Experimental study of superparamagentic scaffolds used to repair rabbit mandibular defect / 医学研究生学报

ABSTRACT

Objective Sperparamagnetic material is widely used in tumor localization and treatment , but there are still few studies in bone tissue engineering .This study aims to investigate the osteogenic efficiency of superparamagnetic scaffolds poly lactic acid hydroxy acetic acid (PLGA)/iron-doped hydroxyapatite (Fe-HA) for repairing rabbit mandibular defects , as well as evaluating the biocompatibility of the material . Methods 36 New Zealand rabbits were randomly selected and randomly divided into 6 groups, control without and with static magnetic field ( SMF ) groups ( no material is implanted), PLGA scaffold without and with SMF groups (implanted PLGA), PLGA/Fe-HA scaffold without and with SMF groups ( im-planted PLGA/Fe-HA), each group has 6 rabbits.We created bilat-eral mandibular defect models , executed the rabbits at 4 weeks and 12 weeks post-surgery, marked the mandibular specimens which detected by general observation, Micro-CT and HE staining, and ana-lyzed the results of bone mineral density in defect area .The hematological detection , pathological examination of liver and kidney sam-ples were carried out at 12 weeks pot-surgery.. Results The PLGA/Fe-HA scaffold without and with SMF groups began to appear rough defect area edge , decreased defect diameter , new bone formation from 4 weeks; the defect area formed a smooth , continuous bone repair from 12 weeks.The PLGA scaffold without and with SMF groups appeared rough , irregular callus repair , visible boundary between defect edge and normal bone tissue .There are still have part of unrepaired bone defect in the center of defect area in the control without and with SMF groups.At 12 weeks , the bone mineral density of PLGA/Fe-HA scaffold with SMF group [(572.50±19.09) mgHA/cm3] , respectively, compared with the PLGA scaffold with SMF group [(467.00±6.24)mgHA/cm3], the control with SMF scaffold group [(480.00±2.08) mgHA/cm3], the PLGA/Fe-HA scaffold without SMF group [(461.00±19.79)mgHA/cm3], the PL-GA scaffold without SMF group [(446.00±11.31)mgHA/cm3] and the control without SMF group [(422.00±28.28) mgHA/cm3], all the differences were statistically significant ( P<0.05).The bone mineral density of PLGA/Fe-HA scaffold with SMF group at 4 weeks [(572.50±19.09)mgHA/cm3] was significantly higher than that at 12 weeks [(276.00±28.28)mgHA/cm3] (P<0.05), the differences between 4 weeks and 12 weeks in other groups were statistically significant (P<0.05). Conclusion The superparama-gentic PLGA/Fe-HA scaffolds can promote the repair of bone defect , optimize the osteogenic effect of the material with SMF .Also ,the scaffold showed a good biocompatibility .