Elementary Research Of Treatment Of Early Rabbit Femoral Head Necrosis With PLA/HA Porous Scaffold Combined With Rabbit MSCs Transfected By VEGF

The experimental research of early osteonecrosis of rabbit femoral head induced by a comibination of methylprednisolone and lipopolysaccharideobjective To research the experimental result of early osteonecrosis of rabbit femoral head induced by a comibination of methylprednisolone and lipopolysaccharide by histopathologic technique, CT scanning and micro CT imaging.Methods 30 male new-Zealand rabbits were divided into experimental group (25 rabbits) and control group (5 rabbits) randomly. Two injections of 10μg/Kg body weight of lipopolysaccharide and three injections of 20 mg/Kg body weight of methylprednisolone were performed in experimental group. Physiologic saline was injected in control group. We scanned the hip joint of every rabbit by CT, and executed 4 rabbits in both groups randomly for micro CT sacnning and histopathology.Results The CT scanning showed non-uniform of bone density of femoral head in experimental group. Osteoporosis, cystis and sclerotization were observed in subchondral bone from micro CT imaging. Bone cell lacunae, increased fat cells and thrombokinesis were observed in histopathologic check.Conclusion A comibination of methylprednisolone and lipopolysaccharide could induce the early osteonecrosis of rabbit femoral head safely. objective To evaluate the ectopic osteogenesis potential of polylactic acid/hydroxyapatite ceramic (PLA/HA) porous scaffold delivery of rat bone marrow-derived mesenchymal stem cells transfected by pcDNA3.1-VEGF165 plasmid.Methods Rat MSCs were separated and cultured with osteoinduction medium. Cells were transfected with pcDNA3.1-VEGF165 plasmid or blank plasmid. RT-PCR and Western blot were used to determine the phenotype of MSCs. There were three groups:plasmid transfection with scaffold group, blank plasmid transfection with scaffold group and only scaffold group. Scanning electron microscope was used to analyzed the biocompatibility of scaffold. Cells-scaffold complexes were implanted into the muscles of rat. Radiographic and histological evaluations were performed to observed the bone formation 2,4 and 8 weeks after operation.Results Rat MSCs were sucessed to be separated and cultured with osteoinduction medium. By RT-PCR test and Western blot analysis, only the pcDNA3.1-VEGF165 transfected MSCs producted VEGF165. Scanning electron microscope showed the 3D-structure with more pores of PLA/HA porous scaffold.4 weeks after operation, ectopic bones were observed in plasmid transfection with scaffold group. little ectopic bones were observed in other groups.Conclusions PLA/HA porous scaffold delivery of rat MSCs transfected by pcDNA3.1-VEGF165 plasmid can induce ectopic osteogenesis of rat in vivo. Objective To observe the blood vessels and osteogenic capacity after implantation the combination of plasmid pcDNA3.1-VEGF165 transfection of rabbit bMSCs with the PLA/HA porous scaffold into the femoral head of rabbit femoral head necrosis model.Methods Rabbit MSCs were isolated and cultured. After transfected with pcDNA3.1-VEGF165 plasmid, we detected VEGF expression by RT-PCR, then we combinated rabbit MSCs with the PLA/HA porous scaffold. There were 4 groups:(1) pcDNA3.1-VEGF165 plasmid transfection with scaffold group, (2)blank vector transfection with scaffold group, (3)simple scaffold group,(4)untreated group. We drilled 3mm diameter tunnel under the greater trochanter to femoral head, and implanted porous scaffolds. Micro-CT and histological evaluations were performed to observe the rabbit femoral head 8 and 12 weeks after operation. X-ray photography was performed after 12 weeks.Result Rabbit MSCs were separated and cultured with osteoinduction medium successfully. After transfected with recombinant plasmid pcDNA3.1-VEGF165, VEGF expressipn level was significantly higher than other groups.8 weeks after operation, we can observe the new bone formation around the necrotic trabecular, ibroblast cells and lymphocyte infiltration, small blood vessel formation in recombinant plasmid transfected MSC group. After 12 weeks, we saw the new trabecular bone generation and scaffold absorption, while the other group had no obvious new bone. Micro-CT showed normal femoral head shape, uniform distribution of trabecular bone in plasmid transfection group, but femoral head deformation, thin subchondral bone and trabecular bone fracture in other groups. X-ray showed morphologically normal femoral heads and uniform bone mineral density in plasmid transfection group, but femoral head deformation obviously and non-uniform bone mineral density in untreated group.Conclusion Plasmid pcDNA3.1-VEGF165 transfection of rabbit MSCs with the PLA/HA porous scaffold could induce the formation of blood vessels and bone in rabbit femoral head, which is a better method for repair of femoral head necrosis.