Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG Utrecht, The Netherlands.
Cell Biology, Neurobiology and Biophysics, Department of Biology, Science Faculty, Utrecht University, 3584 CG Utrecht, The Netherlands.
Int J Mol Sci. 2022 Nov 29;23(23):14974. doi: 10.3390/ijms232314974.
Nanoparticles (NPs) are commonly modified with tumor-targeting moieties that recognize proteins overexpressed on the extracellular membrane to increase their specific interaction with target cells. Nanobodies (Nbs), the variable domain of heavy chain-only antibodies, are a robust targeting ligand due to their small size, superior stability, and strong binding affinity. For the clinical translation of targeted Nb-NPs, it is essential to understand how the number of Nbs per NP impacts the receptor recognition on cells. To study this, Nbs targeting the hepatocyte growth factor receptor (MET-Nbs) were conjugated to PEGylated liposomes at a density from 20 to 800 per liposome and their targeting efficiency was evaluated in vitro. MET-targeted liposomes (MET-TLs) associated more profoundly with MET-expressing cells than non-targeted liposomes (NTLs). MET-TLs with approximately 150-300 Nbs per liposome exhibited the highest association and specificity towards MET-expressing cells and retained their targeting capacity when pre-incubated with proteins from different sources. Furthermore, a MET-Nb density above 300 Nbs per liposome increased the interaction of MET-TLs with phagocytic cells by 2-fold in ex vivo human blood compared to NTLs. Overall, this study demonstrates that adjusting the MET-Nb density can increase the specificity of NPs towards their intended cellular target and reduce NP interaction with phagocytic cells.
纳米粒子（NPs）通常经过修饰，使其带有靶向肿瘤的部分，这些部分能够识别细胞外膜上过度表达的蛋白质，从而增加与靶细胞的特异性相互作用。纳米抗体（Nbs）是重链抗体的可变结构域，由于其体积小、稳定性强、结合亲和力强，因此是一种强大的靶向配体。为了将靶向 Nb-NPs 应用于临床，了解 NP 上的 Nb 数量如何影响细胞上的受体识别至关重要。为了研究这一点，将靶向肝细胞生长因子受体（MET-Nbs）的 Nbs 偶联到聚乙二醇化脂质体上，其密度从每个脂质体 20 个到 800 个不等，并在体外评估其靶向效率。与非靶向脂质体（NTLs）相比，靶向 MET 的脂质体（MET-TLs）与表达 MET 的细胞更紧密地结合。每个脂质体约有 150-300 个 Nbs 的 MET-TLs 与表达 MET 的细胞具有最高的结合和特异性，并且当与来自不同来源的蛋白质预先孵育时，仍保留其靶向能力。此外，与 NTLs 相比，在体外人血液中，每个脂质体上的 MET-Nb 密度超过 300 个时，MET-TLs 与吞噬细胞的相互作用增加了 2 倍。总体而言，这项研究表明，调整 MET-Nb 密度可以提高 NPs 对其预期细胞靶标的特异性，并减少 NP 与吞噬细胞的相互作用。
