15 research outputs found

    Fabrication of asymmetric membranes from polyhydroxybutyrate and biphasic calcium phosphate/chitosan for guided bone regeneration

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    [[abstract]]Chitosan (CS) is known for its biocompatibility, antibacterial function, and wound healing acceleration, while calcium phosphate (CP) can promote bone regeneration. However, to be useful as barrier membrane for guided bone regeneration (GBR) in periodontal treatments, the membranes must have suitable mechanical strength in addition to good barrier properties. Therefore, a dense polyhydroxybutyrate (PHB) layer was integrated with a porous biphasic calcium phosphate/chitosan (BCP/CS) layer to form an asymmetric PHB-BCP/CS membrane. Moreover, for enhancing the interfacial strength, the PHB layer was chemically bonded to the BCP/CS layer through plasma-induced grafting of poly(acrylic acid) on its surface and followed by amidation with CS via carbodiimide activation. The incorporation of the PHB layer greatly increased the initial modulus and ultimate tensile strength of the membrane up to 524 and 16.5 MPa, respectively. In addition, the human gingival fibroblast (HGF) cells could proliferate very well on the PHB layer of the membrane, yet they were prohibited from down-growing through the membrane. Also, the addition of BCP particles in the CS layer increased the proliferation of osteoblast cells. Thus, the asymmetric PHB-BCP/CS membrane has the potential to be used as a barrier membrane for GBR in periodontal tissue engineering.[[incitationindex]]SCI[[booktype]]紙

    Transcriptome analysis of bacteriophage communities in periodontal health and disease

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    BACKGROUND: The role of viruses as members of the human microbiome has gained broader attention with the discovery that human body surfaces are inhabited by sizeable viral communities. The majority of the viruses identified in these communities have been bacteriophages that predate upon cellular microbiota rather than the human host. Phages have the capacity to lyse their hosts or provide them with selective advantages through lysogenic conversion, which could help determine the structure of co-existing bacterial communities. Because conditions such as periodontitis are associated with altered bacterial biota, phage mediated perturbations of bacterial communities have been hypothesized to play a role in promoting periodontal disease. Oral phage communities also differ significantly between periodontal health and disease, but the gene expression of oral phage communities has not been previously examined. RESULTS: Here, we provide the first report of gene expression profiles from the oral bacteriophage community using RNA sequencing, and find that oral phages are more highly expressed in subjects with relative periodontal health. While lysins were highly expressed, the high proportion of integrases expressed suggests that prophages may account for a considerable proportion of oral phage gene expression. Many of the transcriptome reads matched phages found in the oral cavities of the subjects studied, indicating that phages may account for a substantial proportion of oral gene expression. Reads homologous to siphoviruses that infect Firmicutes were amongst the most prevalent transcriptome reads identified in both periodontal health and disease. Some genes from the phage lytic module were significantly more highly expressed in subjects with periodontal disease, suggesting that periodontitis may favor the expression of some lytic phages. CONCLUSIONS: As we explore the contributions of viruses to the human microbiome, the data presented here suggest varying expression of bacteriophage communities in oral health and disease. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-015-1781-0) contains supplementary material, which is available to authorized users
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