Complexes between anionic liposomes and spherical polycationic brushes. An assembly of assemblies.
Complexes between anionic liposomes and spherical polycationic brushes. An assembly of assemblies.
复制标题
阴离子脂质体和球形聚阳离子刷之间的复合物。
作者：
A. Sybachin;O. V. Zaborova;V. N. Orlov;Pavel I. Semenyuk;Matthias Ballauff;E. Kesselman;Judith Schmidt;Y. Talmon;F. Menger;A. Yaroslavov
本文的目的是将脂质体组装到纳米颗粒上。通过这种方式，可以产生具有高负载能力的纳米颗粒。因此，通过在直径约100 nm的单分散聚苯乙烯颗粒表面接枝聚合阳离子单体（三甲基铵）甲基丙烯酸乙酯氯，合成了球形球形聚阳离子“刷”（SPBs）。这些颗粒与小的单层阴离子脂质体络合，直径40-60 nm，由卵磷脂（EL）和阴离子磷脂酰丝氨酸（PS(1-)）组成，PS(1-)/EL比值为0.10 ~ 0.54，关键参数为ν。然后根据电泳迁移率、动态光散射、电导率、荧光和低温透射电镜对这些配合物进行了表征，得出以下主要结论：(a)所有添加的脂质体在一定的饱和浓度（特定于每个ν值）下都与spb完全相关。(b)每个SPB颗粒的脂质体数从40 （ν = 0.1）到14 （ν = 0.5）不等。(c)在足够高的脂质体浓度下，spb经历了从正电荷到负电荷的总体变化。(d)当SPB复合物的初始正电荷被阴离子脂质体精确中和时，它们倾向于聚集。低脂质浓度下的正电荷或高脂质浓度下的负电荷阻碍聚集。(e)在ν≤0.5时，当脂质体与spb相关时，脂质体保持完整（即不泄漏）。(f)在外部[NaCl] = 0.3 M时，ν = 0.1，在0.6 M时，ν = 0.5， SPB/脂质体发生完全解离。ν = 0.54的脂质体即使在高达1.0 m的NaCl溶液中也不会与spb解离。(g) PS(1-)/EL脂质体与spb的络合诱导PS（1-）从内小叶向外小叶的翻转。(h) PS(1-)（圆柱形脂质）和CL(2-)（锥形脂质）造成膜缺陷的能力差异归因于几何因素。
This paper has at its objective the assembling of liposomal assemblies onto nanoparticles. In this manner, one generates nanoparticles with a high loading capacity. Thus, spherical spherical polycationic "brushes" (SPBs) were synthesized by graft polymerizing a cationic monomer, (trimethylammonium)ethylmethacrylate chloride, onto the surface of monodisperse polystyrene particles, ca. 100 nm in diameter. These particles were complexed with small unilamellar anionic liposomes, 40-60 nm in diameter, composed of egg lecithin (EL) and anionic phosphatidylserine (PS(1-)) in PS(1-)/EL ratios from 0.10 to 0.54, a key parameter designated as ν. These complexes were then characterized according to electrophoretic mobility, dynamic light scattering, conductivity, fluorescence, and cryogenic transmission electron microscopy, with the following main conclusions: (a) All added liposomes are totally associated with SPBs up to a certain saturation concentration (specific for each ν value). (b) The number of liposomes per SPB particle varies from 40 (ν = 0.1) to 14 (ν = 0.5). (c) At sufficiently high liposome concentrations, the SPBs experience an overall change from positive to negative charge. (d) SPB complexes tend to aggregate when their initial positive charge has been precisely neutralized by the anionic liposomes. Aggregation is impeded by either positive charge at lower lipid concentrations, or negative charge at higher lipid concentrations. (e) The liposomes remain intact (i.e., do not leak) when associated with SPBs, at ν ≤ 0.5. (f) Complete SPB/liposome dissociation occurs at external [NaCl] = 0.3 M for ν = 0.1 and at 0.6 M for ν = 0.5. Liposomes with ν = 0.54 do not dissociate from the SPBs even in NaCl solutions up to 1.0 M. (g) Complexation of the PS(1-)/EL liposomes to the SPBs induces flip-flop of PS(1-) from the inner leaflet to the outer leaflet. (h) The differences in the ability of PS(1-) (a cylindrical lipid) and CL(2-) (a conical lipid) to create membranes defects are attributed to geometric factors.