Despite clinical advances in immunotherapy, still many therapeutics cause dose‐limiting (auto)immune‐mediated toxicities. Nanoparticle‐based drug delivery systems (DDS) can improve cancer immunotherapy through site‐specific delivery and controlled release of immunotherapeutics in the tumor microenvironment (TME). However, DDS face several challenges, including unspecific release. To address this, vaterite nanoparticles (VNPs) that selectively release immunotherapeutic proteins at low pH conditions find in the TME, are established previously. In the current study, these VNPs are further modified for active targeting without affecting the loaded protein activity, exemplified with Tumor Necrosis Factor α (TNF). Specifically, VNPs are coated with gelatin, a matrix‐metalloprotease sensitive polymer which provides functional groups for further conjugation. Subsequently, streptavidin is covalently linked to the gelatin shell by amine‐epoxy chemistry, enabling coupling of any biotinylated ligand. Exemplified by biotinylated cetuximab and rituximab, targeted VNPs selectively bind to cells expressing epidermal growth factor receptor (EGFR) or CD20, respectively. Importantly, TNF remains functionally active after the modification steps, as VNP treatment increased ICAM‐1 expression on FaDu cells and activated NFκB signaling in a Jurkat.NFκB‐luciferase cell line model. In conclusion, a targetable vaterite‐based DDS is produced that allows for easy surface modification with any biotinylated ligand that may find broad applications in tumor‐selective immunotherapy.

中文翻译：

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用于活性免疫治疗蛋白受控递送的球霰石纳米颗粒的设计

尽管免疫疗法在临床上取得了进展，但许多疗法仍然会导致剂量限制（自身）免疫介导的毒性。基于纳米颗粒的药物递送系统（DDS）可以通过肿瘤微环境（TME）中免疫治疗药物的位点特异性递送和受控释放来改善癌症免疫治疗。然而，DDS面临着一些挑战，包括发布不明确。为了解决这个问题，之前建立了在 TME 中发现的在低 pH 条件下选择性释放免疫治疗蛋白的球霰石纳米颗粒 (VNP)。在当前的研究中，这些 VNP 被进一步修饰以实现主动靶向，而不影响负载的蛋白质活性，例如肿瘤坏死因子 α (TNF)。具体来说，VNP 涂有明胶，这是一种基质金属蛋白酶敏感的聚合物，可为进一步缀合提供官能团。随后，链霉亲和素通过胺-环氧化学共价连接到明胶壳，从而能够偶联任何生物素化配体。以生物素化西妥昔单抗和利妥昔单抗为例，靶向 VNP 分别选择性地结合表达表皮生长因子受体 (EGFR) 或 CD20 的细胞。重要的是，修饰步骤后 TNF 仍保持功能活性，因为 VNP 处理增加了 FaDu 细胞上的 ICAM-1 表达，并激活了 Jurkat.NFκB 荧光素酶细胞系模型中的 NFκB 信号传导。总之，我们生产了一种基于球霰石的靶向 DDS，可以使用任何生物素化配体轻松进行表面修饰，从而可能在肿瘤选择性免疫治疗中得到广泛应用。