Linyi Bai

Supramolecular nanoparticle carriers self-assembled from cyclodextrin- and adamantane-functionalized polyacrylates for tumor-targeted drug delivery

The advancement of nanobiotechnology has led to the development of various techniques for addressing target-specific drug delivery issues. In this article, we successfully developed a supramolecular self-assembly approach for the fabrication of polyacrylate-based nanoparticles with simultaneous loading of the anticancer drug doxorubicin (DOX) for targeted delivery towards cancer treatment in vitro and in vivo. Two types of polyacrylates functionalized with adamantane and β-cyclodextrin respectively could self-assemble to form supramolecular nanoparticles through strong host-guest complexation between adamantane and β-cyclodextrin. Folic acid was incorporated within the supramolecular nanoparticles in order to impart the targeting specificity towards selected cancerous cell lines, namely MDA-MB231 and B16-F10. The as-synthesized supramolecular nanoparticles were fully characterized by several techniques, revealing an average nanoparticle size of 35 nm in diameter, which is small enough for excellent blood circulation. The cytotoxicity studies indicate that the supramolecular nanoparticles without drug loading were non-cytotoxic under the concentrations measured, while DOX-loaded supramolecular nanoparticles showed significant cytotoxicity. In order to investigate the targeting specificity of DOX-loaded supramolecular nanoparticles towards the cancerous cells, a healthy cell line model HEK293 was employed for carrying out the comparison studies. Due to the presence of the targeting ligand, experimental results demonstrate that the supramolecular nanoparticles were highly specific for targeting the cancerous cells, but not for HEK293 cells. After the in vitro investigations, the in vivo drug delivery study using DOX-loaded supramolecular nanoparticles was performed. Tumor-bearing nude mice were treated with DOX-loaded supramolecular nanoparticles, and the analysis results indicate that DOX-loaded supramolecular nanoparticles have the capability to enhance the therapeutic effects of DOX for effectively inhibiting the tumor growth. Thus, the self-assembled polymeric nanoparticles exhibit a highly promising potential to serve as drug carriers for targeted drug delivery towards improved cancer treatment.

Hierarchical Porous LiNi1/3Co1/3Mn1/3O2 Nano-/Micro Spherical Cathode Material: Minimized Cation Mixing and Improved Li(+) Mobility for Enhanced Electrochemical Performance.

Although being considered as one of the most promising cathode materials for Lithium-ion batteries (LIBs), LiNi1/3Co1/3Mn1/3O2 (NCM) is currently limited by its poor rate performance and cycle stability resulting from the thermodynamically favorable Li+/Ni2+ cation mixing which depresses the Li+ mobility. In this study, we developed a two-step method using fluffy MnO2 as template to prepare hierarchical porous nano-/microsphere NCM (PNM-NCM). Specifically, PNM-NCM microspheres achieves a high reversible specific capacity of 207.7 mAh g−1 at 0.1 C with excellent rate capability (163.6 and 148.9 mAh g−1 at 1 C and 2 C), and the reversible capacity retention can be well-maintained as high as 90.3% after 50 cycles. This excellent electrochemical performance is attributed to unique hierarchical porous nano-/microsphere structure which can increase the contact area with electrolyte, shorten Li+ diffusion path and thus improve the Li+ mobility. Moreover, as revealed by XRD Rietveld refinement analysis, a negligible cation mixing (1.9%) and high crystallinity with a well-formed layered structure also contribute to the enhanced C-rates performance and cycle stability. On the basis of our study, an effective strategy can be established to reveal the fundamental relationship between the structure/chemistry of these materials and their properties.

Halogen-Assisted Piezochromic Supramolecular Assemblies for Versatile Haptic Memory

Sensory memory is capable of recording information and giving feedback based on external stimuli. Haptic memory in particular can retain the sensation of the interaction between the human body and the environment and help humans to describe the physical quantities in their environment and manipulate objects in daily activities. Although sensitive and accurate tactile sensors have been produced on optical and electronic devices, their rigorous operation and equipment requirements seriously limit their further applicability. In addition, their poor retainability after the removal of external stimuli also warrants further improvements. Thus, haptic memory materials, having simple structures and high sensitivity, are highly desired. Herein, we successfully developed two piezochromic assemblies assisted by halogen bonding for haptic memory. The halogen bond not only contributes to the fabrication of the network and enhances integrative stability but also broadens the natural piezofluorescent range, thus promoting sensory sensitivity. Moreover, the colorimetric change of the assemblies could be well-retained after the stimulus was removed. Upon mild heating treatment, the piezochromic response could be recovered to its original state, confirming the recyclability of this haptic memory material for use in practical applications. The present work enriches the library of piezochromic materials with enhanced performance for haptic memory.

Superstructure Formation and Topological Evolution Achieved by Self-Organization of a Highly Adaptive Dynamer

The adaptive property of supramolecular building blocks facilitates noncovalent synthesis of soft materials. While it is still a challenging task, fine-tuning and precise control over topological nanostructures constructed from the self-assembly of low-molecular-weight building blocks are an important research direction to investigate the structure-property relationship. Herein, we report controlled self-assembly evolution of a low-molecular-weight building block bearing cholesterol and naphthalene-dicarboximide moieties, showing ultrasensitivity to solvent polarity. In low-polarity solvents (<4), it could form an M-type fiber-constituted organogel (supergel) with high solvent content, columnar molecular packing, and self-healing property. Highly polar solvents (>7.8) favor the formation of P-type helical nanostructures terminated by nanotoroids, having lamellar molecular packing. With a further increase in solvent polarity (up to 9.6), unilamellar and multilamellar vesicles were generated, which could undergo an aggregation-induced fusion process to form branched nanotubes tuned by the concentration. Self-attractive interactions between aggregates were found to be responsible for the formation of superstructures including helix-nanotoroid junctions as well as membrane-fused nanotubes.

