Polymer/nucleotide droplets as bio-inspired functional micro-compartments
Polymer/nucleotide droplets as bio-inspired functional micro-compartments
复制标题
DOI：
10.1039/c2sm25184a
复制
发表时间：
2012-01-01
期刊：
影响因子：
3.4
通讯作者：
Mann, Stephen
中科院分区：
文献类型：
--
作者：
Williams, David S.;Koga, Shogo;Mann, Stephen
利用一系列物理方法，研究了聚二烯基二甲基氯化铵（PDDA）和三磷酸腺苷（ATP）在水中静电诱导络合制备的冷凝液体微滴的形成、结构、稳定性、物理性质和吸收行为。根据PDDA单体与ATP的摩尔比，通过简单的混合可以自发地产生带正电或带中性电的液滴。前者的平均尺寸通常为60-600纳米，在85摄氏度的温度下可以稳定沉积，而后者则生长成直径几十微米的液滴，并聚集成宏观的凝聚相。在pH值小于3和离子强度高的情况下，凝聚被抑制，这证实了电荷相互作用在液滴形成和稳定性中的重要性。液滴内部结构均匀，没有周围的膜，包括部分脱溶的聚合物/核苷酸复合物的动态波动域，并且具有比水低得多的介电常数。因此，染料分子、卟啉大环、无机纳米颗粒或球状蛋白质可以从外部水相隔离到液滴中，从而产生PDDA/ATP液滴，这些液滴包括超分子j聚集体纳米结构、具有磁响应的可变形流体或具有潜在存储和释放特性的软室。
Using a range of physical methods, we describe the formation, structure, stability, physical properties and uptake behavior of condensed liquid micro-droplets prepared by electrostatically induced complexation of poly(diallyldimethylammonium) chloride (PDDA) and adenosine triphosphate (ATP) in water. Depending on the PDDA monomer: ATP molar ratio, positively charged or charge-neutral droplets are produced spontaneously by simple mixing. The former are typically 60-600 nm in mean size and stable with respect to sedimentation up to temperatures of 85 degrees C, whilst the latter grow into droplets several tens of micrometres in diameter that coalesce into a macroscopic coacervate phase. Coacervation is inhibited at pH values less than 3 and at high ionic strength, confirming the importance of charge interactions in droplet formation and stability. The droplet interior is structurally homogeneous with no surrounding membrane, comprises dynamically fluctuating domains of partially desolvated polymer/nucleotide complexes, and has a dielectric constant considerably lower than water. As a consequence, dye molecules, porphyrin macrocycles, inorganic nanoparticles or globular proteins can be sequestered from the external water phase into the droplets to produce PDDA/ATP droplets comprising supramolecular J-aggregate nanostructures, magnetically responsive deformable fluids, or soft compartments with potential storage and release properties.