Cells are powerful carriers that can help to improve the delivery of nanomedicines. One approach to use cells as carriers is to immobilize the nanoparticulate cargo on the cell surface. While a plethora of chemical conjugation strategies are available to bind nanoparticles to cell surfaces, only relatively little is known about the effects of particle size and cell type on the surface immobilization of nanoparticles. This study investigates the biotin–NeutrAvidin mediated immobilization of model polymer nanoparticles with sizes ranging from 40 nm to 1 μm on two different T cell lines, viz., human Jurkat cells as well as mouse SJL/PLP7 T cells, which are of potential interest for drug delivery across the blood–brain barrier. The nanoparticle cell surface immobilization and the particle surface concentration and distribution were analyzed by flow cytometry and confocal microscopy. The functional properties of nanoparticle-modified SJL/PLP7 T cells were assessed in an ICAM-1 binding assay as well as in a two-chamber setup in which the migration of the particle-modified T cells across an in vitro model of the blood–brain barrier was studied. The results of these experiments highlight the effects of particle size and cell line on the surface immobilization of nanoparticles on living cells.

中文翻译：

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生物素-中性亲和素介导的聚合物微粒和纳米颗粒在 T 淋巴细胞上的固定化

细胞是强大的载体，可以帮助改善纳米药物的输送。使用细胞作为载体的一种方法是将纳米颗粒货物固定在细胞表面。虽然有大量的化学共轭策略可用于将纳米粒子结合到细胞表面，但关于粒子大小和细胞类型对纳米粒子表面固定的影响知之甚少。本研究调查了生物素-NeutrAvidin 介导的模型聚合物纳米粒子在两种不同的 T 细胞系（即人类 Jurkat 细胞以及小鼠 SJL/PLP7 T 细胞）上的固定化，其尺寸范围为 40 nm 至 1 μm，具有潜在的意义用于穿过血脑屏障的药物递送。通过流式细胞术和共聚焦显微镜分析纳米颗粒细胞表面固定和颗粒表面浓度和分布。纳米颗粒修饰的 SJL/PLP7 T 细胞的功能特性在 ICAM-1 结合测定以及两室设置中进行评估，其中颗粒修饰的 T 细胞在体外血液模型中的迁移–脑屏障进行了研究。这些实验的结果突出了颗粒大小和细胞系对纳米颗粒在活细胞上的表面固定的影响。纳米颗粒修饰的 SJL/PLP7 T 细胞的功能特性在 ICAM-1 结合测定以及两室设置中进行评估，其中颗粒修饰的 T 细胞在体外血液模型中的迁移–脑屏障进行了研究。这些实验的结果突出了颗粒大小和细胞系对纳米颗粒在活细胞上的表面固定的影响。纳米颗粒修饰的 SJL/PLP7 T 细胞的功能特性在 ICAM-1 结合测定以及两室设置中进行评估，其中颗粒修饰的 T 细胞在体外血液模型中的迁移–脑屏障进行了研究。这些实验的结果突出了颗粒大小和细胞系对纳米颗粒在活细胞上的表面固定的影响。