Immunotherapy has brought great benefits to cancer patients, but only some patients benefit from it. Noninvasive, real-time and dynamic monitoring of the effectiveness of immunotherapy through PET imaging may provide assistance for the treatment plan of immunotherapy. In this study, we designed and synthesized a new targeted PD-L1 peptide NOTA-PEG-Asp-PDL1P, which was labeled with nuclide F to obtain a new imaging agent [F]AlF-NOTA-PEG-Asp-PDL1P. The total radiochemical yield of [F]AlF-NOTA-PEG-Asp-PDL1P was 13.7 % (Uncorrected radiochemical yield, n > 5). [F]AlF-NOTA-PEG-Asp-PDL1P achieved high radiochemical purity (>95 %) with a molar activity more than 51.2 GBq/μmol. [F]AlF-NOTA-PEG-Asp-PDL1P exhibited good hydrophilicity and had good stability both and it can specifically targets B16F10 tumor with PD-L1 expression, and had a relatively high retention in tumor, a relatively fast clearance and a higher tumor-to-non-target ratio, all of which could make [F]AlF-NOTA-PEG-Asp-PDL1P a potential tracer for PD-L1 prediction before clinical immunotherapy.

中文翻译：

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用于PD-L1阳性肿瘤PET成像的新型分子探针[18F]AlF-NOTA-PEG2-Asp2-PDL1P的合成和临床前评价

免疫疗法给癌症患者带来了巨大的好处，但只有部分患者从中受益。通过PET成像无创、实时、动态监测免疫治疗的有效性，可能为免疫治疗的治疗方案提供帮助。本研究设计合成了一种新型靶向PD-L1肽NOTA-PEG-Asp-PDL1P，并用核素F标记，得到新型显像剂[F]AlF-NOTA-PEG-Asp-PDL1P。 [F]AlF-NOTA-PEG-Asp-PDL1P 的总放射化学产率为 13.7%（未校正的放射化学产率，n > 5）。 [F]AlF-NOTA-PEG-Asp-PDL1P 实现了高放射化学纯度 (>95%)，摩尔活性超过 51.2 GBq/μmol。 [F]AlF-NOTA-PEG-Asp-PDL1P表现出良好的亲水性和良好的稳定性，能够特异性靶向表达PD-L1的B16F10肿瘤，在肿瘤中具有较高的滞留性、较快的清除率和较高的肿瘤抑制率。与非靶点的比率，所有这些都可以使 [18F]AlF-NOTA-PEG-Asp-PDL1P 成为临床免疫治疗前 PD-L1 预测的潜在示踪剂。