Transforming Growth Factor-ß3/Chitosan Sponge (TGF-ß3/CS) Facilitates Osteogenic Differentiation of Human Periodontal Ligament Stem Cells.

Periodontal disease is the main reason for tooth loss in adults. Tissue engineering and regenerative medicine are advanced technologies used to manage soft and hard tissue defects caused by periodontal disease. We developed a transforming growth factor-ß3/chitosan sponge (TGF-ß3/CS) to repair periodontal soft and hard tissue defects. We investigated the proliferation and osteogenic differentiation behaviors of primary human periodontal ligament stem cells (hPDLSCs) to determine the bioactivity and potential application of TGF-ß3 in periodontal disease. We employed calcein-AM/propidium iodide (PI) double labeling or cell membranes (CM)-Dil labeling coupled with fluorescence microscopy to trace the survival and function of cells after implantation in vitro and in vivo. The mineralization of osteogenically differentiated hPDLSCs was confirmed by measuring alkaline phosphatase (ALP) activity and calcium content. The levels of COL I, ALP, TGF-ßRI, TGF-ßRII, and Pp38/t-p38 were assessed by western blotting to explore the mechanism of bone repair prompted by TGF-ß3. When hPDLSCs were implanted with various concentrations of TGF-ß3/CS (62.5-500 ng/mL), ALP activity was the highest in the TGF-ß3 (250 ng/mL) group after 7 d (p < 0.05 vs. control). The calcium content in each group was increased significantly after 21 and 28 d (p < 0.001 vs. control). The optimal result was achieved by the TGF-ß3 (500 ng/mL) group. These results showed that TGF-ß3/CS promotes osteogenic differentiation of hPDLSCs, which may involve the p38 mitogen-activated protein kinase (MAPK) signaling pathway. TGF-ß3/CS has the potential for application in the repair of incomplete alveolar bone defects.

Sequentially releasing self-healing hydrogel fabricated with TGFß3-microspheres and bFGF to facilitate rat alveolar bone defect repair.

Resorption and loss of alveolar bone leads to oral dysfunction and loss of natural or implant teeth. Biomimetic delivery of growth factors based on stem cell recruitment and osteogenic differentiation, as the key steps in natural alveolar bone regenerative process, has been an area of intense research in recent years. A mesoporous self-healing hydrogel (DFH) with basic fibroblast growth factor (bFGF) entrapment and transforming growth factor ß3 (TGFß3) - loaded chitosan microspheres (CMs) was developed. The formulation was optimized by multiple tests of self-healing, in-bottle inversion, SEM, rheological, swelling rate and in vitro degradation. In vitro tubule formation assays, cell migration assays, and osteogenic differentiation assays confirmed the ability of DFH to promote blood vessels, recruit stem cells, and promote osteogenic differentiation. The optimum DFH formula is 0.05 ml 4Arm-PEG-DF (20%) added to 1 ml CsGlu (2%) containing bFGF (80 ng) and TGFß3-microspheres (5 mg). The results of in vitro release studied by Elisa kit, indicated an 95% release of bFGF in 7 d and long-term sustained release of TGFß3. For alveolar defects rat models, the expression levels of CD29 and CD45, the bone volume fraction, trabecular number, and trabecular thickness of new bone monitored by Micro-CT in DFH treatment groups were significantly higher than others (*P < 0.05, vs Model). HE and Masson staining show the same results. In conclusion, DFH is a design of bionic alveolar remodelling microenvironment, that is in early time microvessels formed by bFGF provide nutritious to recruited endogenous stem cells, then TGFß3 slowly released speed up the process of new bones formation to common facilitate rat alveolar defect repair. The DFH with higher regenerative efficiency dovetails nicely with great demand due to the requirement of complicated biological processes.

An emerging recombinant human enterovirus 71 responsible for the 2008 outbreak of hand foot and mouth disease in Fuyang city of China.

Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008.

[The study on the enamel remineralization by enamel matrix proteins' inducing].

