Conclusion: The results of this study demonstrate that EPCs are effective as cell-based therapy for healing critical sized bone defects in a rat model. In this model EPCs demonstrated superiority to MSCs with regard to bone healing. In addition, EPCs demonstrated superior angiogenesis over controls in a rat model of fracture healing. These results strongly suggest that EPCs are effective for therapeutic angiogenesis and osteogenesis in fracture healing. There is a clinical need for effective strategies in the management of traumatic bone defects and nonunions. Investigation into the use of MSCs as an effective alternative to autologous bone grafting has failed to translate into clinical use. It is possible that EPCs are more effective at the regeneration of bone in segmental defects because of their synergistic effect on angiogenesis and osteogenesis. Further research into EPC based therapies for fracture healing is warranted.
static and dynamic modes. A paired student’s t test was used to compare the 2 modes.
A post hoc power analysis with &
#945;=0.05 and &
#946;=0.20 revealed that the paired t test on 30 samples was sufficiently powered to determine a difference in mean axial stiffness of 33.0N/mm (6.8% of static stiffness), a difference in mean lateral bending stiffness of 3.6N/mm (3.2% of static stiffness) and a difference in mean torsional stiffness of 3.4N/mm (3.0% of static stiffness).
superior (n=6), inferior (n=6), anterior (n=6), posterior (n=6), central (n=6). All specimens were radiographed in the anterioposterior and lateral planes, and radiographic measurements including TAD and a calcar referenced tip-apex distance (CalTAD) were calculated. All specimens were tested for axial, lateral, and torsional stiffness, and then loaded-to-failure in the axial position using an Instron 8874 (Canton, MA). ANOVA was used to compare means of the five treatment groups. Linear regression analysis was used to compare stiffness and load-to-failure (dependant variables) with radiographic measurements (independent variables). A post hoc power analysis was performed.
There were significant negative linear correlations between stiffness tests with CalTAD, and load-to-failure with TAD. Power was greater than 95% for axial stiffness, torsional stiffness and load-to-failure tests.
osteoblast-hVEGF, fibroblast-hVEGF, Osteoblasts alone, and Fibroblasts only. The cultured cells were harvested at 1, 3 and 7 days after the transfection. The total mRNA was extracted (TRIZOL); both hVEGF and rat VEGF mRNA were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantified by VisionWorksLS.
empty (N=5), iliac crest autograft (N=6), or PLGA/CaP biodegradable scaffold Tissue Regeneration Therapeutics Inc., ON, Canada) (N=7). Fluorescent markers were given at different times: calcein green (six weeks), xylenol orange (nine weeks), and tetracycline (11 and 14 weeks). Animals were sacrificed at 15 weeks and perfused with a barium compound. Radiography, Micro CT, and brightfield and fluorescent microscopy were used for analysis.