Lix Kelsi, Tran Michael V, Massey Melissa, Rees Kelly, Sauvé Ethan R, Hudson Zachary M, Algar W Russ
Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1.
ACS Appl Bio Mater. 2020 Jan 21;3(1):432-440. doi: 10.1021/acsabm.9b00899. Epub 2019 Dec 20.
Brightly fluorescent semiconducting polymer dots (Pdots) are emerging as very useful probes for bioanalysis and imaging. Unfortunately, Pdot materials often suffer from limitations such as poor colloidal and physical stability, nonspecific adsorption, and relatively few reported surface chemistries and bioconjugate chemistries. To help address these limitations, we have developed dextran-functionalized Pdots (Dex-Pdots). This functionalization improves particle stability over a range of pH and at high ionic strength, hinders surface-induced unfolding, and enables the preparation of immunoconjugates via tetrameric antibody complexes (TAC). The utility of TAC-conjugated Dex-Pdots is demonstrated through a proof-of-concept fluorescence-linked immunosorbent assay (FLISA) for human erythropoietin (EPO), and through immunolabeling of human epidermal growth factor receptor 2 (HER2)-positive SK-BR3 breast cancer cells. The conjugates exhibited less nonspecific binding and greater specific binding than Pdots without dextran functionalization. Overall, dextran functionalization is a highly promising surface chemistry for biological applications of Pdots.
具有明亮荧光的半导体聚合物点（Pdots）正逐渐成为生物分析和成像中非常有用的探针。不幸的是，Pdot材料常常存在一些局限性，如胶体稳定性和物理稳定性差、非特异性吸附，以及报道的表面化学和生物共轭化学相对较少。为了帮助解决这些局限性，我们开发了葡聚糖功能化的Pdots（Dex-Pdots）。这种功能化提高了颗粒在一系列pH值和高离子强度下的稳定性，阻碍了表面诱导的解折叠，并能够通过四聚体抗体复合物（TAC）制备免疫共轭物。通过针对人促红细胞生成素（EPO）的概念验证荧光免疫吸附测定（FLISA）以及对人表皮生长因子受体2（HER2）阳性的SK-BR3乳腺癌细胞进行免疫标记，证明了TAC共轭的Dex-Pdots的实用性。与未进行葡聚糖功能化的Pdots相比，这些共轭物表现出更少的非特异性结合和更强的特异性结合。总体而言，葡聚糖功能化是Pdots生物应用中一种非常有前景的表面化学方法。
