LaMaFI-Laboratório de Materiais e Fenômenos de Interface, Chemistry Department, Universidade Tecnológica Federal do Paraná (UTFPR), Medianeira, Curitiba 85884-000, Paraná (PR), Brazil.
Institute of Chemistry, Universidade Estadual de Campinas (UNICAMP), Caixa Postal 6154, Campinas 13083-970, São Paulo State (SP), Brazil.
Molecules. 2023 Jan 3;28(1):398. doi: 10.3390/molecules28010398.
The interaction of DNA with different block copolymers, namely poly (trimethylammonium chloride methacryloyoxy)ethyl)-block-poly(acrylamide), i.e., (PTEA)-b-(PAm), and poly (trimethylammonium chloride methacryloyoxy)ethyl)-block-poly(ethylene oxide), i.e., (PTEA)-b-(PEO), was studied. The nature of the cationic block was maintained fixed (PTEA), whereas the neutral blocks contained varying amounts of acrylamide or (ethylene oxide) units. According to results from isothermal titration microcalorimetry measurements, the copolymers interaction with DNA is endothermic with an enthalpy around 4.0 kJ mol−1 of charges for (PTEA)-b-(PAm) and 5.5 kJ mol−1 of charges for (PTEA)-b-(PEO). The hydrodynamic diameters of (PTEA)-b-(PEO)/DNA and (PTEA)-b-(PAm)/DNA polyplexes prepared by titration were around 200 nm at charge ratio (Z+/−) < 1. At Z+/− close and above 1, the (PTEA)50-b-(PAm)50/DNA and (PTEA)50-b-(PAm)200/DNA polyplexes precipitated. Interestingly, (PTEA)50-b-(PAm)1000/DNA polyplexes remained with a size of around 300 nm even after charge neutralization, probably due to the size of the neutral block. Conversely, for (PTEA)96-b-(PEO)100/DNA polyplexes, the size distribution was broad, indicating a more heterogeneous system. Polyplexes were also prepared by direct mixture at Z+/− of 2.0, and they displayed diameters around 120−150 nm, remaining stable for more than 10 days. Direct and reverse titration experiments showed that the order of addition affects both the size and charge of the resulting polyplexes.
研究了 DNA 与不同嵌段共聚物的相互作用，即聚（三甲基氯化铵甲基丙烯酰氧基乙基）-嵌段-聚（丙烯酰胺），即（PTEA）-b-（PAm）和聚（三甲基氯化铵甲基丙烯酰氧基乙基）-嵌段-聚（氧化乙烯），即（PTEA）-b-（PEO）。阳离子嵌段的性质保持固定（PTEA），而中性嵌段则含有不同量的丙烯酰胺或（氧化乙烯）单元。根据等温滴定微量热法测量结果，共聚物与 DNA 的相互作用是吸热的，对于（PTEA）-b-（PAm），每单位电荷的焓约为 4.0 kJ mol−1，对于（PTEA）-b-（PEO），每单位电荷的焓约为 5.5 kJ mol−1。通过滴定制备的（PTEA）-b-（PEO）/DNA 和（PTEA）-b-（PAm）/DNA 聚集体的水动力学直径在电荷比（Z+/−）<1 时约为 200 nm。在 Z+/−接近和高于 1 时，（PTEA）50-b-（PAm）50/DNA 和（PTEA）50-b-（PAm）200/DNA 聚集体沉淀。有趣的是，即使在电荷中和后，（PTEA）50-b-（PAm）1000/DNA 聚集体仍保持约 300 nm 的尺寸，这可能是由于中性嵌段的尺寸所致。相反，对于（PTEA）96-b-（PEO）100/DNA 聚集体，尺寸分布较宽，表明系统更具异质性。聚集体也通过直接混合在 Z+/−为 2.0 时制备，它们的直径约为 120-150nm，在超过 10 天的时间内保持稳定。直接和反向滴定实验表明，添加顺序会影响所得聚集体的大小和电荷。
