Figure 2.

Most relevant chemical modifications which significantly contribute to improve pharmacokinetic and pharmacodynamic properties of aptamers. A) Flourescent label. B) Most common glycoside modifications: B.1, Trigalactosylated tetrahydroxycholate conjugate, B.2, Galactose conjugate, B.3, Multiple carbohydrates can be attached through a cyclopeptide scaffold like RAFT: radioselectively addressable functionalized template. B.4, Polyamine conjugate with two manosyl and two galactosyl residues. C) Most commonly used covalent linkers to conjugate cell penetrating peptides (CPP) and an oligonucleotide (ON) chain. D) 2’-modified ribonucleosides. E) Cholesterol conjugate. F) Locked nucleotides (LNA).