Protein corona significantly affects in vivo fate of nanoparticles including biodistribution and half-life. Without manipulating the physicochemical properties of nanoparticles with considering their biointerference, attaining effective treatment protocols is impossible. For this reason, protein corona evolution and biodistribution of different chitosan (Ch)-based nanoparticles including Ch and carboxymethyl dextran (CMD)/thiolated dextran (TD) polyelectrolyte complexes (PECs) were studied using highly precious and sensitive methods such as liquid chromatography-mass/mass (LC-MS/MS) spectroscopy and positron emission tomography/computed tomography (PET/CT) scan. The importance of serum presence/absence in culture medium with different pH and corona effect on cellular uptake of PECs investigated by in vitro study. Designed PECs have low amounts of proteins in corona mostly enriched by Apolipoproteins, protein C, hemoglobin subunits, and inter-alpha- trypsin inhibitor that beside improving uptake of nanoparticles, they have low liver uptake and notable heart blood pool accumulation that confirmed the long circulation time of the nanoparticles which is favorable for delivery of nanoparticles to the site of action and achieving required therapeutic effect.