Laser-Activatable CuS Nanodots to Treat Multidrug-Resistant Bacteria and Release Copper Ion to Accelerate Healing of Infected Chronic Nonhealing Wounds

Chronic nonhealing wounds have imposed serious challenges in the clinical practice, especially for the patients infected with multidrug-resistant microbes. Herein, we developed an ultrasmall copper sulfide (covellite) nanodots (CuS NDs) based dual functional nanosystem to cure multidrug-resistant bacteria-infected chronic nonhealing wound. The nanosystem could eradicate multidrug-resistant bacteria and expedite wound healing simultaneously owing to the photothermal effect and remote control of copper-ion release. The antibacterial results indicated that the combination treatment of photothermal CuS NDs with photothermal effect initiated a strong antibacterial effect for drug-resistant pathogens including methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase Escherichia coli both in vitro and in vivo. Meanwhile, the released Cu2+ could promote fibroblast cell migration and endothelial cell angiogenesis, thus accelerating wound-healing effects. In MRSA-infected diabetic mice model, the nanosystem exhibited synergistic wound healing effect of infectious wounds in vivo and demonstrated negligible toxicity and nonspecific damage to major organs. The combination of ultrasmall CuS NDs with photothermal therapy displayed enhanced therapeutic efficacy for chronic nonhealing wound in multidrug-resistant bacterial infections, which may represent a promising class of antibacterial strategy for clinical translation.Peer reviewe

Self-assembled monolayers of copper sulfide nanoparticles on glass as antibacterial coatings

We developed an easy and reproducible synthetic method to graft a monolayer of copper sulfide nanoparticles (CuS NP) on glass and exploited their particular antibacterial features. Samples were fully characterized showing a good stability, a neat photo-thermal effect when irradiated in the Near InfraRed (NIR) region (in the so called \u201cbiological window\u201d), and the ability to release controlled quantities of copper in water. The desired antibacterial activity is thus based on two different mechanisms: (i) slow and sustained copper release from CuS NP-glass samples, (ii) local temperature increase caused by a photo-thermal effect under NIR laser irradiation of CuS NP\u2013glass samples. This behavior allows promising in vivo applications to be foreseen, ensuring a \u201cstatic\u201d antibacterial protection tailored to fight bacterial adhesion in the critical timescale of possible infection and biofilm formation. This can be reinforced, when needed, by a photo-thermal action switchable on demand by an NIR light

Antimicrobial properties of the Ag, Cu Nanoparticle System

ABSTRACT: Microbes, including bacteria and fungi, easily form stable biofilms on many surfaces. Such biofilms have high resistance to antibiotics, and cause nosocomial and postoperative infections. The antimicrobial and antiviral behaviors of Ag and Cu nanoparticles (NPs) are well known, and possible mechanisms for their actions, such as released ions, reactive oxygen species (ROS), contact killing, the immunostimulatory effect, and others have been proposed. Ag and Cu NPs, and their derivative NPs, have different antimicrobial capacities and cytotoxicities. Factors, such as size, shape and surface treatment, influence their antimicrobial activities. The biomedical application of antimicrobial Ag and Cu NPs involves coating onto substrates, including textiles, polymers, ceramics, and metals. Because Ag and Cu are immiscible, synthetic AgCu nanoalloys have different microstructures, which impact tHeir antimicrobial effects. When mixed, the Combination of Ag and Cu NPs act synergistically, offering substantially enhanced antimicrobial behavior. However, when alloyed in Ag–Cu NPs, the antimicrobial behavior is even more enhanced. The reason for this enhancement is unclear. Here, we discuss these results and the possible behavior mechanisms that underlie them

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health

Multifunctional Nanomaterials

This book is a collection of review articles and research articles, which was published in the Special Issue “Multifunctional Nanomaterials: Synthesis, Properties and Applications” of the International Journal of Molecular Sciences

