| Periodontitis is a chronic infectious disease of periodontal supporting tissues and causes the destruction of periodontal supporting tissues,which caused by bacteria in dental plaque.The alveolar bone resorption caused by periodontal local innate immune response stimulated by periodontal pathogenic bacteria is the main clinical symptom of periodontal disease,and it is also the most important cause of adult tooth loss in China.Regeneration and reconstruction of periodontal tissue has always been the focus and difficulty of periodontitis treatment.Recently miR-34 a has been found to be involved in the regulation of bone homeostasis and stimulate bone formation in vitro and in vivo.It can be used for gene therapy of periodontitis,while it possesses limited cellular uptake.N-acetyl-L-Leucine-polyethylenimine(N-Ac-L-Leu-PEI),the derivatives of dendrimer polyethylenimine(PEI),possesses favorable transfection efficiency and biocompatibility,which makes it a potential carrier for miR-34 a delivery.In previous experiments,N-Ac-L-Leu-PEI/miR-34 a complex was successfully transfected into human MG63,and promoted osteogenic differentiation of MG63 in vitro.This article is to detect the effects of N-Ac-L-Leu-PEI/miR-34 a complex on osteogenesis of rat cranial defects in vivo.Method:Oral biofilms loaded with 10 μL phosphate buffer(PBS),8μg N-Ac-L-Leu-PEI,N-Ac-L-Leu-PEI/miR-34 a complex with 2μg miR-34 a included,N-Ac-L-Leu-PEI/NC with 2μg Negative Control included were prepared and freeze-dried for use.32 Wistar male rats were randomly divided into four groups and 0.5cm-diameter left cranial defects were prepared on each rat under anesthesia and aseptic conditions.Oral biofilm of each group covered the defect.After ten weeks culture,the rats were sacrificed and the development of osteogenisis was detected by CBCT,micro-CT and RT-PCR.Hard tissue sections were stained with HE to observe new bone formation.Result:Bone formation is evident in the defects of the N-Ac-L-Leu-PEI / mi R-34 a complex group,while rare new born has been seen in other groups.The BV / TV values and Tb.Th values of N-Ac-L-Leu-PEI/miR-34 a complex group increase significantly,suggesting new bone formation and trabecular thickness increasing.The N-Ac-L-Leu-PEI/miR-34 a group showed more osteoid,osteoblast and new bone formation.The expression of Runx2,SP7 and Col I mRNA is up-regulated by N-Ac-L-Leu-PEI / mi R-34 a complex,which are specific factors of osteogenisis,indicating that N-AcThe L-Leu-PEI/miR-34 a complex promotes osteogenic differentiation of the defect area.The difference was statistically significant(p<0.05)Conclusion:N-Ac-L-Leu-PEI / miR-34 a complex can promote osteogenesis in rat cranial defects. |
