Biocompatible Nanomotors as Active Diagnostic Imaging Agents for Enhanced Magnetic Resonance Imaging of Tumor Tissues In Vivo

Abstract

The limited penetration of imaging agents in solid tumor tissue and cells remains a great challenge to achieve ideal visibility in cancer diagnosis. Herein, a near infrared (NIR) light‐driven Janus mesoporous silica nanomotor (JMS nanomotor) to promote magnetic resonance (MR) imaging in vivo is developed. The JMS nanomotors are prepared by depositing Au on the half‐sphere surface of gadolinium‐doped mesoporous silica nanoparticles. Under NIR irradiation, the nanomotors achieve efficient propulsion through thermophoresis in biological media. To prove the ability of nanomotors as active diagnostic imaging agents, both in vitro and in vivo experiments are carried out. In vitro studies confirm that NIR light can actively propel the JMS nanomotors to effectively seek, adhere to, and mechanically perforate the tumor cells to enhance the cellular uptake and MR imaging. To move a step further, in vivo investigations show that the JMS nanomotors also exhibit improved accumulation and deep penetration in the solid tumor model when exposed to NIR laser, where the MR imaging contrast is significantly enhanced in the majority of tumor tissue. Such JMS nanomotors provide new insight in precise cancer diagnosis and meanwhile MR imaging offers a new tool for real‐time tracking of nanomotors in vivo.

Active nanomotors surpass passive nanomedicines: current progress and challenges

“…So, imaging-guided therapy holds great potential in the field of precision medicine. At present, a variety of biological imaging technologies have been investigated for visualization of nanomotors, such as fluorescence imaging, [62][63][64][65] magnetic resonance (MR) imaging, 19 etc. For instance, Zheng et al 19 prepared a near-infrared propulsion nanomotor based on Janus mesoporous silica nanoparticles (Fig.…”

“…This is the mainstream trend, but the ingenious design and application scenarios of these nanomotors are only limited to the applied proof-of-concept trials. Although the biomedical application of nanomotors has made certain breakthroughs at the cell and tissue level, such as cancer cell killing, 82,83 antibacterial wound treatment, 45 deep tissue imaging, [17][18][19] and biological barrier penetration, [12][13][14][15][16] the benefits of nanomotors over nanomedicines deserve more attention and exploration. Expanding the practical application scenarios of nanomotors is a key to moving nanomotors toward clinical use.…”

“…[1][2][3][4][5][6] The development of nanomotors over the last decade has demonstrated their great potential for diverse applications in biomedical fields, such as targeted drug delivery, [7][8][9] minimally invasive treatment, 10,11 penetration of complex biological barriers, [12][13][14][15][16] and deep tissue imaging. [17][18][19] Attributed to their miniaturization and unique mobility, nanomotors are expected to actively target the lesion area, and accomplish specific tasks in a non-invasive way in future clinical applications.…”

Enzyme‐Powered Micro/Nanomotors for Cancer Treatment

“…Micro/nanomotors provide a new insight into solving this problem, based on their unique properties. [7][8][9][10][11][12][13] Since the micro/ nanomotors possess controlled motility styles, enhanced diffusion as well as increased permeability, based on chemical fuel [14][15][16] or external field stimulation, [17][18][19][20] they have been widely explored in cancer treatment, such as drug delivery, [21][22][23][24] diagnosis and therapy, [25][26][27][28] cell sensing and imaging. [29][30] However, considering the perquisite of biocompatibility for treatment in vivo, it is necessary to explore biocompatible designs, capable of actuating in biological systems without side effects.…”

Refillable Fuel-Loading Microshell Motors for Persistent Motion in a Fuel-Free Environment

“…Micro-/nanomotors, owing to their automatic motion, have become popular in many fields, such as biosensing, drug delivery, microtherapy, and environmental remediation . Similar to biological motors, artificial micro-/nanomotors also harvest environmental energy to move and accomplish on-demand tasks.…”