Insufficient donor dermis and the shortage of three-dimensional vascular networks are the main limitations in the tissue-engineered dermis(TED).To solve these problems,we initially constructed pre-vascularized bone ma...Insufficient donor dermis and the shortage of three-dimensional vascular networks are the main limitations in the tissue-engineered dermis(TED).To solve these problems,we initially constructed pre-vascularized bone marrow mesenchymal stem cell sheet(PBMCS)and pre-vascularized fibroblasts cell sheet(PFCS)by cell sheet technology,and then superimposed or folded them together to construct a pre-vascularized TED(PTED),aiming to mimic the real dermis structure.The constructed PTED was implanted in nude mice dorsal dermis-defect wound and the wound-healing effect was quantified at Days 1,7 and 14 via the methods of histochemistry and immunohistochemistry.The results showed that PTED could rapidly promote the wound closure,especially at Day 14,and the wound-healing rate of three-layer PTED could reach 97.2%(P<0.01),which was faster than the blank control group(89.1%),PBMCS(92.4%),PFCS(93.8%)and six-layer PTED(92.3%).In addition,the vessel density in the PTED group was higher than the other groups on the 14th day.Taken together,it is proved that the PTED,especially three-layer PTED,is more conducive to the fullthickness dermis-defect repair and the construction of the three-dimensional vascular networks,indicating its potential application in dermis-defect repair.展开更多
Objective ： To investigate the effect of cancellous bone matrix gelatin （ BMG ） engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods： Chondrocytes were seeded onto ...Objective ： To investigate the effect of cancellous bone matrix gelatin （ BMG ） engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods： Chondrocytes were seeded onto threedimensional cancellous BMG and .cultured in vitro for 12 days to prepare BMG-chondrocyte complexes. Under anesthesia with 2.5% pentobarbital sodium （ lml/kg body weight）, articular cartilage defects were made on the right knee joints of 38 healthy New Zealand white rabbits （regardless of sex, aged 4-5 months and weighing 2. 5-3 kg） and the defects were then treated with 2.5% trypsin. Then BMG-chondrocyte complex （Group A, n = 18）, BMG （Group B, n =10）, and nothing （Group C, n =10） were implanted into the cartilage defects, respectively. The repairing effects were assessed by macroscopic, histologic, transmission electron microscopic （TEM） observation, immunohistochemical examination and in situ hybridization detection, respectively, at 2, 4, 8, 12 and 24 weeks after operation. Results.. Cancellous BMG was degraded within 8 weeks after operation. In Group A, lymphocyte infiltration was observed around the graft. At 24 weeks after operation, the cartilage defects were repaired by cartilagetissues and the articular cartilage and subchondral bone were soundly healed. Proteoglycan and type II collagen were detected in the matrix of the repaired tissues by Safranin-O