Heterobifunctional PEG Ligands for Bioconjugation Reactions on Iron Oxide Nanoparticles

Ever since iron oxide nanoparticles have been recognized as promising scaffolds for biomedical applications, their surface functionalization has become even more important. We report the synthesis of a novel polyethylene glycol-based ligand that combines multiple advantageous properties for these applications. The ligand is covalently bound to the surface via a siloxane group, while its polyethylene glycol backbone significantly improves the colloidal stability of the particle in complex environments. End-capping the molecule with a carboxylic acid introduces a variety of coupling chemistry possibilities. In this study an antibody targeting plasminogen activator inhibitor-1 was coupled to the surface and its presence and binding activity was assessed by enzyme-linked immunosorbent assay and surface plasmon resonance experiments. The results indicate that the ligand has high potential towards biomedical applications where colloidal stability and advanced functionality is crucial.自氧化铁纳米颗粒（iron oxide nanoparticles）被认定为极具潜力的生物医学应用载体以来，其表面功能化的重要性愈发凸显。本研究报道了一种基于聚乙二醇（polyethylene glycol）的新型配体，该配体兼具多项适用于此类场景的优异性能。该配体通过硅氧烷基团（siloxane group）与颗粒表面共价结合，其聚乙二醇主链可显著提升颗粒在复杂环境中的胶体稳定性。以羧酸（carboxylic acid）对该分子进行端基封端，可拓展多种偶联化学反应的应用可能。本研究将靶向纤溶酶原激活物抑制剂-1（plasminogen activator inhibitor-1）的抗体偶联至颗粒表面，并通过酶联免疫吸附测定（enzyme-linked immunosorbent assay）与表面等离子体共振（surface plasmon resonance）实验评估了抗体的存在状态与结合活性。实验结果表明，该配体在胶体稳定性与先进功能均为核心需求的生物医学应用领域具备极高的应用潜力。