Effect Of Injectable Drug-Loaded Silk Serici/Oxidated Sodium Alginate/Naringin Combined Hydrogel (SS/OSA-NRG) On Bone Formation

Purpose: Naringin (NRG), a flavonoid commonly found in citrus fruits, is also an HMG-CoA reductase inhibitor. Naringin can promote autophagy, proliferation and differentiation of osteoblasts, and increase bone mineral density. Our experiments compared the effect of silk serici/oxidated sodium alginate (SS/OSA) loaded with different concentrations of naringin on osteogenesis. Methods: In this study, thirty-six bone defects (the diameter was 8 mm and the depth was 1 mm) were created in the Skulls of 36 SD rats. SD rats were randomly divided into 6 groups: group A (control), group B (0 μg/mL NRG+SS/OSA), group C (500 μg/mL NRG+SS/OSA), group D (1000 μg/mL NRG+SS/OSA), group E (1500 μg/mL NRG+SS/OSA), group F (2000 μg/mL NRG+SS/OSA). At week 5, the animals were sacrificed and the anatomical defects were prepared for histological evaluation. Results: The amount of newly formed bone area was significantiy greater in the defects grafted with 1000, 1500, and 2000 μg/mL naringin in SS-OSA than in those grafted with the SS-OSA and without bone graft. In addition, the newly formed bone area of SS/OSA group with 2000 μg/mL NRG was significantly higher than that of SS/OSA group with 1500 μg/mL and 1000 μg/mL NRG (P<0.05). There was no obvious new bone formation in the (500 μg/mL NRG+SS/OSA) and SS/OSA group, and the effect of promoting osteogenesis was not significantly different from that of the control group (P>0.05). (2000 μg/mL NRG+SS/OSA) grafted group produced 174.78% more new bone than (1500 μg/mL NRG+SS/OSA) grafted group, 1154.81% more new bone than the (1000 μg/mL NRG+SS/OSA).Conclusion: The higher the concentration of naringin in SS/OSA, the more significant the effect of local increase of new bone formation. In conclusion, SS/OSA-NRG has the potential to be used as bone graft material because of its osteoinductivity.