staining and immunohistochemical staining, respectively. In situ hybridization proved gene expression of type II collagen in the cytoplasm of chondrocytes in the repaired tissues, TEM observation showed that chondrocytes and cartilage matrix in repaired tissues were almost same as those in the normal articular cartilage. In Group B, the defects were repaired by cartilage-fibrous tissues. In Group C, the defects were repaired only by fibrous tissues. Conclusions ： Cancellous BMG can be regarded as the natural cell scaffolds for cartilage tissue engineering. Articular cartilage defects can be repaired by canc展开更多
背景:关于老年股骨转子下骨折不同内固定方式的生物力学研究比较多,但关于比较防旋股骨近端髓内钉(Proximal Femoral Nail Antirotation,PFNA)-Ⅱ和亚洲股骨髓内钉固定老年股骨转子下骨折的研究不多。目的:探讨两种髓内钉PFNA-Ⅱ和亚洲...背景:关于老年股骨转子下骨折不同内固定方式的生物力学研究比较多,但关于比较防旋股骨近端髓内钉(Proximal Femoral Nail Antirotation,PFNA)-Ⅱ和亚洲股骨髓内钉固定老年股骨转子下骨折的研究不多。目的:探讨两种髓内钉PFNA-Ⅱ和亚洲股骨髓内钉固定老年股骨转子下骨折的生物力学特点。方法:建立PFNA-Ⅱ和亚洲股骨髓内钉固定股骨转子下骨折的三维有限元模型,三维有限元法分析股骨转子下骨折PFNA-Ⅱ固定和亚洲股骨髓内钉固定的应力分布和位移情况。结果与结论:(1)PFNA-Ⅱ髓内固定系统的整体最大应力、主钉最大应力和髋螺钉或螺旋刀片最大应力值均高于亚洲股骨髓内钉髓内固定系统,PFNA-Ⅱ髓内固定系统的远端锁钉最大应力值和股骨头表面最大应力值低于亚洲股骨髓内钉髓内固定系统;(2)PFNA-Ⅱ髓内固定系统的最大位移主要集中在大转子部和股骨头下极,亚洲股骨髓内钉髓内固定系统的最大位移主要集中在大转子部,PFNA-Ⅱ髓内固定系统的最大位移高于亚洲股骨髓内钉髓内固定系统的最大位移;PFNA-Ⅱ髓内固定系统的最大轴向分位移高于亚洲股骨髓内钉髓内固定系统;PFNA-Ⅱ髓内固定系统的最大矢状面分位移高于亚洲股骨髓内钉髓内固定系统的最大矢状面分位移;PFNA-Ⅱ髓内固定系统的最大冠状面分位移高于亚洲股骨髓内钉髓内固定系统的最大冠状面分位移;(3)PFNA-Ⅱ髓内固定系统的外侧裂隙、前方裂隙和后方裂隙均高于亚洲股骨髓内钉髓内固定系统的外侧裂隙、前方裂隙和后方裂隙,但差别不太明显;(4)PFNA-Ⅱ髓内固定系统的骨折断面最大应力值低于亚洲股骨髓内钉髓内固定系统的的骨折断面最大应力值;(5)结果表明,与PFNA-Ⅱ髓内固定系统相比,亚洲股骨髓内钉固定股骨转子下骨折具有更好的生物力学稳定性。展开更多
基金supported by The Natural Science Foundation of China(81571829)The Fundamental Research Funds for the Central Universities(lzujbky-2020-it29)the open project of State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences(LSL-1907).
文摘Insufficient donor dermis and the shortage of three-dimensional vascular networks are the main limitations in the tissue-engineered dermis(TED).To solve these problems,we initially constructed pre-vascularized bone marrow mesenchymal stem cell sheet(PBMCS)and pre-vascularized fibroblasts cell sheet(PFCS)by cell sheet technology,and then superimposed or folded them together to construct a pre-vascularized TED(PTED),aiming to mimic the real dermis structure.The constructed PTED was implanted in nude mice dorsal dermis-defect wound and the wound-healing effect was quantified at Days 1,7 and 14 via the methods of histochemistry and immunohistochemistry.The results showed that PTED could rapidly promote the wound closure,especially at Day 14,and the wound-healing rate of three-layer PTED could reach 97.2%(P<0.01),which was faster than the blank control group(89.1%),PBMCS(92.4%),PFCS(93.8%)and six-layer PTED(92.3%).In addition,the vessel density in the PTED group was higher than the other groups on the 14th day.Taken together,it is proved that the PTED,especially three-layer PTED,is more conducive to the fullthickness dermis-defect repair and the construction of the three-dimensional vascular networks,indicating its potential application in dermis-defect repair.
