Light-triggered C60 release from a graphene/cyclodextrin nanoplatform for the protection of cytotoxicity induced by nitric oxide

Recent biomedical advancements in graphene oxide- and reduced graphene oxide-based nanocomposite nanocarriers

Recently, nanocarriers, including micelles, polymers, carbon-based materials, liposomes, and other substances, have been developed for efficient delivery of drugs, nucleotides, and biomolecules. This review focuses on graphene oxide (GO) and reduced graphene oxide (rGO) as active components in nanocarriers, because their chemical structures and easy functionalization can be valuable assets for in vitro and in vivo delivery. Herein, we describe the preparation, structure, and functionalization of GO and rGO. Additionally, their important properties to function as nanocarriers are presented, including their molecular interactions with various compounds, near-infrared light adsorption, and biocompatibility. Subsequently, their mechanisms and the most appealing examples of their delivery applications are summarized. Overall, GO- and rGO-based nanocomposites show great promise as multipurpose nanocarriers owing to their various potential applications in drug and gene delivery, phototherapy, bioimaging, biosensing, tissue engineering, and as antibacterial agents.

Cyclodextrin-Modified Nanomaterials for Drug Delivery: Classification and Advances in Controlled Release and Bioavailability

In drug delivery, one widely used way of overcoming the biopharmaceutical problems present in several active pharmaceutical ingredients, such as poor aqueous solubility, early instability, and low bioavailability, is the formation of inclusion compounds with cyclodextrins (CD). In recent years, the use of CD derivatives in combination with nanomaterials has shown to be a promising strategy for formulating new, optimized systems. The goals of this review are to give in-depth knowledge and critical appraisal of the main CD-modified or CD-based nanomaterials for drug delivery, such as lipid-based nanocarriers, natural and synthetic polymeric nanocarriers, nanosponges, graphene derivatives, mesoporous silica nanoparticles, plasmonic and magnetic nanoparticles, quantum dots and other miscellaneous systems such as nanovalves, metal-organic frameworks, Janus nanoparticles, and nanofibers. Special attention is given to nanosystems that achieve controlled drug release and increase their bioavailability during in vivo studies.

Research Progress on Synthesis and Application of Cyclodextrin Polymers

Cyclodextrins (CDs) are a series of cyclic oligosaccharides formed by amylose under the action of CD glucosyltransferase that is produced by Bacillus. After being modified by polymerization, substitution and grafting, high molecular weight cyclodextrin polymers (pCDs) containing multiple CD units can be obtained. pCDs retain the internal hydrophobic-external hydrophilic cavity structure characteristic of CDs, while also possessing the stability of polymer. They are a class of functional polymer materials with strong development potential and have been applied in many fields. This review introduces the research progress of pCDs, including the synthesis of pCDs and their applications in analytical separation science, materials science, and biomedicine.

A turn-on and lysosome-targeted fluorescent NO releaser in water media and its application in living cells and zebrafishes

Due to the high activity and difficult to transport of nitric oxide, the controlled release of nitric oxide has been a new trend in the research on the biological effect of nitric oxide. In this paper, a water-soluble and turn-on fluorescent NO donor Rh-NO was synthesized. Upon 525 nm irradiation, the fluorescence of the Rh-NO at 568 nm enhanced with the quantum yield (Φ_F) of Rh-NO changing from 5.08% to 35.96%. The mechanism of NO releasing was proved by HRMS and the Dan. The releasing time of 6 min and the releasing yield of 0.61 proved the superiority of Rh-NO. Excellent cell activity above 80% of Rh-NO and Rh guaranteed that nitric oxide was released from Rh-NO in lysosome and zebrafishes successfully, which provided a good platform to understand the biological effects of nitric oxide in lysosomes.

Resveratrol: a review of plant sources, synthesis, stability, modification and food application

Resveratrol, a stilbene molecule belonging to the polyphenol family, is usually extracted from a great many natural plants. The technologies of preparation and extraction methods are developing rapidly. As resveratrol has many beneficial properties, it has been widely utilized in food and medicine industry. In terms of its structure, it is susceptible to degradation and can undergo chemical changes during food processing. Different studies have therefore given more attention to various aspects of resveratrol, including anti-aging, anti-oxidant, and anti-cancer activity. This review classifies the study of resveratrol, considers plant sources, synthesis, stability, common reactions, and food applications, and provides references to boost its food and medical utilization. © 2019 Society of Chemical Industry.

Cyclodextrin-Based Multistimuli-Responsive Supramolecular Assemblies and Their Biological Functions

Cyclodextrins (CDs), which are a class of cyclic oligosaccharides extracted from the enzymatic degradation of starch, are often utilized in molecular recognition and assembly constructs, primarily via host-guest interactions in water. In this review, recent progress in CD-based supramolecular nanoassemblies that are sensitive to chemical, biological, and physical stimuli is updated and reviewed, and intriguing examples of the biological functions of these nanoassemblies are presented, including pH- and redox-responsive drug and gene delivery, enzyme-activated specific cargo release, photoswitchable morphological interconversion, microtubular aggregation, and cell-cell communication, as well as a geomagnetism-controlled nanosystem for the suppression of tumor invasion and metastasis. Moreover, future perspectives and challenges in the fabrication of intelligent CD-based biofunctional materials are also discussed at the end of this review, which is expected to promote the translational development of these nanomaterials in the biomedical field.

