Polymeric nanoparticles can passively target inflamed tissues. How their physicochemical properties affect their distribution pattern among the infiltrating immune cells is unknown. Polyvinyl acetate nanoparticles with different particle size (100 and 300 nm) and surface charge (cationic, non-ionic, and anionic) were prepared and incubated with either LPS-activated or unactivated murine splenocytes. Nanoparticle association with macrophages, dendritic cells, neutrophils, B and T cells was investigated using flow cytometry. Cells associated with nanoparticles as follows: cationic>anionic>non-ionic and 300 nm > 100 nm. 40% of ionic nanoparticles were distributed among unactivated macrophages, reduced to 25% for activated macrophages. 60% of 100 nm and 40% of 300 nm non-ionic nanoparticles were distributed among unactivated and LPS-activated macrophages. This study highlights that particles' physicochemical properties impact the number of nanoparticles associating with immune cells more than their distribution pattern, which is principally determined by the cell activation state. This suggests a disease-dependent distribution pattern for therapeutic nanoparticles.

聚合纳米颗粒可以被动地靶向发炎的组织。它们的理化特性如何影响它们在浸润的免疫细胞中的分布方式尚不清楚。制备具有不同粒径（100和300 nm）和表面电荷（阳离子，非离子和阴离子）的聚乙酸乙烯酯纳米颗粒，并与LPS激活或未激活的鼠脾细胞一起孵育。使用流式细胞术研究了与巨噬细胞，树突状细胞，嗜中性粒细胞，B和T细胞的纳米颗粒缔合。与纳米颗粒相关的细胞如下：阳离子>阴离子>非离子和300 nm> 100 nm。40％的离子纳米颗粒分布在未活化的巨噬细胞中，对于活化的巨噬细胞减少到25％。60％的100 nm非离子纳米颗粒和40％的300 nm非离子纳米颗粒分布在未活化和LPS活化的巨噬细胞之间。这项研究强调，粒子的理化性质对与免疫细胞缔合的纳米粒子数量的影响大于其分布方式，而分布方式主要由细胞活化状态决定。这暗示了治疗性纳米颗粒的疾病依赖性分布模式。