RESUMO
This study aimed to use the sika deer as a model to study the influence of IGF-1 on the expression of Col Ⅰ in antler chondrocytes.The chondrocytes were separated from sika deer antlers,cultured and were treated with recombinant human IGF-1 protein (rIGF-1),both rIGF-1 and PQ401,and transfected with IGF-1 over-expression plasmid or IGF-1 siRNA,respectively.The expression of Col Ⅰ which,a well-known marker for chondrocytes dedifferentiation,was detected by real-time PCR.The results showed that administration of rIGF-1 to antler chondroctyes resulted in an obvious decrease of Col Ⅰ mRNA levels,while PQ401 pretreatment could dramatically attenuate the effects of rIGF-1 on the expression of Col Ⅰ mRNA.After transfection with IGF-1 over-expression plasmid,the expression of Col Ⅰ mRNA was obviously reduced in antler chondrocytes compared with control.Conversely,knockdown IGF1 with specific siRNA could increase the expression of Col Ⅰ in antler chondrocytes.These results indicate that IGF-1 may play an important role in process of antler chondrocyte dedifferentiation.
RESUMO
BACKGROUND:It has been found that the compressive strength and flexural strength of nano-hydroxyapatite combined with light-cured resin matrix can neet the requirements of dental restorative materials. OBJECTIVE:To detect the cytotoxicity of nano-hydroxyapatite/composite resin, and to analyze its effects on the dental restoration. METHODS:In vitro test:passage 5 periodontal ligament fibroblast-like cel s and L-929 cel s suspensions were cultured in the 10%, 50%, 100%of nano-hydroxyapatite/composite resin extracts, respectively, and fresh maintenance medium functioned as negative control group. Absorbance values were detected within 7-day culture. In vivo repair test:57 cases with tooth defect were enrol ed containing 37 males and 20 females aged from 15 to 31 years old, and al were subjected to nano-hydroxyapatite/composite resin treatment. A 3-year fol ow-up was undergone to detect the completeness, marginal adaptation and color matching of the restoration, as wel as the periodontal probing depth, sulcus bleeding index, tooth mobility, dental plaque index, gingival crevicular fluid and aspartate aminotransferase level. RESULTS AND CONCLUSION:In vitro test results showed that the different concentrations of nano-hydroxyapatite/composite resin extracts had no effects on both periodontal ligament fibroblast-like cel s and L-929 cel s. In vivo repair test results found that after 3 years of fol ow-up, the periodontal probing depth, sulcus bleeding index, tooth mobility, dental plaque index, gingival crevicular fluid and aspartate aminotransferase level of patients were significantly decreased than those before repair (P0.05). Unfortunately, three cases with incomplete restoration, four cases with color mismatching, and three cases with the inadaptable edge occurred. To conclude, the nano-hydroxyapatite/composite resin holds good biocompatibility and no cytotoxicity, which can maintain a good periodontal health condition in the dental restoration.
