Objective To review new progress of related research of bone tissue engineering in recent years. Methods Domestic and international l iterature concerning bone tissue engineering was reviewed and analyzed. Results In the recent years, great progression had been made in the research and development of bone tissue engineering, it had been used in more and more hospitals, and relevant national regulations and protocols had been set up. As to seed cells of bone tissue engineering, autologous and allogeneic stem cells had been widely used, while recently embryonic stem cells and induced pluri potent stem cells had attracted most attentions. In the field of scaffolds materials, significant improvementshad been made, from natural extractions to artificial polymers; from single construction to multiple compounds with surface modifications. As to the methods of construction, the static seeding approach had been widely accepted, and the appl ications of bioreactor had provided a stable and various micro-enviroment for the vitro-culture of different stem cells, which had beenregarded as an alternative way of vitro-culture and construction for bone tissue engineering. Conclusion With the tremendous help of the techniques and approaches above, we shall expect a promising future of a new generation bone tissue engineering based medical products in the years to come.
Objective Tissue engineered bone (TEB) lacks of an effective and feasible method of storage and transportation. To evaluate the activity of osteogenesis and capabil ity of ectopic osteogenesis for TEB after freeze-dried treatment in vitro and in vivo and to explore a new method of preserving and transporting TEB. Methods Human bone marrow mesenchymal stem cells (hBMSCs) and decalcified bone matrix (DBM) were harvested from bone marrow and bone tissue of the healthy donators. TEB was fabricated with the 3rd passage hBMSCs and DBM, and they were frozen and dried at extremely low temperatures after 3, 5, 7, 9, 12, and 15 days of culture in vitro to obtain freeze-dried tissue engineered bone (FTEB). TEB and FTEB were observed by gross view and scanning electron microscope (SEM). Western blot was used to detect the changes of relative osteogenic cytokines, including bone morphogenetic protein 2 (BMP-2), transforming growth factor β1 (TGF-β1), and insul in-l ike growth factor 1 (IGF-1) between TEB and FTEB. The ectopic osteogenesis was evaluated by the methods of X-ray, CT score, and HE staining after TEB and FTEB were transplanted into hypodermatic space in athymic mouse. Results SEM showed that the cells had normal shape in TEB, and secretion of extracellular matrix increased with culture time; in FTEB, seeding cells were killed by the freeze-dried process, and considerable extracellular matrix were formed in the pore of DBM scaffold. The osteogenic cytokines (BMP-2, TGF-β1, and IGF-1) in TEB were not decreased after freeze-dried procedure, showing no significant difference between TEB and FTEB (P gt; 0.05) except TGF-β1 15 days after culture (P lt; 0.05). The ectopic osteogenesis was observed in TEB and FTEB groups 8 and 12 weeks after transplantation, there was no significant difference in the calcified level of grafts between TEB and FTEB groups by the analysis of X-ray and CT score. On the contrary, there was no ectopic osteogenesis in group DBM 12 weeks after operation. HE staining showed that DBM scaffold degraded and disappeared 12 weeks after operation. Conclusion The osteogenic activity of TEB and FTEB is similar, which provides a new strategy to preserve and transport TEB.
Objective The combined appl ication of green fluorescent protein (GFP) and confocal laser scanning microscope three-dimensional reconstruction (CLSM-3DR) were used to monitor the construction and in vivo transplantation of tissue engineered bone (TEB), to provide for technology in selection of scaffolds and three-dimensional constructional methods. Methods After bone marrow mesenchymal stem cells (BMSCs) were isolated from a 2-year-old green goat by a combination method of density gradient centrifugation and adherent culture, and the expressions of CD29, CD60L, CD45, and CD44 in BMSCs were detected by flow cytometry. Plasmid of pLEGFP-N1 was ampl ified, digested by enzymes (Hind III, BamH I, Sal I, and Bgl II), and identified. Transfection of pLEGFP-N1 into PT67 cells was performed under the help of l iposome. Positive PT67 cells were picked out with G418, and prol iferated for harvesting virus. Based on the titre of virus, after BMSCs were infected by virus containing pLEGFP-N1, GFP positive BMSCs were collected and prol iferated for seeding cells. TEB was fabricated by GFP positive BMSCs and decalcified bone matrix (DBM) and observed by CLSM-3DR for the evaluation of the distribution and prol iferation of seeding cells. After TEB was transplanted in the defect of goat femur, CLSM was used for observing the survival and distribution of GFP positive cells in the grafts. Results The isolated cells were fibroblast-l ike morphous, with the positive expression of CD29 and CD44, and negative expression of CD60L and CD45. The digested production of pLEGFP-N1 was collected for ionophoresis, whose results showed the correct fragment length (6 900 bp). The virus of pLEGFP-N1 was harvested by transfection of pLEGFP-N1 into PT67 cells and used for further infection to obtain GFP positive BMSCs. The prol iferated GFP positive BMSCs and DBM were used for fabrication of TEB. The distribution, prol iferation, and migration of BMSCs in TEB were observed by CLSM-3DR. GFP positive cells also were observed in images of TEB graft in goat femur 28 days after transplantation. Conclusion The BMSCs labeled by GFP in three-dimensional scaffold in vivo were monitored well by CLSM-3DR. It suggests a wide use potency in monitoring of three-dimensional cultured TEB.
