Gallium-Based Liquid Metal Particles for Therapeutics Xie, Wanjie; Allioux, Francois-Marie; Ou, Jian Zhen ...
Trends in biotechnology (Regular ed.),
June 2021, 2021-Jun, 2021-06-00, 20210601, Letnik:
39, Številka:
6
Journal Article
Recenzirano
Gallium (Ga) and Ga-based liquid metal (LM) alloys offer low toxicity, excellent electrical and thermal conductivities, and fluidity at or near room temperature. Ga-based LM particles (LMPs) ...synthesized from these LMs exhibit both fluidic and metallic properties and are suitable for versatile functionalization in therapeutics. Functionalized Ga-based LMPs can be actuated using physical or chemical stimuli for drug delivery, cancer treatment, bioimaging, and biosensing. However, many of the fundamentals of their unique characteristics for therapeutics remain underexplored. We present the most recent advances in Ga-based LMPs in therapeutics based on the underlying mechanisms of their design and implementation. We also highlight some future biotechnological opportunities for Ga-based LMPs based on their extraordinary advantages.
The surface tension of gallium (Ga)-based liquid metals (LMs) can be broken using mechanical and chemical means, and smaller Ga-based LM particles (LMPs) can be constructed.Ga-based LMPs offer both fluidic and metallic cores and peculiar interfacial properties, which differ fundamentally from the properties of solid metal particles.Ga-based LMPs hold great potential for therapeutics. Functionalized Ga-based LMPs can be designed and activated for drug delivery, cancer treatment, bioimaging, and biosensing on stimulation by light, electromagnetic fields, mechanical means, or chemical reactions.Fundamental understanding of the effects of Ga-based LMPs’ surface oxides, their interactions with cells and their organelles, and their specific alloy composition with other elements should be further explored to expand the horizons of therapeutics using LMPs.
A new platform described as the liquid metal/metal oxide (LM/MO) framework is introduced. The constituent spherical structures of these frameworks are made of micro‐ to nanosized liquid metal spheres ...and nanosized metal oxides, combining the advantages of both materials. It is shown that the diameters of the spheres and the stoichiometry of the structures can be actively controlled. Additionally, the liquid suspension of these spheres demonstrates tuneable plasmon resonances. These spherical structures are assembled to form LM/MO frameworks which are capable of demonstrating high sensitivity towards low concentrations of heavy metal ions, and enhanced solar light driven photocalalytic activities. These demonstrations imply that the LM/MO frameworks are a suitable candidate for the development of future high performance electronic and optical devices.
A new platform described as the liquid metal/metal oxide (LM/MO) framework is introduced. The constituent spherical structures of these frameworks are made of micro‐ to nanosized liquid metal spheres and nanosized metal oxides. These LM/MO frameworks demonstrate high sensitivity towards low concentrations of heavy metal ions and enhanced solar light driven photocalalytic activities.
Chaotic advection plays an important role in microplatforms for a variety of applications. Currently used mechanisms for inducing chaotic advection in small scale, however, are limited by their ...complicated fabrication processes and relatively high power consumption. Here, a soft actuator is reported which utilizes a droplet of Galinstan liquid metal to induce harmonic Marangoni flow at the surface of liquid metal when activated by a sinusoidal signal. This liquid metal actuator has no rigid parts and employs continuous electrowetting effect to induce chaotic advection with exceptionally low power consumption. The theory behind the operation of this actuator is developed and validated via a series of experiments. The presented actuator can be readily integrated into other microfluidic components for a wide range of applications.
A soft actuator is developed which utilizes a droplet of Galinstan liquid metal to induce harmonic Marangoni flow at the surface of liquid metal when activated by a sinusoidal signal. This liquid metal actuator has no rigid parts and can be readily integrated into other microfluidic components for a wide range of applications.
