Sulfonated Starch-Graft-Polyaniline@Graphene Electrically Conductive Nanocomposite: Application for Tyrosinase Immobilization

The interaction of tyrosinase with sulfonated starch-graft-polyaniline@graphene (SSt-g-PANI@G) nanocomposite was investigated by electrochemical methods. The activity of the immobilized tyrosinase (Tyase) was proved by the electrochemical detection of three substrates (L-dopa, caffeic acid, and catechol). The SSt-g-PANI@G nanocomposite was characterized by Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDX), and thermogravimetric analysis (TGA). To immobilize tyrosinase on the surface of the nanocomposite, a simple drop-casting technique was used. The presence of sulfuric acid and hydroxyl groups in SSt, amine groups in PANI, and high surface-to-volume ratio and electrical conductivity of graphene in the prepared nanocomposite led to good enzyme immobilization on the electrode surface. The modified electrode showed a suitable catalytic effect on the electrochemical redox agent, compared with the bare electrode. The peak current responses for three substrates were studied with a calibration curve derived using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In addition, the fabricated SSt-g-PANI@G/Tyase/GCE showed a more suitable response to catechol, L-dopa, and caffeic acid substrates, respectively

Correction to: Injectable hyaluronic acid-based antibacterial hydrogel adorned with biogenically synthesized AgNPs-decorated multi-walled carbon nanotubes (Progress in Biomaterials, (2021), 10, 1, (77-89), 10.1007/s40204-021-00155-6)

The authors found that the TEM image of AgNPs (Fig. 4a) is sent wrongly by the institute that took the TEM image. Even though the TEM images of pure AgNPs (in comparison with Ag-adorned CNTs) were not determinative and it does not affect the other results in this study, as responsibility of the authors to report precise and correct data, a new image (by TEM, Zeiss-EM10C-80 KV, Germany) was taken and now replaced in Fig. 4a. It is worth mentioning that other data and images in Fig. 4 are not altered. The authors do apologize for this inconvenience

Injectable hyaluronic acid-based antibacterial hydrogel adorned with biogenically synthesized AgNPs-decorated multi-walled carbon nanotubes

Injectable materials have shown great potential in tissue engineering applications. However, bacterial infection is one of the main challenges in using these materials in the field of regenerative medicine. In this study, biogenically synthesized silver nanoparticle-decorated multi-walled carbon nanotubes (Ag/MWCNTs) were deployed for adorning biogenic-derived AgNPs which were subsequently used in the preparation of thermosensitive hydrogels based on hyaluronic acid encompassing these green-synthesized NPs. The antibacterial capacity of AgNPs decorated on MWCNTs synthesized through Camellia sinensis extract in an organic solvent-free medium displayed a superior activity by inhibiting the growth of Gram-negative (E. coli and Klebsiella) and Gram-positive (S. aureus and E. faecalis). The injectable hydrogel nanocomposites demonstrated good mechanical properties, as well. The thermosensitive hyaluronic acid-based hydrogels also exhibited Tgel below the body temperature, indicating the transition from liquid-like behavior to elastic gel-like behavior. Such a promising injectable nanocomposite could be applied as liquid, pomade, or ointment to enter wound cavities or bone defects and subsequently its transition in situ to gel form at human body temperature bodes well for their immense potential application in the biomedical sector

Transition metal dichalcogenides (TMDC)-based nanozymes for biosensing and therapeutic applications

Nanozymes, a type of nanomaterial with enzyme-like properties, are a promising alternative to natural enzymes. In particular, transition metal dichalcogenides (TMDCs, with the general formula MX2, where M represents a transition metal and X is a chalcogen element)-based nanozymes have demonstrated exceptional potential in the healthcare and diagnostic sectors. TMDCs have different enzymatic properties due to their unique nano-architecture, high surface area, and semiconducting properties with tunable band gaps. Furthermore, the compatibility of TMDCs with various chemical or physical modification strategies provide a simple and scalable way to engineer and control their enzymatic activity. Here, we discuss recent advances made with TMDC-based nanozymes for biosensing and therapeutic applications. We also discuss their synthesis strategies, various enzymatic properties, current challenges, and the outlook for future developments in this field

