Photothermal interference urease-powered polydopamine nanomotor for enhanced propulsion and synergistic therapy

Enzyme-powered micro- and nano-motors: key parameters for an application-oriented design

“…28,29 This allows for different properties on each side of the structure that enable morphological exibility to encapsulate enzymes or drugs and to generate an asymmetric shape. This is also the case for other examples that have used dual polymeric compounds like poly(ethylene oxide) with poly(lactic-co-glycolic acid) (PEO-PLGA), 30 poly(ethylene glycol) with aggregation-induced emission polymers (PEG-P(AIE)), 31,32 (poly(ethylene oxide-b-butadiene)) (PEO-PB), 33 polystyrene with poly(glycidyl methacrylate) (PS-PGMA), 15 polydopamine with human serum albumin (PDA-HSA) 34 or poly(ethylene glycol) with poly(propylene glycol) (PEG-PPG-PEG) 35 . Even more complex structures are polymeric vesicles made of three-layered polymers such as poly(ethylene glycol) with polycaprolactone and poly(trimethylene carbonate) (PEG-PCL-PTMC) 36 to allow for the mobility of enzymes on the coacervate surface.…”

“…However, as mentioned before, for smaller sizes we nd catalase nanomotors able to navigate even in ionic media, so a different mechanism could be taking place, either (neutral or ionic) self-diffusiophoresis or nanobubble propulsion. Additionally, the main drawback of this enzyme is the high concentrations of toxic substrate (H 2 O 2 ) needed for motion, although recently more motors used low substrate concentrations 26,33,34,40,43,47,58,102,108 and for biomedical applications where this particular substrate is bioavailable, 16,40,57,104 despite being originally used for environmental and sensing applications. 3,54…”

“…4C) that consumes urea (CO(NH 2 ) 2 ) and releases ammonium ions (NH 4 + ) and bicarbonate (CO 3 2À ). 14,[20][21][22]31,34,36,39,44,60,[70][71][72][73][74][78][79][80][81]83,84,86,89,90,92,93,99,[117][118][119][120]129 Interestingly, a study of urease-powered micromotors shows that the gradient of ionic products may be responsible for the self-propulsion, 84 an ionic self-diffusiophoretic mechanism that has been further supported by theoretical models. 82,136 This was proved by the decreasing speed of urease micromotors aer exposing them to different ionic compounds.…”

Enzyme‐Powered Micro/Nanomotors for Cancer Treatment

“…It has been found that properly increasing the temperature is beneficial to improve the urease activity. In order to make full use of this property, urease modified spherical PDA@HSA@Ur@-DOX nanomotors were studied (Figure 4b), [49] with the characteristics of photothermal response, and its photothermal ability could be adjusted by controlling the laser power. The experiment proved that 60 °C was the optimum temperature for immobilized urease, and nanomotors solution (250 μg/mL) could be heated to about 47 °C under laser, which proved that the nanomotors could not only effectively ablate cancer cells by increasing temperature, but also increased urease activity as well as the osmotic ability.…”

“…Copyright © 2018 American Chemical Society. (b) Schematic diagram of synthesis and action PDA@HSA@Ur@DOX nanomotors [49]. Copyright © 2022 Elsevier B.V.…”