Preliminary investigation on cytotoxicity of fluorinated polymer nanoparticles.

As well-known persistent organic pollutants (POPs), organofluorine pollutants such as perfluorooctane sulfonate (PFOS) have been proven to be bioaccumulated and harmful to health. However, toxicological assessment of organofluorinated nanoparticles, which have emerged as a novel tool for biomedical and industrial applications, is lacking, to the best of our knowledge. To assess the biological effects and health risk of fluorinated nanoparticles, trifluoroethyl aryl ether-based fluorinated poly(methyl methacrylate) nanoparticles (PTFE-PMMA NPs) were synthesized with various fluorine contents (PTFE-PMMA-1 NPs 12.0wt.%, PTFE-PMMA-2 NPs 6.1wt.% and PTFE-PMMA-3 NPs 5.0wt.%), and their cytotoxicity was investigated in this study. The in vitro experimental results indicated that the cytotoxicity of PTFE-PMMA NPs was mild, and was closely related to their fluorine (F) contents and F-containing side chains. Specifically, the cytotoxicity of PTFE-PMMA NPs decreased with increasing F content and F-containing side chains. After exposure to PTFE-PMMA NPs at a sublethal dose (50µg/mL) for 24hr, the phospholipid bilayer was damaged, accompanied by increasing permeability of the cell membrane. Meanwhile, the intracellular accumulation of reactive oxygen species (ROS) occurred, resulting in the increase of DNA damage, cell cycle arrest and cell death. Overall, the PTFE-PMMA NPs were found to be relatively safe compared with typical engineered nanomaterials (ENMs), such as silver nanoparticles and graphene oxide, for biomedical and industrial applications.

Preparation of polydopamine coated Fe3O4 nanoparticles and their application for enrichment of polycyclic aromatic hydrocarbons from environmental water samples.

Core/shell structured magnetic Fe3O4/polydopamine (Fe3O4/PDA) nanoparticles have been successfully synthesized and developed as a magnetic solid-phase extraction (SPE) adsorbent in dispersion mode for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental samples. The Fe3O4/PDA synthetic procedure is simple and involves no organic solvents. Only 20mg of Fe3O4/PDA adsorbents are required to extract PAHs from 500mL water samples. The adsorption attains equilibrium rapidly and analysts are eluted with acetonitrile readily. The extraction efficiency is not influenced by salt concentrations up to 300mM and pH values over the range 4-11. Under optimized conditions, the detection limits of PAHs are in the range of 0.5-1.9ngL(-1). The accuracy of the method is evaluated by the recoveries of PAHs from environmental samples. Good recoveries (76.4-107%) with low relative standard deviations from 1.0% to 9.7% are achieved. Comparison study shows that the recoveries of target PAHs are low when they are extracted using traditional SPE method even with the addition of methanol or tetrabutylammonium bromide surfactants in water samples, suggesting great application potential of magnetic SPE method to preconcentrate highly hydrophobic contaminants (such as PAHs) from large volume of water samples. This new SPE method provides several advantages, such as simplicity, low environmental impact, high extraction efficiency, high breakthrough volumes, convenient extraction procedure, and short analysis time.

Polydopamine-coated magnetic nanoparticles for enrichment and direct detection of small molecule pollutants coupled with MALDI-TOF-MS.

Polydopamine-coated Fe(3)O(4) nanoparticles (Fe(3)O(4)@PDA NPs) were synthesized and applied as matrix for the detection of pollutants by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The synthesis of Fe(3)O(4)@PDA NPs was accomplished in 30 min by in situ polymerization of dopamine without any toxic reagent. Using Fe(3)O(4)@PDA NPs as matrix of MALDI-TOF, eleven small molecule pollutants (molecular weight from 251.6 to 499.3), including Benzo(a)pyrene (BaP), three perfluorinated compounds (PFCs), and seven antibiotics, were successfully detected in either positive or negative reflection mode without background interference. Furthermore, the Fe(3)O(4)@PDA NPs can also enrich trace amounts of hydrophobic target, such as BaP, from solution to nanoparticles surface. Then the Fe(3)O(4)@PDA-BaP can be isolated through magnetic sedimentation step and directly spotted on the stainless steel plate for MALDI measurement. With Fe(3)O(4)@PDA NPs as adsorbent and matrix, we also realized the analysis of BaP in tap water and lake water samples. Thus, a magnetic solid-phase extraction (MSPE)-MALDI-TOF-MS method was established for the measurement of BaP.

Biocompatible phosphatidylcholine bilayer coated on magnetic nanoparticles and their application in the extraction of several polycyclic aromatic hydrocarbons from environmental water and milk samples.

In this work, phosphatidylcholine (PC) was coated on magnetic nanoparticles to form lipid bilayer as solid-phase extraction (SPE) sorbents for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from environmental water and milk samples. The lipid bilayer was coated on Fe(3)O(4) nanoparticles using a modified dry lipid film hydration method. The resulted Fe(3)O(4)/PC could be readily isolated from solution with a magnet, and exhibited excellent adsorption performance to organic pollutants. Only 0.1g of sorbents was enough to extract PAHs from 500 mL aqueous solution, and 6 mL of acetonitrile was required to desorb them. The method was fast and relied on 10 min extraction time and 5 min magnetic separation. The proposed method was successfully applied to determine PAHs in some environmental water and milk samples. The detection limit was in the range of 0.2-0.6 ng L(-1). The recoveries of the spiked water samples ranged from 89% to 115% with relative standard deviations (RSD) varying from 1% to 8%. For spiked milk samples, RSD was satisfactory (1-9%), but the recoveries were relatively low (42-62%). We show the potentials of Fe(3)O(4)/PC sorbents in environmental water and biological sample analyses.