Functional Nanomaterials in Biomedicine

The great success of nanotechnology promotes a tremendous revolution in the biomedical field. Functional nanomaterials have been widely applied for the treatment of various diseases, such as cancer, bacterial infection, diabetes, inflammation, and neurodegenerative disorders. Various therapeutic nanoplatforms have been developed with therapeutic functions and intelligent properties. However, the development of nanomedicine suffers from several challenges prior to their clinical applications. For instance, disease detection in an early stage is a critical challenge for nanomedicine. It is difficult to detect disease markers (e.g., proteins, genes, or cancer circulating cells), so nanoprobes with high sensitivity and selectivity are required. Moreover, to overcome drug resistance, it is highly desirable to develop functional nanomedicines with the combination of multiple therapeutic modalities, such as chemotherapy, photothermal therapy, photodynamic therapy, chemodynamic therapy, radiotherapy, starving therapy, and immunotherapy. Additionally, the stability and degradability of most nanomedicines in biofluids should be carefully evaluated before their administration to humans. This book provides researchers with the latest investigations and findings in this field

ENVIRONMENTAL AND BIOLOGICAL APPLICATIONS AND IMPLICATIONS OF SOFT AND CONDENSED NANOMATERIALS

Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge. Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five). This dissertation is presented as follows. Chapter one presents a general review of the characteristic properties, applications, forces dictating nanomaterials, and their biological and environmental implications of the most produced and studied soft and condensed nanomaterials. In addition, dendritic polymers and ZnO nanomaterials are thoroughly reviewed separately. Chapter two investigates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- dendrimer for its potential applications in water purification. The binding mechanisms and capacities of this dendrimer in hosting major environmental pollutants including cationic copper, anionic nitrate, and polyaromatic phenanthrene are discussed. Chapter three exploits a promising use of dendrimers for removal of potentially harmful discharged nanoparticles (NPs). Specifically, fullerenols are used as a model nanomaterial, and their interactions with two different generations of dendrimers are studied using spectrophotometry and thermodynamics methods. Chapter four elucidates two novel optical schemes for sensing environmental pollutants and biological compounds using dendrimer-gold nanowire complex and gold-coated ZnO tetrapods, respectively. The surface plasmon resonance of gold nanowires and NPs are utilized for enhancing the detection limits of Cu(II) down to nanomolar level and protein/lipids down to picomolar level. Chapter five justifies the growing concern of the environmental implications of nanomaterials in light of the increasing environmental and biological applications of nanomaterials based on the previous chapters, using ZnO NPs and single-celled green algae, Chlorella sp. as a model system. Chapter six summarized the key findings in this dissertation and presents future work stimulated by this Doctor of Philosophy (PhD) research. In summary, the key scientific contributions of this dissertation are: 1). we have performed the first study on the versatility of a trifunctional dendrimer for hosting cationic, anionic, and polyaromatic chemical contaminants; 2). we have demonstrated for the first time the concept that a soft, biocompatible nanoparticle--a dendrimer, can be used for hosting discharged, harmful nanoparticles for environmental remediation; and 3). we have shown for the first time the impact of nanoparticles on aquatic organisms is bidirectional

Sustainable stnthesis and properties of CuS and application of its composites for degradation of organic compounds

Copper sulfide (CuS) is a p-type semiconductor, characteristic of high theoretical specific charge capacity, high concentration of charge carriers and excellent ability to absorb light. These properties lead to CuS application in the fields of photocatalysis, energy storage, or green hydrogen production. The ability of CuS to generate free charge carriers by absorbing the irradiation of visible light is harvested by applying CuS for the advanced oxidation process and the degradation of dyes or antibiotics. In particular, the presently mentioned organic molecules are widely known wastewater pollutants whose presence in the water cycle enhances the unexpected acceleration of antimicrobial resistance. However, a sustainable and cost-effective approach to synthesize copper sulfide is not fully developed. The formation of CuS in aqueous solution under hydrothermal conditions by using the waste of sulfuric acid production as secondary raw material of sulfur was investigated in this thesis. The morphology, thermal stability and photocatalytic properties of synthesized samples were also studied in this work. To apply synthesized material on a large scale for the degradation of organic pollutants, the bio composites from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and CuS were produced. The samples in porous and film structures were used to degrade tetracycline and methylene blue. The ability of composite to degrade organic molecules, be reused and degrade several organic molecules simultaneously was examined in this work

Microwave-Assisted Synthesis of Supported Nanocatalysts: A route from nanoparticles to nanoclusters, from batch to continuous.

