ABSTRACT
BACKGROUND:In previous studies, it is satisfied to sorting bone marrow mesenchymal stem cels based on natural sedimentation combined with low permeation. Then, based on particle hydromechanics theory, the settling velocity of bone marrow mesenchymal stem cels in culture liquid is calculated. A simple and easy method of separation, purification and proliferation of bone marrow mesenchymal stem cels is established by natural sedimentation velocity. OBJECTIVE:To explore the feasibility of sorting bone marrow mesenchymal stem cels by natural sedimentation velocity method. METHODS:The density interval of rabbit bone marrow mesenchymal stemcels (ρ1) was determined by density gradient centrifugation method. The diameter of rabbit bone marrow mesenchymal stem cels (d) was measured by scanning electron microscope. The density of culture liquid (ρ2) was measured by liquid density meter. The viscosity of the culture liquid (μ) was measured by viscosity meter. The settling velocity of bone marrow mesenchymal stem cels (Vt) was derived from the above four numerical values with the appropriate formula. Bone marrow mesenchymal stem cels were sorted from bone marrow tissue by natural sedimentation velocity method. Cel proliferation, purity and differentiation were observed. Meanwhile, the primary culture time of three different cel sorting methods was recorded; the colony formation rate of rabbit bone marrow mesenchymal stem cels was determined. RESULTS AND CONCLUSION:(1) The diameter of rabbit bone marrow mesenchymal stem cels was (20.37±4.58) μm, and the setting velocity of rabbit bone marrow mesenchymal stem cels in the culture liquid was 50-55 mm/h. (2) Bone marrow mesenchymal stem cels could be successfuly isolated from bone marrow tissue of rabbits by the natural sedimentation velocity method, which could be induced into osteoblasts and adipocytes. (3) The natural sedimentation velocity group cost less time than the other two density gradient centrifugation groups in the primary culture stage. The colony formation rate of the natural sedimentation velocity group was higher than that of the other two groups. (4) Natural sedimentation velocity method did not impose any intervention measures for sorting cels, which maybe maximaly maintain cel viability and biological characteristics. The whole separation process was simple and safe, which may have little damage to the cels.
ABSTRACT
BACKGROUND:Mesenchymal stem cel s as potential seeded cel s have been widely used in tissue engineering and clinic therapy;thus, the precise, safe, effective isolation of mesenchymal stem cel s is the particular important premise to build culture system. OBJECTIVE:To review the methods of isolating mesenchymal stem cel s and to compare the merit and demerit of different methods, thereby providing theoretical basis for safe and high-effective isolation of mesenchymal stem cel s. METHODS:A computer-based online research of CNKI and PubMed databases was performed to col ect articles, which included reviews, clinical trials and experiments, published between 1965 and 2014 with the key words of“mesenchymal stem cel s (MSCs), isolation methods”in Chinese and English. A total of 52 articles were included according inclusion and exclusion criteria RESULTS AND CONCLUSION:(1) The whole bone marrow culture method can derive a mass of mesenchymal stem cel s, which need to be purified. (2) The density gradient centrifugation method which uses the media with the density of 1.073 g/mL can be used to harvest more purified cel s. (3) The tissue digestion method is suitable for digestion and isolation of adipose tissue and umbilical cord tissue. Type II col agenase digestion is better, but they are both limited by a high demand for operative techniques. (4) Immunomagnetic bead separation is appropriate to study the biological characteristics of a kind of subpopulation of mesenchymal stem cel s which express special surface markers. (5) The combination method is also an optimal way. (6) Some new methods limited by few dates require further studies.
ABSTRACT
BACKGROUND:Thoracic vertebra connected to the corresponding section of the ribs constitute thoracic vertebral, which is deep, and the structure is complicated, so it is difficult to ful y expose thoracic vertebrae. Usual y, corresponding ribs is removed, and the injured site wil be reached through thoracic cavity. The trauma is big. Some complications often occur such as chest pain, and local skin numbness. Therefore, whether it is possible to reach the same target without removal of ribs through intercostal space became a new clinical problem. OBJECTIVE:To explore the safety and efficacy of autologous iliac bone graft and plate fixation for tuberculosis of thoracic vertebra. METHODS:A total of 30 patients diagnosed with tuberculosis of thoracic vertebra from January 2008 to December 2013 were conventional y treated with anti-tuberculosis treatment for 2 to 3 weeks, and then treated with autologous iliac bone fusion through intercostal space and anterior plate fixation. Postoperative fol ow-up was conducted from 6 to 22 months. Fracture healing condition, the degree of pain relief, Cobb angle change, length of incision, blood loss, operation time, postoperative recovery of neurological function were observed. RESULTS AND CONCLUSION:In 30 patients, the length of incision was (12.4±1.8) cm;longitudinal incision distraction width was (10±3.2) cm;the time of opening the chest was (16.0±2 .5) minutes;the time of closing the chest was (12.0±1.5) minutes;intraoperative blood loss amount was (430.0±87.4) mL. Preoperative and postoperative average kyphosis angles were respectively 27° and 8°, with an average rectification of 19°. The pain basical y relieved at 1 to 2 weeks after the surgery. 28 patients were healed, and the symptoms of 2 patients were improved. Postoperative fol ow-up radiographs revealed that autologous bone grafts were thoroughly fused, and the fusion time lasted from 4 to 5 months. These data verified that autologous iliac bone graft through intercostal space and plate fixation is an effective, safe method for tuberculosis of thoracic vertebra. The exposed range through intercostal space can satisfy the operation requirements of complete tuberculosis clearance, autologous iliac bone graft and plate fixation, and can ensure the integrity of the whole thorax and spine stability.