van Dongen Mallory A, Vaidyanathan S, Banaszak Holl Mark M
Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, USA ; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Soft Matter. 2013 Dec 21;9(47). doi: 10.1039/C3SM52250D.
The desire to synthesize soft supramolecular structures with size scales similar to biological systems has led to work in assembly of polymeric nanomaterials. Recent advances in the isolation of generationally homogenous poly(amidoamine) (PAMAM) dendrimer enables their use as quantized building blocks. Here, we report their assembly into precise nanoclusters. In this work, click-functional ligands are stochastically conjugated to monomeric generation 5 PAMAM dendrimer and separated via reverse-phase HPLC to isolate dendrimers with precise numbers of click ligands per dendrimer particle. The click-ligand/dendrimer conjugates are then employed as modular building blocks for the synthesis of defined nanostructures. Complimentary click chemistry employing dendrimers with 1, 2, 3, or 4 ring-strained cyclooctyne ligands and dendrimers with 1 azide ligand were utilized to prepare megamer structures containing 2 to 5 ~30,000 kDa monomer units as characterized by mass spectrometry, size exclusion chromatography, and reverse-phase liquid chromatography. The resulting structures are flexible with masses ranging from 60,000 to 150,000 kDa, and are soluble in water, methanol, and dimethylsulfoxide.
合成尺寸与生物系统相似的软超分子结构的愿望推动了聚合物纳米材料组装方面的研究工作。在分离世代均一的聚（酰胺胺）（PAMAM）树枝状大分子方面的最新进展使其能够用作量化的构建单元。在此，我们报告了它们组装成精确的纳米簇。在这项工作中，点击功能配体随机共轭到第5代单体PAMAM树枝状大分子上，并通过反相高效液相色谱法分离，以分离出每个树枝状大分子颗粒具有精确数量点击配体的树枝状大分子。然后将点击配体/树枝状大分子共轭物用作合成特定纳米结构的模块化构建单元。采用具有1、2、3或4个环张力环辛炔配体的树枝状大分子和具有1个叠氮化物配体的树枝状大分子的互补点击化学被用于制备含有2至5个~30,000 kDa单体单元的巨型分子结构，通过质谱、尺寸排阻色谱和反相液相色谱进行表征。所得结构具有柔韧性，质量范围为60,000至150,000 kDa，可溶于水、甲醇和二甲基亚砜。
