Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece.
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635, Athens, Greece; Department of Pharmaceutical Technology, Faculty of Pharmacy, Panepistimioupolis Zografou 15771, National and Kapodistrian University of Athens, Athens, Greece.
Chem Phys Lipids. 2021 Jan;234:105008. doi: 10.1016/j.chemphyslip.2020.105008. Epub 2020 Nov 9.
Mixed liposomes of dipalmitoylphosphatidylcholine (DPPC) and gradient (pseudodiblock) poly(2-methyl-2-oxazoline)-grad-poly(2-phenyl-2-oxazoline) (MPOx) copolymers are investigated by small angle neutron scattering (SANS). All experimental data, from different phospholipid-copolymer compositions, concentrations and temperatures are fitted with one model. This model allows the determination of the separate contributions from vesicular populations of different lamellarity and size. MPOx copolymers are proved to modify both the size and lamellarity of DPPC liposomes. The gradient copolymer with higher hydrophilic content induces shrinkage of the uni- and bi-lamellar DPPC vesicles. The copolymer with lower hydrophilic content causes dramatic changes on the lamellarity of DPPC vesicles by the formation of hexa-lamellar vesicles. The tendency of multi-lamellar vesicles to transform into uni-lamellar ones as temperature increases is more pronounced in the presence of the copolymers. These findings may have direct implications on the drug loading and release properties of liposomes and their interactions with cells.
混合二棕榈酰磷脂酰胆碱 (DPPC) 和梯度 (伪两嵌段) 聚(2-甲基-2-恶唑啉)-梯度-聚(2-苯基-2-恶唑啉) (MPOx) 共聚物的小角中子散射 (SANS) 研究。所有实验数据，来自不同的磷脂-共聚物组成、浓度和温度，都用一个模型进行拟合。该模型允许确定不同层状和大小的囊泡群体的单独贡献。MPOx 共聚物被证明可以改变 DPPC 脂质体的大小和层状结构。具有较高亲水性含量的梯度共聚物诱导单双层 DPPC 囊泡的收缩。亲水性较低的共聚物通过形成六双层囊泡导致 DPPC 囊泡层状结构的剧烈变化。随着温度的升高，多层层状囊泡向单层层状囊泡转化的趋势在共聚物存在下更为明显。这些发现可能对脂质体的药物负载和释放特性及其与细胞的相互作用有直接影响。
