Polymer mechanochemistry is a promising technology to convert mechanical energy into chemical functionality by breaking covalent and supramolecular bonds site-selectively. Yet, the mechanochemical reaction rates of covalent bonds in typically used ultrasonication setups lead to reasonable conversions only after comparably long sonication times. This can be accelerated by either increasing the reactivity of the mechanoresponsive moiety or by modifying the encompassing polymer topology.
View Article and Find Full Text PDFMechanochemistry uses mechanical force to break, form, and manipulate chemical bonds to achieve functional transformations and syntheses. Over the last years, many innovative applications of mechanochemistry have been developed. Specifically for the synthesis and activation of carbon-rich π-conjugated materials, mechanochemistry offers reaction pathways that either are inaccessible with other stimuli, such as light and heat, or improve reaction yields, energy consumption, and substrate scope.
View Article and Find Full Text PDFPhotosystem II (PSII) is a fascinating photosynthesis-involved enzyme, participating in sunlight-harvest, water splitting, oxygen release, and proton/electron generation and transfer. Scientists have been inspired to couple PSII with synthetic hierarchical structures via biomimetic assembly, facilitating attainment of natural photosynthesis processes, such as photocatalytic water splitting, electron transfer and ATP synthesis, . In the past decade, there has been significant progress in PSII-based biomimetic systems, such as artificial chloroplasts and photoelectrochemical cells.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2021
We report robust control over the dynamic assembly, disassembly, and reconfiguration of light-activated molybdenum disulfide (MoS ) colloidal motor swarms with features not possible in equilibrium systems. A photochemical reaction produces chemical gradients across the MoS colloidal motors to drive them to move. Under illumination of a gradient light, these colloidal motors display a positive phototactic motion.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2020
Organization of gold nanoobjects by oligonucleotides has resulted in many three-dimensional colloidal assemblies with diverse size, shape, and complexity; nonetheless, autonomous and temporal control during formation remains challenging. In contrast, living systems temporally and spatially self-regulate formation of functional structures by internally orchestrating assembly and disassembly kinetics of dissipative biomacromolecular networks. We present a novel approach for fabricating four-dimensional gold nanostructures by adding an additional dimension: time.
View Article and Find Full Text PDFSurface engineering of synthetic carriers is an essential and important strategy for drug delivery . However, exogenous properties make synthetic nanosystems invaders that easily trigger the passive immune clearance mechanism, increasing the retention effect caused by the reticuloendothelial systems and bioadhesion, finally leading to low therapeutic efficacy and toxic effects. Recently, a cell membrane cloaking technique has been reported as a novel interfacing approach from the biological/immunological perspective, and has proved useful for improving the performance of synthetic nanocarriers .
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2018
We report a near-infrared (NIR) light-powered Janus mesoporous silica nanomotor (JMSNM) with macrophage cell membrane (MPCM) cloaking that can actively seek cancer cells and thermomechanically percolate cell membrane. Upon exposure to NIR light, a heat gradient across the Janus boundary of the JMSNMs is generated by the photothermal effect of the Au half-shells, resulting in a self-thermophoretic force that propels the JMSNMs. In biological medium, the MPCM camouflaging can not only prevent dissociative biological blocks from adhering to JMSNMs but also improve the seeking sensitivity of the nanomotors by specifically recognizing cancer cells.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2018
We report a carbonaceous nanobottle (CNB) motor for near infrared (NIR) light-driven jet propulsion. The bottle structure of the CNB motor is fabricated by soft-template-based polymerization. Upon illumination with NIR light, the photothermal effect of the CNB motor carbon shell causes a rapid increase in the temperature of the water inside the nanobottle and thus the ejection of the heated fluid from the open neck, which propels the CNB motor.
View Article and Find Full Text PDFTargeted drug delivery is an emerging technological strategy that enables nanoparticle systems to be responsive for tumor therapy. Magnetic mesoporous silica nanoparticles (MMSNs) were cloaked with red blood cell membrane (RBC). This integrates long circulation, photosensitizer delivery, and magnetic targeting for cancer therapy.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2017
Engineering self-propelled micromotors with good biocompatibility and biodegradability for actively seeking disease sites and targeted drug transport remains a huge challenge. In this study, neutrophils with intrinsic chemotaxis capability were transformed into self-guided hybrid micromotors by integrating mesoporous silica nanoparticles (MSNs) with high loading capability. To ensure the compatibility of neutrophil cells with drug-loaded MSNs, bacteria membranes derived from E.
