Chemically Modified Aptamers in Biological Analysis

Abstract

Recently, nucleic acid aptamers have been widely used in biological analysis due to their high affinity, binding selectivity, and programmability. Researchers have introduced the idea that chemical modification endows aptamers with rich spatial conformations and functions, extending the application of aptamers in biological analysis. Currently, reviews about aptamers in the bioanalytical field usually focus on the complexes of aptamers and functional materials. Few reviews pay attention to the chemically modified aptamers. In this review, we introduce the synthesis and screening of chemically modified nucleic acids. In addition, we summarize the recent works about chemically modified aptamers in the field of bioanalysis, aiming to provide a promising step toward an aptamer-based versatile platform for biological analysis.

Profiling Cancer Cells by Cell-SELEX: Use of Aptamers for Discovery of Actionable Biomarkers and Therapeutic Applications Thereof

“…Compared to antibodies, aptamers possess many advantages for cancer therapeutic applications, such as low size that allows high tissue penetration, physiological stability, no or low immunogenicity and minimized batch-to-batch variation [18][19][20][21]. Moreover, aptamers support many kinds of chemical modifications, which improve their activity, half-life, renal clearance and, importantly, allow sophisticated combination therapies by conjugating aptamers with other types of innovative therapeutic molecules or conventional drugs [22][23][24].…”

“…activity, half-life, renal clearance and, importantly, allow sophisticated combination therapies by conjugating aptamers with other types of innovative therapeutic molecules or conventional drugs [22][23][24].…”

Rationally Designed Multivalent Aptamers Targeting Cell Surface for Biomedical Applications

“…The emergence of nucleic acid aptamers has provided opportunities for investigating of receptor–ligand interactions and related cell biology . Aptamers, also called chemical antibodies, are single-stranded nucleic acid oligomers that form unique secondary and tertiary structures upon binding to target receptors . They can highly and selectively bind to diverse targets, ranging from metal ions to small molecules, proteins, whole cells, and tissues .…”

“…To improve the stability in complex environments, chemical modification of nucleotides has been attempted. For instance, 2′-methoxy nucleotides, locked nucleic acid, peptide nucleic acid, 2′-aminopyrimidine, and so on have been incorporated into aptamers to increase nuclease resistance . On the other hand, polyethylene glycol (PEG) has been conjugated with aptamers to increase the size and molecular weight to decrease renal clearance and increase the circulation time in vivo .…”

“…3 Aptamers, also called chemical antibodies, are single-stranded nucleic acid oligomers that form unique secondary and tertiary structures upon binding to target receptors. 4 They can highly and selectively bind to diverse targets, ranging from metal ions to small molecules, proteins, whole cells, and tissues. 5 Compared to antibodies, aptamers have several advantages.…”