Objective To study the effect of the allogeneic bone sheet that has been treated by the freezedrying and radiation sterilization in preventing the epidural adhesion after laminectomy in sheep. Methods Laminectomy was performed on L3,4and L4,5 of 12 adult male sheep. Afteroperation, one site of L3,4 or L4,5was covered by the allogeneicbone sheet in “H” shape after the freeze-drying and radiation sterilization treatment; and the other site was used as a control. The sheep were killed and the specimens were retrieved at 4，8，12，16，20 and 24 weeks after operation to observe the scar formation process. X-ray andCT scan were performed in the segments of L3,4and L4,5at 4 and 24weeks. Results Four weeks after operation, the position and the shape of the allogeneic bone sheet were good in condition, and no lumbar spinal stenosis or compression of the dura was found in the experimental sections. Twentyfour weeks after operation theexamination on the experimental sections revealed that the vertebral canal reconstruction was completed, the allograft was absorbed almost completely, and inosculation with the lamina of the vertebra and the shape of the lumbar spine were good, with no fibroid tissues found in the epidural area. Compared with the control segment, the dura adhesion degree in the laminoplasty segment was significantly decreased (Plt;0.01), and the dura sac remained in a good shape. There was no obvious compression on the dura. Conclusion The allogeneic bone sheet after the treatment of freeze-drying and radiation sterilization can effectively reduce the scar formation after laminectomy and prevent postoperative recurrence of the spinal stenosis.
Objective To investigate the clinical results of allograft and sural neurovascular flap in repairing calcaneus and skin defects.Methods From February 1996 to December 2002, allograft and sural neurovascular flap were used to repair calcaneusand skin defects in 6 cases. The causes included road accident in 3 cases, strangulation in 2 cases and crashing object in 1 case. The defect locations were at theback of the calcaneus( 1/3, 1/2 and 2/3 of calcaneus in 3 cases, 2 cases and 1case respectively). The flap area ranged from 6 cm×7 cm to 12 cm×17 cm. Results The flaps survived completely in 4 cases; the distal flaps necrosed partly in 2 cases and the wound healed by dressing. The postoperative X-ray films showed that the repaired bone and joint had normal position and the arcus plantaris recovered. After a follow upof 6 months to 3 years all the patients were achieved bone union in allograft and had no complications of absorption, infection and repulsion. The weightbearing and walking functions were restored and the injured foot obtained a satisfactory contour. After 36 months of operation, the sensory recovery of foot occurred. Conclusion The used-allograft iseasy to be obtained and arcus plantaris is easy to recover. The reversesural neurovascular- flap in repairing calcaneus and skin defects has the following advantages: the maintenance of blood supply for injured foot, the less dangerous operation, the simple procedure, the recovery of walking function, and the good appearance and sensation.
ObjectiveTo explore the feasibility of chitosan/allogeneic bone powder composite porous scaffold as scaffold material of bone tissue engineering in repairing bone defect. MethodsThe composite porous scaffolds were prepared with chitosan and decalcified allogeneic bone powder at a ratio of 1∶5 by vacuum freeze-drying technique. Chitosan scaffold served as control. Ethanol alternative method was used to measure its porosity, and scanning electron microscopy (SEM) to measure pore size. The hole of 3.5 mm in diameter was made on the bilateral femoral condyles of 40 adult Sprague Dawley rats. The composite porous scaffolds and chitosan scaffolds were implanted into the hole of the left femoral condyle (experimental group) and the hole of the right femoral condyle (control group), respectively. At 2, 4, 8, and 12 weeks after implantation, the tissues were harvested for gross observation, histological observation, and immunohistochemical staining. ResultsThe composite porous scaffold prepared by vacuum freeze-drying technique had yellowish color, and brittle and easily broken texture; pore size was mostly 200-300μm; and the porosity was 76.8%±1.1%, showing no significant difference when compared with the porosity of pure chitosan scaffold (78.4%±1.4%) (t=-2.10, P=0.09). The gross observation and histological observation showed that the defect area was filled with new bone with time, and new bone of the experimental group was significantly more than that of the control group. At 4, 8, and 12 weeks after implantation, the bone forming area of the experimental group was significantly larger than that of the control group (P < 0.05). The immunohistochemical staining results showed that osteoprotegerin (OPG) positive expression was found in the experimental group at different time points, and the positive expression level was significantly higher than that in the control group (P < 0.05). ConclusionChitosan/allogeneic bone powder composite porous scaffold has suitable porosity and good osteogenic activity, so it is a good material for repairing bone defect, and its bone forming volume and bone formation rate are better than those of pure chitosan scaffold.
