Selection and characterization of DNA aptamer against glucagon receptor by cell-SELEX

In vitro selection of DNA aptamers against staphylococcal enterotoxin A

Staphylococcal enterotoxin A (SEA) is the most frequently reported in staphylococcal food poisoning (SFP) outbreaks. Aptamers are single-stranded nucleic acids that are seen as promising alternatives to antibodies in several areas, including diagnostics. In this work, systematic evolution of ligands by exponential enrichment (SELEX) was used to select DNA aptamers against SEA. The SELEX protocol employed magnetic beads as an immobilization matrix for the target molecule and real-time quantitative PCR (qPCR) for monitoring and optimizing sequence enrichment. After 10 selection cycles, the ssDNA pool with the highest affinity was sequenced by next generation sequencing (NGS). Approximately 3 million aptamer candidates were identified, and the most representative cluster sequences were selected for further characterization. The aptamer with the highest affinity showed an experimental dissociation constant (KD) of 13.36 ± 18.62 nM. Increased temperature negatively affected the affinity of the aptamer for the target. Application of the selected aptamers in a lateral flow assay demonstrated their functionality in detecting samples containing 100 ng SEA, the minimum amount capable of causing food poisoning. Overall, the applicability of DNA aptamers in SEA recognition was demonstrated and characterized under different conditions, paving the way for the development of diagnostic tools.

Diversifying Design of Nucleic Acid Aptamers Using Unsupervised Machine Learning

Inverse design of short single-stranded RNA and DNA sequences (aptamers) is the task of finding sequences that satisfy a set of desired criteria. Relevant criteria may be, for example, the presence of specific folding motifs, binding to molecular ligands, sensing properties, and so on. Most practical approaches to aptamer design identify a small set of promising candidate sequences using high-throughput experiments (e.g., SELEX) and then optimize performance by introducing only minor modifications to the empirically found candidates. Sequences that possess the desired properties but differ drastically in chemical composition will add diversity to the search space and facilitate the discovery of useful nucleic acid aptamers. Systematic diversification protocols are needed. Here we propose to use an unsupervised machine learning model known as the Potts model to discover new, useful sequences with controllable sequence diversity. We start by training a Potts model using the maximum entropy principle on a small set of empirically identified sequences unified by a common feature. To generate new candidate sequences with a controllable degree of diversity, we take advantage of the model's spectral feature: an "energy" bandgap separating sequences that are similar to the training set from those that are distinct. By controlling the Potts energy range that is sampled, we generate sequences that are distinct from the training set yet still likely to have the encoded features. To demonstrate performance, we apply our approach to design diverse pools of sequences with specified secondary structure motifs in 30-mer RNA and DNA aptamers.

Capture-SELEX: Selection Strategy, Aptamer Identification, and Biosensing Application

Small-molecule contaminants, such as antibiotics, pesticides, and plasticizers, have emerged as one of the substances most detrimental to human health and the environment. Therefore, it is crucial to develop low-cost, user-friendly, and portable biosensors capable of rapidly detecting these contaminants. Antibodies have traditionally been used as biorecognition elements. However, aptamers have recently been applied as biorecognition elements in aptamer-based biosensors, also known as aptasensors. The systematic evolution of ligands by exponential enrichment (SELEX) is an in vitro technique used to generate aptamers that bind their targets with high affinity and specificity. Over the past decade, a modified SELEX method known as Capture-SELEX has been widely used to generate DNA or RNA aptamers that bind small molecules. In this review, we summarize the recent strategies used for Capture-SELEX, describe the methods commonly used for detecting and characterizing small-molecule-aptamer interactions, and discuss the development of aptamer-based biosensors for various applications. We also discuss the challenges of the Capture-SELEX platform and biosensor development and the possibilities for their future application.

Surface acoustic wave-assisted microfluidic isolation of aptamers

Aptamers are synthetic single-stranded nucleic acid molecules that bind to biochemical targets with high affinity and specificity. The method of systematic evolution of ligands by exponential enrichment (SELEX) is widely used to isolate aptamers from randomized oligonucleotides. Recently, microfluidic technology has been applied to improve the efficiency and reduce the cost in SELEX processes. In this work, we present an approach that exploits surface acoustic waves to improve the affinity selection process in microfluidic SELEX. Acoustic streaming is used to enhance the interactions of the solution-based oligonucleotide molecules with microbead-immobilized target molecules, allowing the identification of high-affinity aptamer candidates in a more efficient manner. For demonstration, a DNA aptamer is isolated within three rounds of selection in 5 h to specifically bind to immunoglobulin E, a representative target protein, with an equilibrium dissociation constant of approximately 22.6 nM.

