Biocomposite Cryogels for Photothermal Decontamination of Water.

An effective and sustainable approach to deal with the scarcity of freshwater is interfacial solar-driven evaporation. Nonetheless, some serious challenges for photothermal materials still need to be considered, such as long-term stability in harsh environments, eco-friendly materials, and cost-effective and simple fabrication processes. Keeping these points in mind, we present a multifunctional silver-coated vegetable waste biocomposite cryogel that not only exhibits high porosity and enhanced wettability and stability but also possesses high light absorption and low thermal conductivity favorable for heat localization, solar steam generation, and efficient photothermal conversion efficiency. The achieved solar evaporation rate is 1.17 kg m-2 h-1 with a solar-to-vapor conversion efficiency of 81.11% under 1 Sun irradiation. The developed material is able to effectively desalinate artificial seawater and decontaminate synthetic wastewater (e.g., water containing dye molecules and mercury ions) with an efficiency of >99%. Most importantly, the composite cryogel presents antifouling properties, and in particular, salt antifouling ability and anti-biofouling properties. Thus, the numerous functionalities of the biocomposite cryogel make it a cost-effective promising device for prolonged water decontamination processes.

Grouping of orally ingested silica nanomaterials via use of an integrated approach to testing and assessment to streamline risk assessment.

BACKGROUND: Nanomaterials can exist in different nanoforms (NFs). Their grouping may be supported by the formulation of hypotheses which can be interrogated via integrated approaches to testing and assessment (IATA). IATAs are decision trees that guide the user through tiered testing strategies (TTS) to collect the required evidence needed to accept or reject a grouping hypothesis. In the present paper, we investigated the applicability of IATAs for ingested NFs using a case study that includes different silicon dioxide, SiO2 NFs. Two oral grouping hypotheses addressing local and systemic toxicity were identified relevant for the grouping of these NFs and verified through the application of oral IATAs. Following different Tier 1 and/or Tier 2 in vitro methods of the TTS (i.e., in vitro dissolution, barrier integrity and inflammation assays), we generated the NF datasets. Furthermore, similarity algorithms (e.g., Bayesian method and Cluster analysis) were utilized to identify similarities among the NFs and establish a provisional group(s). The grouping based on Tier 1 and/or Tier 2 testing was analyzed in relation to available Tier 3 in vivo data in order to verify if the read-across was possible and therefore support a grouping decision. RESULTS: The measurement of the dissolution rate of the silica NFs in the oro-gastrointestinal tract and in the lysosome identified them as gradually dissolving and biopersistent NFs. For the local toxicity to intestinal epithelium (e.g. cytotoxicity, membrane integrity and inflammation), the biological results of the gastrointestinal tract models indicate that all of the silica NFs were similar with respect to the lack of local toxicity and, therefore, belong to the same group; in vivo data (although limited) confirmed the lack of local toxicity of NFs. For systemic toxicity, Tier 1 data did not identify similarity across the NFs, with results across different decision nodes being inconsistent in providing homogeneous group(s). Moreover, the available Tier 3 in vivo data were also insufficient to support decisions based upon the obtained in vitro results and relating to the toxicity of the tested NFs. CONCLUSIONS: The information generated by the tested oral IATAs can be effectively used for similarity assessment to support a grouping decision upon the application of a hypothesis related to toxicity in the gastrointestinal tract. The IATAs facilitated a structured data analysis and, by means of the expert's interpretation, supported read-across with the available in vivo data. The IATAs also supported the users in decision making, for example, reducing the testing when the grouping was well supported by the evidence and/or moving forward to advanced testing (e.g., the use of more suitable cellular models or chronic exposure) to improve the confidence level of the data and obtain more focused information.

Mutagenic effects of gold nanoparticles induce aberrant phenotypes in Drosophila melanogaster.

