Nontoxic and biodegradable chitosan is potentially useful in various applications. We prepared submicron chitosan particles with high dispersibility in aqueous solution utilizing the electrostatic interaction phase separation method described in a previous report, but using citric acid as the polyvalent anionic compound instead of sodium sulfate. The submicron chitosan particles showed significant antibacterial activity and anti-adhesive action against Streptococcus mutans, even at around neutral pH. However, chitosan granules showed no antibacterial activity under the same conditions. The addition of the chitosan particles to dental polishing paste provided stainless steel discs (the same hardness as dental enamel) with a smoother surface than polishing paste without additives. In view of their submicron size and antibacterial activity, chitosan particles could potentially be multifunctional components of oral and dental cleaning materials.

中文翻译：

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分散的壳聚糖颗粒对变形链球菌具有抑菌作用，并具有牙齿抛光作用。

无毒且可生物降解的壳聚糖可能在各种应用中有用。我们使用先前报告中描述的静电相互作用相分离方法制备了在水溶液中具有高分散性的亚微米壳聚糖颗粒，但是使用柠檬酸作为多价阴离子化合物代替了硫酸钠。即使在中性pH值附近，亚微米的壳聚糖颗粒也具有显着的抗菌活性和对变形链球菌的抗粘附作用。然而，壳聚糖颗粒在相同条件下没有显示抗菌活性。向牙齿抛光膏中加入壳聚糖颗粒可以使不锈钢圆盘（硬度与牙科瓷釉相同）比不含添加剂的抛光膏具有更光滑的表面。鉴于其亚微米尺寸和抗菌活性，