OBJECTIVE To investigate the effect of allogeneic decalcified bone graft in the treatment of nonunion in children. METHODS From April 1990 to September 1997, 17 children with nonunion were adopted in this study. Among them, there were 10 boys and 7 girls, the age ranged from 2 to 13 years. The allogeneic decalcified bone graft taken from fresh corpse by aseptic manipulation were used to repair 3 cases of congenital nonunion and 14 cases of acquired nonunion. RESULTS All cases were followed up 2 to 9 years after operation, 9 cases were cured successfully and 7 cases were cured after twice operations. One case of congenital pseudoarthrosis of the tibia was operated twice and there were callus grown half years after the second operation, but reoccurred after one year. Although there were 1.5 cm to 3 cm shortening deformity of extremity including another 2 cases of congenital pseudoarthrosis of the tibia and 5 cases of nonunion caused by chronic osteomyelitis, the function of joint was normal. CONCLUSION Treatment of nonunion in children by allogeneic decalcified bone graft is a valuable technique in clinical practice. It is characterised by high capacity of osteoinduction, low antigenicity, rapid bony union, plentiful source of bone graft and convenient utilization.
【Abstract】 Objective To investigate the impact of dermal papillary cells on vascularization of tissue engineered skinsubstitutes consisting of epidermal stem cells and allogeneic acellular dermal matrix. Methods Human foreskins from routinecircumcisions were collected to separate epidermal cells by using dispase with trypsogen. Collagen type IV was used to isolateepidermal stem cells from the 2nd and 3rd passage keratinocytes. Dermal papilla was isolated by the digestion method of collagenaseI from fetus scalp and cultured in routine fibroblast medium. Tissue engineered skin substitutes were reconstructed by seedingepidermal stem cells on the papillary side of allogeneic acellular dermis with (the experimental group) or without (the controlgroup) seeding dermal papillary cells on the reticular side. The two kinds of composite skin substitutes were employed to cover skindefects (1 cm × 1 cm in size) on the back of the BALB/C-nu nude mice (n=30). The grafting survival rate was recorded 2 weeks aftergrafting. HE staining and immunohistochemistry method were employed to determine the expression of CD31 and calculate themicrovessel density at 2 and 4 weeks after grafting. Results Those adhesion cells by collagen type IV coexpressed Keratin 19 andβ1 integrin, indicating that the cells were epidermal stem cells. The cultivated dermal papillary cells were identified by expressinghigh levels of α-smooth muscle actin. The grafting survival rate was significantly higher in experimental group (28/30, 93.3%), thanthat in control group (24/30, 80.0%). HE staining showed that the epithelial layer in experimental group was 12-layered with largeepithelial cells in the grafted composite skin, and that the epithelial layer in control group was 4-6-layered with small epithelial cells.At 2 and 4 weeks after grafting, the microvessel density was (38.56 ± 2.49)/mm2 and (49.12 ± 2.39)/mm2 in experimental group andwas (25.16 ± 3.73)/mm2 and (36.26 ± 3.24)/mm2 in control group respectively, showing significant differences between 2 groups(P lt; 0.01). Conclusion Addition of dermal papillary cells to the tissue engineered skin substitutes can enhance vascularization,which promotes epidermis formation and improves the grafting survival rate.
OBJECTIVE: To observe the difference of the fracture reparation using autogeneic-iliac bone and allogenic bone. METHODS: Comminuted fracture of humerus in two sides were made in rabbits. Autogeneic-iliac bone was implanted in one side, while allogenic bone of equal capacity was implanted in the other side. General observation, X-ray, and HE histologic section were done when the rabbits were put to death in different stages. RESULTS: One week after implantation, the graft had been enclosed by connective tissue without infiltration of the inflammatory cells. At the 2nd week, the graft had been enclosed in osteoplastic granulation tissue, and the cartilage callus had formed. At the 3rd week, there had been broken sequestrum among the callus; the cartilage had actively formed the bone; and the medulla had been making. At the 4th week, the sequestrum had disappeared, and the mature callus had appeared; the osteoblasts had arranged in a line around the edge of the mature callus. At the 5th week, the callus was b, compact and approached mature bones. At the 6th week, there had been the compact lamellar structures and the complete haversian’s systems. There was no significant difference between callus of two sides by using image quantitative analysis in the 3rd, 4th week (P gt; 0.05). CONCLUSION: The allogenic bone has good histocompatibility and bone conduction effect, and can be used for bone transplantation substitute with autogenous-iliac bone.
