Modification of primary amines to higher order amines reduces in vivo hematological and immunotoxicity of cationic nanocarriers through TLR4 and complement pathways

Randall Toy; Pallab Pradhan; Vijayeetha Ramesh; Nelson C. Di Paolo; Blake Lash; Jiaying Liu; Emmeline L. Blanchard; Philip J. Santangelo; Dmitry M. Shayakhmetov; Krishnendu Roy

We then tested if IAA modification could reduce the in vitro innate immune response to chitosan nanoparticles. First, we evaluated the uptake of unmodified and IAA-modified chitosan nanoparticles by mouse endothelial cells (MEC, Supplementary Fig. 8C ). A stark difference was observed in chitosan nanoparticle uptake after IAA modification. We found that 80% of the MECs had internalized IAA-modified chitosan nanoparticles after 24 hours, while fewer than 20% of MECs internalized unmodified chitosan nanoparticles at the same time point. In association with higher cellular uptake, the IAA-modified chitosan nanoparticles were more inflammatory to mouse BMDCs than unmodified chitosan nanoparticles. While there were no significant differences in levels of secreted IL-6 ( Fig. 5E) , both secreted IL-1b (Fig. 5F ) and TNF-a (Fig. 5G ) levels were elevated in BMDCs treated with IAA-modified chitosan nanoparticles.