Author/Authors :
Liu, Xiaoyuan Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Ye, Jianqiang Department of Pathology - Wuxi Huishan District People’s Hospital - Wuxi, China , Zhang, Yan Department of Pharmacy - The AffiliatedWuxi Maternity and Child Health Care Hospital of Nanjing Medical University - Wuxi - Jiangsu, China , Liu, Quan Department of Oncology - Affiliated Hospital of Jiangnan University - Wuxi, China , Bai, Ruizhen Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Yuan, Wenbo Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Cai, Dongyan Department of Oncology - Affiliated Hospital of Jiangnan University - Wuxi, China , Zheng, Xiaoyuan Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Bian, Yun Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Zhou, Shijun Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Lv, Juan Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Ding, Yongjuan Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Xie, Fen Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Lu, Hongwen Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China , Xie, Bingxue Department of Pharmacy - Affiliated Hospital of Jiangnan University - Wuxi, China
Abstract :
Background: Despite studies on positron emission tomography/magnetic resonance imaging (PET/MRI) in oncological imaging
with high soft-tissue contrast resolution, PET/MRI has not been studied in ophthalmology. 89Zr-bevacizumab, designed as a probe
for PET, targets vascular endothelial growth factor, which is highly expressed in ocular angiogenesis. Intravitreal injections of bevacizumab
agents have curative effects on ocular disease.
Objectives: To study the ocular biodistribution of 89Zr-bevacizumab in New Zealand rabbits using PET/MRI.
Materials and Methods: 89Zr-bevacizumab, synthesized from conjugated bevacizumab and 89Zr-oxalate, and the purity of radiolabeled
antibodies were determined using radio high-performance liquid chromatography (radio-HPLC). Instant thin-layer chromatography
(ITLC) was utilized to differentiate the labeled product from aggregates and unlabeled 89Zr. 89Zr-bevacizumab was
injected 2 mm from the left limbus into the vitreous humor of six normal New Zealand white rabbits. Micro-PET was utilized for
dynamic imaging from 5 minutes to 60 minutes postinjection and for static imaging at 4 hours, 24 hours, 48 hours, 120 hours, and
144 hours (10-minutes scans) postinjection. PET/MRI scans were fused using PMOD software.
Results: 89Zr-bevacizumab with a radiochemical purity of 93.21% was monitored via PET imaging. Radioactivity levels in the eyes
plateaued approximately 5 minutes after administration of 89Zr-bevacizumab, and the measured vitreous values decreased from
340.52 41.6% injected dose (ID)/g to 21.53 3.39%ID/g by 144 hours. The half-life of the drug in the eye was calculated for 84.25
hours.
Conclusion: 89Zr-bevacizumab could be monitored in animals by PET imaging, and the radiolabel exhibited high sensitivity in the
vitreous body. Radioactivity levels in the eyes plateaued approximately 5 minutes after administration. This study clearly demonstrates
the biodistribution of 89Zr-bevacizumab.
