Abstract: Objective:To investigate the partial delivery ability in vivo of oligonucleotide MT01 mediated by polyethyleneimine(PEI) derivative PEN, and to illuminate its effect on the alveolar bone reconstruction and the biological safety in the rats with experimental tooth movement. Methods:Forty-eight Wistar male rats were randomly divided into PEN,MT01, sulfuration-modified MT01 (MT01s), and PEN/MT01 groups. The rat experimental tooth model was established, and the above four drugs were injected into the mesial buccal mucosa of the first molar in the left sides of the rats as drug intervention sides,and the PBS were injected into the mesial buccal mucosa of the first molar in the right sides as PBS control sides;once every 3 d. After 14 d, the rats were sacrificed. HE staining was used to detect the histopathological changes of important organs of the rats;the photos and X-ray films were applied to measure the distance of tooth movement, and RT-PCR was used to detect the expression levels of the osteogenic marker genes Runt-related transcription factor 2(Runx2),special protein 7(SP7) and osteocalcin(OCN) mRNA. Results:After local injection of the above drugs, no obvious inflammatory cell infiltration and structural differences were found in the main organs of the rats and no obvious abnormalities were found in all organs tissues. Compared with the PBS control sides, the movement distance of the first molars in the drug intervention sides in MT01, MT01s, and PEN/MT01 groups was reduced (P<0.05 or P<0.01), but there was no significant difference in PEN group (P>0.05). The data of the distance between the two teeth of the rats in various groups was PEN/MT01 group > MT01s group > MT01 group>PEN group, and the difference between PEN/MT01 group and MT01s group was statistically significant (P<0.05).The expression levels of Runx2, SP7, and OCN mRNA in the periodontium tissue in the drug intervention sides of the rats in MT01s and PEN/MT01 groups were significantly higher than those in the PBS control sides (P<0.05 or P<0.01), especially in PEN/MT01 group.Compared with the PBS control sides,the expression level of Runx2 mRNA in the periodontium tissue in the drug intervention sides of the rats in MT01 group was decreased(P<0.05), and the expression levels of SP7 and OCN mRNA in the periodontal tissue of the rats in MT01 group were increased(P<0.05);the expression level of Runx2 mRNA in the periodontium tissue in the drug intervention sides of the rats in PEN group was decreased(P<0.05), and there were no significant differences in the expression levels of SP7 and OCN mRNA (P>0.05). Conclusion:PEI derivative PEN can transfer MT01 into the cell safely and efficiently; it can increase the expression levels of Runx2, SP7 and OCN mRNA in the periodontium tissue and decrease the tooth movement distance in the experimental tooth movement rats.

Key words: PEN, polyetylenimine derivative oligodeoxynucleotide MT01, Runt-related transcription factor 2, special protein 7, osteocalcin