Gene delivery has become an increasingly important strategy for treating a variety of human diseases,
including infections, genetic disorders and tumours. To avoid the difficulties of using viral carriers, more
and more non-viral gene delivery nanoparticles are developed. Among these new approaches polyethylene
imine (PEI) is currently considered as one of the most effective polymer based method solution and
considered as the gold standard.
The toxicity of nanoparticles is a major concern when used for medical application. In this study we
chose two nanoparticles for an in depth toxicological and ecotoxicological evaluation, one well characterized,
PEI, and another novel polymer, poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA). In the
present study we have assessed the toxicity of these cation nanoparticles as such and of the polyplexes
- nanoparticles covered with DNA. As these nanoparticles are also frequently used in high volumes in
various industries and as such may enter in the environment, we also made an initial assessment of
ecotoxicological effects assessment.
The following nanoparticles related aspects have been studied during the project: development and
characterization, ecotoxicity, general toxicity and specific toxicity. To this end a battery of different tests
was used. The conclusion of these tests is that toxicity is varying between different nanoparticles and
between different DNA covering ratios. In general, in the different systems tested, the PEI polymer is
more toxic than thePDMAEMApolymer. The same difference is seen for the polyplexes and the higher the
charge ratio, the more toxic are the polyplexes. Our study also clearly shows the need for a broad spectrum
of toxicity assays for a comprehensive risk assessment. Our study has performed such a comprehensive
analysis of two biomedical nanoparticles.