View Article and Find Full Text PDFSelf-propelled micro/nanomotors possess tremendous exciting promise in diverse fields. We describe an asymmetric, fuel-free and near-infrared light-powered torpedo micromotor, which is constructed by using a porous membrane-assisted layer-by-layer sol-gel method to form silica multilayer inside the pores, following by the deposition of gold nanoparticles on one end of the pores. In the absence of chemical fuels, the high propulsion of microtorpedoes under illumination of near-infrared light is owing to the photo-thermal effect of gold clusters, generating a thermal gradient inside the microtorpedoes.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2017
Lipid bilayer membranes supported on polyelectrolyte multilayers are widely used as a new biomembrane model that connects biological and artificial materials since these ultrathin polyelectrolyte supports may mimic the role of the extracellular matrix and cell skeleton in living systems. Polyelectrolyte multilayers were fabricated by a layer-by-layer self-assembly technique. A quartz crystal microbalance with dissipation was used in real time to monitor the interaction between phospholipids and polyelectrolytes in situ on a planar substrate.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2017
In this review, we summarize the recent progress made in the fabrication of pure natural materials such as biogenic capsules. Unlike polyelectrolyte capsules, biogenic capsules are primarily prepared with pure natural components using layer-by-layer (LbL) assembly on sacrificial templates. These capsules have been developed as smart materials for guest molecule encapsulation and delivery in the last two decades.
View Article and Find Full Text PDFBackground: The rapid emergence of nanotechnology and biotechnology has enabled revolutionary developments for drug delivery systems. Recently, drug delivery has attracted extensive research interest; applied to improve the functions of these carriers and their applications.
Objective: Active drug delivery is currently approved as an ideal approach for targeted transport in a biological entity and can cooperate with therapeutic mediums in transporting cargoes.
We describe fuel-free, near-infrared (NIR)-driven Janus mesoporous silica nanoparticle motors (JMSNMs) with diameters of 50, 80, and 120 nm. The Janus structure of the JMSNMs is generated by vacuum sputtering of a 10 nm Au layer on one side of the MSNMs. Upon exposure to an NIR laser, a localized photothermal effect on the Au half-shells results in the formation of thermal gradients across the JMSNMs; thus, the generated self-thermophoresis can actively drive the nanomotors to move at an ultrafast speed, for instance, up to 950 body lengths/s for 50 nm JMSNMs under an NIR laser power of 70.
View Article and Find Full Text PDFMacrophage cell membrane (MPCM)-camouflaged gold nanoshells (AuNS) that can serve as a new generation of photothermal conversion agents for in vivo photothermal cancer therapy are presented. They are constructed by the fusion of biocompatible AuNSs and MPCM vesicles. The resulting MPCM-coated AuNSs exhibited good colloidal stability and kept the original near-infrared (NIR) adsorption of AuNSs.
View Article and Find Full Text PDFSeeking safe and effective water-soluble drug carriers is of great significance in nanomedicine. To achieve this goal, we present a novel drug delivery system based on biointerfacing hollow polymeric microcapsules for effectively encapsulating water-soluble antitumor drug and gold nanorod (GNR) functionalization for triggered release of therapeutic drugs on-demand using low power near-infrared (NIR) radiation. The surface of polymeric microcapsules is covered with fluidic lipid bilayers to decrease the permeability of the wall of polymeric capsules.
View Article and Find Full Text PDFSynthetic micro-/nanomotors (MNMs) are capable of performing self-propelled motion in fluids through harvesting different types of energies into mechanical movement, with potential applications in biomedicine and other fields. To address the challenges in these applications, a promising strategy that combines controlled assembly (bottom-up approaches) with top-down approaches for engineering autonomous, multifunctionalized MNMs is under investigation, beginning in 2012. These MNMs, derived from layer-by-layer assembly or molecular self-assembly, display the advantages of: i) mass production, ii) response to the external stimuli, and iii) access to multifunctionality, biocompatibility, and biodegradability.
View Article and Find Full Text PDFPhotothermal therapy based on gold nanostructures has been widely investigated as a state-of-the-art noninvasive therapy approach. Because single nanoparticles cannot harvest sufficient energy, self-assemblies of small plasmonic particles into large aggregates are required for enhanced photothermal performance. Self-assembled gold nanorods in lipid bilayer-modified microcapsules are shown to localize at tumor sites, generate vapor bubbles under near-infrared light exposure, and subsequently damage tumor tissues.
View Article and Find Full Text PDFWe report a self-propelled Janus silica micromotor as a motion-based analytical method for achieving fast target separation of polyelectrolyte microcapsules, enriching different charged organics with low molecular weights in water. The self-propelled Janus silica micromotor catalytically decomposes a hydrogen peroxide fuel and moves along the direction of the catalyst face at a speed of 126.3 μm s(-1) .
View Article and Find Full Text PDFThe synthesis of an innovative self-propelled Janus nanomotor with a diameter of about 75 nm that can be used as a drug carrier is described. The Janus nanomotor is based on mesoporous silica nanoparticles (MSNs) with chromium/platinum metallic caps and propelled by decomposing hydrogen peroxide to generate oxygen as a driving force with speeds up to 20.2 μm s(-1) (about 267 body lengths per second).
View Article and Find Full Text PDF