Explore the vast range of titles available.

With the growth of global fossil-based resource consumption and the environmental concern, there is an urgent need to develop sustainable and environmentally friendly materials, which exhibit promising properties and could maintain an acceptable level of performance to substitute the petroleum-based ones. As elite nanomaterials, cellulose nanocrystals (CNC) derived from natural renewable resources, exhibit excellent physicochemical properties, biodegradability and biocompatibility and have attracted tremendous interest nowadays. Their combination with other nanomaterials such as graphene-based materials (GNM) has been revealed to be useful and generated new hybrid materials with fascinating physicochemical characteristics and performances. In this context, the review presented herein describes the quickly growing field of a new emerging generation of CNC/GNM hybrids, with a focus on strategies for their preparation and most relevant achievements. These hybrids showed great promise in a wide range of applications such as separation, energy storage, electronic, optic, biomedical, catalysis and food packaging. Some basic concepts and general background on the preparation of CNC and GNM as well as their key features are provided ahead.

Advances in materials science and bionanotechnology have allowed the refinements of current drug delivery systems, expected to facilitate the development of personalized medicine. While dermatological topical pharmaceutical formulations such as foams, creams, lotions, gels, etc., have been proposed for decades, these systems target mainly skin-based diseases. To treat systemic medical conditions as well as localized problems such as joint or muscle concerns, transdermal delivery systems (TDDSs), which use the skin as the main route of drug delivery, are very appealing. Over the years, these systems have shown to offer important advantages over oral as well as intravenous drug delivery routes. Besides being non-invasive and painless, TDDSs are able to deliver drugs with a short-half-life time more easily and are well adapted to eliminate frequent administrations to maintain constant drug delivery. The possibility of self-administration of a predetermined drug dose at defined time intervals makes it also the most convenient personalized point-of-care approach. The transdermal market still remains limited to a narrow range of drugs. While small and lipophilic drugs have been successfully delivered using TDDSs, this approach fails to deliver therapeutic macromolecules due to size-limited transport across the , the outermost layer of the epidermis. The low permeability of the to water-soluble drugs as well as macromolecules poses important challenges to transdermal administration. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to iontophoresis and microneedle-based concepts, thermal-based approaches have shown great promise to enhance transdermal drug delivery of different therapeutics. In this inaugural article for the section \"Frontiers in Bioengineering and Biotechnology,\" the advances in this field and the handful of examples of thermal technologies for local and systemic transdermal drug delivery will be discussed and put into perspective.

The wetting properties of superhydrophobic surfaces have generated worldwide research interest. A water drop on these surfaces forms a nearly perfect spherical pearl. Superhydrophobic materials hold considerable promise for potential applications ranging from self cleaning surfaces, completely water impermeable textiles to low cost energy displacement of liquids in lab-on-chip devices. However, the dynamic modification of the liquid droplets behavior and in particular of their wetting properties on these surfaces is still a challenging issue. In this review, after a brief overview on superhydrophobic states definition, the techniques leading to the modification of wettability behavior on superhydrophobic surfaces under specific conditions: optical, magnetic, mechanical, chemical, thermal are discussed. Finally, a focus on electrowetting is made from historical phenomenon pointed out some decades ago on classical planar hydrophobic surfaces to recent breakthrough obtained on superhydrophobic surfaces.

The slow healing process of diabetic wound due to persisting infections in wound bed, owing to hyperglycemia, makes the search for efficient treatments pending. While it is complicated to increase the wound closure rate in diabetic‐related wounds due to the complex pathology, the treatment of such wound with hydrogels is seen as a promising approach and pursued over the years. However, where is this research currently standing in terms of clinical translation of these different multifunctional and stimuli‐responsive hydrogel bandages to accelerate diabetic foot ulcer healing and help to improve the life of the patients and the future of diabetic wound management? This perspective article will review some of the most important advancements in the field and will conclude with some perspectives, considered as relevant in the clinical context. Delayed diabetic cutaneous healing is one of the side effects of increased blood glucose levels with multifunctional wound bandages being an efficient means for accelerated and better wound management, as discussed herewith.

Bismuth vanadate (BiVO 4 ) nanostructured films were prepared and successfully applied for peroxymonosulfate (PMS) activation for the degradation of rhodamine B (RhB) in aqueous solution. The BiVO 4 thin films were obtained by thermal reaction between electrodeposited bismuth (Bi) films and vanadium precursor. The as-prepared BiVO 4 porous, nanoflowers, and cluster nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and BET analysis. The catalytic performance of BiVO 4 nanostructures has been carefully evaluated in activating PMS for the degradation of RhB. The nanoflower-like BiVO 4 nanostructures exhibit the best catalytic activity. Under optimized conditions, the complete catalytic degradation of RhB using BiVO 4 nanoflowers/PMS system was achieved in 17 min at room temperature as revealed by high-performance liquid chromatography (HPLC) analysis. Quenching experiments suggested that sulfate radicals are the main active species in the degradation process. Additionally, BiVO 4 catalyst remained stable without any apparent activity loss after five cycling runs.

