ABSTRACT: The aim of this paper was to observe and visualize the changes in osteoblasts by electron microscopy during osteogenesis using
tissue engineering technique. We also studied the feasibility of improving tissue vascularization of the engineered bone by
using small intestine submucosa (SIS) as the scaffold. Bone mesenchymal stem cells (BMSCs) were isolated by gradient centrifugation
method. Bone mesenchymal stem cells were seeded in the SIS, and the scaffold-cell constructs were cultured in vitro for 2 weeks. Small intestine submucosa without BMSCs served as control. Both SIS scaffolds were then implanted subcutaneously
in the dorsa of athymic mice. The implants were harvested after in vivo incubation for 4, 8 and 12 weeks. The changes in osteoblasts and vascularization were observed under a transmission electron
microscope and a scanning electron microscope. The BMSCs grew quite well, differentiating on the surface of the SIS and secreting
a great deal of extracellular matrices. The scaffold-cell constructs formed a lot of bone and blood vessels in vivo. The scaffold degraded after 12 weeks. No osteoblasts, but vascularization and fibroblasts were observed, in the control.
The SIS can be used as a scaffold for constructing tissue-engineered bone as it can improve the formation of bone and vessels
Frontiers of Medicine in China 04/2012; 1(2):181-184.
ABSTRACT: To study an optimal ratio of small intestinal submucosa (SIS) and (hydroxyapatite-tricalcium phosphate, HA-TCP, SIS/HA-TCP) compositions according to the effect of SIS/HA-TCP compositions with different ratios on repairing rabbit femoral condyle defect.
Thirty-six rabbits were made into bone defect models of 6 mm in diameter and 10 mm in depth in both sides of femoral condyles. Three different ratios of SIS/HA-TCP compositions (w/w: 1, 0. 5, 0. 25) were implanted into rabbit femoral condyle defect. After 2, 4, 8 and 12 weeks of operation, the repair effect was observed grossly. The histological evaluations were performed by histological scoring system and computer imaging analysis system.
The amount of new bone formation in SIS/HA-TCP(0. 5) group was more than that in SIS/HA-TCP(1) and SIS/HA-TCP(0. 25) groups. Histological observation: In SIS/HA-TCP (1) group, few new bone formation was seen and bone defect was repaired in the 12th week. In SIS/HA-TCP (0.5) group, immature woven bone was found in the defect in the 2nd week; more immature woven bone appeared and formed trabeculae in the 4th week; the regenerated bone was vigorously growing into the interspaces of the implanted materials in the 8th week; the implanted materials was basically replaced by bony structure and the lamellar bone appeared in the 12th week. The results of SIS/HA-TCP (0. 25) group were similar to that of SIS/HA-TCP(0. 5) group. The histological scoring was higher in SIS/HA-TCP (0.5) and SIS/HA-TCP (0.25) groups than that in SIS/HA-TCP (1) group (P<0.05) in the 2nd, 4th, 8th, and 12th weeks. The scoring was higher in SIS/HA-TCP (0.5) group than that in SIS/HA-TCP (0.25) group in the 2nd and 12th weeks (P< 0.05). In new bone formation and the degradation of HA-TCP, SIS/HA-TCP (0.5) and SIS/HA-TCPC (0.25) groups were superior to SIS/HA-TCP (1) group (P<0.05), SIS/HA-TCP (0.5) group was superior to SIS/HA-TCP (0.25) group (P<0.05).
SIS/ HA-TCP (0.5) has better effects of repairing bone defect and it can be used as a reference ratio in constructing bone scaffolds.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 11/2006; 20(11):1061-5.
ABSTRACT: To evaluate the surgical technique, clinical results, and the complications of modified free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head.
From October 2000 to August 2004, 124 patients (139 hips) with osteonecrosis of the femoral head were treated with modified free vascularized fibular grafting. There were 83 males(93 hips) and 41 females (46 hips), with a mean age of 36.4 years (16-57). The disease was caused by trauma in 49 cases(54 hips), use of steroids in 29 cases (32 hips), consumption of alcohol in 19 cases (21 hips) and idiopathic condition in 27 cases (32 hips). Of 139 hips, 50 were classified as stage II ; 71 as stage II, 18 as stage IV according to Steinberg system; the Harris hip scores were 79.3, 69.3 and 58.4, respectively. At the operation, modified technique of the fibular osteotomy was adopted. A front-hip operative approach was designed and a modified technique of removing the necrotic bone in femoral head was applied. During operation, the duration of operation, the bleeding volume, and the length of incisions were recorded. The follow-up items included the results of X-ray examination, the Harris score of the hip, and the evaluation of the complications.
The duration of the fibular osteotomy was 10 to 30 min (15 min on average). The duration of the total operation was 80 to 120 min (90 min on average). The length of incision at the hip was 6 to 12 cm (8 cm on average). The bleeding volume was 100 to 300 ml (200 ml on average). The average hospitalization days was 7 days. After operation, Harris hip scores in most cases were improved. According to postoperative X-ray, 62 hips (79.5%) were improved to different extents and 14 hips (17.9%) had no significant changes. Deterioration occurred in 2 hips (2.6%).
The modified free vascularized fibular grafting has lots of virtues, such as less bleeding volume, more clear anatomic structure, more convenience for operation, less damage, less complications, and better results of function recovery. It is an effective method for treating osteonecrosis of the femoral head.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 10/2005; 19(9):692-6.