Bone defect repair using layered double hydroxyapatite scaffold coated with alendronate combined with adipose-derived stem cells (ASCs)

IntroductionTissue engineering is new therapeutic protocols for the treatment of large osseous defects in the craniofacial area. Many combinations of cells and scaffolds have been utilized for tissue engineering of craniofacial region. Bisphosphonates, includingalendronate, are also commonly used to prevent and treat all forms of osteoporosis. Although the principal of action of alendronate is inhibition of osteoclast function by inhibiting the mevalonate pathway of cholesterol synthesis, recent studies showed that local delivery of alendronate by scaffolds promote osteoblast differentiation and mineralization in vitro.ObjectivesThe aim of this study was to investigate the effects of scaffold alendronate combined with Adipose-Derived Stem Cells (ASCs)on the bone defect repair.MethodsThis experimental study was conducted on 30 male New Zealand rabbits that were divided randomly into five groups with critical defect; including control, scaffold, scaffold + cell, scaffold + Alendronate and scaffold + cell + Alendronate (drug dosage in each scaffold is one-tenth of the weight of the animal receiving scaffold). In this study, adipose-derived mesenchymal stem cells between the shoulders of rabbits were isolated and loaded onto gelatin-anionic clays scaffold with and without drug and then implanted into bone defects. The rabbits were killed after 12 weeks. The level of bone defect repair was assessed through radiography and histomorphometry.ResultsThe histomorphometric analysis on H&E stained sections and densitometric calculations on radiographic images revealed that the Layered Double Hydroxyapatite scaffold has an important role in the repair compared to the control group. After twelve weeks the defect size was significantly greater in control group compared to other groups. The addition of Alendronate decreased Bone density in Group scaffold + Alendronate (p=0.001). The scaffold combined with Adipose-Derived Stem Cells shows positive and valuable results in bone defect repair compared with the scaffold alone (p = 0.011).ConclusionOur results showed that the repair of critical size defects was accelerated by LDH/HA scaffold. However, Alendronate reduced optimum effect of the scaffold.

کلیدواژه ها:

Rabbit ، Mesenchymal stem cell ، Bone defect ، Alendronate