羟乙基纤维素与再生氧化纤维素止血纱布理化性质的对比研究

目的:研究比较羟乙基纤维素止血纱布(HEC-AHG)和氧化再生纤维素止血纱布(ORCAHG)两者的理化性质,为临床应用提供支持。方法:实验测定HEC-AHG与ORC-AHG两者的溶解度、溶解速率、pH值、电导率和纤维素酶作用下的降解动力学。结果:HEC-AHG在去离子水和生理盐水中的溶解度和溶解速率分别为12%~15%和6.5~7.2 mg·ml^(-1)·min~(^(-1)),明显高于ORC-AHG0.08%~0.1,4×10^(-5)~64×10^(-5) mg·ml^(-1)·min^(-1)。HEC-AHG的pH值为6~7,在去离子水中的电导率与纯水(14μS/cm)接近,而ORC-AHG的pH值为2~3,具有较高的电导率(250~450(μS/cm)。室温下HEC-AHG在0.1%纤维素酶作用下降解速率高于ORC-AHG。结论:与ORC-AHG比较,HEC-AHG有更好的溶解性能和较小酸性,降解较快,是一种有前景的新型止血材料。

“互联网+”视角下的城市智慧交通管理问题思考

论文首先论述了"互联网+"视角下智慧交通管理发展研究的意义,然后指出了"互联网+"视角下智慧交通管理发展研究的内容,分析了"互联网+"视角下智慧交通管理发展的趋势和特点,最后基于"互联网+"视角对城市智慧交通管理的发展进行了深入思考。

共轭亚油酸-紫杉醇自组装纳米粒的结构分析

目的制备共轭亚油酸-紫杉醇自组装纳米粒(conjugated linoleic acid-paclitaxel conjugate self-assembled nanoparticles,CLA-PTX NPs)。方法本实验采用纳米沉淀法制备,通过动态光散射、核磁共振氢谱、拉曼光谱、傅里叶变换红外光谱及氮元素分布分析等方法对所制备的CLA-PTX NPs的表面和内部基团进行表征,确定CLA-PTX NPs的表面基团和内部基团,为阐述其自组装机制提供依据。结果PTX中C-1位和C-7位的羟基、C-4位和C-10位的乙酰基位于CLA-PTX NPs的表面,CLA碳链、PTX中C-2位和C-3'位的苯环及C-3'位的酰胺键位于CLA-PTX NPs的内部。据此推测CLA-PTX的自组装方式是非极性的CLA碳链因疏水作用而自发向内聚集,PTX中亲水的含氧基团羟基、羰基等在纳米粒表面从而形成纳米粒。结论CLAPTX NPs表面基团的确定也为其可能的表面修饰提供参考和依据。更为重要的是,本实验还为其他自组装纳米粒结构的表征提供了相关可行的方法。

Synthesis of poly(amidoamine)-poly(ethyleneglycol)-poly(amidoamine) and preparation of its hydrogel solution containing doxorubicin

Many pH-and temperature-responsive polymers have been designed for preparing hydrogel.In the present study,in order to decrease the pH sensitivity of reported poly(amidoamine)-poly(ethyleneglycol)-poly(amidoamine)(PAA1580-PEG4600-PAA1580),we designed and synthesized poly(amidoamine)-poly(ethyleneglycol)-poly(amidoamine)(PAA-PEG-PAA)with shorter length of PAA chain by decreasing reaction temperature for preparing PAA-PEG-PAA hydrogel solution containing doxorubicin(DOX).The PAA-PEG-PAA was synthesized via the Michael-addition polymerization.The characteristic of PAA-PEG-PAA was evaluated.The PAA-PEG-PAA hydrogel solution was prepared and investigated.DOX-loaded PAA-PEG-PAA hydrogel solution was prepared,and its in vitro DOX release and in vitro anti-tumor activity were evaluated.Our results indicated that the viscosity of PAA-PEG-PAA hydrogel solution was concentration-and temperature-dependent.The sol-gel transition temperature of PAA-PEG-PAA hydrogel solution(12%,w/w)ranged from 35 to 29℃,and its pH ranged from 6.0 to 7.4.The released DOX from DOX-loaded PAA-PEG-PAA hydrogel showed sustained release characteristics.The in vitro anti-tumor activity of DOX-loaded PAA-PEG-PAA hydrogel was confirmed in B16 F10 cell line.Considering the acidic tumor microenvironment,this DOX-loaded PAA-PEG-PAA hydrogel solution would be easy in situ administration for intra-tumor injection or para-tumor injection forming hydrogel at body temperature.We suggested that this DOX-loaded PAA-PEG-PAAhydrogel solution,if containing photothermal conversion agents,would have a potential further use for photothermal therapy.