Small-Molecule Binding Aptamers: Selection Strategies, Characterization, and Applications

Abstract

Aptamers are single-stranded, synthetic oligonucleotides that fold into 3-dimensional shapes capable of binding non-covalently with high affinity and specificity to a target molecule. They are generated via an in vitro process known as the Systematic Evolution of Ligands by EXponential enrichment, from which candidates are screened and characterized, and then used in various applications. These applications range from therapeutic uses to biosensors for target detection. Aptamers for small molecule targets such as toxins, antibiotics, molecular markers, drugs, and heavy metals will be the focus of this review. Their accurate detection is needed for the protection and wellbeing of humans and animals. However, the small molecular weights of these targets, including the drastic size difference between the target and the oligonucleotides, make it challenging to select, characterize, and apply aptamers for their detection. Thus, recent (since 2012) notable advances in small molecule aptamers, which have overcome some of these challenges, are presented here, while defining challenges that still exist are discussed.

Strategies to develop endogenous stem cell-recruiting bioactive materials for tissue repair and regeneration

“…Aside from isolating stem cells, another interesting application of aptamers is their use as a biological tracking device to monitor stem cell migration in a tissue [82]. This concept is particularly relevant to evaluate the stem cell’s interactions with the extracellular environment and to discover new signaling pathways responsible for their recruitment.…”

Comparison of In-Solution Biorecognition Properties of Aptamers against Ochratoxin A

“…In the last few years, several aptamers have been reported for mycotoxins, with OTA as the most investigated one [24]. As a result, several OTA aptamer sequences have been reported by three separate groups [25,26,27].…”

Rapid Selection of Single-Stranded DNA Aptamers Binding Staphylococcus Epidermidis in Platelet Concentrates

“…To identify specific aptamers binding S. epidermidis , we applied the whole-cell-based rapid isolation of DNA aptamers (RIDA) method [30]. RIDA is an in vitro rapid one-step method to isolate high-affinity and high-selectivity aptamers without iterative cycles and amplification steps; it can be completed in 1 or 2 days, compared to conventional SELEX enrichment, which requires months and numerous rounds of selection (typically more than 10) to eliminate the large number of nonspecific DNA aptamers collected along with those of high affinity and specificity [6,31]. Using RIDA, we obtained a pool of DNA aptamers that went through selection and counter-selection steps from an aptamer library without requiring any amplification steps.…”