Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from p...Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from piglets and cultured in different mediums including either vascular endothelial growth factor(VEGF)or platelet derived growth factor BB(PDGF-BB)to observe their expansion and differentiation.The aortas harvested from canines were processed by a multi-step decellularizing technique to erase.The bone marrow mononuclear cells cultured in the mediums without any growth factors were seeded to the acellular matrix.The cells-seeded grafts were incubated in vitro for 6 d and then implanted to the cells-donated piglets to substitute parts of their native pulmonary arteries.Results After 4 d culturing,the cells incubated in the medium including VEGF showed morphological feature of endothelial cells(ECs)and were positive to ECs-specific monoclonal antibodies of CD31,FLK-1,VE-Cadherin and vWF.The cells incubated in the medium including PDGF-BB showed morphological feature of smooth muscle cells(SMCs)and were positive to SMCs-specific monoclonal antibodies of α-SMA and Calponin.One hundred days after implantation of seeded grafts,the inner surfaces of explants were smooth without thrombosis,calcification and aneurysm.Under the microscopy,plenty of growing cells could be seen and elastic and collagen fibers were abundant.Conclusion Mesenchymal stem cells might exist in mononuclear cells isolated from bone marrow.They would differentiate into endothelial cells or smooth muscle cells in proper in vitro or in vivo environments.The bone marrow mononuclear cells might be a choice of seeding cells in constructing tissue-engineered graft.展开更多
Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, P...Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, Pseudohynobius puxiongensis （Caudata： Hynobiidae）. The second case discovered in living salamanders is reported in this article, which is present in one of five specimens ofHynobius maoershanensis, a species endemic to China. This case is again regarded as individual variation. Thus, the presence of an ＂internasal bone＂ may represent intraspecific variation and is thus a misleading taxonomic character.展开更多
Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defect...Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.展开更多
3D打印个性化钛网作为引导骨再生(guided bone regeneration,GBR)的屏障膜在牙槽骨缺损重建中应用,具有新骨重建空间维持好和可预期水平和垂直骨增量的优点。本文通过对3D打印个性化钛网厚度和孔隙度、成骨性能、设计与制作、手术方法...3D打印个性化钛网作为引导骨再生(guided bone regeneration,GBR)的屏障膜在牙槽骨缺损重建中应用,具有新骨重建空间维持好和可预期水平和垂直骨增量的优点。本文通过对3D打印个性化钛网厚度和孔隙度、成骨性能、设计与制作、手术方法、并发症和术后骨增量与术前预期骨增量的比较,以及3D-PITM暴露的影响因素与防治等方面进行综述。展开更多
Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relat...Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relatively ideal solution to these problems. Methods Bone marrow was aspirated from sternum of lamb goats to isolate BMCs. Cells were identified by flow cytometry and its capacity of differentiation. Cellular viability was assessed with Rhdomine 123 staining. 1 × 10^7cells were seeded on a patch of PGA sheet. After two-day in vitro culture, autologous cell/ scaffold sheets were used to replace the right posterior pulmonary valve leaflets under cardiopulmonary bypass. The leaflets were explanted at 2 days, 2, 6, 8 and 10 weeks after implantation. The samples were examined macroscopically, histologically, immunohistochemically, and by Scanning Electron Microscope （SEM）. Two goats were implanted with acellular sheets and established as a control group. Results BMCs exhibited fibroblastoid morphology with good viability. Flow cytometry showed negative CD14 and CD45 expression. In vitro cultured BMCs demonstrated the potential to differentiate into adipocytes. The explanted leaflets resembled the characteristics of native extracellular matrix was leaflets macroscopicaIly in the cellular group. Histology showed synthesized and cells were distributed in the single-layered leaflets.Immunohistochemistry revealed positive staining for yon Willebrand factor, α-SMA, vimentin. A confluent cell surface was formed on the explanted TEHLs. No calcium deposited on the leaflets. In control group, the acellular scaffolds were completely degraded, without leaflet remained at 8 weeks. Conclusions It is possible to create tissue-engineered heart valves in vivo using autologous bone marrow-derived cells.展开更多
基金Supported by Shanghai Nature Science Foundation,China(99ZB14018)
文摘Objective To create a method for constructing a tissue-engineered graft with self-derived bone marrow cells and heterogeneous acellular matrix.Methods The mononuclear cells were isolated from bone marrows drawn from piglets and cultured in different mediums including either vascular endothelial growth factor(VEGF)or platelet derived growth factor BB(PDGF-BB)to observe their expansion and differentiation.The aortas harvested from canines were processed by a multi-step decellularizing technique to erase.The bone marrow mononuclear cells cultured in the mediums without any growth factors were seeded to the acellular matrix.The cells-seeded grafts were incubated in vitro for 6 d and then implanted to the cells-donated piglets to substitute parts of their native pulmonary arteries.Results After 4 d culturing,the cells incubated in the medium including VEGF showed morphological feature of endothelial cells(ECs)and were positive to ECs-specific monoclonal antibodies of CD31,FLK-1,VE-Cadherin and vWF.The cells incubated in the medium including PDGF-BB showed morphological feature of smooth muscle cells(SMCs)and were positive to SMCs-specific monoclonal antibodies of α-SMA and Calponin.One hundred days after implantation of seeded grafts,the inner surfaces of explants were smooth without thrombosis,calcification and aneurysm.Under the microscopy,plenty of growing cells could be seen and elastic and collagen fibers were abundant.Conclusion Mesenchymal stem cells might exist in mononuclear cells isolated from bone marrow.They would differentiate into endothelial cells or smooth muscle cells in proper in vitro or in vivo environments.The bone marrow mononuclear cells might be a choice of seeding cells in constructing tissue-engineered graft.
