OBJECTIVE To investigate the feasibility of freeze-dried demineralized bone matrix (FDBM) as scaffold material in bone tissue engineering. METHODS Osteoblasts which were isolated from cranial periosteum of New Zealand rabbits were cultured as the seeding cells, then the cells were cocultured with heterogenous FDBM in vitro. The cell-material complex was observed under phase microscope, light microscope and electronic scanning microscope in order to evaluate the interaction between cells and FDBM. RESULTS Eight hours after coculture, the osteoblasts adhered to FDBM scaffolds. Seven days later, the osteoblasts differentiated and proliferated in FDBM network. Extracellular matrix was secreted and calcium nodes were formed among osteoblasts. CONCLUSION FDBM is a good scaffold material for the bone tissue engineering.
OBJECTIVE: To study the expression of interleukin-1 receptor in normal mice sciatic nerves and in transected sciatic nerves treated with or without extrinsic interleukin-1 locally at different periods. METHODS: Seventy-two KM mice were equally divided into two groups. All the left sciatic nerves were transected. The stumps in experimental group were soaked in liquid with interleukin-1, whereas those in control group without interleukin-1. Then all the stumps were repaired end to end. At the 3rd hour, 1st day, 3rd day, 7th day, 14th day, and 28th day after operation respectively, every proximal stump was dissected and the expression of interleukin-1 receptor was carried out by immunohistochemistry method (LSAB method). The expression level of interleukin-1 of ten normal sciatic nerves of mice was studied, too. RESULTS: Normal nerves showed interleukin-1 receptor expression on the membrane of Schwann cells. After nerve injury, the interleukin-1 receptor expression increased biphasically in both groups, but the intensity of increase was lower in the experimental group than in the control group. CONCLUSION: Schwann cell is the target cell of interleukin-1.
OBJECTIVE: To investigate a cryophylactic agent (CPA) to protect tissue engineered tendon (TET) in deep low temperature. METHODS: Sixty-four BALB/C inbred nude mice were chosen, which included 4 as blank control group, left sides of 60 as experimental group and their right sides as control group. Transformed human embryonic tendon cells of the 54th passage and artificial materials of carbon fiber (CF) and polyglycolic acid (PGA) were co-cultured in vitro to construct TET. TET was frozen in liquid nitrogen with four kinds of CPA (groups A, B, C, and D) for 2 months. They were thawed quickly and transplanted into hind limbs of nude mice to repair the defects of Achilles tendon, which was 5 mm in length and 65.7% of total Achilles tendon. In control group, no cryopreservation treatment was taken. The morphological, histological, ultrastructure, and immunohistochemistry examinations were made and short tandem repeat loci were detected 2, 4, 6, 8, and 12 weeks later. RESULTS: In the experimental group, the morphological properties of tendon cells resumed gradually and the capability of synthesizing collagen enhanced by degrees. Tendon cells survived and could secret type I collagen and there was less difference between experimental and control groups 12 weeks after transplantation. In group A, vacuole in mitochondrion of tendon cell decreased, tendon cell arranged in order and abundant collagen fibers were found and linked. CONCLUSION: The cryopreservation agent in group A can protect TET in deep low temperature.
OBJECTIVE: To determine an optimal co-culture ratio of the rabbit periosteal osteoblasts (RPOB) and rabbit renal vascular endothelial cells(RRVEC) without direct contact for future study of bone tissue engineering. METHODS: RPOB and RRVEC in the ratios of 1:0(control group), 2:1(group 1), 1:1(group 2) and 1:2(group 3) were co-cultured by six well plates and cell inserts. Four days later, the proliferation of RPOB and RRVEC were examined through cell count. Differentiated cell function was assessed by alkaline phosphatase (ALP) activity assay and 3H proline incorporation assay. RESULTS: When RPOB and RRVEC were indirectly co-cultured, the proliferation of RPOB and 3H proline incorporation was higher in group 1 than in the other experimental groups and control group (P lt; 0.05). ALP activity of RPOB was higher in group 1 than in control group and group 3 (P lt; 0.05), but there was no significant difference between group 1 and group 2 (P gt; 0.05). CONCLUSION: These results suggest that RPOB and RRVEC co-cultured in a ratio of 2:1 is optimal for future study of bone tissue engineering.