文摘Objective ： To investigate the effect of cancellous bone matrix gelatin （ BMG ） engineered with allogeneic chondrocytes in repairing articular cartilage defects in rabbits. Methods： Chondrocytes were seeded onto threedimensional cancellous BMG and .cultured in vitro for 12 days to prepare BMG-chondrocyte complexes. Under anesthesia with 2.5% pentobarbital sodium （ lml/kg body weight）, articular cartilage defects were made on the right knee joints of 38 healthy New Zealand white rabbits （regardless of sex, aged 4-5 months and weighing 2. 5-3 kg） and the defects were then treated with 2.5% trypsin. Then BMG-chondrocyte complex （Group A, n = 18）, BMG （Group B, n =10）, and nothing （Group C, n =10） were implanted into the cartilage defects, respectively. The repairing effects were assessed by macroscopic, histologic, transmission electron microscopic （TEM） observation, immunohistochemical examination and in situ hybridization detection, respectively, at 2, 4, 8, 12 and 24 weeks after operation. Results.. Cancellous BMG was degraded within 8 weeks after operation. In Group A, lymphocyte infiltration was observed around the graft. At 24 weeks after operation, the cartilage defects were repaired by cartilagetissues and the articular cartilage and subchondral bone were soundly healed. Proteoglycan and type II collagen were detected in the matrix of the repaired tissues by Safranin-O staining and immunohistochemical staining, respectively. In situ hybridization proved gene expression of type II collagen in the cytoplasm of chondrocytes in the repaired tissues, TEM observation showed that chondrocytes and cartilage matrix in repaired tissues were almost same as those in the normal articular cartilage. In Group B, the defects were repaired by cartilage-fibrous tissues. In Group C, the defects were repaired only by fibrous tissues. Conclusions ： Cancellous BMG can be regarded as the natural cell scaffolds for cartilage tissue engineering. Articular cartilage defects can be repaired by canc
文摘背景:关于老年股骨转子下骨折不同内固定方式的生物力学研究比较多,但关于比较防旋股骨近端髓内钉(Proximal Femoral Nail Antirotation,PFNA)-Ⅱ和亚洲股骨髓内钉固定老年股骨转子下骨折的研究不多。目的:探讨两种髓内钉PFNA-Ⅱ和亚洲股骨髓内钉固定老年股骨转子下骨折的生物力学特点。方法:建立PFNA-Ⅱ和亚洲股骨髓内钉固定股骨转子下骨折的三维有限元模型,三维有限元法分析股骨转子下骨折PFNA-Ⅱ固定和亚洲股骨髓内钉固定的应力分布和位移情况。结果与结论:(1)PFNA-Ⅱ髓内固定系统的整体最大应力、主钉最大应力和髋螺钉或螺旋刀片最大应力值均高于亚洲股骨髓内钉髓内固定系统,PFNA-Ⅱ髓内固定系统的远端锁钉最大应力值和股骨头表面最大应力值低于亚洲股骨髓内钉髓内固定系统;(2)PFNA-Ⅱ髓内固定系统的最大位移主要集中在大转子部和股骨头下极,亚洲股骨髓内钉髓内固定系统的最大位移主要集中在大转子部,PFNA-Ⅱ髓内固定系统的最大位移高于亚洲股骨髓内钉髓内固定系统的最大位移;PFNA-Ⅱ髓内固定系统的最大轴向分位移高于亚洲股骨髓内钉髓内固定系统;PFNA-Ⅱ髓内固定系统的最大矢状面分位移高于亚洲股骨髓内钉髓内固定系统的最大矢状面分位移;PFNA-Ⅱ髓内固定系统的最大冠状面分位移高于亚洲股骨髓内钉髓内固定系统的最大冠状面分位移;(3)PFNA-Ⅱ髓内固定系统的外侧裂隙、前方裂隙和后方裂隙均高于亚洲股骨髓内钉髓内固定系统的外侧裂隙、前方裂隙和后方裂隙,但差别不太明显;(4)PFNA-Ⅱ髓内固定系统的骨折断面最大应力值低于亚洲股骨髓内钉髓内固定系统的的骨折断面最大应力值;(5)结果表明,与PFNA-Ⅱ髓内固定系统相比,亚洲股骨髓内钉固定股骨转子下骨折具有更好的生物力学稳定性。
