I formulated chitosan nanoparticles from chitosan and TPP by ionic gelation method. But when I started the cell experiment, I found the toxicity of chitosan nanoparticles to cell is very large which is different with some published studies.
Because of pH-sensitive of chitosan, I use 5Mm HEPES to dilute the nanoparticles suspension. I seed 1 million/well BMDCs in 24 wells plate. After 12 hours, then I add diluted nanoparticles into wells with 24h, I found the cells almost die. How can I solve this problem?