| In China, spinal tumors, spinal infectious diseases and the instability ofspine fracture incidence is increasing these years. The consequences often leadsto severe destruction of the vertebral body, thus having the potential spinalinstability and spinal cord or nerve root injury, and some may even causeparalysis. Spinal anterior decompression and vertebral total or sub total resectionis considered the major clinical-surgical treatment method for spinal tumor,spinal infectious diseases and the instability of vertebral fractures. However,during surgery, the surgeon had to reconstruct the intact stability of the spine. Inthe past, surgeon commonly used the autologous such as iliac crest or fibula tofill the vertebral defect. But some researchers have found that simpleautogenous bone graft are lack of self-body bone mass after surgery and can notprovide sufficient immediate stability. Titanium mesh and artificial vertebralbody as vertebral substitutes have been widely used in clinical practice. However, currently used titanium mesh or artificial vertebrae are simplemechanical support material. Thus, these instruments have no osteoconductivity,osteoinductivity and osteogenesis in the recovery of spinal stability. Some othermaterials are friable and fatigue easily so that long-term implantation may bringproblems such as bone stress concentration and bone resorption, resulting ininstability of the titanium mesh or artificial vertebral body, sinking or increaseclose to the risk of fractures of the spine segment, especially for osteoporosis(OP) patients.Tissue engineering technology is the rise in recent years. The integration ofnew engineering and life sciences research, the technology has been able to builtin vitro biological activity of the implant, and has been part of clinicalapplication. However, the applied artificial vertebrae in vitro and in vivobiological activity has not been reported in the literature. Therefore, tissueengineering techniques to design a in line with the spine biomechanicalproperties of the material combination of surface treatment methods, but alsowith bone conduction, bone induction and bone formation, tissue engineeringartificial vertebral spinal tumors, spinal infectious diseases and the instability ofvertebral fractures in the field of surgical treatment of hot.Objective:1. To evaluate the effect of the tantalum-coated tissue engineering vertebralbody;2. To study the biological effects of tantalum-coated tissue engineeringvertebral body in the process of restoration of vertebral body defect.Methods:1. Prepare the porous titanium (Ti-6A1-4V) scaffold according to the New-Zealand white rabbit lumbar spine (L6) Micro-CT scan analysis of theanatomical structure and the maximum compressive loadand anti-fatiguebiomechanical experiments was carried out contrasted rabbit L6vertebrae andtitanium mesh.2. Application of chemical vapor deposition method tantalumcoatings on porous titanium alloy scaffold and scaffold scanning electronmicroscopy, compressive strength and X-ray diffraction analysis.3. The poroustitanium scaffolds after the tantalum coating composite New Zealand whiterabbit bone marrow stromal cells (BMSCs), contrast-eluting scaffold, the use ofhistological staining, Mehtyl Thiazolyl Tetrazolium (MTT) observed the abilityof bone marrow stromal cells on the scaffold surface adhesion, added value anddifferentiation.4. Composite rabbit BMSCs tantalum-coated tissue engineeringartificial vertebral body implant lumbar defect rabbit model of in vivopostoperative8weeks,12weeks, respectively based on the Micro-CT analysis,and histological observation and biomechanical testing.Results:1. A porous titanium alloy scaffold, titanium mesh and the rabbit lumbarvertebral body biomechanical experimental rabbit L6vertebral body with poroustitanium alloy scaffold between the maximum compressive load and fatigueexperiments before and after the change in stiffness, no significant statisticaldifference (P>0.05); titanium mesh between its maximum compression loadand stiffness changes in value over the previous two statistically significantdifferences (P <0.01).2. Tantalum coating treatment to form a layer of poroustitanium alloy scaffold surface homogeneous, porous tantalum metal layer, theaverage porosity of700±50μm, the thickness is about3μm. The averagecompressive strength of83.8±4.2MPa, the yield strength of74.6±3.5MPa, theelastic modulus is11.3±0.4GPa, and the bone is closer to, and obviously better than that of porous tantalum metal scaffold (P <0.05);3. Bone marrow stromalcells in tantalum coated porous titanium alloy scaffold surface morphology thanthe uncoated group, pseudopod extension more fully the value-added of thecoating of cell adhesion and differentiation were significantly better than theuncoated group (P <0.05);4. Rabbit lumbar defects in vivo experiments, thevertical stiffness and rotation stiffness of the tantalum coating group weresignificantly higher than the uncoated group group (P <0.05), Micro-CT andhistological examination showed a large number of new bone formed in thetantalum-coated tissue engineering around the artificial vertebral body,trabecular bone quantity and quality are superior to the uncoated group group (P<0.05).Conclusions:1. The mechanical strength and resistance to deformation of porous titaniumalloy scaffold are close to rabbit lumbar vertebral body.2. Tantalum coated porous titanium alloy scaffold not only have good porestructure but also its modulus of elasticity is similar to human bone.3. Tantalum coating on the surface of the porous titanium scaffolds isbeneficial to bone marrow stromal cell pseudopodia commence, and it alsoincreased the ability of bone marrow stromal cell adhesion, added value anddifferentiation.4. Tantalum coated porous titanium alloy scaffold-based tissue engineeredvertebral body enhances its osteogenic activity, and both bone conduction,bone induction and bone formation and more conducive to the vertebraldefect.5. Tantalum coated porous titanium alloy scaffold-based tissue engineeredvertebral body have good mechanical properties, excellent tissue compatibility and unique osteoconductivity, osteoinductivity andosteogenesis. It may used clinically in the future provide a reliabletheoretical actual basis. |
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