Patrycja Kurtycz

Recent advances in graphene family materials toxicity investigations

Recently, graphene family materials (GFMs) have been introduced among all fields of science and still get numerous attention. Also, the applicability of these materials in many areas makes them very attractive. GFMs have attracted both academic and industrial interest as they can produce a dramatic improvement in materials properties at very low filler content. This article presents recent findings on GFMs toxicity properties based on the most current literature. This article studies the effects of GFMs on bacteria, mammalian cells, animals, and plants. This article also reviews in vitro and in vivo test results as well as potential anticancer activity and toxicity mechanisms of GFMs. The effect of functionalization of graphene on pacifying its strong interactions with cells and associated toxic effects was also analyzed. The authors of the article believe that further work should focus on in vitro and in vivo studies on possible interactions between GFMs and different living systems. Further research should also focus on decreasing GFMs toxicity, which still poses a great challenge for in vivo biomedical applications. Consequently, the potential impact of graphene and its derivatives on humans and environmental health is a matter of academic interest. However, potential hazards sufficient for risk assessment first need to be investigated.

Morphology, structure, and photoactivity of two types of graphene oxide-TiO2 composites

Two types of graphene oxide-TiO2 composites were prepared: one by including graphene oxide flakes in the TiO2 sol, followed by thermal treatment (GI composite) at 300°C, and the second by including graphene oxide flakes in the calcined (at 500°C) TiO2 xerogel (GII composite). The composites were characterized by SEM, TEM-EDS, TEM-SADP, STEM-HAADF, HRTEM coupled with FT, XRD, and XPS. Photocatalysis results were fitted to different kinetic models (pseudo-first and pseudo-second kinetics, intraparticle Weber-Morris diffusion, film diffusion, and external mass transfer). The results showed that by introducing graphene oxide flakes in the TiO2 sol, followed by thermal treatment at 300°C (GI composite), an efficient graphene oxide-TiO2 catalyst with high specific surface area, heterogeneity, and many graphitized areas can be obtained. Complete crystallization of the composite is not the key issue for the best photoactivity achievement. The rate limiting step in the photocatalytic process is the photooxidation of SA molecules on the TiO2 surface.

Nano-titanium oxide doped with gold, silver, and palladium — synthesis and structural characterization

Nano-titania doped with noble metals (Au/TiO2, Ag/TiO2, Pd/TiO2) has been synthesized by mild hydrolysis of the mixture of metal salts or complexes and titanium isopropoxide ((iPr-O)4Ti). After thermal decomposition of the obtained precursors, nanomaterials were formed. Morphological characterization of the nanomaterials was provided by scanning electron microscopy (SEM) and stereological analysis, determining the BET specific surface area, and BJH nanoporosity (pore volume, pore size). It has been found that the structure of nanomaterials (size of nanoparticles and agglomerates) depended strongly on the method of the (iPr-O)4Ti hydrolysis. A minor dependence on the kind of solvents and precursors of noble metals was observed. The presence of doping metal nanoparticles was confirmed by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). Nanomaterial phases were identified by X-ray diffraction (XRD). According to the XRD patterns, Ag/TiO2 and Pd/TiO2 products with doping metals in their oxidized form contain Ag-Ti and Pd-Ti phases. Peaks of the metal oxides Ag2O and PdO are absent in the XRD patterns. The average size of TiO2 nanoparticles is situated in the region of 20–60 nm, whereas metals are present as about 10–15 nm sized particles and fine nanoparticles.

Electrospun Poly(L-lactic)Acid/Nanoalumina (PLA/Al2O3) Composite Fiber Mats with Potential Biomedical Application - Investigation of Cytotoxicity

PLA fibrous mats containing nanoalumina filler were fabricated by electrospinning method. The morphology of the mats was characterized by SEM, and TEM. In vitro biocompatibility of the electrospun fiber mats was also evaluated. Indirect cytotoxicity evaluation of the fiber mats with human skin fibroblasts revealed that the materials were non-toxic to living cells. The cells cultured on the fibrous mat exhibited normal cells shapes and were integrated well with surrounding fibers. The obtained results confirmed the potential for use of the electrosupun PLA/Al2O3 fiber mats for biomedical application.