A Review on Conventional and Advanced Methods for Nanotoxicology Evaluation of Engineered Nanomaterials.

Nanotechnology can be defined as the field of science and technology that studies material at nanoscale (1-100 nm). These nanomaterials, especially carbon nanostructure-based composites and biopolymer-based nanocomposites, exhibit excellent chemical, physical, mechanical, electrical, and many other properties beneficial for their application in many consumer products (e.g., industrial, food, pharmaceutical, and medical). The current literature reports that the increased exposure of humans to nanomaterials could toxicologically affect their environment. Hence, this paper aims to present a review on the possible nanotoxicology assays that can be used to evaluate the toxicity of engineered nanomaterials. The different ways humans are exposed to nanomaterials are discussed, and the recent toxicity evaluation approaches of these nanomaterials are critically assessed.

Nanobiocomposite Polymer as a Filter Nanosponge for Wastewater Treatment.

A multifunctional nanobiocomposite polymer was developed in this study through a cross-linking polymerization of cyclodextrin with phosphorylated multi-walled carbon nanotubes followed by sol-gel to incorporate TiO2 and Ag nanoparticles. This work's novelty was to prove that the developed nanobiocomposite polymer is a potential filter nanosponge capable of removing organic, inorganic, and microorganisms' pollutants from wastewater samples. The synthesized multifunctional nanobiocomposite polymer was characterized using a range of spectroscopy and electron microscopy techniques. Fourier-transform infrared (FTIR) confirmed the presence of oxygen-containing groups on the developed nanobiocomposite polymer and carbamate linkage (NH(CO)) distinctive peak at around 1645 cm-1, which is evidence that the polymerization reaction was successful. The scanning electron microscopy (SEM) image shows that the developed nanobiocomposite polymer has a rough surface. The Dubinin-Radushkevich and the pseudo-second-order kinetic models best described the adsorption mechanism of Co2+ and TCE's onto pMWCNT/CD/TiO2-Ag. The efficacy of the developed nanobiocomposite polymer to act as disinfectant material in an environmental media (e.g., sewage wastewater sample) compared to the enriched media (e.g., nutrient Muller Hinton broth) was investigated. From the results obtained, in an environmental media, pMWCNT/CD/TiO2-Ag nanobiocomposite polymer can alter the bacteria's metabolic process by inhibiting the growth and killing the bacteria, whereas, in enriched media, the bacteria's growth was retarded.

Macromolecular Prodrugs Containing Organoiron-Based Compounds in Cancer Research: A Review.

Among the methods used for the treatment of cancer, chemotherapy is widely used, and it is by far one of the most unpleasant procedures given to a patient because of its severe side effects; while being necessary. One of the major problems in cancer chemotherapy is the limited selectivity of most of the drugs in current clinical use. Following administration, the active agent is distributed over the entire body and reaches not only the target cells or tissues but also interacts with healthy cells. In an attempt to overcome the side effects of anticancer drugs, the modification of the anticancer bioactive compounds has been a topic of active research for years. Numerous delivery systems such as drugcontaining liposomes, microencapsulation, nanoparticles, and water-soluble polymers have been used for the delivery of bioactive compounds to the site of action. Water-soluble polymeric conjugates and co-conjugates have remained the most outstanding delivery technique. This review will discuss the development of polymeric conjugates and co-conjugates of ferrocene in cancer research.

Removal of cobalt and lead ions from wastewater samples using an insoluble nanosponge biopolymer composite: adsorption isotherm, kinetic, thermodynamic, and regeneration studies.

In this study, an insoluble nanosponge biopolymer composite was synthesized, using a combined process of amidation reaction, cross-linking polymerization, and sol-gel method to obtain a phosphorylated multiwalled carbon nanotube-cyclodextrin/silver-doped titania (pMWCNT-ßCD/TiO2-Ag). This work mainly emphasized on the removal of lead (Pb2+) and cobalt (Co2+) metal ions from synthetic and real wastewater samples using the synthesized pMWCNT-ßCD/TiO2-Ag as a biosorbent. The new material was characterized by Fourier transform infrared (FTIR) spectroscopy, zeta potential, Brunauer-Emmett-Teller (BET) method, and scanning electron microscopy (SEM). Adsorption studies for the model pollutants were performed in batch mode. The effect of the solution pH, adsorbent dosage and the presence of competiting ions were investigated. The isotherm, kinetic, thermodynamic, and regeneration studies were also undertaken. The ability of the new material to effectively remove Pb2+ and Co2+ from synthetic wastewater and mine effluent samples was tested. The maximum removal capacities achieved for the removal of Pb2+ and Co2+ from mine effluent sample were 35.86 and 7.812 mg/g, respectively.

Photocatalytic degradation of the diazo dye naphthol blue black in water using MWCNT/Gd,N,S-TiO2 nanocomposites under simulated solar light.

A simple sol-gel method was employed to prepare gadolinium, nitrogen and sulphur tridoped titania decorated on oxidised multiwalled carbon nanotubes (MWCNT/Gd,N,S-TiO2), using titanium (IV) butoxide and thiourea as titanium and nitrogen and sulphur source, respectively. Samples of varying gadolinium loadings (0.2%, 0.6%, 1.0% and 3.0% Gd3+) relative to titania were prepared to investigate the effect of gadolinium loading and the amounts of carbon nanotubes, nitrogen and sulphur were kept constant for all the samples. Furthermore, the prepared nanocomposites were evaluated for the degradation of naphthol blue black (NBB) in water under simulated solar light irradiation. Higher degradation efficiency (95.7%) was recorded for the MWCNT/Gd,N,S-TiO2 (0.6% Gd) nanocomposites. The higher photocatalytic activity is attributed to the combined effect of improved visible light absorption and charge separation due to the synergistic effect of Gd, MWCNTs, N, S and TiO2. Total organic carbon (TOC) analysis revealed a higher degree of complete mineralisation of naphthol blue black (78.0% TOC removal) which minimises the possible formation of toxic degradation by-products such as the aromatic amines. The MWCNT/Gd,N,S-TiO2 (0.6% Gd) was fairly stable and could be re-used for five times, reaching a maximum degradation efficiency of 91.8% after the five cycles.