Towards an alternative testing strategy for nanomaterials used in nanomedicine: lessons from NanoTEST.

In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project ( www.nanotest-fp7.eu ) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed.

Biological activity of plant extract isolated from Papaver rhoeas on human lymfoblastoid cell line.

Varied medicinal plants are known as a source of natural phytochemicals with antioxidant activities that can protect organisms from oxidative stress and from various chronic diseases. Papaver rhoeas has a long history of medicinal usage, especially for ailments in adults and children. The possible cytotoxicity, genotoxicity and potential antioxidant effect of plant extract isolated from flowers of Papaver rhoeas was investigated in human lymfoblastoid cell line (TK6). Antioxidant activity of this extract was determined using the DPPH assay. The plant extract exhibited dose dependent free radical scavenging ability. The growth activity assay was used for determination of cytotoxicity. To assess potential genotoxicity the comet assay was used. The lower extract concentrations (0.25 and 0.5 mg/ml) neither exerted cytotoxic, nor genotoxic effects in TK6 cells but they stimulated cell proliferation. The concentration 25 mg/ml scavenged almost 85% of DPPH free radical. On the other hand, this concentration had strong cytotoxic and genotoxic effect on TK6 cells. The balance between beneficial and harmful effects should be always considered when choosing the effective dose.