Objective To investigate and analyze the three-dimensional anatomic structure of glenoid bone in some Chinese people so as to provide the accurate anatomic data to design the new prosthesis of glenoid bone for Chinese people. Methods A total of 90 volunteers with two healthy shoulders (52 males and 38 females, aging 19-60 years with an average of 39.6 years) were selected. Five parameters were measured by use of three-dimensional computed tomography, volumerendering technique (VRT) and multiplanar reformation (MPR), including the maximum antero-posterior width (MAPW),antero-posterior radius of curvature (APROC), maximum supero-inferior height (MSIH), supero-inferior radius of curvature(SIROC) and version angle (VA) of glenoid. All parameters were measured two times, and the average values were analysed by SPSS13.0. The level of significance was set at P lt; 0.05. Results The average MAPW was (2.51 ± 0.32) cm, the average APROC was (5.50 ± 1.21) cm, the average MSIH was (3.45 ± 0.29) cm, the average SIROC was (3.98 ± 0.55) cm, and the average VA was (— 0.03 ± 4.66)°. There were no significant differences (P gt; 0.05) in MAPW, APROC, MSIH, SIROC and VA between two sides. There were significant differences (P lt; 0.05) in MAPW, MSIH, SIROC and VA, and no significant difference (P gt; 0.05) in APROC between female and male. MAPW was correlated with APROC, MAPW was correlated with MSIH, APROC was correlated with SIROC, and the correlation coefficient was 0.298, 0.495 and 0.262, respectively. Conclusion There are no significant differences in MAPW, APROC, MSIH, SIROC and VA of glenoid between two sides. There are sexual significant differences in MAPW, MSIH, SIROC and VA. The data and its statistical results may serve as guidel ines for the design of the glenoid component.
Objective?To analyze the effect of different surgery techniques on the tendon-bone healing of rotator cuff insertion.?Methods?Forty-two adult Japanese rabbits, weighing 2.0-2.5 kg and male or female, were selected. Thirty-six rabbits were given a sharply left-lateral tenotomy of the supraspinatus tendon with subsequent re-attachment of the tendon. According to the depth of re-attachment, 36 rabbits were equally randomized into the cancellous-fixation group (a cancellous bed was prepared with a dental burr) and the cortical-fixation group (the same treatment was performed except the preparation of the bone bed). Six rabbits served as the controls without treatment (control group). At 4 and 8 weeks after operation, the general observation, HE staining, and the biomechanical test were performed.?Results?At 4 weeks after operation, the supraspinatus-humerus specimens morphologically showed atrophy and vague between tendon and new bone in the cancellous-fixation group and the cortical-fixation group; at 8 weeks, no obvious difference was observed between 2 groups and the control group. The histological results of the cortical-fixation group at 4 weeks revealed the interface between tendon and new bone became smooth. The interface became transitional at 8 weeks, and the shape of bone tissue was nearly normal. The interface obtained from the cancellous-fixation group at 4 weeks became sclerotic, and collagen fibers formed in disorder. With ingrowth of new bone and re-establishment of collagen-fiber continuity at 8 weeks, thickness of interface became thin, and bone tissue was remodeling. The ultimate load were significantly higher in the cortical-fixation group than in the cancellous-fixation group at both 4 and 8 weeks, and the results gained at 8 weeks is significantly higher than that at 4 weeks in each group (P lt; 0.05). Except rupture strength at 4 weeks between 2 groups and all tensile strength (P gt; 0.05), there were significant differences in the results of others (P lt; 0.05).?Conclusion?In this model, the tendon-bone healing process and the biomechanical properties of cortical-fixation is superior to those of cancellous-fixation.
Objective To compare the cl inical outcomes of the core decompression combined with autologous bone marrow mesenchymal stem cells (BMSCs) transplantation with the isolated core decompression for the treatment of earlyavascular necrosis of the femoral head (ANFH). Methods From May 2006 to October 2008, 8 patients (16 hips) with earlyANFH were treated. There were 7 males and 1 female with an average age of 35.7 years (range, 19-43 years). According to the system of the Association Research Circulation Osseous (ARCO): 4 hips were classified as stage II a, 2 as stage II b, 1 as stage II c, and 1 as stage III a in group A; 2 hips were classified as stage II a, 2 as stage II b, 3 as stage II c, and 1 as stage III a in group B. The average disease course was 1.1 years (range, 4 months to 2 years). The patients were randomly divided into 2 groups according to left or right side: group A, only the core decompression was used; group B, both the core decompression and autologous BMSCs transplantation were used. The Harris score and visual analogue scale (VAS) score were determined, imaging evaluation was carried out by X-rays and MRI pre- and post-operatively. The erythrocyte sedimentation rate, C-reactive protein, l iver function, renal function, and immunoglobul in were detected for safety evaluation. Results All incisions healed by first intention. Eight patients were followed up 12-42 months (23.5 months on average). The cl inical symptoms of pain and claudication were gradually improved. The Harris scores and VAS scores of all patients were increased significantly at 3, 6, and 12 months after operation (P lt; 0.05). There was no significant difference between groups A and B 3 and 6 months after operation (P gt; 0.05), but there was significant difference between groups A and B 12 months after operation (P lt; 0.05). The necrosis area of femoral head in groups A and B were 18.13% ± 2.59% and 13.25% ± 2.12%, respectively, showing significant difference (P lt; 0.05). In group A, femoral head collapsed 12 months after operation in 1 case of stage III. No compl ication of fever, local infectionoccurred. Conclusion The core decompression and the core decompression combined with BMSCs transplantation are both effective for the treatment of early ANFH. The core decompression combined with BMSCs transplantation is better than core decompression in the rel ief of pain and postponing head collapse.