Table 2.

Effect of different NPs charges on tissue biodistribution: charged NPs are cleared rapidly by the immune system.

Authors	NPs type	Charge	Uptake	Biodistribution
Xiao et al. [44]	PEG-micellar nanoparticles	Surface charge: high negative (<−10 mV) and high positive	High uptake by slightly negative charged NPs	All charged NPs cleared by the Kupffer cells
He et al. [45]	Polymeric NPs	Negative (−10 mV) neutral and positive charge (+35 mV)	High uptake of slight negative charged NP	Liver > spleen > lung > tumor > kidney > blood
Walczak et al. [46]	Polystyrene NPs 50 nm	Negative (−7, 7 mV) positive NPs and neutral	High uptake of negatively charged NPs than the neutral and positive one	Kidney > heart > stomach > small intestine
Verma et al. [47]	Encapsulated paclitaxel	Negative pectin NPs	—	(i) Major accumulation in liver > kidney > lung > spleen (ii) Tissue prolonged plasma retention