Objective To study the potential of a bioderived material combined with Pluronic F-127 in vitro as a delivery vehicle for WO-1 in the bone repair therapy. Methods Bio-derived materials were fabricated and loaded with WO-1 by Pluronic F-127. Micromorphology and porosity were detected by the scanning electron microscope and the digital image analysis system respectively. The WO-1 release from the system in vitro was studied by the high performance liquid chromatography. Results Bio-derived material-WO-1 drug delivery systems were created with the interconnected pore network. Theporosity and pore size of the system were 55% and 522.43±16.75 μm respectively, compared with those of bio-derived materials, which were 75% and 623.67±12.31 μm respectively. And the main composition of the system was HA. The in vitrorelease kinetics of WO-1 revealedthat an effective therapeutic concentration(0.2-0.8 μg/ml) of WO-1 was maintained for 6 days after a high initial burst release. Conclusion The bio-derived material-WO-1 drug delivery system can be used in the bone repair therapy. However, the in vivostudy on it is still needed.
Objective To evaluate the effect of WO-1 on repair of the bone defect in the New Zealand rabbit radius by an oral or local administration. Methods Bone defects were surgically created in the bilateral radii of 36 Zealand rabbits (1.6-2.0 kg), which were randomly divided into3 groups. In Group A, the defective areas were given WO-1 0.1 ml (50 mg/ml) by the local injections; in Group B, the rabbits were given WO-1 5 mg each day by the oral administration. Group C was used as a control group. Among each of the 3 groups, 4 rabbits were randomly selected and were sacrificed at 20, 30 and 60 days after operation, respectively. Then, the serological, X-ray and histological examinations were performed. Results The serum alkaline phosphatase and bone glaprotein levels were significantly higher at 20 and 30 days after operation in Groups A and B than in Group C, but significantly lower at 60 days after operation in Groups A and B than in Group C（Plt;0.01）. The X-ray and histological examinations at 20, 30 and 60 days after operation revealed that the callus formation and remodeling were earlier in Groups A and B thanin Group C, and the remodeling was earlier and better in Group A than in Group B. Conclusion WO-1 can promote the repair of the radial defect in a rabbit; however, further studies on the doseeffect relationship, administration time, and administration route are still needed.
Objective To investigate the effect of WO-1 on the proliferation and differentiation of human embryonic osteoblasts (HEO) and to provide research methods of bone tissue engineering. Methods HEO were isolated from periosteum and calvaria and then cultrued in vitro. The doseeffect relationship between WO-1 concentration and biological effect of HEO was evaluated by growth curve and 3 H-TdR count. The effect of WO-1 on cell activity and proliferation was investigated by cloning efficiency,cell cycle analysis was determined by flow cytometer and morphological was examined through transmission electron microscope. Moreover, the effect of WO-1 on osteoblastic function was evaluated at protein and mRNA levels by ALP activity, 3 H-proline incorporation, osteocalcin secretion (RIA) and mRNA expression of type I collagen and osteocalcin (RT-PCR). Results The proliferation of HEO was inhibited in high concentration of WO-1,while it was promoted in low concentration of WO-1. The optimal dose was 8 μg/ml, and there was dose-effect relationship in the certain range of WO-1 concentration (0.25 μg/ml to 8 μg/ml). In 8 μg/ml of WO-1, the cloning efficiency and cloning volume of HEO were inereased, population doubling time was decreased.All indexes of ostoblastic function including ALP activity, type I collagen synthesis and osteocalcin secertion were inereased, the more sufficed cell organs were observed under transmission electron microscope than control group(P＜0.05). Conclusion WO-1 can promote the cell activity and proliferation of HEO cultured in vitro inlow concentration, enhance the synthesis of extracellular mamix, such as type Icollagen and osteocalcin, and accelerate the mineralization of osteoid. WO-1 can be used as a stimulant of proliferation and differentiation of HEO in the research of bone tissue engineering, which provide the theoretical basis in clinical application.
Objective To develop a new tissue engineering bone material which has an antiinfective function. Methods Collagen loaded bio-derived bone material was made by using type I collagen and allograft bone. WO-1was absorbed to collagen loaded bio-derived bone, then the morphological feature of the new bone material was observed by scanning electronic microscopy.3 H tetracycline was diluted by WO-1 solution, and was absorbed to collagen loaded bio-derived bone，then the releasing kinetics of WO-1 was detected by 3 Htetracycline in vitro. WO-1 bioderived bone material was grafted into a culturemedium with staphylococcus aureus, escherichia coli, and pseudomonas aeruginosato observe its bacteriostasis ability. WO-1 bio-derived bone material was grafted into radius of defected rabbits, the concentration of WO-1 was detected onthe 9th, 16th, 23th, and 30th day byHLPC in blood, in bone and in muscle. The bacteriostasis ability of WO-1 loaded bio-derived bone was tested in vitro and in vivo. Results WO-1 loaded bioderived bone maintained natural network pore system and the surface of network pore system was coated with collagen membrane. The release of WO-1 from WO-1 loaded bioderived bone showed bursting release on the 1st day, then showed stable release. WO-1 loaded bioderived bone showed lasting and stable bacteriostasis to common pathogens of orthopaedic infections. The high concentration of WO-1 was observed in bone tissue and in muscle tissue at differenttime points and the difference among groups had no significance（P＞0.05）, while the concentration of WO-1 in blood was very low（P＜0.05). Conclusion WO-1 loaded bioderived bone has good capability of drug controlled-release and bacteriostasis.
Objective To provide the chosen scaffold materials for experiment and application of tissue engineering and to detect the properties of the collagenbio-derived bone scaffold material loading WO-1. Methods The purebio-derived bone scaffold material, bio-derived bone scaffold material loading collagen, collagen bio-derived bone scaffold material loading WO-1 were made by use of allograftbone, and typeI collagen, and WO-1. The morphological features, constitute components and mechanical properties were examined by scanning electron microscopy,X- rays diffraction and mechanical assay. Results The bio-derived bone scaffold material maintained natural network pore system; the bio-derived bone scaffold material loading collagen maintained natural network pore system, the surface of network pore system was coated by collagen membrane; the collagen bio-derived bone scaffold material loading WO-1 maintained natural network pore system, thesurface of network pore system was coated by collagen membrane. The pore sizes of the 3materials were 90-700 μm, 75-600 μm and 80-600 μm, respectively, and the porosities were 87.96%, 80.47%, 84.2%. There was no significant difference between them(P＞0.05).The collagen bio-derived bone scaffold material loading WO-1 consisted of ［HA,Ca10(OH)2(PO4)6］. There was no significant difference in the mechanical strength of the three scaffold materials. Conclusion The bio-derived bone scaffold material loading WO-1 is as good as bio-derived bone scaffold material and collagen bio-derived bone scaffold material, and it is an effective scaffold material for tissue engineering bone.