Sub-micrometer particles (0.10-1.0 μm) are of great significance to study, e.g., microvesicles and protein aggregates are targets for therapeutic intervention, and sub-micrometer fluorescent ...polystyrene (PS) particles are used as probes for diagnostic imaging. Focusing of sub-micrometer particles - precisely control over the position of sub-micrometer particles in a tightly focused stream - has a wide range of applications in the field of biology, chemistry and environment, by acting as a prerequisite step for downstream detection, manipulation and quantification. Microfluidic devices have been attracting great attention as desirable tools for sub-micrometer particle focusing, due to their small size, low reagent consumption, fast analysis and low cost. Recent advancements in fundamental knowledge and fabrication technologies have enabled microfluidic focusing of particles at sub-micrometer scale in a continuous, label-free and high-throughput manner. Microfluidic methods for the focusing of sub-micrometer particles can be classified into two main groups depending on whether an external field is applied: 1) passive methods, which utilize intrinsic fluidic properties without the need of external actuation, such as inertial, deterministic lateral displacement (DLD), viscoelastic and hydrophoretic focusing; and 2) active methods, where external fields are used, such as dielectrophoretic, thermophoretic, acoustophoretic and optical focusing. This article mainly reviews the studies on the focusing of sub-micrometer particles in microfluidic devices over the past 10 years. It aims to bridge the gap between the focusing of micrometer and nanometer scale (1.0-100 nm) particles and to improve the understanding of development progress, current advances and future prospects in microfluidic focusing techniques.
Liquid Metal Marbles Sivan, Vijay; Tang, Shi-Yang; O'Mullane, Anthony P. ...
Advanced functional materials,
January 14, 2013, Letnik:
23, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Liquid metal marbles that are droplets of liquid metal encapsulated by micro‐ or nanoparticles are introduced. Droplets of galinstan liquid metal are coated with insulators (including Teflon and ...silica) and semiconductors (including WO3, TiO2, MoO3, In2O3 and carbon nanotubes) by rolling over a powder bed and also by submerging in colloidal suspensions. It is shown that these marbles can be split and merged, can be suspended on water, and are even stable when moving under the force of gravity and impacting a flat solid surface. Furthermore, the marble coating can operate as an active electronic junction and the nanomaterial coated liquid metal marble can act as a highly sensitive electrochemical based heavy metal ion sensor. This new element thus represents a significant platform for the advancement of research into soft electronics.
Liquid metal marbles are formed by encapsulating droplets of liquid metal in micro/nanoparticles that are insulating or semiconducting. The physical properties of the liquid metal marbles are investigated. The ability to form active electronic junctions using liquid metal marbles and its use as a highly sensitive, electrochemical‐based, heavy metal ion sensor is demonstrated.
Microfluidic systems enable rapid diagnosis of diseases, biological analysis, drug screening, and high‐precision materials synthesis. In spite of these remarkable abilities, conventional microfluidic ...systems are microfabricated monolithically on a single platform and their operations rely on bulky expensive external equipment. This restricts their applications outside of research laboratories and prevents development and assembly of truly versatile and complex systems. Here, novel magnetorheological elastomer (MRE) microactuators are presented including pumps and mixers using an innovative actuation mechanism without the need of delicate elements such as thin membranes. Modularized elements are realized using such actuators, which can be easily integrated and actuated using a single self‐contained driving unit to create a modular, miniaturized, and robust platform. The performance of the microactuators is investigated via a series of experiments and a proof‐of‐concept modular system is developed to demonstrate the viability of the platform for self‐contained applications. The presented MRE microactuators are small size, simple, and efficient, offering a great potential to significantly advance the current research on complex microfluidic systems.
Novel magnetorheological elastomer (MRE) microactuators are presented including pumps and mixers using an innovative actuation mechanism. Modularized elements are realized using MRE actuators, which can be easily integrated and actuated using a single self‐contained driving unit to create a modular and miniaturized platform. Such a system will offer a great potential to advance the current research on complex microfluidic systems.
The use of ligands to control regioselectivity in transition‐metal‐catalyzed CH activation/functionalization is a highly desirable but challenging task. Recently, Itami et al. reported an important ...finding relating to Pd‐catalyzed ligand‐controlled α/β‐selective CH arylation of thiophenes. Specifically, the use of the 2,2′‐bipyridyl ligand resulted in α‐arylation, whereas the use of the bulky fluorinated phosphine ligand POCH(CF3)23 resulted in β‐arylation. Understanding of this surprising ligand‐controlled α/β‐selectivity could provide important insights into the development of more efficient catalyst systems for selective CH arylation, and so we carried out a detailed computational study on the problem with use of density functional theory methods. Three mechanistic possibilities—SEAr and migration, metalation/deprotonation, and Heck‐type arylation mechanisms—were examined. The results showed that the SEAr and migration mechanism might not be plausible, because the key Wheland intermediates could not be obtained. On the other hand, our study indicated that the metalation/deprotonation and Heck‐type arylation mechanisms were both involved in Itami’s reactions. In the metalation/deprotonation pathway the α‐selective product (C5‐product) was preferred, whereas in the Heck‐type arylation mechanism the β‐selective product (C4‐product) was favored. The ligands played crucial roles in tuning the relative barriers of the two different pathways. In the 2,2′‐bipyridyl‐assisted system, the metalation/deprotonation pathway was energetically advantageous, leading to α‐selectivity. In the POCH(CF3)23‐assisted system, on the other hand, the Heck‐type arylation mechanism was kinetically favored, leading to β‐selectivity. An interesting finding was that POCH(CF3)23 could produce a CH⋅⋅⋅O hydrogen bond in the catalyst system, which was crucial for stabilization of the Heck‐type transition state. In comparison, this CH⋅⋅⋅O hydrogen bond was absent with the other phosphine ligands i.e., P(OMe)3, PPh3, PCy3 and these phosphine ligands therefore favored the metalation/deprotonation pathway leading to α‐selectivity. Furthermore, in this study we have provided theoretical evidence showing that the Heck‐type arylation reaction could proceed through an anti‐β‐hydride elimination process.
