Lloyd A W, Olliff C J, Rutt K J
Department of Pharmacy, University of Brighton, Moulsecoomb, UK.
J Pharm Pharmacol. 1994 Sep;46(9):704-7. doi: 10.1111/j.2042-7158.1994.tb03887.x.
Glycinebetaine and N-modified betaines have been previously shown to be effective at reducing leakage from liposomes on freeze-thaw procedures. This study involved the preparation of a series of other modified betaines and the comparison of their abilities to reduce leakage from frozen multilamellar liposomes. All the compounds investigated, with the exception of the octyl ester of betaine, reduced the degree of leakage on freezing and thawing with additive concentrations up to 0.6 M. The betaine esters were less effective than betaine as cryoprotective additives and caused an increase in the leakage from unfrozen liposomes. Taurinebetaine, a sulphobetaine, was also less effective at reducing leakage on freezing than betaine and again increased leakage from unfrozen liposomes. Increasing the number of methylene groups between the carboxylate group and the nitrogen improved the ability to reduce leakage, particularly at lower additive concentrations.
先前已表明，甘氨酸甜菜碱和N-修饰的甜菜碱在冻融过程中能有效减少脂质体的渗漏。本研究涉及一系列其他修饰甜菜碱的制备，并比较了它们减少冷冻多层脂质体渗漏的能力。除甜菜碱辛酯外，所有研究的化合物在添加剂浓度高达0.6 M时，都能降低冻融时的渗漏程度。甜菜碱酯作为冷冻保护添加剂的效果不如甜菜碱，且会导致未冷冻脂质体的渗漏增加。牛磺酸甜菜碱（一种磺基甜菜碱）在减少冷冻时的渗漏方面也不如甜菜碱有效，并且同样会增加未冷冻脂质体的渗漏。增加羧酸盐基团与氮之间的亚甲基数量可提高减少渗漏的能力，尤其是在较低的添加剂浓度下。