Drug delivery (nano)platforms for oral and dental applications: Tissue regeneration, infection control and cancer management

The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally-administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically-administered medications, drug resistance and adverse side-effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle-containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug-release platforms than conventional treatment approaches. The present review provides an overview of newly-developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine

Ionic liquid-based antimicrobial materials for water treatment, air filtration, food packaging and anticorrosion coatings

International audienceEfforts to widen the scope of ionic liquids applications across diverse research areas have flourished in the last two decades with developments in understanding and tailoring their physical, chemical, and biological properties. The promising applications of ionic liquids-based materials as antimicrobial systems is due to their ability and flexibility to be tailored in varying sizes, morphologies, and surface charges. Ionic liquids are also considered as greener materials. Common methods for the preparation of ionic liquid-based materials include crosslinking, loading, grafting, and combination of ionic liquids with other polymeric materials. Recent research focuses on the tuning of the biological properties to design novel ionic liquids-based antimicrobial materials. Here, the properties, synthesis and applications of ionic liquids and ionic liquids-based materials are reviewed with focus on antimicrobial activities applied to water treatment, air filtration, food packaging, and anticorrosion

Toxicity and remediation of pharmaceuticals and pesticides using metal oxides and carbon nanomaterials

International audienceThe worldwide development of agriculture and industry has resulted in contamination of water bodies by pharmaceuticals, pesticides and other xenobiotics. Even at trace levels of few micrograms per liter in waters, these contaminants induce public health and environmental issues, thus calling for efficient removal methods such as adsorption. Recent adsorption techniques for wastewater treatment involve metal oxide compounds, e.g. Fe2O3, ZnO, Al2O3 and ZnOeMgO, and carbon-based materials such as graphene oxide, activated carbon, carbon nanotubes, and carbon/graphene quantum dots. Here, the small size of metal oxides and the presence various functional groups has allowed higher adsorption efficiencies. Moreover, carbon-based adsorbents exhibit unique properties such as high surface area, high porosity, easy functionalization, low price, and high surface reactivity. Here we review the cytotoxic effects of pharmaceutical drugs and pesticides in terms of human risk and ecotoxicology. We also present remediation techniques involving adsorption on metal oxides and carbon-based materials

Biofabricated Nanostructures and Their Composites in Regenerative Medicine

Biosynthesis of nanomaterials is gaining attention as a sustainable, environmentally friendly, and reliable method for manufacturing a extensive array of nanostructures, such as metal/metal oxides and organic and hybrid materials. Green synthesis is considered a crucial tool to reduce the harsh effects associated with conventional synthesis. Nanocomposite materials containing biosynthesized nanostructures are highly sought after in regenerative medicine. In the present Review, biosynthesis of metal/metal oxides and carbon-based nanomaterials using microorganisms (e.g., bacteria and fungi) and natural compounds (e.g., polysaccharides, proteins, fruit juices, and plant extracts) is highlighted. The toxicity of biosynthesized nanoparticles for biomedical application is also reviewed in depth. The applications of bionanocomposites prepared from these ecofriendly nanoparticles in tissue engineering are reviewed to provide readers with a background for future studies.<br/

Non-spherical nanostructures in nanomedicine: from noble metal nanorods to transition metal dichalcogenide nanosheets

Non-spherical metal nanomaterials such as noble metal or transition metal dichalcogenides and MXenes have been employed in different biomedical facets. Because the biological properties of these nanocompounds are governed by their architecture and composition, such factors should be considered prior to their adoption for clinical use. The architecture of metal-based nanomaterials affects cell viability by virtue of the variable geometry of these nanomaterials as well as their physicochemical interactions with mammalian cell membranes. In the present review, the effects of parameters such as interfacial interaction and aspect ratio on cellular uptake of non-spherical metallic nanomaterials will be discussed. The application of these nanomaterials as biosensors, in cancer diagnosis and therapy, tissue engineering and regenerative medicine will also be thoroughly reviewed

Drug delivery (nano)platforms for oral and dental applications: tissue regeneration, infection control, and cancer management

The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally-administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically-administered medications, drug resistance and adverse side-effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle-containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug-release platforms than conventional treatment approaches. The present review provides an overview of newly-developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine