壳聚糖-质粒DNA层层组装及携载DNA量的评价方法

目的 壳聚糖与质粒DNA可以层层组装形成多层膜,可用于金属表面载基因涂层.本研究采用表面等离子共振(SPR)技术,实时检测金属表面与壳聚糖、壳聚糖与质粒DNA(pDNA)的相互作用,并分析壳聚糖携载质粒DNA的能力以及壳聚糖-质粒DNA多层膜在液流作用下的稳定性.方法 在11-巯基十一羧酸处理过的裸金芯片上自组装不同浓度、不同相对分子量的壳聚糖(50～400 ku)和质粒DNA分子.结果 层层组装方法中壳聚糖对质粒的携载量与相对分子量和浓度密切相关,即高浓度、高分子量的壳聚糖可以形成更加厚实的多层膜,并可以携载更多的质粒DNA,自组装形成的多层膜还具有耐液流冲刷性,物理性质稳定.结论 采用壳聚糖与治疗基因的多层自组装可以在血管支架上携载质粒DNA,为探索载基因血管支架涂层的构建提供了新的方法和手段.

Layer-by-layer assembly of chitosan and plasmid DNA on metal surface

Objective To investigate the technology for layer-by-layer assembly of chitosan and plasmid DNA on metal surface, which has a potential in vascular stent mediated gene delivery. Methods Chitosan and plasmid DNA were loaded on the surface of 11-MUA treated gold chip through layer by layer deposition. The real- time monitoring of interactions of various molecular weight (Mw) chitosan samples with 11-MUA and chitosan with plasmid DNA were evaluated by surface plasmon resonance (SPR). The pDNA loading capacity of chitosan and the stability of the muhilayer under flow condition were profiled. Results The amount of DNA loaded by chitosan on the metal surface was dependent on the concentration and molecular weight of chitosan. Thicker multilayer and higher loading of pDNA were obtained with higher concentration and/or higher molecular weight of chitosan. The multilayer is stable under running buffer flushed through the system. Conclusion The assembled multilayer of chitosan and pDNA is stable on the metal surface and can be used as a new tool for stent mediated gene delivery.