Research progress of periodontal tissue regeneration by combined biomaterials of dental derived mesenchymal stem cells / 口腔医学

@#The ultimate treatment goal of periodontitis is the structural and functional regeneration of periodontium. However, existing methods for periodontal regeneration have difficulties in regenerating the hierarchical structure. Therefore, stem cell-based tissue engineering has attracted more and more attention for its advantages of self-renewal and multi-lineage differentiation potential. This review summarized the progress of research on periodontal tissue regeneration by combined biomaterials of dental-derived stem cells. It is pointed out that the application of autologous stem cell transplantation is limited by the donor source, and the subsequent research should focus on the development of multi-phase scaffold materials and the attempt to establish a stem cell bank.

Keratinized tissue augmentation techniques around dental implants / 中华口腔医学杂志

Research have indicated that inadequate keratinized tissue has a negative effect on patient oral hygiene, resulting in peri-implant inflammation. It has been recommended that an apically repositioned flap alone or in combination with autogenous soft tissue grafts can increase the width of keratinized mucosa around dental implants, which promotes long term peri-implant health. This review summarized research progress on augmentation techniques of keratinized tissue arround implants in recent years, so as to provide reference for clinical practice and research design in the future.

Long-term stability of periodontal root coverage procedures for gingival recession / 中华口腔医学杂志

Gingival recession could result in root exposure, dental hypersensitivity and poor aesthetics. It has been demonstrated that varieties of root coverage procedures can significantly improve gingival recession in short-term (≤6 months), of which coronally advanced flap combined with connective tissue graft is the gold standard technique for treatment of gingival recession. It could obtain the optimally complete root coverage and maintain long-term stability (≥2 years). However, clinical knowledge about the long-term effectiveness of the other alternative graft materials remain very limited. Based on the existing clinical evidence, this article reviews coronally advanced flap, coronally advanced flap combined with connective tissue graft or alternative graft materials, with particular attention to the long-term stability of them, in order to provide reference for the design of further clinical trials and the plan of clinical treatments.

Delta12-prostaglandinJ2-nano capsule up-regulates growth factor expression and enhances bone regeneration in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of local delivery of delta12-prostaglandinJ2-loaded poly (lactic-co-glycolic acid) (Δ(12)-PGJ2-NC) on growth factors expression and bone formation.</p><p><b>METHODS</b>Δ(12)-PGJ2-NC was prepared by the emulsion solvent diffusion method. The physical and chemical properties of the nanoparticles were evaluated by particle size analysis, transmission electron microscopy, drug-loading ratio and the in vitro release study. Then standardized transcortical defect (5.0 mm × 1.5 mm) was conducted in the femur of 48 male Wistar rats which were randomly divided into four groups (n = 12), S, K, F, and N. Thirty microliter of saline (S), unloaded nanoparticles (K), Δ(12)-PGJ2 (F) and Δ(12)-PGJ2-NC(N) in a collagen vehicle were delivered inside a titanium chamber fixed over the defect. Then, four subgroups were randomly divided in each group named as D3, D7, D14, and D28 (n = 3) according to the days 3, 7, 14, and 28 after the surgery. At days 3, 7, 14, and 28, the mRNA expression of the bone morphogenetic protein-6 (BMP-6), platelet-derived growth factor-B (PDGF-B) in defect aera was analyzed by real time quantitive-polymerase blotting. HE staining was employed to reveal new bone formation in weeks 2 and 4.</p><p><b>RESULTS</b>Δ(12)-PGJ2-NC appeared opalescent white and remained relatively stable, with an average particle size of (135.2 ± 0.85) nm. The images from transmission electron microscopy showed that Δ(12)-PGJ2-NC was spherical in shape and homogeneously distributed. The encapsulation efficiency of Δ(12)-PGJ2 with the poly (lactic-co-glycolic acid) (PLGA) nanocapsules was about 92%. The in vitro release of Δ(12)-PGJ2-NC at 37 °C showed a sustained fashion and the average accumulated amount was 30%, 52%, 77%, 91%, and 98% respectively, at 0.5, 1, 2, 4 and 6 h. Compared with the animals treated with saline, after dose of 100 mg/L Δ(12)-PGJ2 and Δ(12)-PGJ2-NC apllication, the mRNA expression level of BMP-6, PDGF-B increased significantly (P < 0.05, P < 0.001). The protein expression of BMP-6, Ephrin-B2 also was up-regulated. Histomorphometry revealed that new bone formation increased at the same dose of 100 mg/L. But the unloaded nanoparticles did not have the same effect (P > 0.05).</p><p><b>CONCLUSIONS</b>A stable Δ(12)-PGJ2 loaded nanoparticle was successfully prepared. Δ(12)-PGJ2-NC may upregulate the expression of BMP-6, PDGF-B and Ephrin-B2, and promote new bone formation in bone defect area.</p>

Effects of naringin on proliferation, differentiation and matrix mineralization of MC3T3-E1 cells / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of naringin on the proliferation, differentiation and matrix mineralization of MC3T3-E1 cells in vitro.</p><p><b>METHOD</b>MC3T3-E1 cell lines were taken in vitro model. CCk-8 method was used to observe the proliferation of MC3T3 cells. Lactic acid dehydrogenase cytotoxicity (LDH) test was used to observe the cell toxicity. Bone morphogenetic protein-2 (BMP-2), alkaline phosphatase (ALP) and osteocalcin (OC) were used to observe the cell differentiation. Von kossa calcification staining method was used to observe the cell calcification.</p><p><b>RESULTS</b>The high dosages of the naringin could promote the proliferation of MC3T3-E1 cells at both 12 h and 24 h. While, low dosages did not show the same capability. LDH test showed that the cytotoxicity percentages in all six naringin treated groups were quite low. BMP-2 cytoimmunochemistry test showed that the three naringin treated group (10, 1, 0.1 micromol x L(-1)) showed higher brown coloration in cytoplasm than the control group at both 24 h and 48 h. 1, 0.1 micromol x L(-1) naringin raised ALP activity of MC3T3-E1 cells at 48 h (P < 0.05). Meanwhile, 0.1 micromol x L(-1) naringin increased the ALP activity at 72 h (P < 0.05). 10 and 1 micromol x L(-1) naringin increased the capability of MC3T3-E1 cell to synthesize osteocalcin during 8th - 12th dsince adding the medicine (P < 0.05). Naringin did not show the positive effects on cell calcification.</p><p><b>CONCLUSIONS</b>Naringin could promote proliferation and differentiation of MC3T3-E1 cells.</p>