Monika Dvořáková has her expertise in evaluation of oxidative stress in different free radical diseases. Recently, her attention has been devoted to studying the potential risk of metal and metaloxide nanoparticles used for biomedical application with focus on the NP influence on the oxidative status.
In recent years, the interest in nanotechnology in medicine involves mainly prevention, diagnostics and treatment of human diseases such as cancer. Nanoparticles (NPs) are able to target the drug delivery into the exact place of the body, to protect drugs from degradation in gastrointestinal tract, as well as to carry slightly water soluble drugs. Despite the increasing popularity of nanomedicine, application of NPs has been limited due to their potential toxicity. It is known they can induce production of reactive oxygen species, leading to an oxidative stress. Our goal was to evaluate the effect of the polymeric NP, poly(ethylene glycol)−block−poly(lactic acid) (PEG−b−PLA) on the activity of selected antioxidant enzymes of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG−b−PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We determined activities of catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) female rats. In adult vehicle-treated animals (controls), a significant decrease in catalase activity was observed, but, on the other hand, a significant increase in GPx and SOD activity compared to infantile controls was confirmed. In the hemolysates of infantile rats, both doses of PEG−b−PLA NPs after neonatal administration increased catalase, Gpx as well as SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after neonatal administration of both doses of PEG−b−PLA NPs.Obtained data indicate a possible age-related association between the activities of antioxidant enzymes and neonatal PEG−b−PLA NPs administration in female rats. Therefore, further investigation is necessary to clarify the mechanism of NPs effect and to evaluate their impact on the organism.
Zhifu Yin has completed his PhD at the age of 30 years from Dalian University of Technology. He is a lecture in Jilin University from July 2016. He has published more than 30 papers in reputed journals and has been serving as an reviewer for more than 5 reputed journals.
All polymer-based nanofluidic chips are becoming increasingly important for biological and medical applications. Future advances in nanofluidics and its utilization in commercial applications depend on the development and fabrication of low cost and high fidelity nanofluidic chips. It is easy to improve replication precision of nano-trenches by means of increasing imprinting temperature, pressure and duration. However, without the support of nano-mold, the replicated nanochannels are apt to block after bonding process. The fabrication of high fidelity nanofluidic chips depends on bonding process rather than imprinting process. This work presents a novel bonding method for nanochannels based on PDMS spincoating. With optimized parameters, the size of the nanochannels can be decreased by 67 % after PDMS spincoating. Experimental results show that 60 nm (both for width and depth) nanochannels with high uniformity can be fabricated without any block.