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This study radiologically and histologically compared two bioresorbable bone substitutes with different compositions carbonate apatite (Cytrans® Granules; CGs) and ß-tricalcium phosphate (ß-TCP) for vertical bone augmentation on a rat skull using a polytetrafluoroethylene (PTFE) tubes. This PTFE tube was placed at the center of the skull, fixed with Super Bond, and augmented with CGs or ß-TCP granules. Specimens with surrounding tissue were harvested at 4, 8, and 12 weeks postoperatively, and radiological and histological evaluations were performed. The bone volume to total volume ratio (BV/TV) of the ß-TCP-implanted group was markedly higher than that of the CG-implanted group at 4 and 12 weeks postoperatively. Compared to CGs, ß-TCP exhibited the ability to form blood vessels into the graft material for a short period after transplantation, as well as an elevated production of collagen into ß-TCP granules during the bone formation process. [ABSTRACT FROM AUTHOR]

Senescence-associated secretory phenotype (SASPs) secreted from senescent cells often cause the deleterious damages to the surrounding tissues. Although dedifferentiated fat (DFAT) cells prepared are considered a promising cell source for regenerative therapies, SASPs from DFAT cells undergoing long-term cell culture, which latently induce replicative senescence, have barely been explored. The present study was designed to investigate senescent behaviors in rat-derived DFAT cells at high passage numbers and to analyze the possible types of SASPs. Our data show that DFAT cells undergo senescence during replicative passaging, as determined by multiple senescent hallmarks including morphological changes in cell shape and nucleus. Moreover, RT2 PCR array analysis indicated that senescent DFAT cells expressed higher levels of 16 inflammatory cytokines (Ccl11, Ccl12, Ccl21, Ccl5, Csf2, Cxcl1, Cxcl12, Ifna2, IL11, IL12a, IL13, IL1a, IL1rn, IL6, Mif, and Tnf) associated with SASPs than non-senescent cells. This study implicates that rat DFAT cells undergo cellular senescence after long-term cell culture; cautious consideration should be paid to treat SASP secretion when senescent DFAT cells are used in regenerative medicine. [ABSTRACT FROM AUTHOR]

The objective of this study was to genetically engineer dendritic cells (DC) for biological activation and evaluate their anti-tumor activity in a tumor-bearing mouse model. Mouse DC were incubated on the surface of culture dishes which had been coated with the complexes of a cationized dextran and luciferase plasmid DNA complexes plus a cell adhesion protein, Pronectin®, for gene transfection (reverse transfection). When compared with the conventional transfection where DC were transfected in the medium containing the complexes, the level of gene expression by the reverse method was significantly higher and the time period of gene expression was prolonged. Following the reverse transfection of DC by a plasmid DNA of mouse interleukin-12 (mIL-12) complexed with the cationized dextran, the mIL-12 protein was secreted at higher amounts for a longer time period. When injected intratumorally into mice carrying a mass of B16 tumor cells, the DC genetically activated showed significant anti-tumor activity. [ABSTRACT FROM AUTHOR]

The objective of this study is to prepare a non-viral carrier of gene transfection from various polysaccharides and evaluate the feasibility in gene expression for mesenchymal stem cells (MSCs). Various amounts of spermine were chemically introduced into pullulan, dextran and mannan with a molecular weight of around 40 000 or pullulan with different molecular weights to prepare cationized polysaccharides with different extents of spermine introduced (spermine–polysaccharide). Each cationized polysaccharide was complexed with a plasmid DNA at various ratios and in vitro gene transfection was investigated for rat bone marrow-derived MSCs. The level of gene expression depended on the type of cationized polysaccharide. The highest level was observed for the complex of spermine–pullulan and plasmid DNA. Additionally, the level also depended on the molecular weight of pullulan and the extent of spermine introduced to pullulan. Suppression of gene expression with chlorpromazine and methyl-β-cyclodextrin of endocytosis inhibitors demonstrated that the cellular uptake of spermine–pullulan–plasmid DNA complexes was mediated by clathrin- and raft/caveolae-dependent endocytic pathways. The cationized pullulan is a promising non-viral carrier of plasmid DNA for MSCs. [ABSTRACT FROM AUTHOR]

The objective of this study is to prepare a non-viral carrier of gene expression from the polysaccharide dextran and evaluate the effect of amine compounds introduced to dextran on the level of gene expression. Dextran with a molecular weight of 74 × 103 was cationized by the chemical introduction of different amine compounds. The cationized dextran was complexed with a plasmid DNA and the vitro gene transfection was investigated for HeLa cells. The level of gene expression depended on the amine compound introduced to dextran. The highest level was observed for the complex of spermine-introduced dextran and plasmid DNA. The highest cellular internalization and the best buffering effect were observed among every cationized dextran. Every complex did not show any cytotoxicity. It is concluded that the superior properties of spermine-introduced dextran enabled the plasmid DNA to enhance the expression level to a great extent compared with other cationized dextrans. Cationized dextran is a promising non-viral carrier of plasmid DNA. [ABSTRACT FROM AUTHOR]