基金supported by the grants of the National Natural Science Foundation of China(NSFC)(30870287)the Chinese Academy of Sciences(KSCX2-EW-J-22)to Xiaomao ZENGthe grants of NSFC(30900138)and Henan University of Science and Technology Foundation(09001367)to Jianli XIONG
文摘Internasal bones have generally been recorded in teleostean and tetrapod fossils, being absent in most extant vertebrates. Presently, there has been one case of the internasal bone discovered in a living salamander, Pseudohynobius puxiongensis （Caudata： Hynobiidae）. The second case discovered in living salamanders is reported in this article, which is present in one of five specimens ofHynobius maoershanensis, a species endemic to China. This case is again regarded as individual variation. Thus, the presence of an ＂internasal bone＂ may represent intraspecific variation and is thus a misleading taxonomic character.
基金This project was supported by national high technology re search and development program of China ( 863 Program,2001AA216031), key technologies research and developmentprogram of Beijing (H020920050031).
文摘Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1.073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in “creep substitution” way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond “creep substitution” way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.
文摘3D打印个性化钛网作为引导骨再生(guided bone regeneration,GBR)的屏障膜在牙槽骨缺损重建中应用,具有新骨重建空间维持好和可预期水平和垂直骨增量的优点。本文通过对3D打印个性化钛网厚度和孔隙度、成骨性能、设计与制作、手术方法、并发症和术后骨增量与术前预期骨增量的比较,以及3D-PITM暴露的影响因素与防治等方面进行综述。
基金supported by the grant from Guangdong Nature Science Foundation(7001117)
文摘Background Currently used heart valve prostheses are associated with anticoagulation complications or limited durability. The advancement of stem cell study and tissue-engineered heart valve research may offer a relatively ideal solution to these problems. Methods Bone marrow was aspirated from sternum of lamb goats to isolate BMCs. Cells were identified by flow cytometry and its capacity of differentiation. Cellular viability was assessed with Rhdomine 123 staining. 1 × 10^7cells were seeded on a patch of PGA sheet. After two-day in vitro culture, autologous cell/ scaffold sheets were used to replace the right posterior pulmonary valve leaflets under cardiopulmonary bypass. The leaflets were explanted at 2 days, 2, 6, 8 and 10 weeks after implantation. The samples were examined macroscopically, histologically, immunohistochemically, and by Scanning Electron Microscope （SEM）. Two goats were implanted with acellular sheets and established as a control group. Results BMCs exhibited fibroblastoid morphology with good viability. Flow cytometry showed negative CD14 and CD45 expression. In vitro cultured BMCs demonstrated the potential to differentiate into adipocytes. The explanted leaflets resembled the characteristics of native extracellular matrix was leaflets macroscopicaIly in the cellular group. Histology showed synthesized and cells were distributed in the single-layered leaflets.Immunohistochemistry revealed positive staining for yon Willebrand factor, α-SMA, vimentin. A confluent cell surface was formed on the explanted TEHLs. No calcium deposited on the leaflets. In control group, the acellular scaffolds were completely degraded, without leaflet remained at 8 weeks. Conclusions It is possible to create tissue-engineered heart valves in vivo using autologous bone marrow-derived cells.
