可降解聚己内酯修复骨缺损的实验研究

AN EXPERIMENTAL STUDY ON REPAIRING BONE DEFECT WITH THE BIODEGRADABLE POLYCAPROLACTONE MATERIAL

目的探讨聚己内酯(polycaprolactone,PCL)修复骨缺损的能力,为组织工程骨支架材料的可行性提供依据。方法新西兰大白兔65只,双侧股骨髁制成4.5mm×12mm的骨缺损动物模型。将PCL圆柱体植入到右侧骨缺损为实验组(n=60),羟基磷灰石(hydroxyapatite,HA)植入左侧骨缺损为对照组(n=60),空白组不植入任何物质(n=5)。于术后3、6、9和12个月将实验组及对照组取材进行大体观察、X线摄片、骨密度测定、99mTc-MDP扫描γ-显像比值测定及扫描电镜观察。空白组于术后12个月取材行大体观察。结果术后各时间点大体标本及X线片检查显示:实验组随着PCL材料的降解,骨缺损逐步被增生的骨质填充,无迟发性炎性反应出现;对照组无骨组织形成,为结缔组织充填;空白组大体观察缺损区未发现骨组织形成。骨密度测定表明:实验组骨密度增加,在各时间点与对照组比较有统计学意义(P<0.05)。99mTc-MDP扫描γ-显像显示:实验组比对照组有更多的放射性核素聚集。扫描电镜观察:术后12个月,实验组随着PCL材料的逐步降解,PCL纤维移行处界面形成较多的密质骨样组织;对照组HA-组织之间可见较多的排列不规则的胶原纤维包绕。结论PCL材料具有良好的生物相容性、缓慢降解和骨引导能力,可修复骨缺损。

Objective To investigate the ability of the biodegradable polycaprolactone (PCL) material to repair bone defect and to evaluate the feasibility of using the PCL as the scaffold in tissue engineering bone. Methods The bone defect models of 4.5 mm×12 mm were made in the bilateral femoral condyle of 65 New Zealand white rabbits. The PCL cylinder was implanted into the right side of defect(experimental group, n=60), the high dense crystality hydroxyapatite was implanted into the left side of defect (control group, n=60), and the incision was sutured without any implants (blank group, n=5). The samples were harvested and observed by examinations of gross, X-ray, bone density, ^(99m)Tc-MDP bone scanning, γ-display ratio and scanning electron microscope (SEM) after 3, 6, 9 and 12 months of operation. The results were compared between the experimental group and control group. Results At 3, 6, 9 and 12 months after operation, the gross and X-ray examinations indicated that the bone defect filled with the new bone on the PCL-tissue surface, and no delayed inflammatory reaction appeared. The average bone mineral density was greater in the experimental group than that in the control group, and the difference had statistical significance(P<0.05). The results of ^(99m)Tc-MDP bone scanning and γ-display ratio showed that the nuclide uptake was more in the PCL group than that in the control group. The SEM result proved that the new compact bone formed on the PCL migrating surface as the PCL degraded gradually,but the collagen fiber sheathe formed around the hydroxyapatite in the control group. Conclusion PCL possesses good biocompatibility and high bone inductive potentiality, it can be used to repair bone defect.