Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, 3126 Dentistry/Pharmacy Centre, Edmonton, Alberta, Canada T6G 2N8.
AAPS J. 2011 Mar;13(1):20-9. doi: 10.1208/s12248-010-9240-y. Epub 2010 Nov 6.
This study evaluated the use of isothermal microcalorimetry (ITMC) to detect macrophage-nanoparticle interactions. Four different nanoparticle (NP) formulations were prepared: uncoated poly(isobutyl cyanoacrylate) (PIBCA), polysorbate-80-coated PIBCA, gelatin, and mannosylated gelatin NPs. Changes in NP formulations were aimed to either enhance or decrease macrophage-NP interactions via phagocytosis. Alveolar macrophages were cultured on glass slabs and inserted in the ITMC instrument. Thermal activities of the macrophages alone and after titration of 100 μL of NP suspensions were compared. The relative interactive coefficients of macrophage-NP interactions were calculated using the heat exchange observed after NP titration. Control experiments were performed using cytochalasin B (Cyto B), a known phagocytosis inhibitor. The results of NP titration showed that the total thermal activity produced by macrophages changed according to the NP formulation. Mannosylated gelatin NPs were associated with the highest heat exchange, 75.4 ± 7.5 J, and thus the highest relative interactive coefficient, 9,269 ± 630 M-1. Polysorbate-80-coated NPs were associated with the lowest heat exchange, 15.2 ± 3.4 J, and the lowest interactive coefficient, 890 ± 120 M-1. Cyto B inhibited macrophage response to NPs, indicating a connection between the thermal activity recorded and NP phagocytosis. These results are in agreement with flow cytometry results. ITMC is a valuable tool to monitor the biological responses to nano-sized dosage forms such as NPs. Since the thermal activity of macrophage-NP interactions differed according to the type of NPs used, ITMC may provide a method to better understand phagocytosis and further the development of colloidal dosage forms.
本研究评估了等温微量量热法（ITMC）在检测巨噬细胞-纳米颗粒相互作用中的应用。制备了四种不同的纳米颗粒（NP）制剂：未包覆的聚异丁基氰基丙烯酸酯（PIBCA）、聚山梨酯 80 包覆的 PIBCA、明胶和甘露糖化明胶 NPs。改变 NP 制剂的目的是通过吞噬作用增强或降低巨噬细胞-NP 相互作用。肺泡巨噬细胞在玻璃片上培养，并插入 ITMC 仪器中。比较了单独培养巨噬细胞和加入 100 μL NP 悬浮液后巨噬细胞的热活性。使用 NP 滴定后观察到的热交换来计算巨噬细胞-NP 相互作用的相对相互作用系数。使用细胞松弛素 B（Cyto B）进行对照实验，Cyto B 是一种已知的吞噬作用抑制剂。NP 滴定的结果表明，巨噬细胞产生的总热活性根据 NP 制剂而变化。甘露糖化明胶 NPs 与最高的热交换相关，为 75.4 ± 7.5 J，因此具有最高的相对相互作用系数，为 9,269 ± 630 M-1。聚山梨酯 80 包覆的 NPs 与最低的热交换相关，为 15.2 ± 3.4 J，以及最低的相互作用系数，890 ± 120 M-1。Cyto B 抑制了巨噬细胞对 NPs 的反应，表明记录的热活性与 NP 吞噬作用之间存在联系。这些结果与流式细胞术结果一致。ITMC 是监测纳米级剂型（如 NPs）生物反应的有价值的工具。由于巨噬细胞-NP 相互作用的热活性根据所用 NPs 的类型而不同，因此 ITMC 可能提供一种方法来更好地理解吞噬作用，并进一步开发胶体剂型。
