Objective To review new progress of related research of peri pheral nerve defect treatment with tissue engineering in recent years. Methods Domestic and internationl l iterature concerning peri pheral nerve defect treatment with tissue engineering was reviewed and analyzed. Results Releasing neurotrophic factors with sustained release technology included molecular biology techniques, poly (lactic-co-glycol ic acid) microspheres, and polyphosphate microspheres. The mixture of neurotrophic factors and ductus was implanted to the neural tube wall which could be degraded then releasing factors slowly. Seed cells which were the major source of active ingredients played an important role in the repair and reconstruction of tissue engineering products. The neural tube of Schwann cells made long nerve repair and the quality of nerve regeneration was improved. Nerve scaffold materials included natural and synthetic biodegradable materials. Tube structure usually was adopted for nerve scaffold, which performance would affect the nerve repair effects directly. Conclusion With the further research of tissue engineering, the treatment of peripheral nerve defects with tissue engineering has made significant progress.
【Abstract】 Objective To develop a novel cartilage acellular matrix (CACM) scaffold and to investigate its performance for cartilage tissue engineering. Methods Human cartilage microfilaments about 100 nm-5 μm were prepared after pulverization and gradient centrifugation and made into 3% suspension after acellularization treatment. After placing the suspension into moulds, 3-D porous CACM scaffolds were fabricated using a simple freeze-drying method. The scaffolds were cross-l inked by exposure to ultraviolet radiation and immersion in a carbodiimide solution 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysucinimide. The scaffolds were investigated by histological staining, SEM observation and porosity measurement, water absorption rate analysis. MTT test was also done to assess cytotoxicity of the scaffolds. After induced by conditioned medium including TGF-β1, canine BMSCs were seeded into the scaffold. Cell prol iferation and differentiation were analyzed using inverted microscope and SEM. Results The histological staining showed that there are no chondrocytefragments in the scaffolds and that toluidine blue, safranin O and anti-collagen II immunohistochemistry staining werepositive. The novel 3-D porous CACM scaffold had good pore interconnectivity with pore diameter (155 ± 34) μm, 91.3% ± 2.0% porosity and 2 451% ± 155% water absorption rate. The intrinsic cytotoxicity assessment of novel scaffolds using MTT test showed that the scaffolds had no cytotoxic effect on BMSCs. Inverted microscope showed that most of the cells attached to the scaffold. SEM micrographs indicated that cells covered the scaffolds uniformly and majority of the cells showed the round or ell iptic morphology with much matrix secretion. Conclusion The 3-D porous CACM scaffold reserved most of extracellular matrix after thoroughly decellularization, has good pore diameter and porosity, non-toxicity and good biocompatibil ity, which make it a suitable candidate as an alternative cell-carrier for cartilage tissue engineering.
Objective To summarize the critical point of diagnosis and endovascular repairment (EVR) to thoracic aortic aneurysm (TAA), thoracic pseudoaneurysm (TPA) and aortic dissection (AD), by comparison the computerized tomography angiography (CTA) images before and after EVR to observe effects, so as to explore a unique index of imageology to assess the pathological development and evaluate therapeutically effect in dynamic and systemic reviews in pre, intra, postEVR and followup period. Methods Fortyeight patients involving aneurysm or dissection of thoracic aorta were treated with EVR based on the preoperative CTA imaging. Before and after the introducing of stentgraft, digital substation angiography (DSA) was taken place and sequential enhanced CTA was followed to evaluate the effects of the treatment. All imagings of CTA and DSA were collected and induced into e-FilmTM database to select key sections for analyses and measurement. Results Fortynine EVR were preformed and 54 stent grafts were implanted in 48 cases, with endothelial tears sealed in 42 cases of dissection, aneurismal cavities excluded in 2 cases of aortic aneurysm, and rupture site closed in 4 cases of pseudoaneurysm. Endoleakage happened in 9 cases, which were treated successfully by appropriate measures. One case suffered hemorrhage from introducing artery (iliac) which was controled by surgery, but he died of disseminated intravascular coagulation and then multiple organs failure. Fortyseven cases were followed up in 6-51 months with a satisfied clinical effect. Conclusion EVR is favorable in the effect of repairment to true, false and dissection of thoracic descending aorta. Chest pain and CTA scan is the key of early diagnosis of aortic dissection. Certain sections and leftanterior oblique viewing are the crucial profile for assessment and evaluation before and after operation.
