Nanoparticles (NPs) have emerged as potent, multifunctional platforms that enabled new advances in biomedicine and biotechnology. Among those, superparamagnetic NPs have been widely used in magnetic resonance imaging and other imaging techniques as contrast agents. Numerous studies have focused on the surface functionalization of NPs to improve their biocompatibility, in vivo distribution and targeting. Still, NPs can cause toxicity, stress response and activation of NF-?B through their functionality and presence alone. Polyacrylic acid (PAA) is an anionic biocompatible polymer with carboxylic groups that enables high intracellular loading with relatively low toxicity, and can thus be applied for applications such as cell labelling, separation and hyperthermia. On the other hand, PEI is a cationic polymer that induces lysosomal leakage and thus PEI NPs are used for applications that require delivery into the cytosol such as DNA and drug delivery. However, PEI toxicity still represents a major obstacle for its use. The purpose of this study was to analyze the stress and NF-?B response in primary human myoblasts following incubation with PAA or PEI coated cobalt ferrite magnetic NPs. We showed that PAA NPs are nontoxic, do not induce ROS or NF-kB activation. On the other hand, PEI NPs caused severe NP toxicity through membrane damage and a corresponding concentration dependent increase in ROS following 24 h incubation. Moreover, PEI NPs induced NF-?B phosphorylation through activation of TLR4 activation, as suggested by TLR4 inhibitors. With this study, we established the protocols for western blot and detection of pNF-?B protein, as well as appropriate protocols to follow time dependent changes in NP-induced cell signaling. Moreover, with the use of inhibitors we determined the mode of activation of pNF-?B, which is important for better understanding as well as counteracting the toxicity mechanisms of NPs. This knowledge can be also applied to the ongoing projects.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 11736148