Yan Xuejiao, Wu Guoqiu, Qu Qingrong, Fan Xiaobo, Xu Xudong, Liu Naifeng
Department of Cardiology, Affiliated Zhongda Hospital, Medical School of Southeast University Nanjing, China.
Center of Clinical Laboratory Medicine of Zhongda Hospital, Institute of Biotechnology and Clinical Pharmacy, Medical School of Southeast University Nanjing, China.
Front Pharmacol. 2016 Mar 8;7:51. doi: 10.3389/fphar.2016.00051. eCollection 2016.
Intravital imaging provides invaluable readouts for clinical diagnoses and therapies and shows great potential in the design of individualized drug dosage regimes. Ts is a mammalian free cell membrane-penetrating peptide. This study aimed to introduce a novel approach to the design of a cancer-selective peptide on the basis of a membrane-penetrating peptide and to explore its potential as a carrier of medical substances.
Ts was linked with a αvβ3-binding peptide P1c to create a hybrid referred to as PTS. The hybrid was labeled with an FITC or Cy5.5 as an imaging indicator to evaluate its in vitro and in vivo bioactivity.
Hemolysis tests proved that in comparison with Ts, PTS caused similar or even less leakage of human erythrocytes at concentrations of up to 1 mmol/L. Flow cytometry assay and confocal microscopy demonstrated the following. (1) P1c alone could target and mostly halt at the cancer cell membrane. (2) Ts alone could not bind to the membrane sufficiently. (3) P1c greatly enhanced the binding affinity of PTS with MDA-MB-231 breast cancer cells that upregulated αvβ3. (4) Ts conferred PTS with the ability to traverse a cell membrane and thus facilitate the transmembrane delivery of imaging probes. In vivo near-infrared fluorescence (NIRF) imaging demonstrated that the imaging probes were rapidly concentrated in a MDA-MB-231 tumor tissue within 1 h after intravenous injection.
PTS exhibited the capability of targeting specific tumors and greatly facilitating the transmembrane delivery of imaging probes.
活体成像为临床诊断和治疗提供了宝贵的信息，在个性化药物剂量方案设计中显示出巨大潜力。Ts是一种哺乳动物游离细胞膜穿透肽。本研究旨在引入一种基于细胞膜穿透肽设计癌症选择性肽的新方法，并探索其作为药物载体的潜力。
将Ts与αvβ3结合肽P1c连接，形成一种称为PTS的杂合体。用异硫氰酸荧光素（FITC）或Cy5.5标记该杂合体作为成像指示剂，以评估其体外和体内生物活性。
溶血试验证明，与Ts相比，在浓度高达1 mmol/L时，PTS导致人红细胞的渗漏相似甚至更少。流式细胞术分析和共聚焦显微镜显示如下：（1）单独的P1c可以靶向并大多停留在癌细胞膜上。（2）单独的Ts不能充分结合到膜上。（3）P1c大大增强了PTS与上调αvβ3的MDA-MB-231乳腺癌细胞的结合亲和力。（4）Ts赋予PTS穿越细胞膜的能力，从而促进成像探针的跨膜递送。体内近红外荧光（NIRF）成像表明，静脉注射后1小时内，成像探针迅速集中在MDA-MB-231肿瘤组织中。
PTS表现出靶向特定肿瘤并极大促进成像探针跨膜递送的能力。
