用於免疫療法之磁振分子顯影劑SPIO-anti-PD-L1

Abstract

本團隊設計功能性的磁性奈米粒子SPIO-anti-PD-L1應用於磁振造影的對比劑。我們合成氧化鐵奈米粒子，並表面上修飾對細胞程式死亡-配體1 (PD-L1)具有高度專一性的抗體anti-PD-L1，使之具有標靶診斷的功效。動態光散射儀顯示其水合粒徑大小為18.89 ± 3.931nm，表面電位約為 + 4.5 ± 2.32mV，用MTT assay證實其對於細胞的毒性不大，可以被生物體所接受。在體外細胞實驗所選用的細胞有兩株，分別為PD-L1高表現量的MDA-MB-231人乳腺癌細胞株及PD-L1低表現量的MCF7人乳腺癌细胞株。用流式細胞儀與西方點墨法測得SPIO-anti-PD-L1具有專一性辨識的能力。流式細胞儀與磁振造影實驗結果得知此對比劑與目標受體結合的時間持久性。由體外細胞實驗與老鼠活體實驗的磁振造影結果證實SPIO-anti-PD-L1為有效的對比劑。本文研究已成功設計出用於PD-L1的高度專一性的功能性磁性奈米粒子，利用磁振造影確認其位置，可用於癌症的早期診斷。

Our team designed the functional magnetic nanoparticle SPIO-anti-PD-L1 to be used as a contrast agent for magnetic resonance imaging. We synthesized superparamagnetic iron oxide nanoparticles and immobilized the surface by anti-PD-L1 antibody, which is highly specific to Programmed death-ligand 1 (PD-L1) presented in cancer cells. The dynamic light scattering showed that the hydrated particle size and surface zeta potential were 18.89 ± 3.931 nm and + 4.5 ± 2.32 mV, respectively. MTT assay showed that it was not toxic to cells. These two experiment showed that SPIO-anti-PD-L1 could be biocompatibility. We selected two cell lines for in vitro experiments, MDA-MB-231, human breast cancer cell line with PD-L1 high-performance and MCF7, human breast cancer cell line with PD-L1 low-expression. The western blotting and flow cytometry study showed that the antibodies effectively recognized the receptor on MDA-MB-231. The flow cytometry and in vitro magnetic resonance imaging showed that the time-point of SPIO-anti-PD-L1 bind to the target receptor and binding persistence. In vitro and in vivo magnetic resonance imaging experiments showed that SPIO-anti-PD-L1 was an effective contrast agent. Therefore, we believe the highly specific SPIO-anti-PD-L1 nanoparticles introduced in this study could potentially be used in MRI for early detection of cancer.