasm Transplantation ; Paclitaxel ; pharmacology ; Particle Size ; Polyethylene Glycols ; chemistry ; Polyglutamic Acid ; analogs & derivatives ; chemistry ; Polymers ; Random Allocation

Objective To observe the effects of Zuogui Jiangtang Jieyu Prescription (ZGJTJYP) on pathological morphology of hippocampal neurons in rats of diabetes mellitus with depression (DD); To discuss its protective mechanism of action. Methods DD rat model was established by tail vein injection of STZ combined with chronic stress. Totally seventy-two SPF rats were randomly divided into normal group, model group, positive medicine group, ZGJTJYP low-, medium-, and high-dose groups, with 12 cases in each group, and were given corresponding medicine. After the last administration, blood glucose and behavioral changes were measured in each group. HE staining, Nissl staining, and Golgi staining were used to observe the changes of pathological morphology in rat hippocampus. The expression of Caspase-3 in hippocampus was detected by immunohistochemistry. Results Compared with the normal group, blood glucose level was significantly increased in the model group; the number of neurons in the hippocampus decreased in the model group; the apoptosis increased in the model group; the neuronal soma showed deformation and reduced dendritic spines and other pathological damages in the model group. After intervention of ZGJTJYP, hyperglycemia and depression-like status of the model rats were relieved; the number of hippocampal neurons increased significantly; neuronal morphology basically returned to normal. The expression of Caspase-3 in ZGJTJYP high-and medium-dose groups was significantly lower than that in model group. Conclusion ZGJTJYP can significantly improved blood glucose and learning and memory abilities in DD rats, which may be related to slowing hippocampal injury and apoptosis, and restoring neuronal quantity and morphology.

OBJECTIVETo evaluate the repairing effect of the rabbits radial defects of by polyester/tricalcium phosphate scaffolds prepared by rapid forming technology loaded with bovine BMP, and find a new carrier for growth factor.

METHODSPolyester/Tricalcium phosphate scaffolds prepared by rapid prototyping (RP) technology loaded with and without bovine BMP were used to repair the 15 mm radial defect of rabbit. Then results of radiography, histology, scaffolds degrade rates and bone density were appraised to examine the repairing effects of the scaffolds at 12 weeks.

RESULTSAt 12 weeks, all defects treated with bBMP were radiographically repaired. No radii implanted polyester/tricalcium phosphate scaffolds alone showed radiographic and historical union. At experimental groups, longitudinal alignment of lamellar structure was observed histologically at 12 weeks, indicating that remodeling of regenerated bone almost completed, the scaffolds degradation rates were different by 12 weeks, and no abnormalities were observed in the surrounding soft tissue in all groups.

CONCLUSIONPolyester/tricalcium phosphate scaffolds prepared by rapid prototyping technology loaded with bovine BMP can repair the rabbits radical defects. As for the effects, the poly (L-lactic-co-glycolide)/tricalcium phosphate (PLGA/TCP) scaffold are ideal and better than poly (L-lacide-co-D, L-lactide)/tricalcium phosphate (PDLLA/TCP) scaffold, but the poly (L-lactic acid)/tricalcium phosphate (PLLA/TCP) is not so good for its low degradation rates.

Animals ; Bone Density ; Bone Morphogenetic Proteins ; Bone Substitutes ; therapeutic use ; Calcium Phosphates ; Lactic Acid ; Male ; Polyesters ; Polyglycolic Acid ; Polymers ; Rabbits ; Radius ; injuries ; pathology ; surgery ; Tissue Engineering ; methods

Objective To investigate the effect of polylactic-co-glycolic acid (PLGA)/graphene oxide (GO) nanofibers combined with brain derived neurotrophic factor (BDNF) on neural stem cells (NSCs) proliferation and differentiation as well as on the spinal cord injury repair.Methods PLGA/GO nanofibers were manufactured and absorbed with BDNF,and the microstructure of PLGA/GO nanofibers was observed by scanning electron microscope.The loading efficiency and release curve of BDNF on PLGA/GO nanofibers were measured by ELISA.NSCs were implanted on the surface of PLGA/GO and PLGA/GO/BDNF nanofibers.The absorbance values of each group were measured by MTT method,and the expression of Tuj-1 was observed by immunofluorescence and PCR.A total of 30 female SD rats were divided into control group (n =10),PLGA/GO group (n =10) and PLGA/GO/BDNF group (n =10) according to random number table.T9 spinal cord tissue was cut by Venus scissors to establish spinal cord hemisection injury model of rats.PLGA/GO and PLGA/GO/BDNF nanofibers were implanted onto the surface of injury site.BBB score was used to assess the motion functional recovery of the rats at 1,7,14 and 28 days after operation.Immunofluorescence staining of neuron specific nucleoprotein (NeuN)and glial fibrillary acidic protein (GFAP) were performed to observe the expressions of neurons and astrocytes at the injured site respectively one month after injury.Results The PLGA/GO nanofibers showed an irregular smooth fiber-like structure,and the average fiber diameter was (987.5 ± 176.3)nm.NSCs could differentiate into neurons on the nanofibers.The result of ELISA showed loading rate of BDNF on PLGA/GO nanofibers was about 47.5％.The release curve showed that BDNF was first released about 30％ on the first day and then about 60％ on the 21st day.The results of MTT and PCR showed that optical density value and Tuj-1 gene expression in the PLGA/GO/BDNF group were significantly higher than those in the PLGA/GO group (P ＜ 0.05).The animal experiment results showed that the BBB score of PLGA/GO/BDNF group was (15.3 ±0.7) points at 28 days after injury,which was significantly higher than that of the injury control group [(11.8 ± 0.8) points] and that of PLGA/GO group [(12.7 ±0.8) points] (P ＜ 0.05).Immunofluorescence results showed that the expression of NeuN in PLGA/GO/BDNF group was 13.7 ± 2.2,significantly higher than that in injury control group (4.3 ± 2.9) (P ＜0.05),and the expression of GFAP in PLGA/GO group was (25.6 ± 4.3) ％ significantly lower than that in injury control group [(38.5 ± 6.2) ％] and PLGA/GO group [(36.7 ± 7.3) ％] (P ＜ 0.05).Conclusion PLGMGO nanofibers combined with BDNF can effectively promote the proliferation and neuron differentiation of NSCs in vitro and repair spinal cord injury in vivo through orthotopic transplantation at the injury site.