Photomagnetically Powered Spiky Nanomachines with Thermal Control of Viscosity for Enhanced Cancer Mechanotherapy

Abstract

geon". Nanomachines can be manipulated inside the human body to break through biological barriers for drug delivery, [2] diagnosis, [3] and active elimination of tumor cells using mechano-destruction. [4] Efficient conversion of energy into a mechanical motion is the basis for actuating nanomachines to achieve multiple functions. Compared with chemical fuels, [5] external fields, such as magnetic, light, ultrasonic, and electric fields, are considered more appropriate for in vivo applications owing to their high controllability. [6] Among various propelling platforms, magnetically driven nanomachines are promising candidates with biocompatibility and deep-tissue controllability for in vivo applications. [7] A typical magneticfield-actuated method is a magnetic force and torque-powered propulsion under alternating magnetic fields. [8] Using this method, nanomachines generate piconewton forces, and thus they can be utilized for precise cancer cell destruction. [9] Moreover, owing to the complex environment and biological barriers in vivo, achieving an efficient mechanical energy conversion remains a major challenge for designing nanoscale motors. At present, assembly approaches and strong magnetic field setups are typically used to enhance the mechanical energy output in vivo, which put forward high requirements for instrument development. [10] To overcome the viscous bioenvironment, the development of Nanomachines with active propulsion have emerged as an intelligent platformfor targeted cancer therapy. Achieving an efficient locomotion performance using an external energy conversion is a key requirement in the design of nanomachines. In this study, inspired by diverse spiky structures in nature, a photomagnetically powered nanomachine (PMN) with a spiky surface and thermally dependent viscosity tunability is proposed to facilitate mechanical motion in lysosomes for cancer mechanotherapy. The hybrid nanomachine is integrated with magnetic nanoparticles as the core and covered with gold nanotips. Physical simulations and experimental results prove that the spiky structure endows nanomachines with an obvious photomagnetic coupling effect in the NIR-II region through the alignment and orienting movement of plasmons on the gold tips. Using a coupling-enhanced magnetic field, PMNs are efficiently assembled into chain-like structures to further elevate energy conversion efficiency. Notably, PMNs with the thermal control of viscosity are efficiently propelled under simultaneously applied dual external energy sources in cell lysosomes. Enhanced mechanical destruction of cancer cells via PMNs is confirmed both in vitro and in vivo under photomagnetic treatment. This study provides a new direction for designing integrated nanomachines with active adaptability to physiological environments for cancer treatment.

Urchin-like Fe3O4@Bi2S3 Nanospheres Enable the Destruction of Biofilm and Efficiently Antibacterial Activities

“…65 In addition, urchin-like structures could stimulate macrophage polarization toward M1. 66 Then, flow cytometry assay, immunofluorescence staining, and Western blot assay (WB) were employed to investigate the effect of Fe 3 O 4 @Bi 2 S 3 on RAW246.7 polarization. The experiment was divided into six groups (PBS, RMF+AMF, Fe 3 O 4 @Bi 2 S 3 , Fe 3 O 4 @Bi 2 S 3 +AMF, Fe 3 O 4 @Bi 2 S 3 +RMF, Fe 3 O 4 @Bi 2 S 3 +RMF+AMF).…”

In vivoapplications of micro/nanorobots

“…Apart from the studies conducted on animal skin, subcutaneous tumor models have been a widely preferred way of investigating micro/nanorobots in vivo. [119][120][121][122][123][124][125][126][127] In general, different cancer cell lines, e.g., breast and cervical, were subcutaneously injected into animals to establish tumors. When the tumor models reached a considerable size, micro/nanorobots were injected into the blood or directly into the tumor site.…”

“…Apart from the studies conducted on animal skin, subcutaneous tumor models have been a widely preferred way of investigating micro/nanorobots in vivo . 119–127 In general, different cancer cell lines, e.g. , breast and cervical, were subcutaneously injected into animals to establish tumors.…”

On-Particle Hyperbranched Rolling Circle Amplification-Scaffolded Magnetic Nanoactuator Assembly for Ferromagnetic Resonance Detection of MicroRNA

“…1−3 Actuated by external magnetic fields, MNPs can convert energy into various mechanical motions and conformational changes. 4 Rotating magnetic field (RMF)-controlled MNPs have been applied in, e.g., nanorobotics, 5,6 mechanotherapy, 7,8 sensing, 9−11 imaging, 12 drug delivery, 13,14 and artificial cell construction. 15 In the field of biosensing, MNP swarms with RMF-induced shape deformation were adopted for reaction acceleration and generating light modulation signals.…”

“…The past decade has seen the widespread application of magnetic nanoparticles (MNPs) in bioengineering and biomedical engineering. − Actuated by external magnetic fields, MNPs can convert energy into various mechanical motions and conformational changes . Rotating magnetic field (RMF)-controlled MNPs have been applied in, e.g., nanorobotics, , mechanotherapy, , sensing, − imaging, drug delivery, , and artificial cell construction . In the field of biosensing, MNP swarms with RMF-induced shape deformation were adopted for reaction acceleration and generating light modulation signals. , Moreover, MNPs are ideal carriers of bioresponsive nanomachines due to the merits of easy manipulation and biocompatibility. − In spite of the rapidly gained interest, DNA nanomachines rely on nucleic acid strands that diffuse, competitively hybridize, and operate on slow (second) time scales, resulting in limited amplification efficiency. , Coincidentally, magnetic nanoactuators can help to address this problem by introducing magnetic field-controlled particle collision and assembly, namely, magnetic incubation.…”