Transition from unilamellar to bilamellar vesicles induced by an amphiphilic biopolymer
Transition from unilamellar to bilamellar vesicles induced by an amphiphilic biopolymer
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DOI：
10.1103/physrevlett.96.048102
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发表时间：
2006-02-03
影响因子：
8.6
通讯作者：
Raghavan, SR
中科院分区：
文献类型：
--
作者：
Lee, JH;Agarwal, V;Raghavan, SR
我们报告了一些不寻常的结构转变在添加两亲性生物聚合物到单层表面活性剂囊泡。该聚合物是一种疏水改性的壳聚糖，它将疏水膜嵌入到囊泡双层中。我们利用小角中子散射（SANS）和低温透射电镜（cryo-TEM）研究了囊泡-聚合物混合物。当少量的聚合物加入到直径约为120nm的单层囊泡中时，囊泡的大小减小了约50%。在进一步添加聚合物后，在高散射矢量处的SANS光谱中观察到层状峰。我们证明了这些光谱对应于单层和双层囊泡的共存。低温透射电镜进一步证实了双层囊泡的转变以及单层囊泡大小的变化。提出了聚合物诱导的囊泡形态转变的机制。
We report some unusual structural transitions upon the addition of an amphiphilic biopolymer to unilamellar surfactant vesicles. The polymer is a hydrophobically modified chitosan and it embeds its hydrophobes in vesicle bilayers. We study vesicle-polymer mixtures using small-angle neutron scattering (SANS) and cryotransmission electron microscopy (cryo-TEM). When low amounts of the polymer are added to unilamellar vesicles of ca. 120 nm diameter, the vesicle size decreases by about 50%. Upon further addition of polymer, lamellar peaks are observed in the SANS spectra at high scattering vectors. We show that these spectra correspond to a co-existence of unilamellar and bilamellar vesicles. The transition to bilamellar vesicles as well as the changes in unilamellar vesicle size are further confirmed by cryo-TEM. A mechanism for the polymer-induced transitions in vesicle morphology is proposed.