Helicobacter pylori cells undergo chemotaxis toward several small molecules, called chemo‐attractants, including urea produced by the epithelial cells of the stomach. The biophysical mechanisms of chemotaxis are not well understood in H. pylori. Here, we developed point sources of urea by encapsulating it in Poly(lactic‐co‐glycolic acid) or PLGA microbeads for H. pylori chemotaxis studies. Microscopy and Dynamic Light Scattering characterization indicated that the PLGA particles had an average diameter of < 0.8 μm. The particles were relatively stable and had a net negative surface charge. Absorbance measurements indicated that the beads released ~70% of the urea over a 2‐week period, with most of the release occurring within the first 24‐h period. Varying pH (2.0–7.0) had little effect on the rate of urea release. A diffusion model predicted that such beads could generate sufficient urea gradients to chemotactically attract H. pylori cells. Single‐bead single‐cell chemotaxis assays confirmed the predictions, revealing that H. pylori continued to be attracted to beads even after most of the urea had been released in the first 24 h. Our work highlights a novel use of PLGA microbeads as delivery vehicles for stimulating a chemotaxis response in H. pylori, with potential applications in bacterial eradication strategies.

中文翻译：

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负载尿素的 PLGA 微球作为幽门螺杆菌的趋化性刺激剂


幽门螺杆菌细胞对几种称为趋化因子的小分子进行趋化性，包括由胃上皮细胞产生的尿素。幽门螺杆菌趋化性的生物物理机制尚不清楚。在这里，我们通过将尿素封装在聚（乳酸-羟基乙酸共聚物）或 PLGA 微珠中来开发尿素的点源，用于幽门螺杆菌趋化性研究。显微镜和动态光散射表征表明，PLGA 颗粒的平均直径为 < 0.8 μm。这些颗粒相对稳定，并且具有净负表面电荷。吸光度测量表明，珠子在 2 周内释放了 ~70% 的尿素，其中大部分释放发生在前 24 小时内。不同的 pH 值 （2.0–7.0） 对尿素释放速率几乎没有影响。扩散模型预测，这种珠子可以产生足够的尿素梯度来化学定向地吸引幽门螺杆菌细胞。单珠单细胞趋化性测定证实了这些预测，揭示了幽门螺杆菌即使在前 24 小时内大部分尿素释放后仍继续被珠子吸引。我们的工作强调了 PLGA 微珠作为刺激幽门螺杆菌趋化性反应的递送载体的新用途，在细菌根除策略中具有潜在应用。