The main objective of this study concerns the sonochemical synthesis of 1,3-dioxolane derivatives using graphene oxide catalyst by applying two methods. In the first method, we described the synthesis of 1,3-dioxolane by ring-opening of epoxides in the presence of ketones catalyzed by graphene oxide (GO) under ultrasonic irradiation. In the second sonochemical procedure, we described the synthesis of 1,3-dioxolane derivatives by the reaction of 1,2-diols with ketones using same GO catalyst. Mild reaction conditions, high yields, short reaction times, reusability of catalyst and easy isolation of the products make the developed methods very useful. Graphic Abstract

Over the last decades, carbon-based nanostructures have generated a huge interest from both fundamental and technological viewpoints owing to their physicochemical characteristics, markedly different from their corresponding bulk states. Among these nanostructured materials, carbon nanotubes (CNTs), and more recently graphene and its derivatives, hold a central position. The large amount of work devoted to these materials is driven not only by their unique mechanical and electrical properties, but also by the advances made in synthetic methods to produce these materials in large quantities with reasonably controllable morphologies. While much less studied than CNTs and graphene, diamond nanowires, the diamond analogue of CNTs, hold promise for several important applications. Diamond nanowires display several advantages such as chemical inertness, high mechanical strength, high thermal and electrical conductivity, together with proven biocompatibility and existence of various strategies to functionalize their surface. The unique physicochemical properties of diamond nanowires have generated wide interest for their use as fillers in nanocomposites, as light detectors and emitters, as substrates for nanoelectronic devices, as tips for scanning probe microscopy as well as for sensing applications. In the past few years, studies on boron-doped diamond nanowires (BDD NWs) focused on increasing their electrochemical active surface area to achieve higher sensitivity and selectivity compared to planar diamond interfaces. The first part of the present review article will cover the promising applications of BDD NWS for label-free sensing. Then, the potential use of diamond nanowires as inorganic substrates for matrix-free laser desorption/ionization mass spectrometry, a powerful label-free approach for quantification and identification of small compounds, will be discussed.

This study investigated, for the first time, the antimicrobial properties of polyethylene glycol-functionalized poly( N -phenylglycine) nanoparticles (PNPG-PEG NPs). PNPG-PEG NPs exhibit high extinction coefficient in the near-infrared (NIR) region; they can convert light energy into heat energy with high thermal transformation efficiency. Additionally, they can generate cytotoxic reactive oxygen species (ROS) upon light irradiation. Also, PNPG-PEG NPs are not cytotoxic. All these properties make them appropriate for combined dual-modal photothermal and photodynamic therapies. The antibacterial activity of PNPG-PEG NPs was assessed using Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) pathogenic strains. The results revealed that NIR light (810 nm) irradiation for 10 min could kill effectively the planktonic bacteria and destroy Escherichia coli and Staphylococcus aureus biofilms. The results demonstrated that PNPG-PEG NPs represent a very effective nanoplatform for killing of pathogenic bacteria. Graphical abstract

Advances in materials science have accelerated the development of diagnostic tools with the last decade witnessing the development of enzyme-free sensors, owing to the improved stability, low cost and simple fabrication of component materials. However, the specificity of non-enzymatic sensors for certain analytes still represents a challenging task, for example the determination of cholesterol level in blood is vital due to its medical relevance. In this work, a reagent displacement assay for cholesterol sensing in serum samples was developed. It is based on coating of a glassy carbon electrode with a polymer of intrinsic microporosity (PIM) that forms a host-guest complex with methylene blue (MB). In the presence of cholesterol, the MB electroactive probe was displaced due to the stronger association of cholesterol guest to the PIM host. The decrease in the oxidative current was proportional to the cholesterol concentration achieving a detection limit of approximately 0.1 nM. Moreover, to further assist the experimental studies, comprehensive theoretical calculations are also performed by using density functional theory (DFT) calculations.

The ongoing highly contagious Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), underlines the fundamental position of diagnostic testing in outbreak control by allowing a distinction of the infected from the non-infected people. Diagnosis of COVID-19 remains largely based on reverse transcription PCR (RT-PCR), identifying the genetic material of the virus. Molecular testing approaches have been largely proposed in addition to infectivity testing of patients via sensing the presence of viral particles of SARS-CoV-2 specific structural proteins, such as the spike glycoproteins (S1, S2) and the nucleocapsid (N) protein. While the S1 protein remains the main target for neutralizing antibody treatment upon infection and the focus of vaccine and therapeutic design, it has also become a major target for the development of point-of care testing (POCT) devices. This review will focus on the possibility of surface plasmon resonance (SPR)-based sensing platforms to convert the receptor-binding event of SARS-CoV-2 viral particles into measurable signals. The state-of-the-art SPR-based SARS-CoV-2 sensing devices will be provided, and highlights about the applicability of plasmonic sensors as POCT for virus particle as well as viral protein sensing will be discussed.