این سایت در حال حاضر پشتیبانی نمی شود و امکان دارد داده های نشریات بروز نباشند
Cell Journal، جلد ۱۷، شماره Suppl ۱، صفحات ۱۶-۱۷
عنوان فارسی
چکیده فارسی مقاله
کلیدواژه‌های فارسی مقاله
عنوان انگلیسی Is-21: Mechanical Stimulation as Anabolic and Anti-Catabolic Agents in Bone Tissue Engineering
چکیده انگلیسی مقاله Objective: In clinical situations, bone defects are often located at load bearing sites and hence bone substitutes or scaffolds are subjected to mechanical stimulation. Thus, it is critical to understand the effect of mechanical stimulation on bone formation inside bioresorbable bone scaffold. In fracture healing, the loading effect has been often reported to enhance the bone healing process. However, little is known on the effect of loading on bone formation inside scaffold. The goal of this study is to test the hypothesis that cyclic loading enhances bone formation inside a polymeric bioresobable bone scaffold. Materials and Methods: Both femoral condyles of 8 female Wistar rats of weight 245-250 g were drilled (Veterinary Authority from the Canton of Vaud, authorizations No. 2140) and PLA + 5% wt β-TCP scaffolds of the same size were implanted inside the drilled holes. Prior to surgery, scaffolds were perfused with PBS to remove the air bubbles trapped inside. No cells or growth factors were added in the scaffold. Three days after surgery, the right knee of all rats were loaded and the left knee was used as control. A compressive load of 10 N at 4 Hz for 5 minutes was applied by a compression machine 5 times every other day. Both knees were micro-scanned in vivo (SkyScan 1076, Belgium) at 2, 4, 6, 9 and 13 weeks after surgery. For the scanning, the knee was extended. The CT parameters were: 18 μm resolution, 80 kV voltage, 124 μA current, 1mm Al filter and 600 ms exposure time. Reconstruction and analysis were done using NRecon and CTan software (SkyScan, Belgium), respectively. Bone mineral density (BMD) was calibrated using two phantoms. BMD of 0.5 g/cm3 was chosen to segment bone. Accordingly, bone volume (BV) and BMD of bone inside scaffold were measured. Results: Already at 2 weeks, small amount of bone formation can be seen inside the scaffold, which was mainly formed at the outermost part of the scaffold. At 13 weeks, new bone invaded the interior of scaffold and was well spread. For BV, both intercept and slope of equation 1 were highly significantly different (P value < 0.0001) for control and loaded groups. This means that loading had a negative effect at the beginning, but a positive effect later. The bone formation rate inside the scaffold was indeed increased by 28%, which after 13 weeks resulted in more bone formation in the loaded group. Conclusion: This study confirmed the hypothesis that mechanical stimulation enhances the bone formationinside a resorbable bone scaffold. We also observed that a short stimulation period after surgery resulted in a long-term increase of bone volume. The observed early negative effect of mechanical stimulation might be due to high strains at the bone-scaffold interface. This adverse effect could be avoided by a gradual increase of the load. Nevertheless, this negative effect was cancelled after 6 weeks, and at 13 weeks the bone volume was significantly higher in the loaded group. In conclusion, mechanical stimulation can be a potent stimulatory signal signal for bone Formation within bioresobable bone scaffolds.
کلیدواژه‌های انگلیسی مقاله
نویسندگان مقاله a روشن غیاث | a roshan ghias


dp pioletti | dp pioletti


نشانی اینترنتی http://celljournal.org/journal/article/abstract/45
فایل مقاله فایلی برای مقاله ذخیره نشده است
کد مقاله (doi)
زبان مقاله منتشر شده en
موضوعات مقاله منتشر شده
نوع مقاله منتشر شده
برگشت به: صفحه اول پایگاه   |   نسخه مرتبط   |   نشریه مرتبط   |   فهرست نشریات