Qin Xiaofei, Engwer Christoph, Desai Saaketh, Vila-Sanjurjo Celina, Goycoolea Francisco M
Institute of Plant Biology and Biotechnology, University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Roorkee, India.
Colloids Surf B Biointerfaces. 2017 Jan 1;149:358-368. doi: 10.1016/j.colsurfb.2016.10.031. Epub 2016 Oct 17.
We examined the interaction between chitosan-based nanocapsules (NC), with average hydrodynamic diameter ∼114-155nm, polydispersity ∼0.127, and ζ-potential ∼+50mV, and an E. coli bacterial quorum sensing reporter strain. Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) allowed full characterization and assessment of the absolute concentration of NC per unit volume in suspension. By centrifugation, DLS, and NTA, we determined experimentally a "stoichiometric" ratio of ∼80 NC/bacterium. By SEM it was possible to image the aggregation between NC and bacteria. Moreover, we developed a custom in silico platform to simulate the behavior of particles with diameters of 150nm and ζ-potential of +50mV on the bacterial surface. We computed the detailed force interactions between NC-NC and NC-bacteria and found that a maximum number of 145 particles might interact at the bacterial surface. Additionally, we found that the "stoichiometric" ratio of NC and bacteria has a strong influence on the bacterial behavior and influences the quorum sensing response, particularly due to the aggregation driven by NC.
我们研究了壳聚糖基纳米胶囊（NC）与大肠杆菌群体感应报告菌株之间的相互作用。该纳米胶囊平均流体动力学直径约为114 - 155nm，多分散性约为0.127，ζ电位约为 +50mV。动态光散射（DLS）和纳米颗粒跟踪分析（NTA）可对悬浮液中每单位体积NC的绝对浓度进行全面表征和评估。通过离心、DLS和NTA，我们通过实验确定了约80个NC/细菌的“化学计量”比。通过扫描电子显微镜（SEM）可以观察到NC与细菌之间的聚集情况。此外，我们开发了一个定制的计算机模拟平台，以模拟直径为150nm且ζ电位为 +50mV的颗粒在细菌表面的行为。我们计算了NC - NC和NC - 细菌之间的详细力相互作用，发现细菌表面最多可能有145个颗粒相互作用。此外，我们发现NC与细菌的“化学计量”比对细菌行为有强烈影响，并影响群体感应反应，特别是由于NC驱动的聚集作用。