Six cases of old fracture of the tibia with large sear, bony defect, and shortening deformity of the limb were treated by elongation osteotomy at epiphysis and compression fixation of the fracture with external semilunar fixation frame. The bony defect ranged from 3cm to 6cm. Bony healing developed in all patients 4-7 months after operation. Early postoperative movement was suggested. The results revealed that there was an obvious improvement of the joint function and the shortened legs were corrected. The advantages of this method are that there is no need of bone grafting and operative treatment of the scar prior to treatment of the bone.
ObjectiveTo investigate the effectiveness of anterior subcutaneous internal fixator combined with posterior plate in the treatment of unstable pelvic fractures.MethodsBetween January 2015 and January 2019, 26 cases of unstable pelvic fractures were treated with anterior subcutaneous internal fixator combined with posterior plate. There were 16 males and 10 females, with an average age of 42.8 years (range, 25-66 years). According to the Tile classification, 9 of them belonged to type B2, 6 to type B3, 7 to type C1, 3 to type C2, 1 to type C3. The injury severity score (ISS) was 6-43 (mean, 18.3). Four cases combined with brain injury, 7 with limb fractures, 3 with hemopneumothorax, 1 with sciatic nerve injury. The time from injury to operation was 4-12 days (mean, 6.4 days). The intraoperative blood loss, operation time, and the complications were recorded. The fracture reduction and the postoperative function of patients were evaluated.ResultsAll patients were followed up 12-26 months (mean, 16.8 months). The operation time was 65-142 minutes (mean, 72.5 minutes) and the intraoperative blood loss was 42-124 mL (mean, 64.2 mL). There were 2 cases of unilateral lateral femoral cutaneous nerve stimulation, 1 case of femoral nerve paralysis, and 1 case of superficial infection of incision, which were cured after corresponding treatment. X-ray films showed that all fractures healed at 3 months after operation. At last follow-up, according to Matta criteria for fracture reduction, the results were excellent in 8 cases, good in 15 cases, fair in 2 cases, and poor in 1 case, with an excellent and good rate of 88.5%. According to Majeed scoring system for pelvic function, the results were excellent in 10 cases, good in 12 cases, and fair in 4 cases, with an excellent and good rate of 84.6%.ConclusionFor unstable pelvic fractures, the anterior subcutaneous internal fixator combined with posterior plate has fewer operative complications, high security, and achieve good effectiveness.
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 effects, advantages and disadvantages of simple internal fixation to that of l imited internal fixation with external supporting frame fixation in the treatment of complex fractures of tibial plateau. Methods From July 2002 to August 2006, 66 cases of complex fractures of the tibial plateau were divided into the internal fixation group (n=39) and the external fixator group (n=27). The interal fixation group had 18 cases of IV, 7 cases V and 14 cases VI according to Schatzker, including 25 males and 14 females aged 18-79 years with an average of 45.4 years. The external fixator group had 13 cases of IV, 6 cases V and 8 cases VI according to Schatzker, including 18 males and 9 femles aged 18-64 years with an average of 44.2 years. No significant difference was evident between the two groups (P gt; 0.05). Patients were treated by using screws, steel plates or external supporting frame fixation strictly based on the princi ple of internalfixation. Results All patients were followed up for 1-5 years. Fracture healed with no occurrence of nonunion. Two cases inthe internal fixation group presented partial skin infection and necrosis, and were cured through the dressing change and flap displacement. Fracture heal ing time was 6-14 months with an average of 7.3 months. The time of internal fixator removal was 6-15 months with an average of 8.3 months. In the external fixation group, 11 cases had nail treated fluid 7 days to 3 months after operation, combining with red local skin; 3 cases had skin necrosis; and 3 cases had loose bolts during follow-up. Through debridement, dressing change and flap displacement, the skin wounds healed. Fracture heal ing time was 3-11 months with an average of 5.1 months. The time of external fixator removal was 5-11 months with an average of 6.4 months. At 8-14 months after operation, the knee function was assessed according to Merchant criteria. In the internal fixation group, 29 cases were excellent, 4 good, 5 fair and 1 poor, while in the external fixation group, 20 cases were excellent, 3 good, 2 fair and 2 poor. There was no significant difference between the two groups (P gt; 0.05). Conclusion The therapeutic effects of simple internal fixation and l imited internal fixation with external supporting frame fixation were similar in the treatment of complex fractures of tibial plateau. Fixation materials should be selected according to the state of injury and bone conditions for the treatment of tibial plateau fracture of type IV, V and VI based on Sehatzker classification.