A tumor-associated bacteria-responsive magnetic exosome as a clearable T1 contrast agent for targeted imaging of tumors. (April 2023)

• Record Type: Journal Article
• Authors: Wei, Xiaoqing; Mu, Dan; Li, Yingping; Zhao, Jingya; Zhou, Shaobing
• Is Part Of: Nano today. Volume 49(2023)
• Publication Date: 2023-04
• Subjects: Magnetic nanoparticles -- Exosomes -- Tumor-associated bacteria -- Magnetic resonance imaging -- Tumor diagnosis; Nanotechnology -- Periodicals; Nanosciences -- Périodiques; 620.505
• DOI: 10.1016/j.nantod.2023.101796
• Languages: English
• ISSNs: 1748-0132

Abstract

Abstract: Bacteria can colonize and grow in tumors due to the hypoxic and immunosuppressive tumor microenvironment. Indeed, recent studies have revealed that bacteria are intrinsic and integral components of the tumors. Herein, a tumor-associated bacteria-responsive magnetic exosome (Exo@ESIONs) with switchable magnetic resonance imaging (MRI) property is developed for sensitive tumor imaging. The magnetic exosomes loaded with extremely small iron oxide nanoparticles (ESIONs) possess the excellent properties of long circulation in blood, high accumulation in tumor tissues and rapid response in the tumor microenvironment. Stimulated by the pore-forming toxins (PFTs) secreted from the bacteria in the tumors, the Exo@ESIONs can be disintegrated and the ESIONs are rapidly released, enabling dynamic switchable T2/T1 MRI of the tumors. As a result, the T1 contrast effect of the magnetic nanomaterials can be selectively enhanced in the tumor tissues, even the tumor size is as small as 10 mm 3 . Moreover, the ESIONs can be rapidly elimination from the body via renal clearance after the MRI to avoid the potential toxicity. Graphical Abstract: ga1 Highlights: A tumor-associated bacteria-responsive magnetic exosome was developed for sensitive tumor imaging. The magnetic exosomes can be activated by the bacteria in the tumors, enabling dynamic switchable MRI of small tumors. The ultrasmall iron oxide nanoparticles released from the magnetic exosomes could be rapidly excreted from the body. This work provides a new perspective that the bacteria in the tumors can become a stimulating factor for tumor diagnosis.