著者

Ling Zheng Lin Wang Jie Qin Xiaolin Sun Tingting Yang Yuxin Ni Yanmin Zhou

出版者

硬組織再生生物学会

雑誌

Journal of Hard Tissue Biology (ISSN:13417649)

巻号頁・発行日

vol.24, no.1, pp.54-60, 2015 (Released:2015-01-20)

参考文献数

20

被引用文献数

1 10

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The temperature-sensitive triblock copolymer poly-(D, L-lactic acid-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) is an FDA-approved material that has the ability to provide a sustained release of drugs and/or proteins. Platelet-rich fibrin(PRF)is second generation platelet concentration that contains growth factors such as transforming growth factor-β1 (TGF-β1), platelet derived growth factor-AB (PDGF-AB), and insulin-like growth factor-I (IGF-I). These growth factors affect the migration and proliferation of diverse cell types, including endothelial cells, smooth muscle cells, and osteoblast-like cells. This study sought to combine the hydrogel into scaffolds in order to serve as a sustained release system for PRF-derived growth factors. Poly (lactic-co-glycolic) acid (PLGA) and nano-hydroxyapatite (nHA) were used to prepare the hydrogel-containing scaffolds with the PRF-derived growth factors. We then investigated the effects of the hydrogel on modulating the activity of osteoblasts in vitro. We indicated that the hydrogel (Gel) was well-distributed in the inner surface of scaffolds, which themselves exhibited relatively interconnected pores with uniform sizes. The addition of the hydrogel didn’t affect their inherently high porosity. In vitro release tests indicated that the system containing nHA/PLGA/Gel/PRF provided for a slow and sustained release of PRF-derived growth factors. The results from our in vitro studies indicated that the MG63 cells cultured with both scaffold media extracts did not appear to have cytotoxic responses, and the nHA/PLGA/Gel/PRF system could improve the adhesion and proliferation of MG63 cells when compared to controls (p < 0.05). This in vitro evaluation suggests that the hydrogel-scaffold system is suitable as a model for bone tissue engineering, and that it allows for the sustained release of growth factors to improve bone reconstruction.

著者

Shunichiro Sasaki Shiyu Xie Shinsuke Ikeda Jie Qin Yoshiro Tsutsui

出版者

行動経済学会

雑誌

行動経済学 (ISSN:21853568)

巻号頁・発行日

vol.5, pp.15-25, 2012 (Released:2012-06-01)

参考文献数

16

被引用文献数

2

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This paper pursues two aims by conducting economic experiments in Shanghai. One aim of this paper is to investigate the following three anomalies on time discounting: the delay, interval, and magnitude effects. We confirmed all the three anomalies. Particularly, by separating the delay effect from the interval effect, the delay effect is found when the delay is relatively short, which has seldom been reported in former studies. Another feature of our experiment is that it is immune to the criticism that the subjects recruited for the experiment did not have sufficient incentives to report their true preferences because the highest reward that was offered to the subjects was approximately equivalent to their monthly household incomes. The second aim of this paper is its explanation of the subjects’ procrastinating behaviors by their time discount rates and the degrees of the delay effect. Our analysis suggested that higher time discounting always promotes procrastination; however, the delay effect is negatively associated with procrastination. An interpretation of the latter result can be that our subjects, i.e., the students of Fudan University, are sophisticates rather than naïfs.