School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 30072, PR China.
Biomaterials. 2012 Jan;33(2):604-13. doi: 10.1016/j.biomaterials.2011.09.067. Epub 2011 Oct 11.
A lauric acid modified dextran-agmatine bioconjugate (Dex-L-Agm) was prepared by 1,1'-carbonyldiimidazole (CDI) activation and the nucleophilic reaction between tosyl of tosylated dextran and primary amine of agmatine. Dextran-agmatine bioconjugates (Dex-Agm) were capable of condensing DNA into nanocomplexes, and combining lauric acid promoted the complexation with DNA supposedly due to the cooperative binding effect attributed to hydrophobic interaction. Higher degree substitution of agmatine and hydrophobic grafting resulted in increased luciferase activities expressed in COS-7 and HEK293 cells; Semiquantitative assay of GFP expression by flow cytometry in COS-7, HEK293 and CHOK1 cells further demonstrated that conjugation of fatty acid could remarkably increase gene transfection of Dex-Agm in spite of 1.1-2.3-fold lower efficiency compared to Exgen 500. The biocompatibilities of Dex-Agm and Dex-L-Agm were assessed in detail by hemolytic activity determination, red blood cell aggregation assay as well as MTT evaluation of degraded products. Dex-Agm and Dex-L-Agm were shown to be highly cytocompatible without causing hemolysis and red blood cell aggregation presumably owing to the bidentate hydrogen bonding of guanidine with the constituents present in cell membrane rather than electrostatic interactions alone which could cause cell damage. Importantly, cells cultured with the degraded products of Dex-Agm and Dex-L-Agm retained more than 80% viability, suggest their potential application as a gene delivery vector.
一种月桂酸修饰的葡聚糖-胍基丁胺生物缀合物（Dex-L-Agm）通过 1,1'-羰基二咪唑（CDI）活化和对甲苯磺酰化葡聚糖的 tosyl 与胍基丁胺的伯胺之间的亲核反应制备。葡聚糖-胍基丁胺缀合物（Dex-Agm）能够将 DNA 缩合为纳米复合物，并且结合月桂酸由于疏水性相互作用的协同结合效应，据称促进了与 DNA 的复合。由于胍基丁胺的取代度较高和疏水性接枝，导致 COS-7 和 HEK293 细胞中的荧光素酶活性增加；通过流式细胞术对半定量测定 COS-7、HEK293 和 CHOK1 细胞中 GFP 的表达进一步表明，尽管与 Exgen 500 相比，效率降低了 1.1-2.3 倍，但脂肪酸的缀合可以显著增加 Dex-Agm 的基因转染。通过溶血活性测定、红细胞聚集测定以及对降解产物的 MTT 评估详细评估了 Dex-Agm 和 Dex-L-Agm 的生物相容性。Dex-Agm 和 Dex-L-Agm 显示出高度的细胞相容性，不会引起溶血和红细胞聚集，可能是由于胍基与细胞膜中存在的成分形成双氢键，而不仅仅是静电相互作用，这可能会导致细胞损伤。重要的是，用 Dex-Agm 和 Dex-L-Agm 的降解产物培养的细胞保持超过 80%的活力，表明它们作为基因传递载体的潜在应用。
