Table 1.

Aptamers to cell-surface targets for intracellular delivery.

DNA/RNA	Aptamers	Capable of directing internalization	Ref.
RNA	PSMA	Yes	[16,19,21,34,46–49,72–77]
RNA	CD4	Yes	[18,45,60,67]
RNA	gp120	Yes	[20,22]
RNA	Tenascin-C (TN-C)	Yes	[51,78]
RNA	4-1BB	Uncertain	[31]
RNA	CTLA-4	Uncertain	[79]
RNA	OX40	Uncertain	[80]
RNA	EGFR	Yes	[57]
RNA	EGFRvIII	No	[81]
RNA	TGF-β type III receptor	Uncertain	[59]
RNA	HER3	Uncertain	[58]
RNA	BACE	Uncertain	[82]
RNA	L-selectin	Uncertain	[83]
RNA	β-catenin	Uncertain	[84]
RNA	KRAS	Uncertain	[85]
RNA	Acetylcholine receptor (AChR)	Uncertain	[86]
RNA	Neurotensin-1 (NTS-1)	Uncertain	[87]
RNA	African trypanosomes (42 kDa protein)	Uncertain	[88]
RNA	RET receptor tyrosine kinase	Uncertain	[55]
DNA	Immunoglobulin heavy mu chain (IGHM)	Uncertain	[89]
DNA	Hemagglutinin	Uncertain	[90]
DNA	Mucin (MUC1)	Yes	[54,91]
DNA	Nucleolin (NCL)	Yes	[53,92–94]
DNA	Transferrin receptor (TfR)	Yes	[50]
DNA	PTK7	Yes	[95–97]

RNA and DNA aptamers selected to cell-surface targets. Several of these aptamers have been used as vehicles to deliver various cargos (siRNAs, toxins, chemotherapeutic agents and radionuclides) to cells expressing the aptamer target. BACE: β-secretase; EGFRvIII: Epidermal growth factor receptor variant III; gp120: Glycoprotein 120; HER: Human epidermal growth factor receptor; PSMA: Prostate-specific membrane antigen; PTK: Protein tyrosine kinase; TGF-β: Transforming growth factor-β.