The peculiar physical/chemical characteristics of engineered nanomaterials have led to a rapid increase of nanotechnology-based applications in many fields. However, before exploiting their huge and wide potential, it is necessary to assess their effects upon interaction with living systems. In this context, the screening of nanomaterials to evaluate their possible toxicity and understand the underlying mechanisms currently represents a crucial opportunity to prevent severe harmful effects in the next future. In this work we show the in vivo toxicity of gold nanoparticles (Au NPs) in Drosophila melanogaster, highlighting significant genotoxic effects and, thus, revealing an unsettling aspect of the long-term outcome of the exposure to this nanomaterial. After the treatment with Au NPs, we observed dramatic phenotypic modifications in the subsequent generations of Drosophila, demonstrating their capability to induce mutagenic effects that may be transmitted to the descendants. Noteworthy, we were able to obtain the first nanomaterial-mutated organism, named NM-mut. Although these results sound alarming, they underline the importance of systematic and reliable toxicology characterizations of nanomaterials and the necessity of significant efforts by the nanoscience community in designing and testing suitable nanoscale surface engineering/coating to develop biocompatible nanomaterials with no hazardous effects for human health and environment. FROM THE CLINICAL EDITOR: While the clinical application of nanomedicine is still in its infancy, the rapid evolution of this field will undoubtedly result in a growing number of clinical trials and eventually in human applications. The interactions of nanoparticles with living organisms determine their toxicity and long-term safety, which must be properly understood prior to large-scale applications are considered. The paper by Dr. Pompa's team is the first ever demonstration of mutagenesis resulting in clearly observable phenotypic alterations and the generation of nano-mutants as a result of exposure to citrate-surfaced gold nanoparticles in drosophila. These groundbreaking results are alarming, but represent a true milestone in nanomedicine and serve as a a reminder and warning about the critical importance of "safety first" in biomedical science.

Nanosensors for Visual Detection of Glucose in Biofluids: Are We Ready for Instrument-Free Home-Testing?

Making frequent large-scale screenings for several diseases economically affordable would represent a real breakthrough in healthcare. One of the most promising routes to pursue such an objective is developing rapid, non-invasive, and cost-effective home-testing devices. As a first step toward a diagnostic revolution, glycemia self-monitoring represents a solid base to start exploring new diagnostic strategies. Glucose self-monitoring is improving people's life quality in recent years; however, current approaches still present vast room for improvement. In most cases, they still involve invasive sampling processes (i.e., finger-prick), quite discomforting for frequent measurements, or implantable devices which are costly and commonly dedicated to selected chronic patients, thus precluding large-scale monitoring. Thanks to their unique physicochemical properties, nanoparticles hold great promises for the development of rapid colorimetric devices. Here, we overview and analyze the main instrument-free nanosensing strategies reported so far for glucose detection, highlighting their advantages/disadvantages in view of their implementation as cost-effective rapid home-testing devices, including the potential use of alternative non-invasive biofluids as samples sources.

Colorimetric Nanoplasmonics to Spot Hyperglycemia From Saliva.

Early diagnostics and point-of-care (POC) devices can save people's lives or drastically improve their quality. In particular, millions of diabetic patients worldwide benefit from POC devices for frequent self-monitoring of blood glucose. Yet, this still involves invasive sampling processes, which are quite discomforting for frequent measurements, or implantable devices dedicated to selected chronic patients, thus precluding large-scale monitoring of the globally increasing diabetic disorders. Here, we report a non-invasive colorimetric sensing platform to identify hyperglycemia from saliva. We designed plasmonic multibranched gold nanostructures, able to rapidly change their shape and color (naked-eye detection) in the presence of hyperglycemic conditions. This "reshaping approach" provides a fast visual response and high sensitivity, overcoming common detection issues related to signal (color intensity) losses and bio-matrix interferences. Notably, optimal performances of the assay were achieved in real biological samples, where the biomolecular environment was found to play a key role. Finally, we developed a dipstick prototype as a rapid home-testing kit.