Materials and Methods
General Procedures: All solvents and chemicals were purchased from reagent vendors and no purification was performed prior to use. HZ20 were custom synthesized by ChinaPeptides Co., Ltd (Shanghai, China) or CSBio (San Diego, California). Sep-Pak Accell Plus QMA and Sep-Pak C18-Light cartridges were purchased from Waters (Ireland). Acrodisc 25 mm syringe filter (0.22 µm) was purchased from Pall Corporation (USA). The labeling yield, radiochemical purity and stability were analyzed by radio-high performance liquid chromatography (HPLC) (1200, Agilent, USA) equipped with γ detector (Flow-count, Bioscan, Washington. D.C., USA), using a C18 column (Eclipse Plus C18, 4.5 × 250 mm, 5µm, Agilent, USA). The Micro-PET/CT imaging studies of small animals were performed on the Micro-PET/CT of PINGSENG Healthcare Inc (Shanghai, China). The68Ge-68Ga generator was purchased from ITM Co., Ltd, Germany. rhACE2 purchased from Sydlabs (BP003061). RIPA lysate purchased from Solarbio (R0010).
The Radiolabeling and quality control of68Ga-HZ20 were conducted as previously reported procedures with some modifications [Supplemental Information].