High Mobility Group Box 1 Protein Level as a Novel Biomarker for the Development of Peri-Implant Disease.

Peri-implant disease is a chronic inflammation of the soft and hard tissues around a dental implant, resulting from bacterial infection. Recent evidence indicates that some pro-inflammatory cytokines and chemokines released by immunocytes are substantially responsible for the progress and consequence of inflammation. High mobility group box 1 (HMGB1) is released into the extracellular matrix and acts as a key pro-inflammatory factor during injury, necrosis and inflammation. A higher concentration of HMGB1 has been found in gingival crevicular fluid from inflammatory gingival tissue than from healthy sites. HMGB1 mRNA and protein are overexpressed in murine periodontal ligament fibroblasts stimulated with lipopolysaccharide (LPS) and IL-1ß. Thus, this study sought to assess HMGB1 expression in peri-implant crevicular fluid (PICF) at each stage of peri-implant disease and to investigate the correlation between HMGB1 and peri-implant disease progress. The results demonstrated that the HMGB1 expression level in PICF is indicative of the progress of peri-implant disease and hence may be a useful diagnostic and prognostic biomarker for peri-implant tissue.

[The comparison of platelet-rich fibrin and platelet-rich plasma in releasing of growth factors and their effects on the proliferation and differentiation of adipose tissue-derived stem cells in vitro].

OBJECTIVE: To compare the releasing of growth factors between platelet-rich fibrin (PRF) and platelet-rich plasma (PRP) as well as their effects on the proliferation and differentiation of adipose tissue-derived stem cells (ADSCs) in vitro. METHODS: Blood was taken from central artery of rabbits, acquiring PRF was acquired through one time centrifuge and PRP through two times centrifuge. Five milliliters of fresh alpha-MEM was added to PRF and PRP and incubated at 37 degrees C. The time points to collect exudates was in day 1, 7, 14, 21, 28 and the mass concentrations of transforming growth factor-beta1 (TGF-beta1) and platelet derived growth factor-AB(PDGF-AB) were quantified in PRF and PRP. Then the exudates of PRF and PRP were used to culture ADSCs and evaluate the effects of PRF and PRP on proliferation and differentiation of ADSCs. RESULTS: 1) Growth factor release: In the PRF exudates at different time points, the mass concentration of TGF-beta1 was the highest at day 14 and the highest mass concentration of PDGF-AB at day 7, the mass concentration of both TGF-beta1 and PDGF-AB was the highest at the first day and then gradually declined. 2)The effect on proliferation and differentiation: PRF exudates of day 14 expressed the maximum proliferation and alkaline phosphatase (ALP) activity. PRF exudates of day 1 demonstrat the maximum proliferation and ALP activity. CONCLUSION: Comparing to PRP, PRF releases growth factors gradually and expressed stronger and more durable effect on proliferation and differentiation of ADSCs in vitro.