OBJECTIVE: To find the enamel matrix proteins on the impact of enamel mineralization through experiments. METHODS: A combination of protein and beneficial carboxyl groups was grafted on the surface of enamel defects of rats through UV radiation then put into the enamel matrix proteins of calcium phosphate agar acetate solution systems, through scanning enamel surface with the electron microscopy to observe the morphological changes of enamel then analyse the regulation that enamel matrix proteins have done to the white hydroxyapatite crystals on the composition and morphology. RESULTS: In the enamel matrix protein added gel system, we can see the growth of hydroxyapatite crystals, and crystal showed a good degree of crystallinity and contained a small amount of CO3(2-) substituted hydroxyapatite crystals. CONCLUSION: The temperature at 37 degrees C water bath, after adding the enamel matrix proteins to gel system, the new hydroxyapatite crystals were numerous which proved that enamel matrix proteins played an important role in nucleation and growth of hydroxyapatite crystal, so it could be indicated that enamel matrix proteins could induce the enamel remineralization.

Complete genome analysis of the C4 subgenotype strains of enterovirus 71: predominant recombination C4 viruses persistently circulating in China for 14 years.

Genetic recombination is a well-known phenomenon for enteroviruses. To investigate the genetic characterization and the potential recombination of enterovirus 71 (EV71) circulating in China, we determined the 16 complete genome sequences of EV71 isolated from Hand Foot Mouth Disease (HFMD) patients during the large scale outbreak and non-outbreak years since 1998 in China. The full length genome sequences of 16 Chinese EV71 in present study were aligned with 186 genome sequences of EV71 available from GenBank, including 104 China mainland and 82 international sequences, covering the time period of 1970-2011. The oldest strains of each subgenotype of EV71 and prototype strains of HEV-A were included to do the phylogenetic and Simplot analysis. Phylogenetic analysis indicated that all Chinese strains were clustered into C4 subgenotype of EV71, except for HuB/CHN/2009 clustered into A and Xiamen/CHN/2009 clustered into B5 subgenotype. Most of C4 EV71 were clustered into 2 predominant evolutionary branches: C4b and C4a evolutionary brunches. Our comprehensive recombination analysis showed the evidence of genome recombination of subgenotype C4 (including C4a and C4b) sequences between structural genes from genotype C EV71 and non-structural genes from the prototype strains of CAV16, 14 and 4, but the evidence of intratypic recombination between C4 strains and B subgenotype was not enough strong. This intertypic recombination C4 viruses were first seen in 1998 and became the predominant endemic viruses circulating in China mainland for at least 14 years. A shift between C4a and C4b evolutionary brunches of C4 recombination viruses were observed, and C4a viruses have been associated with large scale nationwide HFMD outbreak with higher morbidity and mortality since 2007.

[Role of enamel matrix proteins in inducing biomimetic mineralization of the enamel: a study with quartz crystal microbalance technique].

OBJECTIVE: To investigate the adsorption behavior of enamel matrix proteins (EMPs) on the enamel surface and study their effect on biomineralization of enamel using quartz crystal microbalance (QCM) technique. METHODS AND RESULTS: The EMPs were adsorbed on the enamel surface to form a protein film, which was soaked in simulated body fluid solutions. After 30 days of biomimetic mineralization, the hydroxyapatite nucleation, growth and aggregation occurred with hydroxyapatite crystal formation on the enamel surface. CONCLUSION: The EMPs play a key role in regulating enamel mineralization.

[Grafting functional groups on enamel surface by a self-assembled monolayer technique].

OBJECTIVE: To study the influence of various active groups grafted on the enamel surface by means of self assembly on enamel biomineralization. METHODS: The enamel was prepared by immersing the bicuspid tooth into 1 mmol/L ethanolic solution of a omega-functionalized (omega=PO4H2, SO3H, COOH or OH) group and deionized water solution of HSCH2CH2SO3Na for 24 h at room temperature. The contact angles and infrared (IR) images were used to identify the morphological changes of the enamel with chemisorption of the functional groups. RESULTS: The contact angles and IR images showed that the omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group was chemisorbed on the enamel surface. CONCLUSION: Self assembled monolayers with omega-functionalized (omega=-PO4H2, -SO3H, -COOH, -OH or -CH3) group can be successfully formed on the enamel surface by hydrolyzation.