Biocatalytic Micro‐ and Nanomotors

Abstract

Enzyme‐powered micro‐ and nanomotors are tiny devices inspired by nature that utilize enzyme‐triggered chemical conversion to release energy stored in the chemical bonds of a substrate (fuel) to actuate it into active motion. Compared with conventional chemical micro‐/nanomotors, these devices are particularly attractive because they self‐propel by utilizing biocompatible fuels, such as glucose, urea, glycerides, and peptides. They have been designed with functional material constituents to efficiently perform tasks related to active targeting, drug delivery and release, biosensing, water remediation, and environmental monitoring. Because only a small number of enzymes have been exploited as bioengines to date, a new generation of multifunctional, enzyme‐powered nanorobots will emerge in the near future to selectively search for and utilize water contaminants or disease‐related metabolites as fuels. This Minireview highlights recent progress in enzyme‐powered micro‐ and nanomachines.

Medical Micro/Nanorobots in Precision Medicine

“…For example, enzymes have substituted platinum, allowing them to use a variety of biomolecules, such as glucose or urea as fuel. [104][105][106][107][108][109][110] Moreover, biodegradable metals, such as zinc or magnesium have been used as propellants. These can react with the acidic environment of the stomach (Figure 2c).…”

Self-diffusiophoresis of Janus particles that release ions

“…calculate the integral (36). The auxiliary velocity field (11) can be presented in terms of stretched variable ρ as…”

“…The most known catalytic swimmers are bi-metallic particles in hydrogen peroxide solution 9,10 , in which only one type of ions (H + ) is released. Rapid development of enzymatic motors 11 have raised interest in a different type of swimmers, which produce both anions and cations (NH + 4 , HCO − 3 for urease motors 12 , Ag + and Cl − for AgCl particles 13 ). However, theoretical studies for this kind of motors are still limited 14,15 .…”

Starfish-inspired Ultrasound Ciliary Bands for Microrobotic Systems

“…Microrobots could facilitate specialized tasks in medicine 17 , including surgical procedures and drug delivery to hard-to-access sites in vivo. Chemical [18][19][20][21][22][23][24][25][26] and external field-driven, such as magnetic [27][28][29][30][31][32][33][34][35] , light [36][37][38] , electrical 39 , biohybrid [40][41][42] or ultrasound [43][44][45][46][47][48] -microrobots are attractive because they do not require an onboard power supply or intricate moving parts and allow wireless control of the microrobot. Nonlinear ultrasound provides an alternate and attractive method to generate propulsion in vivo.…”