Switching regioselectivity: Pd‐catalyzed ligand‐controlled α/β‐selective CH arylation of thiophenes was studied computationally: metalation/deprotonation and Heck‐type arylation mechanisms were found to be involved (see figure). The ligands played a crucial role in tuning the relative barriers of the two pathways. Interestingly, POCH(CF3)23 could produce a CH⋅⋅⋅O hydrogen bond, crucial for stabilization of the Heck‐type transition state.
The size and doping effects in methane activation by Ti−Si−O clusters have been explored by using a combination of gas‐phase experiments and quantum chemical calculations. All TimSinO2(m+n).+ (m+n=2, ...3, 8, 10, 12, 14) clusters can extract a hydrogen from methane. The associated energies and structures have been revealed in detail. Moreover, the doping and size effects have been discussed involving generalized Kohn‐Sham energy decomposition analysis, natural population analysis, Wiberg bond indexes (WBI), molecular polarity index (MPI) and ionization potential (IP). It suggested that Ti−Si−O clusters with a low Ti : Si ratio is beneficial to adsorbing methane and inclination to the hydrogen atom transfer (HAT) process, while the clusters with a high Ti : Si ratio favors the generation of a terminal oxygen radical and results in high reactivity and turnover frequency. On the other hand, a cluster size of m+n=12 is recommended considering both the ionization potential and the turnover frequency of the reaction. Hopefully, these finding will be instructive for the design of high‐performance Ti−Si−O catalyst toward methane conversion.
The influence of the size and doping effects of TimSinO2(m+n)⋅+ (m+n=2, 3, 8, 10, 12, 14) clusters towards methane activation have been explored by using a combination of gas‐phase experiments and quantum chemical calculations.
Renal tubulointerstitial fibrosis was a crucial pathological feature of diabetic nephropathy (DN), and renal tubular injury might associate with abnormal mitophagy. In this study, we investigated the ...effects and molecular mechanisms of AMPK agonist metformin on mitophagy and cellular injury in renal tubular cell under diabetic condition. The high fat diet (HFD) and streptozotocin (STZ)-induced type 2 diabetic mice model and HK-2 cells were used in this study. Metformin was administered in the drinking water (200 mg/kg/d) for 24 weeks. Renal tubulointerstitial lesions, oxidative stress and some indicators of mitophagy (e.g., LC3II, Pink1, and Parkin) were examined both in renal tissue and HK-2 cells. Additionally, compound C (an AMPK inhibitor) and Pink1 siRNA were applied to explore the molecular regulation mechanism of metformin on mitophagy. We found that the expression of p-AMPK, Pink1, Parkin, LC3II, and Atg5 in renal tissue of diabetic mice was decreased obviously. Metformin reduced the levels of serum creatinine, urine protein, and attenuated renal oxidative injury and fibrosis in HFD/STZ induced diabetic mice. In addition, Metformin reversed mitophagy dysfunction and the over-expression of NLRP3. In vitro pretreatment of HK-2 cells with AMPK inhibitor compound C or Pink1 siRNA negated the beneficial effects of metformin. Furthermore, we noted that metformin activated p-AMPK and promoted the translocation of Pink1 from the cytoplasm to mitochondria, then promoted the occurrence of mitophagy in HK-2 cells under HG/HFA ambience. Our results suggested for the first time that AMPK agonist metformin ameliorated renal oxidative stress and tubulointerstitial fibrosis in HFD/STZ-induced diabetic mice via activating mitophagy through a p-AMPK-Pink1-Parkin pathway.
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