Toxicity evaluation of nanocrystalline silver-impregnated coated dressing on the life cycle of worm Caenorhabditis elegans

Nanomaterials as a Potential Target for Infectious Parasitic Agents

Despite the technological advancement in the era of personalized medicine and therapeutics development, infectious parasitic causative agents remain one of the most challenging areas of research and development. The disadvantages of conventional parasitic prevention and control are the emergence of multiple drug resistance as well as the non-specific targeting of intracellular parasites, which results in high dose concentration needs and subsequently intolerable cytotoxicity. Nanotechnology has attracted extensive interest to reduce medication therapy adverse effects including poor bioavailability and drug selectivity. Numerous nanomaterials-based delivery systems have previously been shown in animal models to be effective in the treatment of various parasitic infections. This review discusses a variety of nanomaterials-based antiparasitic procedures and techniques as well as the processes that allow them to be targeted to different parasitic infections. This review focuses on the key prerequisites for creating novel nanotechnology-based carriers as a potential option in parasite management, specifically in the context of human-related pathogenic parasitic agents.

Adverse effects of silver nanoparticles on aquatic plants and zooplankton: A review

With the rapid development of nanotechnology in the past decades, AgNPs are widely used in various fields and have become one of the most widely used nanomaterials, which leads to the inevitable release of AgNPs to the aquatic environment through various pathways. It is important to understand the effects of AgNPs on aquatic plants and zooplankton, which are widely distributed and diverse, and are important components of the aquatic biota. This paper reviews the effects of AgNPs on aquatic plants and zooplankton at the individual, cellular and molecular levels. In addition, the internal and external factors affecting the toxicity of AgNPs to aquatic plants and zooplankton are discussed. In general, AgNPs can inhibit growth and development, cause tissue damage, induce oxidative stress, and produce genotoxicity and reproductive toxicity. Moreover, the toxicity of AgNPs is influenced by the size, concentration, and surface coating of AgNPs, environmental factors including pH, salinity, temperature, light and co-contaminants such as NaOCl, glyphosate, As(V), Cu and Cd, sensitivity of test organisms, experimental conditions and so on. In order to investigate the toxicity of AgNPs in the natural environment, it is recommended to conduct toxicity evaluation studies of AgNPs under the coexistence of multiple environmental factors and pollutants, especially at natural environmental concentrations.

Effects of environmental factor fulvic acid on AgNPs food chain delivery and bioavailability

Due to its antimicrobial activity, silver nanoparticles (AgNPs) have become the most commonly applied nanomaterials. However, the potential ecotoxicological toxicity of AgNPs in the environment is still unclear. Here we assessed the trophic transfer and toxicity of commercially manufactured polyvinyl pyrrolidone (PVP)-coated AgNPs using a model food chain from Escherichia coli (E. coli) to Caenorhabditis elegans (C. elegans). Our results demonstrated that AgNPs could be accumulated in E. coli and transferred to C. elegans that preyed on the bacteria. Although low concentration of AgNPs had no significant inhibition on E. coli, they could affect germ cell apoptosis, reproduction ability and population size of C. elegans through food chain. Importantly, natural organic matter (NOM), which is omnipresent in environmental system, could increase the accumulation of AgNPs in E. coli and C. elegans, and significantly enhance the ecotoxicity of AgNPs. Our findings indicated that potential risks of nanomaterial through food chain should be considered for higher trophic organisms. And environmental factors could play an important role in transport of nanomaterials and altering their accumulation and toxicity in ecosystem.

Antimicrobial coatings for environmental surfaces in hospitals: a potential new pillar for prevention strategies in hygiene

Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Characterization, stability, and in vivo effects in Caenorhabditis elegans of microencapsulated protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts

This study aimed to microencapsulate protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts produced by Alcalase (HA) and Protamex (HP) by spray drying, using maltodextrin as wall material. The physicochemical characteristics, and in vitro antioxidant and Angiotensin-I converting enzyme-inhibitory activities were evaluated during storage. Both microencapsulated hydrolysates showed spherical shape (~3.6 µm particle diameter), low water activity (<0.155) during storage and reduced hygroscopicity (~30%) compared to the free hydrolysate. Infrared spectroscopy evidenced the maltodextrin-hydrolysate interaction. Based on the in vitro results, nematoid C. elegans in L1 larval stage were treated with free and microencapsulated HP, which demonstrated a protective effect on nematoid exposed to oxidative stress (survival ~ 13% control, 77% free HP, and 85% microencapsulated HP) and improved their growth and reproduction rate. Thus, microencapsulation appears to be a good alternative to maintain hydrolysates stability during storage, showing bioactivity in C. elegans.

Algae-Laden Fouling Control by Gravity-Driven Membrane Ultrafiltration with Aluminum Sulfate-Chitosan: The Property of Floc and Cake Layer

Gravity-driven membrane (GDM) ultrafiltration is a promising water treatment method due to its low energy consumption and low maintenance. However, the low stable permeability in algae-laden water treatment is currently limiting its wider application. With the ultimate goal of increasing permeability, the aim of this study was to evaluate the effect of a composite coagulant of aluminum sulfate-chitosan (AS-CS) on the GDM filtration performance. In parallel tests with a single AS coagulant and without pre-coagulation, the analysis of membrane fouling resistance and the membrane fouling mechanism were evaluated. The results indicated that the AS-CS/GDM system can alleviate 23.74% and 58.80% membrane fouling, respectively, compared with AS/GDM and the GDM system. The AS-CS/GDM system can effectively remove humic-like substances having a molecular weight (MW) of 3–100 kDa, resulting in removal of 98.32% of algae cells and removal of 66.25% of dissolved organic carbon; the AS-CS/GDM system thereby improved the concentration of attached biomass on the membrane surface with the stronger biodegradability of organic matters. The application of AS-CS pre-coagulation in the GDM process could enhance the proliferation of microorganisms and the removal of low molecular weight humic-like substances. Therefore, the AS-CS/GDM system is a potentially important approach for algae-laden water treatment.