Enzyme-Powered Gated Mesoporous Silica Nanomotors for On-Command Intracellular Payload Delivery

Abstract

The introduction of stimuli-responsive cargo release capabilities on self-propelled micro- and nanomotors holds enormous potential in a number of applications in the biomedical field. Herein, we report the preparation of mesoporous silica nanoparticles gated with pH-responsive supramolecular nanovalves and equipped with urease enzymes which act as chemical engines to power the nanomotors. The nanoparticles are loaded with different cargo molecules ([Ru­(bpy)3]­Cl2 (bpy = 2,2′-bipyridine) or doxorubicin), grafted with benzimidazole groups on the outer surface, and capped by the formation of inclusion complexes between benzimidazole and cyclodextrin-modified urease. The nanomotor exhibits enhanced Brownian motion in the presence of urea. Moreover, no cargo is released at neutral pH, even in the presence of the biofuel urea, due to the blockage of the pores by the bulky benzimidazole:cyclodextrin-urease caps. Cargo delivery is only triggered on-command at acidic pH due to the protonation of benzimidazole groups, the dethreading of the supramolecular nanovalves, and the subsequent uncapping of the nanoparticles. Studies with HeLa cells indicate that the presence of biofuel urea enhances nanoparticle internalization and both [Ru­(bpy)3]­Cl2 or doxorubicin intracellular release due to the acidity of lysosomal compartments. Gated enzyme-powered nanomotors shown here display some of the requirements for ideal drug delivery carriers such as the capacity to self-propel and the ability to “sense” the environment and deliver the payload on demand in response to predefined stimuli.

Monitoring the collective behavior of enzymatic nanomotors in vitro and in vivo by PET-CT

“…(1) In this regard, micro-and nanomotors have demonstrated enhanced targeting properties (2)(3)(4)(5) and superior drug delivery efficiency compared to passive particles. (6)(7)(8)(9) Additionally, they outperform traditional nanoparticles in terms of penetration into biological material, such as mucus, (10)(11)(12)(13) cells (14)(15)(16) or spheroids. (4,17) Particularly, using enzymes as biocatalysts is emerging as an elegant approach when designing self-propelled particles, due Nanomotors were prepared by synthesizing mesoporous silica nanoparticles (MSNPs) using a modification of the Stöber method (see experimental section for details), (46) and their surface was modified with amine groups by attaching aminopropyltriethoxysilane 7 temperature) of the nanomotors with the prosthetic group.…”

Recent Advances in Motion Control of Micro/Nanomotors

“…Cargo delivery [120] Cell-membrane-coated bacteria Blood circulation Tumor imaging [121] Cell hybrid Red blood cell-mimicking micromotor Ultrasound energy and magnetotactic control Oxygen transportation [16] Platelet-camouflaged nanorobots Magnetic propulsion and magnetotactic control Isolation of biological threats [124] Macrophage-Mg biohybrid motors Hydrogen bubble propulsion Endotoxin neutralization [125] Neutrophil-based micromotors Cell-driven and chemotactic control Target drug delivery [126] Enzyme-propelled Enzyme-powered microshell motors Catalase-trigged bubble propulsion and chemotactic control, size Drug delivery [141] Mesoporous silica-based nanomotors Urease-powered and pH responsive Target drug delivery [142] Micromotors equipped with DNA nanoswitches Urease-powered and pH responsive Microenvironment sensing and micromotor activity status indicator [143] Ultrasmall stomatocyte motors Biocatalyst catalase and chemotactic control Drug delivery [144] capability through the whole process of performing tasks. Also, the single chemotaxis to the egg cells restricts the potential application of this biohybrid machines.…”

“…Reproduced with permission. [142] Copyright 2019, American Chemical Society. C) Schematic diagram of the self-sensing enzyme-powered micromotors equipped with pH-responsive DNA nanoswitches.…”

“…These findings provide a new strategy for the design and development of microshell motors. Llopis-Lorente et al [142] reported new ( Figure 12B) nanomotors consisting of MSNs loaded with different cargo molecules gated with pH-responsive supramolecular nanovalves, equipped with urease enzymes which served as chemical engines. The results indicated that these nanomotors exhibited an enhanced Brownian motion in the presence of urea.…”

Mapping and identification of soft corona proteins at nanoparticles and their impact on cellular association

“…Therefore, we have developed a SPAAC click reaction between azide-modified HC proteins on nanoparticles (HC-N 3 ) and Dibenzocyclooctyne (DBCO)-activated SC proteins (FBS-D) ( Fig.1a) in order to trap the transiently binding SC proteins on the NP surface (HC+SC sample). Silica nanoparticles (SNPs, 70 nm) and carboxylate-modified polystyrene nanoparticles (PsNPs, 100 nm) were used in this study as model nanoparticles [26][27][28] . We used four control samples representing HC and FBS with and without chemical modifications (hard corona (HC), hard corona modified with azide (HC-N 3 ), FBS-D added to HC (D Ctrl), FBS added to HC-N3 (N 3 Ctrl)) and one HC+SC sample that encompasses proteins in both HC and captured SC states.…”