d'Arcy Richard, Gennari Arianna, Donno Roberto, Tirelli Nicola
NorthWest Center for Advanced Drug Delivery (NoWCADD), Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Manchester, M13 9PT, UK.
Macromol Rapid Commun. 2016 Dec;37(23):1918-1925. doi: 10.1002/marc.201600481. Epub 2016 Sep 27.
Families of amphiphilic oxidation-responsive polymers (poly(ethylene glycol)-polysulfides) with different architectures (linear, 4, 6, and 8-armed stars and 10, 15, and 20-armed combs) and compositions (variable ethylene sulfide/propylene sulfide ratio) are prepared. In water, all the polymers assemble in spherical micelles, with critical micellar concentrations <0.01 mg mL for all the branched polymers. Triple-detection gel permeation chromatography (GPC) and asymmetric field flow fractionation (AFFF) with dynamic and static light scattering detection, respectively, show an increasing compaction of the polymeric coil and a strong reduction of the aggregation number with increasing degree of branching. The key finding of this study is that the kinetics of the oxidative response sharply depend on the branching; in particular, it is highlighted that the degree of branching influences the lag time before a response can be observed rather than the speed of the response itself, a phenomenon that is attributed to a branching-dependent solubility of the oxidant in the polysulfide matrix.
制备了具有不同结构（线性、4臂、6臂和8臂星形以及10臂、15臂和20臂梳形）和组成（可变的乙硫醚/丙硫醚比例）的两亲性氧化响应聚合物（聚乙二醇-多硫化物）家族。在水中，所有聚合物都组装成球形胶束，所有支化聚合物的临界胶束浓度均<0.01 mg/mL。三重检测凝胶渗透色谱（GPC）和分别带有动态和静态光散射检测的不对称场流分级（AFFF）表明，随着支化度的增加，聚合物线团的致密程度增加，聚集数大幅减少。本研究的关键发现是氧化响应动力学强烈依赖于支化；特别是，突出表明支化度影响观察到响应之前的滞后时间，而不是响应本身的速度，这一现象归因于氧化剂在多硫化物基质中的支化依赖性溶解度。
