Atherosclerosis is a chronic progressive disease involving inflammatory events, such as the overexpression of adhesion molecules including the endothelial Vascular Cell Adhesion Molecule-1 (VCAM-1). VCAM-1 is rapidly overexpressed in the first stages of atherosclerosis, thus representing a promising target for early atheroma detection. Two novel Positron Emission Tomography (PET) radiopharmaceuticals (MacroP and NAMP), based on the VCAM-1-binding peptide having sequence VHPKQHRGGSKGC, were synthesized and characterized. MacroP is derived from the direct conjugation of a DOTA derivative with the peptide, while NAMP is a biotin derivative conceived to be employed in a three-step pretargeting system, involving the use of a double-chelating derivative of DOTA. The identity of the newly synthesized radiopharmaceuticals was confirmed by mass spectrometry and, after radiolabeling with 68Ga, both showed high radiochemical purity; in vitro tests on human umbilical vein endothelial cells evidenced their VCAM-1 binding ability, with higher radioactive uptake in the case of NAMP. Moreover, NAMP might also be employed in a theranostic approach in association with functionalized biotinylated nanoparticles.
动脉粥样硬化是一种慢性进行性疾病,涉及炎症事件,例如过度表达粘附分子,包括内皮细胞血管细胞粘附分子-1(VCAM-1)。 VCAM-1在动脉粥样硬化的早期阶段迅速过度表达,因此代表了早期动脉粥样硬化检测的有希望的靶点。基于VCAM-1结合肽序列VHPKQHRGGSKGC的两种新型正电子发射断层扫描(PET)放射性药物(MacroP和NAMP)已经合成和表征。MacroP是由DOTA衍生物与肽直接共轭而来,而NAMP是一种生物素衍生物,旨在用于三步预先靶向系统,涉及使用DOTA的双螯合衍生物。新合成的放射性药物的身份已经通过质谱确认,在与68Ga标记后,两者都显示出高放射化学纯度;对人脐静脉内皮细胞的体外测试显示它们具有VCAM-1结合能力,在NAMP的情况下放射性摄取率更高。此外,NAMP也可能与功能化生物素化纳米颗粒一起用于治疗和诊断联合应用。