Nowadays, cell membrane-targeted therapy, which owns high antitumor efficacy by avoiding cell barriers, has received great attention. Here, a cell membrane-targeted self-delivery theranostic chimeric peptide CMP-PpIX is designed for simultaneously targeted photodynamic therapy (PDT) of tumor and real-time therapeutic feedback. Self-assembled CMP-PpIX nanoparticles can effectively accumulate in tumor by enhanced permeability and retention effect without additional vector. And this chimeric peptide CMP-PpIX has low background fluorescence, which is due to its relatively high intramolecular Förster resonance energy transfer (FRET) quenching efficiency between 5(6)-carboxyfluorescein (FAM) and 4-(dimethylaminoazo)-benzene-4-carboxylic acid (Dabcyl). More importantly, CMP-PpIX can be anchored on the tumor cell membrane for more than 8 h. Under irradiation, reactive oxygen species produced by CMP-PpIX directly damage cell membrane and rapidly induce apoptosis, which significantly improve the efficacy of PDT in vitro and in vivo. Then, peptide sequence Asp-Glu-Val-Asp (DEVD) is subsequently cleaved by activated caspase-3 and activated caspase-7, which separates the FAM and Dabcyl and terminates the FRET process. Therefore, fluorescence of FAM is recovered to monitor the expression of activated caspase-3 in vitro and in vivo to feedback real-time PDT therapeutic efficacy. In general, a novel cell membrane-targeted self-delivery theranostic chimeric peptide offers new promise for effective imaging-guided PDT.

中文翻译：

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细胞膜靶向自递送嵌合肽，可增强光动力治疗和原位治疗反馈。

如今，通过避免细胞屏障而具有高抗肿瘤功效的细胞膜靶向疗法已受到广泛关注。在这里，针对细胞膜的自送治疗型治疗型嵌合肽CMP-PpIX被设计为同时靶向肿瘤的光动力疗法（PDT）和实时治疗反馈。自组装的CMP-PpIX纳米颗粒可以通过增强的通透性和保留效果有效地在肿瘤中蓄积，而无需其他载体。而且这种嵌合肽CMP-PpIX具有较低的背景荧光，这是由于其在5（6）-羧基荧光素（FAM）和4-（二甲基氨基偶氮）-苯-4-之间的相对较高的分子内Förster共振能量转移（FRET）猝灭效率。羧酸（Dabcyl）。更重要的是，CMP-PpIX可以锚定在肿瘤细胞膜上超过8小时。在辐照下，CMP-PpIX产生的活性氧直接破坏细胞膜并迅速诱导细胞凋亡，从而显着提高了PDT的体内外功效。然后，肽序列Asp-Glu-Val-Asp（DEVD）随后被活化的caspase-3和活化的caspase-7裂解，从而将FAM和Dabcyl分开并终止FRET过程。因此，FAM的荧光被回收以在体外和体内监测活化的caspase-3的表达，以反馈实时PDT治疗功效。总的来说，一种新型的靶向细胞膜的自我递送的治疗性嵌合抗体为有效的影像引导PDT提供了新的希望。然后，肽序列Asp-Glu-Val-Asp（DEVD）随后被活化的caspase-3和活化的caspase-7裂解，从而将FAM和Dabcyl分开并终止FRET过程。因此，FAM的荧光得以恢复，以在体外和体内监测活化的caspase-3的表达，以反馈实时PDT治疗功效。总的来说，一种新型的靶向细胞膜的自我递送的治疗性嵌合抗体为有效的影像引导PDT提供了新的希望。然后，肽序列Asp-Glu-Val-Asp（DEVD）随后被活化的caspase-3和活化的caspase-7裂解，从而将FAM和Dabcyl分开并终止FRET过程。因此，FAM的荧光被回收以在体外和体内监测活化的caspase-3的表达，以反馈实时PDT治疗功效。总的来说，一种新型的靶向细胞膜的自我递送的治疗性嵌合抗体为有效的影像引导PDT提供了新的希望。