Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
Standard BioTools Canada Inc., Suite 400, 1380 Rodick Road, Markham, ON L3R 4G5, Canada.
Biomacromolecules. 2024 Sep 9;25(9):6115-6126. doi: 10.1021/acs.biomac.4c00801. Epub 2024 Aug 27.
Mass cytometry (MC), a powerful single-cell analysis technique, has limitations in detecting low-abundance biomarkers. Nanoparticle (NP) reagents offer the potential for enhancing sensitivity by carrying large numbers of heavy metal isotopes. Here, we report NP reporters for imaging mass cytometry (IMC) based on NaYF:Yb/Er NPs. A two-step ligand exchange was used to coat NP surfaces with either methoxy-PEG-neridronate (PEG-Ner) and/or poly(sulfobetaine methacrylate)-neridronate (PSBMA-Ner). Both modifications provided long-term colloidal stability in PBS buffer. IMC measurements on tonsil tissue showed that PSBMA-Ner or a 1:1 mixture of PSBMA-Ner + PEG-Ner effectively suppressed nonspecific binding (NSB) at 2 × 10 NPs/mL, unlike PEG-Ner alone. However, breast cancer tissue samples showed increased NSB at titers above 2 × 10 NPs/mL. Reduced NSB with mixed PEG-Ner and PSBMA-Ner coatings opens the door for using heterobifunctional PEGs for the development of NP conjugates with bioaffinity agents, enabling more sensitive and specific MC analyses.
质谱流式细胞术（MC）是一种强大的单细胞分析技术，但在检测低丰度生物标志物方面存在局限性。纳米颗粒（NP）试剂通过携带大量重金属同位素，具有提高灵敏度的潜力。在这里，我们报告了基于 NaYF:Yb/Er NPs 的用于成像质谱流式细胞术（IMC）的 NP 报告器。采用两步配体交换法将 NP 表面涂覆甲氧基-聚乙二醇-依替膦酸（PEG-Ner）和/或聚（磺酸甜菜碱甲基丙烯酸酯）-依替膦酸（PSBMA-Ner）。两种修饰均在 PBS 缓冲液中提供了长期的胶体稳定性。对扁桃体组织的 IMC 测量表明，PSBMA-Ner 或 PSBMA-Ner + PEG-Ner 的 1:1 混合物在 2×10 NPs/mL 时有效抑制了非特异性结合（NSB），而单独的 PEG-Ner 则不然。然而，在高于 2×10 NPs/mL 的滴度时，乳腺癌组织样本显示出增加的 NSB。具有混合 PEG-Ner 和 PSBMA-Ner 涂层的 NSB 减少为开发具有生物亲和性试剂的 NP 缀合物打开了大门，使 MC 分析更灵敏和更特异。
