Table 2.

Summary of the endocytic mechanisms used by CPP–cargo conjugates.

Macropinocytosis	Clathrin-mediated endocytosis (CME)	Caveolae-mediated endocytosis (CvME)	Clathrin- and caveolae-independent endocytosis
TAT-protein conjugates [60]	unconjugated TAT [83]	TAT-protein conjugates [92–93]	p18 and p28 azurin fragments [98–99]
poly-arginines [65–67]	MPG/siRNA conjugate [84–85]	proline-rich CPPs [94]	transportan [95]
NickFect51 [77]	NickFect51-cargo conjugates [77]	transportan-10-protein conjugates [95]	low molecular weight protamine (LMWP)/siRNA conjugate [104]
	octa-arginine (R8) [44]	PepFect14/DNA conjugate [97]
		p18 and p28 azurin fragments [98–99]
		CVP1 [100]