Table 1.

Major properties of nanotechnologies for intracellular delivery

	Efficiency	Toxicity	Throughput	Precision at single cell level	Applicability	Pore size	Cargo size that can be delivered	Mechanisms of membrane permeabilization	Documented cellular responses
Nanowires and nanostraws	Low	Low	High	Medium	In vitro, ex vivo	≤ 100 nm	Several MDa	Combination of direct penetration and stimulated endocytosis	A, D, E
Pore forming toxins	High	High	High	Low	In vitro	15–30 nm	Up to 150 kDa	Membrane insertion	A, E
Electroporation	High	Medium	High	Low	In vitro, ex vivo	1–400 nm	Several MDa	Formation of electropores	B, C, F
Sonoporation	Medium	High	High	Low	In vitro, in vivo	50–250 nm	Several MDa	Different types of mechanical forces including shock waves and shear stress	A, B, C, E, F
Microfluidic cell squeezing	High	Low	High	Medium	In vitro, ex vivo	ND	15 nm AuNP, QD and antibodies	Mechanical deformation	ND
Direct laser-induced photoporation	High	Medium	Low	High	In vitro	80–160 nm	Several MDa	A combination of thermal, mechanical and chemical effects	A, B, C
Nanoparticle-mediated photoporation	High	Low	High	High	In vitro, ex vivo	10–500 nm	100–1000 s of kDa	Photothermal heating, high-pressure shockwaves or liquid jet formation	A, B, C, E
PEN photoporation	High	Low	High	High	In vitro, ex vivo	ND	up to 500 kDa	Photothermal heating	ND

A, ion fluxes; B, cytoskeletal remodeling; C, morphological changes; D, DNA damage; E, ER stress; F, delay in cell cycle progression; ND, Not Determined