The main drawbacks of the traditional batch chemical processes are the excessive energy consumption, the variable product quality, the limited scaled‐up and the poor efficiency. The European Training Network for Continuous Sonication and Microwave Reactors (ETN‐COSMIC) aims to support the transition of the chemical industry from batch to continuous flow technologies with the investigation of alternative no contact energy sources, such as ultrasounds and microwaves. The current PhD work targets the development of high efficient nanocatalysts suitable for heterogeneous catalytic reactions, focusing on the effects of microwaves and continuous flow reactors. This thesis covers the following aspects to successfully design the synthesis reactor and the final high efficient nanocatalysts:‐ Development of a method to accurately control the temperature in microwave-heated continuous flow microreactor for the synthesis of metallic nanoparticles.‐ Definition of the optimum heating patterns for the synthesis of metallic nanoclusters.‐ Development of a synthesis procedure, based on microwave heating, for the in-situ synthesis of metallic nanoclusters on catalytic supports.‐ Testing of catalytic activity.The thesis is structured in five experimental chapters. In chapter 2, it is introduced the microwave‐heated continuous flow reactor used in this PhD research, benchmarking its efficiency with a common silver nanoparticles procedure that is carried out in a batch‐type reactor comparing a conventional heating mode, such as an oil bath, and the alternative electromagnetic heating. An accurate investigation of the temperature mapping, performed by integrating simulated and experimental results, confirmed that microwaves guarantee a higher heating rate and consequently higher synthesis yield. Furthermore, the different heating profile counteracts the wall fouling and then, improves the quality of the final product. In chapter 3, the optimization of the heating pattern for the production of ultra-small nanocatalysts was conducted in a batch‐type process, evidencing the effects of the nucleation rate on the size distribution of the resulting nanoparticles. A detailed analysis of the temperature profile evidenced that the quality of the final product may increase by adopting a rapid selective heating rate, function of the microwave irradiation power. The quality of the produced nanomaterials was remarkable not only for their high activity in the tested conditions but also for their long‐term stability which is more than 18‐months. The nanoparticles produced were deposited into mesoporous SBA‐15, obtaining the first catalyst B-AgNPs@SBA-15, and its activity was tested using the hydrogenation of 4‐Nitrophenol with sodium borohydride, comparing the developed nanosystem with literature results.In chapter 4, the process was switched to continuous flow, including a rapid quenching step. The nanoclusters were uniformly supported over the mesoporous channels of SBA‐15, and the catalyst C-AgNCs@SBA-15 was tested for alkynes’ hydrogenation. The high density of uncoordinated Ag atoms was responsible for the high activity observed, confirming that supported nanoclusters may represent a bridge between low active nanoparticles and unrecoverable silver salts. In chapter 5, an alternative reactor for in‐situ nucleation of silver nanoclusters was introduced with the purpose of increasing the loading yield, lowering the metal loss. The clusters size was still reduced and the synthesis yield was higher than 90%. The higher metal loading may play a crucial role in accelerate some catalytic reaction, as demonstrated by the hydrogenation of 4‐Nitrophenol. Furthermore, the nanocatalyst synthesized confirmed its usefulness for a wide range of C≡C cyclization and its morphological and catalytic stability was proved after one year of storage. To conclude, the scalability of the batch method was evaluated moving from 100 mg to 1 g of catalyst, in 2 minutes synthesis time.Finally, chapter 6 is focused on the production of bimetallic nanoclusters, which may present interesting and fascinating properties. The continuous flow reactor was properly modified to allow a dual‐step reducing process, and bimetallic structures were synthesized, investigating the effects of residence time and temperature profile. The bimetallic nanoclusters were directly synthesized on the carbon support in the continuous flow, maximizing the synthesis yield and optimizing clusters distribution.<br /