Calcein retention

Fluoromax-3 spectrofluorometer (Edison, NJ). The total calcein content of the vesicles was determined after lysis of the membranes with Triton X-100 (1% (v/v)). Calcein retention of vesicles was estimated from the fluorescence before and after the addition of Triton X-100. Prior to calcein retention analysis, the freeze-dried samples were rehydrated at room temperature. 

UF was tested for the filtration of FA, HA, and a Calcein model solution. FA and Calcein retention increased with pH and decreased with ionic strength, while HA rejection was constant. Anion retention was proportional to charge. A FA and HA retention of >70% was obtained (Kiichler and Miekeley (1994)). 

Effect of cholesterol addition on the retention of calcein by DPPC-cholesterol liposomes. 

Ollila et al. (2002) studied the interaction between flavonoids and membranes composed of di-palmitoylphosphatidylcholine by means of nonco-valent immobilized artificial membrane chromatography and flavonoid-induced calcein release from fluid egg phosphatidylcholine vesicles. Flavonoids with more hydroxyl groups showed longer retention delays in the immobilized artificial membrane studies, suggesting stronger interactions between the flavonoids, which are rich in hydroxyl groups, and the dipalmitoylphosphatidylcholine membrane interface. Both polar and nonpolar forces were shown to have a significant impact on the flavonoid-biomembrane interactions. 

We have reported that an efficient content release occurs from the thermosensitive polymer-modified DOPE liposomes above the polymer s LCST. " However, when phosphatidylcholines are used for the liposomal lipid, only a limited portion of the contents is released from the thermosensitive polymer-modified liposomes under the same condition. W examined retention of calcein in the copoly(APr-NIPAM)-2Ci2-modified EYPC liposomes and found that 82 and 81 % of the loaded calcein molecules were retained after 3 h incubation in DMEM with 10 % FBS at 37 and 42°C, respectively. Also, we did not observe remarkable difference in... 

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