Objective To investigate the adhesiveness of osteoblasts and vascular endothel ial cells from rat BMSCs co-cultured on allogeneic freeze-dried partially bone in vitro. Methods The BMSCs were isolated from 4-week-old SD rats (weighing 100-110 g) and cultured in vitro. The third generation of BMSCs were induced into osteoblasts and vascular endothel ial cells. The osteoblasts and vascular endothel ial cells after being induced for 7 days in a ratio of 1 to 1 were directlyco-cultured (experimental group), while the second generation of uninduced BMSCs was used as a control (control group). The growth and prol iferation abil ity were analyzed by MTT examination and the growth curve was drawn at 1-8 days. The osteoblasts and vascular endothel ial cells after being induced for 14 days were implanted in the allogeneic freeze-dried partially bone coated by 20% Col I or not at different densities (0.25 × 106/mL、0.50 × 106/mL、1.00 × 106/mL、2.00 × 106/mL、4.00 × 106/mL), as modified group and unmodified group, the cell adherence rate was calculated after 24 hours. These two kinds of cells were implanted in the pre-disposal treated allogeneic freeze-dried partially bone and observed by scanning electron microscope. Results ALP staining of osteoblasts showed that there were blue grains in cytoplasm at 7 days. CD31 and CD34 immunocytochemical staining of vascular endothelial cell showed that there were positive signals in the cytoplasm at 14 days. The MTT test showed that the prol iferation level of the experimental group was lower than those of the control group. There were significant differences in absorbance value between two group from 3 days to 8 days (P lt; 0.05). The cell adherence rate increased with increasing seeding density when the seeding density was (0.25-1.00) × 106/mL. The cell adherence rate reached the peak when the seeding density was 1.00 × 106/mL. The cell adherence rate decreased when the seeding density was more than 2.00 × 106/mL. There were significant differences in cell adherence rate between modified group and unmodified group at different seeding densities (P lt; 0.05). The prol iferation of the osteoblasts and endothel ial cells presented better growth and histocompatibil ity under scanning electron microscope. Conclusion The growing behavior of two kinds of cells is good in the allogeneic freezedried partially bone coated by 20% Col I , which can be used in reconstrction of vascularized tissue engineered bone.
Objective To explore the feasibility of allogeneic marrow stromal stem cells(MSCs) as seed cells to construct tissue engineered bone bydetecting the expressions of interleukin 2(IL-2) and IL-2 receptor in rhesus monkeys after implanting these tissue engineered bones.Methods Engineered bones were constructed with osteoblasts which derived from allogeneic MSCs and bio-derived materials in vitro, and then were implanted to bridge 2.5 cm segmental bone defects of left radius in 15 rhesus monkeys as experimental group, bioderived materials only were implanted to bridge same size defects of right radius as control group. Every 3 monkeys were sacrificed in the 1st, the 2nd, the 3rd, the 6th andthe 12th weeks postoperatively and the expressions of IL-2 and IL-2 receptor in blood and graft samples were detected quantitatively by enzymelinked immuneosorbent assay (ELISA).Results There was no significant difference in the contents of IL-2 and its receptor between 2 groups（P＞0.05）. The contents ofIL-2 and its receptor increased from the 2nd week and maintained high level from the 2nd to the 6th week, but decreased after 6 weeks.ConclusionTissue engineered bones constructed with allogeneic MSCs and bio-derived materials show low immunogenicity. Allogeneic MSCs may be used as seed cells to construct tissue engineered bone.
Objective To compare the effectiveness between arthroscopic double-bundle and single-bundle anterior cruciate l igament (ACL) reconstruction with deep-frozen allografts. Methods Between January 2008 and January 2009, 105 patients undergoing arthroscopic ACL reconstruction with deep-frozen allografts were selected and randomly divided intosingle-bundle (n=59) or double-bundle (n=46) groups. Patients were evaluated preoperatively and postoperatively 6, 12, and 24 months. Of the patients, 93 (51 in the single-bundle group and 42 in the double-bundle group) were available for full evaluation. There was no significant difference in gender, age, height, weight, disease duration, compl ication, the International Knee Documentation Committee (IKDC) score, and Lysholm score between 2 groups (P gt; 0.05). The anterior drawer test and the Lachman test for all were rated as + in 2 groups, and the pivot shift test were rated as ++ before operation. Results All wounds healed by first intention, and no related compl ication such as fracture, infection, or deep venous thrombosis was observed. There was no significant difference in the IKDC score, Lysholm score, anterior drawer test, pivot shift test, and Lachman test between 2 groups at 6-month and 12-month follow-up (P gt; 0.05). The IKDC score, Lysholm score, pivot shift test, Lachman test, and the side-to-side difference measured by KT-1000 arthrometer in the double-bundle group were significantly better than those in single-bundle group at 24-month follow-up (P lt; 0.05). Conclusion The double-bundle ACL reconstruction with deep-frozen allografts has better effectiveness than the single-bundle ACL reconstruction.
ObjectiveTo reporte the nursing experience of non-healing incision due to allograft rejection after osteosarcoma surgery. MethodsOne patient with non-healing incision due to allograft rejection after osteosarcoma surgery treated in September 2013 was selected. The suitable moist healing dressings was chosen to control inflammation, prevent infection, manage exudation, promote the growth of granulation, protect the surrounding skin, shorten the dressing time and reduce the suffering of patients. ResultThe wound healed well after 65 days of dressing with the function of the right upper limb recovered. ConclusionThe moist healing dressing not only improved the quality of patient's life and increased the patient's confidence of overcoming the disease, but also made the patients more active to cooperate in the next treatment.