General Thermodynamic-Controlled Coating Method to Prepare Janus Mesoporous Nanomotors for Improving Tumor Penetration

Abstract

Artificial nanomotors are undergoing significant developments in several biomedical applications. However, current experimental strategies for producing nanomotors still have inherent drawbacks such as the requirement for expensive equipment, strict controlling of experimental conditions, and strenuous processes with several complex procedures. In this study, we describe for the first time a facile single-step thermodynamic-controlled coating method to prepare Janus mesoporous organosilica nanomotors. By controlling the total free energy of organosilica oligomers (G) from a low development level to a high level in the reaction system, the nonspontaneous nucleation on the platinum (Pt) nanosurface and the spontaneous nucleation in a solvent can be controlled, respectively. More importantly, we reveal that the molecular arrangement and contact angle of deposited organosilica on Pt cores vary with the total free energy of organosilica oligomers (G). Different values of θ would change the trend of detachment from Pt for organosilica nucleated cores and carry out diverse coating modes. These are indicated by the morphology evolution of platinum/ organosilica hybrids, from naked platinum nanoparticles, evenly distributed organosilica shell/core, nonconcentric to typical Janus nanomotor. The prepared Janus mesoporous nanomotor (JMN) showed typical mesopore structures and active propelling behaviors under H 2 O 2 stimulation. In addition, the JMN modified with hyaluronic acid exhibited excellent biocompatibility and improved tumor penetration under H 2 O 2 stimulation. The successful construction of other nanomotor frameworks based on a gold-templated core proves the perfect applicability of the thermodynamic-coating method for the production of nanomotors. In conclusion, this work establishes a manufacturing methodology for nanomotors and drives nanomotors for promising biomedical applications.

In vivoapplications of micro/nanorobots

“…For the micro/nanorobots actuated with an on-board method, the power source can be local (chemical reactions) or biological (motile microorganisms). [22][23][24][25][26][27][28][29] Chemical reactions were widely utilized as the locomotion source in the early studies conducted with animal models. 30 For instance, microrobots based on mag-nesium (Mg) and zinc (Zn) hold the ability to react with waterand/or acid-based biofluids.…”

On The Approach to Nanoscale Robots: Understanding the Relationship between Nanomotor's Architecture and Active Motion

“…Reproduced with permission. [ 116 ] Copyright 2021 American Chemical Society. C) TEM image of the dumbbell‐shaped MnO 2 nanomotors and the unique dual‐bubble generating motion.…”

“…With H 2 O 2 as the fuel, the nanomotors exhibited active propelling behaviors which endowed the nanomotors enhanced tumor penetrating ability and excellent therapeutic performances. [ 116 ]…”

“…With H 2 O 2 as the fuel, the nanomotors exhibited active propelling behaviors which endowed the nanomotors enhanced tumor penetrating ability and excellent therapeutic performances. [116] Another kind of "nanobottle" shape asymmetric nanomotor is also widely used. [117] These nanobottles are fabricated through an emulsion templated method (Figure 6B).…”

“…B) TEM images with different magnifications of the Fe 3 O 4 nanocrystals loaded streamlined mesoporous silica nanomotors and schematic illustration of how curvature affects motion. Reproduced with permission [116]. Copyright 2021 American Chemical Society.…”