Monitor Tumor pHe and Response Longitudinally during Treatment Using CEST MRI-Detectable Alginate Microbeads

作者：Peng Xiao, Jianpan Huang, Xiongqi Han, Jacinth Wing‐Sum Cheu, Yang Liu, Lok Hin Law, Joseph H. C. Lai, Jiyu Li, Se Weon Park, Carmen Chak‐Lui Wong, Raymond H. W. Lam, Kannie W. Y. Chan · 发表于：ACS Applied Materials & Interfaces · 年份：2022 · DOI：10.1021/acsami.2c10493 · 被引用次数：14 · 研究领域：Lanthanide and Transition Metal Complexes、Advanced MRI Techniques and Applications、MRI in cancer diagnosis

High Resolution Image Download MS PowerPoint Slide Imaging pHe of the tumor microenvironment has paramount importance for characterizing aggressive, invasive tumors, as well as therapeutic responses. Here, a robust approach to image pH changes in the tumor microenvironment longitudinally and during sodium bicarbonate treatment was reported. The pH-sensing microbeads were designed and prepared based on materials approved for clinical use, i.e., alginate microbead-containing computed tomography (CT) contrast-agent (iopamidol)-loaded liposomes (Iop-lipobeads). This Iop-lipobead prepared using a customized microfluidic device generated a CEST contrast of 10.6% at 4.2 ppm at pH 7.0, which was stable for 20 days in vitro. The CEST contrast decreased by 11.8% when the pH decreased from 7.0 to 6.5 in vitro. Optimized Iop-lipobeads next to tumors showed a significant increase of 19.7 ± 6.1% ( p < 0.01) in CEST contrast at 4.2 ppm during the first 3 days of treatment and decreased to 15.2 ± 4.8% when treatment stopped. Notably, percentage changes in Iop-lipobeads were higher than that of amide CEST (11.7% and 9.1%) in tumors during and after treatment. These findings demonstrated that the Iop-lipobead could provide an independent and sensitive assessment of the pHe changes for a noninvasive and longitudinal monitoring of the treatment effects using multiple CEST contrast.