Two-dimensional C60 nano-meshes via crystal transformation

Developing a rational and general approach towards complex two-dimensional (2D) nanostructures represents potential promising applications in a wide variety of fields, such as electronics, catalysis, and energy conversion. However, the synthesis of 2D nanoscale superstructures remains a great challenge because of the great difficulty in arranging the growth units in a rational manner. Here, we develop a simple yet effective solution-phase strategy to achieve hexagonal mesh networks made of aligned nanorods which are obtained via crystal transformation of 2D C60 microplates. The transformation is triggered by the removal and inclusion of solvent molecules and hence, driven by a small free energy difference. The change in the local solvent environment leads to the formation of pores in the C60 plates and the subsequent growth of nanorods. The epitaxial growth of ordered nanorod arrays is due to the matching lattice between the (111) facet of the fcc plate and the (101[combining macron]0) facet of the hcp rod. This route of co-solvent induced crystal transformation provides a unique mechanistic perspective and a new direction for designing complex crystals. Furthermore, more complicated 2D C60 mesh networks, such as multi-layer hexagonal meshes, have also been rationally achieved via such a facile crystal transformation strategy.

Host-guest supramolecular assembly directing beta-cyclodextrin based nanocrystals towards their robust performances

Fluorescent CdTe nanocrystals (NCs) capped with beta-cyclodextrin (β-CD) are successfully synthesized by host-guest supramolecular assembly of the hydrophobic alkyl chains of N-acetyl-l-cysteine (NAC) on the surface of CdTe NCs and eco-friendly β-CD via the promising simple hydrothermal method in our experiments. The as-prepared NCs display better stability and lower toxicity compared with traditional those only capped with NAC. Specially, cytotoxicity experiments to human umbilical vein endothelial cells in vitro and zebrafish embryo toxicological tests in vivo are performed to determine the toxicity of CdTe NCs. For their practical applications, the promising red-luminescent NCs are employed as stable and low poison red phosphors to fabricate white light-emitting diodes (WLEDs) with remarkable color-rendering index (CRI) being 91.6. This research offers significance for solving the difficulty in toxicity and instability of heavy metal based NCs, which has potential applications in future optoelectronic devices and biomarkers.

Practical PBT/PC/GNP composites with anisotropic thermal conductivity

The selective distribution of thermally conductive fillers in a co-continuous polymer blends provides an industrialized preparation method that takes into account both the properties and functions of thermally conductive composites.

Azobenzene-based solar thermal fuels: design, properties, and applications

Development of renewable energy technologies has been a significant area of research amongst scientists with the aim of attaining a sustainable world society. Solar thermal fuels that can capture, convert, store, and release solar energy in the form of heat through reversible photoisomerization of molecular photoswitches such as azobenzene derivatives are currently in the limelight of research. Herein, we provide a state-of-the-art account on the recent advancements in solar thermal fuels based on azobenzene photoswitches. We begin with an overview on the importance of azobenzene-based solar thermal fuels and their fundamentals. Then, we highlight the recent advances in diverse azobenzene materials for solar thermal fuels such as pure azobenzene derivatives, nanocarbon-templated azobenzene, and polymer-templated azobenzene. The basic design concepts of these advanced solar energy storage materials are discussed, and their promising applications are highlighted. We then introduce the recent endeavors in the molecular design of azobenzene derivatives toward efficient solar thermal fuels, and conclude with new perspectives on the future scope, opportunities and challenges. It is expected that continuous pioneering research involving scientists and engineers from diverse technological backgrounds could trigger the rapid advancement of this important interdisciplinary field, which embraces chemistry, physics, engineering, nanoscience, nanotechnology, materials science, polymer science, etc.

Light triggered interfacial damage self-healing of poly(p-phenylene benzobisoxazole) fiber composites

The interfacial microcracks in the resin matrix composites are difficult to be detected and repaired. However, the self-healing concept provides opportunities to fabricate composites with unusual properties. In the present study, photothermal conversion Ag-Cu₂S nanoparticles were immobilized onto poly(p-phenylene benzobisoxazole) (PBO) fibers via a polydopamine chemistry. Benefitting from the photothermal effects of Ag-Cu₂S, the obtained PBO fibers (Ag-Cu₂S-PBO) efficiently converted the light energy into heat under Xenon lamp irradiation. Then, single PBO fiber composites were prepared using thermoplastic polyurethane as the matrix. It was found that the interfacial damage caused by single fiber pull-out was simply self-healed by Xe light irradiation. This wonderful interfacial damage self-healing property was mainly attributed to the in situ heating generation via photothermal effects of Ag-Cu₂S in the composite interface. This paper reports a novel strategy to construct advanced composites with light-triggered self-healing properties, which will provide inspiration for preparing high performance composite materials.

Synthesis and evaluation of water soluble pH sensitive poly (vinyl alcohol)-doxorubicin conjugates

The accuracy of spatiotemporal control cargo delivery and release are primordial to enhance the therapeutic efficiency and decrease the undesirable effects, in this context a novel prodrug were developed based on biocompatible polyvinyl alcohol (PVA) substrate. PVA was conjugated to doxorubicin (PVA-DOX) via an acid-labile hydrazone linkage. PVA was first functionalized with acidic groups, then reacted with hydrazine hydrate to form an amide bond. The amine group of PVA hydrazide was linked to carbonyl group (C = O) of DOX to form a pH sensitive hydrazone bond. The molecular structure of the PVA-DOX was confirmed by FTIR, XPS, and ¹H-NMR analysis methods. The degree of grafting were evaluated by TGA and confirmed by XPS, which reveals the successful bond attachment of DOX to PVA. Our findings confirm pH dependent DOX release from PVA-DOX prodrug with faster release rate in acidic environment (pH 5.0, pH 6.0) and slower release rate in neutral pH environment (pH 7.4). Compared to the primary DOX, our synthesized PVA-DOX conjugates could exhibit a promising therapeutic effect, high biocompatibility and zero premature release. The results prove the successful synthesis of PVA-DOX conjugates with high efficiency.