Liposome formulations can be broadly divided into cationic, anionic and neutral subtypes. Charged liposomes are used in many different types of studies such as, blood complement studies, gene transfer studies and other biomedical applications to name a few. Cellsome® liposomes made from anionic PEGylated lipids provide certain benefits.
Anionic liposomes offer a number of attributes, relative to the challenges associated with cationic formulations such as, the administration of cationic liposomes results in higher cytotoxicity levels, both in vitro (Zhong et al., 2009) and in vivo (Balazs and Godbey, 2010). Anionic liposomes demonstrate greater stability in solution (Zhigaltsev et al., 2002, Phillips and Heydari, 1996), lead to lower aggregation when compared with neutrally charged liposomes, and have increased endocytosis when compared with cationic (Bajoria et al., 1997) and neutral liposomes.
To improve liposome stability and enhance their circulation times in the blood, a sterically-stabilized, hydrophilic polymer, polyethylene glycol (PEG), has been shown to be the optimal choice for obtaining sterically-stabilized liposomes. Using an Anionic Liposome with PEG will protect the liposomes from circulating proteins, improving their plasma clearance and enhancing their therapeutic effects.
The four products provided that are made from Anionic PEGylated Lipids provided here consist of either DSPC:Chol:DSPG:DSPE-PEG(2000) (60:30:5:5 molar ratio), DOPC:Chol:DOPG:DOPE-PEG(2000) (60:30:5:5 molar ratio), DSPC:Chol:DSPS:DSPE-PEG(2000) (60:30:5:5 molar ratio), or DOPC:Chol:DOPS:DOPE-PEG(2000) (60:30:5:5 molar ratio).
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免疫组织化学又称免疫细胞化学,是指带显色剂标记的特异性抗体在组织细胞原位通过抗原抗体反应和组织化学的呈色反应,对相应抗原进行定性、定位、定量测定的一项新技术。它把免疫反应的特异性、组织化学的可见性巧妙地结合起来,借助显微镜的现像和放大作用,在细胞,亚细胞水平检测各种抗原物质,并可在原位显示相应的基因和基因表达产物。免疫组织化学技术现已有:免疫荧光组织(细胞)化学技术、免疫酶组织(细胞)化学技术、亲和组织化学技术、免疫金银及铁标记免疫组织化学技术等。免疫荧光组织(细胞)化学技术是采用荧光素标记的已知抗体(或抗原)作为探针,检测待测组织、细胞标本中的靶抗原(或抗体),形成的抗原抗体复合物上带有荧光素,在荧光显微镜下,由于受高压汞灯光源的紫外光照射,荧光素发出明亮的荧光,这样就可以分辨出抗原(或抗体)的所在位置及其性质,并可利用荧光定量技术计算抗原的含量。以达到对抗原物质定位、定性、定量测定的目的。
Bone Mesenchymal Stem Cells 作为一个细胞群体,还没有发现有特定细胞表面marker. 对于那些可以代表自我更新和分化的marker, 也不清楚到底要发现哪一个的表达才能确定该细胞就是BMSC。
目前常用的方法,就是采用培养,colony-forming unit-fibroblasts (CFU-F)这个方法。一般BMSC可以24-48小时贴壁。
流式细胞计数,比如STRO-1,但是一般认为STRO-1阳性的细胞更趋向于造血干细胞,和BMSC简单区别还不是很清楚。
这里有个培养分化的产品
http://www.rndsystems.com/pdf/SC020.pdf