Two fully conjugated covalent organic frameworks as anode materials for lithium ion batteries

Energy storage has attracted more and more attention for its close connection with our daily life. Since there are some unceasing issues about the eco-friendliness and sustainability of energy storage, eco-friendly storage materials are always what we highly desire. While covalent organic frameworks (COFs) promise numerous benefits in gas adsorption, catalysis and optoelectronic devices, synergistic combination of effective storage and eco-friendliness using COFs as storage materials has not been well studied. Herein, we present two fully conjugated porous COFs with high capability of selective gas adsorption and large capacity for Li ion storage. In the aspect of gas selective adsorption, their selectivity ratio for H2 and CO2 to N2 reached ∼15 : 1 and 7 : 1, respectively. In Li ion storage, the COFs exhibited a high capacity (∼700 mA h g−1) and a stable long life (500 cycles). Such good performance confirmed the high potential of COFs to be employed for eco-friendly energy storage. Importantly, using conjugated COFs not only avoids complex synthesis of classical conjugated polymers and multilayered or doped hybrids, but also translates their superb properties including structural diversity, flexibility, and high electrochemical activity into energy storage-related applications. The present work opens up a promising route for further utilization of COFs in energy-related fields such as electrode materials, supercapacitors, and Li–gas batteries.

Macroscopic Architecture of Charge Transfer-Induced Molecular Recognition from Electron-Rich Polymer Interpenetrated Porous Frameworks

Fluorescent and electron-rich polymer threaded into porous framework provides a scaffold for sensing acceptor molecules through noncovalent interactions. Herein, poly(9-vinylcarbazole) (PVK) threaded MIL-101 with confined nanospace was synthesized by vinyl-monomer impregnation, in situ polymerization, and interpenetration. The pore size of the resulted hybrid could be controlled by varying the time of polymerization and interpenetration. The interaction of PVK-threaded MIL-101 with guest molecules showed a charge-transfer progress with an obvious red shift in the optical spectra. Depending on the degree of the interaction, the solution color changed from blue to green or to yellow. In particular, electron-rich PVK-threaded MIL-101 could effectively probe electron-poor nitro compounds, especially 1,3,5-trinitrobenzene (TNP), a highly explosive material. This sensing approach is a colorimetric methodology, which is very simple and convenient for practical analysis and operation.

Fabrication of novel hybrid nanoflowers from boron nitride nanosheets and metal–organic frameworks: a solid acid catalyst with enhanced catalytic performance

A double solvent replacement method was employed for the synthesis of novel hybrid nanoflowers from boron nitride nanosheets (BNNSs) and the metal–organic framework (MOF) MIL-53 in aqueous solutions under hydrothermal treatments. The strong binding ability of aluminum ions onto the surface of BNNSs determines the 3D flowerlike architectures of the BNNSs/MOFs hybrid, and the BNNSs act as a structure-directing template. The BNNSs/MOFs showed an enhanced catalytic activity in the acetalization of benzaldehyde with methanol owing to the facilitated diffusion process in the hierarchical architectures.

“Turn-on” fluorescence probe integrated polymer nanoparticles for sensing biological thiol molecules

A “turn-on” thiol-responsive fluorescence probe was synthesized and integrated into polymeric nanoparticles for sensing intracellular thiols. There is a photo-induced electron transfer process in the off state of the probe, and this process is terminated upon the reaction with thiol compounds. Configuration interaction singles (CIS) calculation was performed to confirm the mechanism of this process. A series of sensing studies were carried out, showing that the probe-integrated nanoparticles were highly selective towards biological thiol compounds over non-thiolated amino acids. Kinetic studies were also performed to investigate the relative reaction rate between the probe and the thiolated amino acids. Subsequently, the Gibbs free energy of the reactions was explored by means of the electrochemical method. Finally, the detection system was employed for sensing intracellular thiols in cancer cells, and the sensing selectivity could be further enhanced with the use of a cancer cell-targeting ligand in the nanoparticles. This development paves a path for the sensing and detection of biological thiols, serving as a potential diagnostic tool in the future.

Refined Sulfur Nanoparticles Immobilized in Metal–Organic Polyhedron as Stable Cathodes for Li–S Battery

The lithium-sulfur (Li-S) battery presents a promising rechargeable energy storage technology for the increasing energy demand in a worldwide range. However, current main challenges in Li-S battery are structural degradation and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling, resulting in the corrosion and loss of active materials. Herein, we developed novel hybrids by employing metal-organic polyhedron (MOP) encapsulated PVP-functionalized sulfur nanoparticles (S@MOP), where the active sulfur component was efficiently encapsulated within the core of MOP and PVP as a surfactant was helpful to stabilize the sulfur nanoparticles and control the size and shape of corresponding hybrids during their syntheses. The amount of sulfur embedded into MOP could be controlled according to requirements. By using the S@MOP hybrids as cathodes, an obvious enhancement in the performance of Li-S battery was achieved, including high specific capacity with good cycling stability. The MOP encapsulation could enhance the utilization efficiency of sulfur. Importantly, the structure of the S@MOP hybrids was very stable, and they could last for almost 1000 cycles as cathodes in Li-S battery. Such high performance has rarely been obtained using metal-organic framework systems. The present approach opens up a promising route for further applications of MOP as host materials in electrochemical and energy storage fields.

Morphology Tuning of Self-Assembled Perylene Monoimide from Nanoparticles to Colloidosomes with Enhanced Excimeric NIR Emission for Bioimaging

Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.