Deák Róbert, Mihály Judith, Szigyártó Imola Cs, Wacha András, Lelkes Gábor, Bóta Attila
Research Group of Biological Nanochemistry, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar tudósok körútja 2, Hungary.
Central Laboratory of the National Institute of Rheumatology and Physiotherapy, 1023 Budapest, Frankel Leó u. 25-29, Hungary.
Colloids Surf B Biointerfaces. 2015 Nov 1;135:225-234. doi: 10.1016/j.colsurfb.2015.07.066. Epub 2015 Jul 26.
Colloidal stabile nanoerythrosomes with 200 nm average diameter were formed from hemoglobin-free erythrocyte ghost membrane via sonication and membrane extrusion. The incorporation of extra lipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC), added to the sonicated ghosts, caused significant changes in the thermotropic character of the original membranes. As a result of the increased DPPC ratio the chain melting of the hydrated DPPC system and the characteristic small angle X-ray scattering (SAXS) of the lipid bilayers appeared. Significant morphological changes were followed by transmission electron microscopy combined with freeze fracture method (FF-TEM). After the ultrasonic treatment the large entities of erythrocyte ghosts transformed into nearly spherical nanoerythrosomes with diameters between 100 and 300 nm and at the same time a great number of 10-30 nm large membrane proteins or protein clusters were dispersed in the aqueous medium. The infrared spectroscopy (FT-IR) pointed out, that the sonication did not cause changes in the secondary structures of the membrane proteins under our preparation conditions. About fivefold of extra lipid--compared to the lipid content of the original membrane--caused homogeneous dispersion of nanoerythrosomes however the shape of the vesicles was not uniform. After the addition of about tenfold of DPPC, monoform and monodisperse nanoerythrosomes became typical. The outer surfaces of these roughly spherical objects were frequently polygonal, consisting of a net of pentagons and hexagons.
通过超声处理和膜挤压，由无血红蛋白的红细胞膜形成了平均直径为200纳米的胶体稳定纳米红细胞。向超声处理后的膜泡中添加额外的脂质（1,2-二棕榈酰-sn-甘油-3-磷酸胆碱，DPPC），导致原始膜的热致性发生显著变化。由于DPPC比例增加，水合DPPC系统的链熔化和脂质双层的特征性小角X射线散射（SAXS）出现。通过透射电子显微镜结合冷冻断裂法（FF-TEM）观察到显著的形态变化。超声处理后，红细胞膜泡的大实体转变为直径在100至300纳米之间的近球形纳米红细胞，同时大量10至30纳米大小的膜蛋白或蛋白簇分散在水介质中。红外光谱（FT-IR）指出，在我们的制备条件下，超声处理不会导致膜蛋白二级结构的变化。与原始膜的脂质含量相比，约五倍的额外脂质导致纳米红细胞均匀分散，然而囊泡的形状并不均匀。添加约十倍的DPPC后，单形和单分散的纳米红细胞变得典型。这些大致球形物体的外表面通常是多边形的，由五边形和六边形的网络组成。