OBJECTIVE To prevent early closure of growth plate and developmental deformities of limbs by allografts of cultured cartilages into growth plate defects of rabbits. METHODS Chondrocytes isolated from articular cartilage of 1-month rabbits formed cartilage after cultivation in centrifuge tubes. The cartilages cultured for two weeks were implanted into growth plate defects of proximal tibiae of 6-weeks rabbits. At 4th and 16th weeks, X-ray, histologic and immunohistochemical examination were performed. RESULTS The tibiae had no marked deformities after 4 weeks of operation. Histologic examinations showed that the defects were filled with cartilage. Immunohistochemical results of type II collagen were positive. The tibiae with allografts of cultured cartilages had no evident deformities after 16 weeks of operation. Histologic examination showed nearly closure of growth plates. On the contrary, the tibiae on control side formed severe deformities and growth plate were closed. CONCLUSION Allograft of cultured cartilages into growth plate defects may replace lost growth plate tissues, maintain normal growth of limbs and prevent developmental deformity.
OBJECTIVE: To observe the proliferation and differentiation properties of primary human embryonic skeletal myoblasts cultured in vitro. METHODS: The skeletal muscle samples were obtained from 20 to 25-week abortion fetus, the family history of inherited myopathies of parental generation was negative. With a modified method of Blau, the muscle sample was digested with trypsin and collagenase. The isolated cell suspension was a mixture of myoblasts and fibroblasts, the latter was removed by repeated attachment to culture dishes. The morphological, immunohistochemical observation, the proliferation and differentiation of primary myoblasts were studied. RESULTS: The isolated myoblasts were spherical in cell suspension and spindle-like after attached to culture dishes. The myosin specialized immunohistochemical staining was bly positive. A large quantity of skeletal muscle specialized creatine kinase (CK-MM) was synthesized in cultured myoblasts. Additionally, while the cell density of myoblasts increased, the monocyte myoblasts would fused to form multinucleated myotube. All those indicated that the cultured cells were myoblasts. Primary myoblasts proliferated quickly, the doubling time, measured in growth curve, was 4.8 days. CONCLUSION: A large number of myoblasts can be available with digestion and repeated attachment method. The cultured cells can be proved as myoblasts by morphological and immunohistochemical detection. The cultured myoblasts have good ability of proliferation and differentiation.
OBJECTIVE To evaluate the clinical results of Darrach’s procedure and Sauve-Kapandji’s procedure in the treatment of old derangement of distal radioulnar joint. METHODS Twenty-three patients with old derangement of distal radioular joint were divided into two groups, in which 11 patients received resection of distal end of ulna by Darrach’s procedure and 12 patients received pseudoarthrosis operation of the distal ulna by Sauve-Kapandji’s procedure. RESULTS Fifty-six months after Darrach’s procedure, complete relief of pain was obtained in 6 cases (P lt; 0.01), the flexion-extension movement improved from 104 degrees to 125 degrees (P lt; 0.01), rotation movement of the forearm improved from 106 degrees to 128 degrees (P lt; 0.01) and grippig strength improved from 17 kg to 28 kg (P lt; 0.01). Fifty-five months after Sauve-Kapandji’s procedure, complete relief of pain was obtained in 9 cases (P lt; 0.01), the movement flexion-extension improved from 108 degrees to 126 degrees (P lt; 0.01), rotation movement of the forearm improved from 101 degrees to 135 degrees (P lt; 0.01) and grippig strength improved from 17 kg to 35 kg (P lt; 0.01). CONCLUSION 1. The two operation showed no difference in relief of the wrist pain, improvement of the movement of the wrist and that of the forearm; 2. Sauve-Kapandji’s procedure was superior to Darrach’s procedure in increasing gripping strength; and 3. So the Sauve-Kapandji’s procedure was superior to Darrach’s procedure, especially in the long-term result, in the treatment of old derangement of the distal radioulnar joint.