Generation and Selection of Specific Aptamers Targeting Brucella Species through an Enhanced Cell-SELEX Methodology

Brucellae are Gram-negative, aerobic, non-motile coccobacilli causing brucellosis in man and animals. The disease is one of the most significant yet neglected global zoonoses. Especially in developing countries, brucellosis is causing public health problems and economic losses to private animal owners and national revenues. Composed of oligonucleotides, aptamers are chemical analogues of antibodies that are promising components for developing aptamer-based rapid, sensitive, and specific tests to identify the Brucella group of bacteria. For this purpose, aptamers were generated and selected by an enhanced protocol of cell systematic evolution of ligands by exponential enrichment (cell-SELEX). This enhanced cell-SELEX procedure involved the combination of both conventional and toggle cell-SELEX to boost the specificity and binding affinity to whole Brucella cells. This procedure, combined with high-throughput sequencing of the resulting aptamer pools, comprehensive bioinformatics analysis, and wet lab validation assays, led to the selection of a highly sensitive and specific aptamer for those Brucella species known to circulate in Egypt. The isolated candidate aptamer showed dissociation constant (K_D) values of 43.5 ± 11, 61.5 ± 8, and 56 ± 10.8 nM for B. melitensis, B. abortus, and B. suis, respectively. This is the first development of a Brucella-specific aptamer using an enhanced combination of conventional and toggle cell-SELEX to the authors’ best knowledge.

Recent advances in the selection of cancer-specific aptamers for the development of biosensors

An early diagnosis has the potential to greatly decrease cancer mortality. For that purpose, specific cancer biomarkers have been molecularly targeted by aptamer sequences to enable an accurate and rapid detection. Aptamer-based biosensors for cancer diagnostics are a promising alternative to those using antibodies, due to their high affinity and specificity to the target molecules and advantageous production. Synthetic nucleic acid aptamers are generated by in vitro Systematic Evolution of Ligands by Exponential enrichment (SELEX) methodologies that have been improved over the years to enhance the efficacy and to shorten the selection process. Aptamers have been successfully applied in electrochemical, optical, photoelectrochemical and piezoelectrical-based detection strategies. These aptasensors comprise a sensitive, accurate and inexpensive option for cancer detection being used as point-of-care devices. This review highlights the recent advances in cancer biomarkers, achievements and optimizations made in aptamer selection, as well as the different aptasensors developed for the detection of several cancer biomarkers.

Biosensors based on aptamer-conjugated gold nanoparticles: A review

Simply synthetized gold nanoparticles have been highly used in medicine and biotechnology as a result of their biocompatibility, conductivity, and being easily functionalized with biomolecules such as aptamer. Aptamer-conjugated gold nanoparticle structures synergically possess characteristics of both aptamer and gold nanoparticles including high binding affinity, high biocompatibility, enhanced target selectivity, and long circulatory half-life. Aptamer-conjugated gold nanoparticles have extensively gained considerable attention for designing of biosensing systems due to their interesting optical and electrochemical features. Moreover, biosensors based on aptamer-gold nanoparticles are easy to use, with fast response, and inexpensive which make them ideal in individualized medicine, disease markers detection, food safety, and so forth. Moreover, due to high selectivity and biocompatibility of aptamer-gold nanoparticles, these biosensing platforms are ideal tools for targeted drug delivery systems. The application of this nanostructure as diagnostic and therapeutic tool has been developed for detection of cancer in the early stage by detecting cancer biomarkers, pathogens, proteins, toxins, antibiotics, adenosine triphosphate, and other small molecules. This review obviously demonstrates that this nanostructure effectively is applicable in the field of biomedicine and possesses potential of commercialization aims.

Selection of aptamers against triple negative breast cancer cells using high throughput sequencing

Triple-negative breast cancer is the most aggressive subtype of invasive breast cancer with a poor prognosis and no approved targeted therapy. Hence, the identification of new and specific ligands is essential to develop novel targeted therapies. In this study, we aimed to identify new aptamers that bind to highly metastatic breast cancer MDA-MB-231 cells using the cell-SELEX technology aided by high throughput sequencing. After 8 cycles of selection, the aptamer pool was sequenced and the 25 most frequent sequences were aligned for homology within their variable core region, plotted according to their free energy and the key nucleotides possibly involved in the target binding site were analyzed. Two aptamer candidates, Apt1 and Apt2, binding specifically to the target cells with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$K_{d}$$\end{document}Kd values of 44.3 ± 13.3 nM and 17.7 ± 2.7 nM, respectively, were further validated. The binding analysis clearly showed their specificity to MDA-MB-231 cells and suggested the targeting of cell surface receptors. Additionally, Apt2 revealed no toxicity in vitro and showed potential translational application due to its affinity to breast cancer tissue sections. Overall, the results suggest that Apt2 is a promising candidate to be used in triple-negative breast cancer treatment and/or diagnosis.

Aptamer-enhanced fluorescence determination of bisphenol A after magnetic solid-phase extraction using Fe3O4@SiO2@aptamer

Bisphenol A (BPA) is used as a stabilizing agent in many food packaging plastics and is a known endocrine-disrupting chemical that can alter the development of mammary glands, affect egg cells, and cause chromosomal defects. However, the pretreatment of traditional assays for detecting BPA is difficult. In this work, a novel aptamer functionalized magnetic adsorbent was developed and combined with magnetic solid-phase extraction (MSPE) for the selective enrichment of BPA. First, magnetic silica-coated Fe₃O₄ microspheres (Fe₃O₄@SiO₂) were synthesized by the sol-gel method, and functional magnetic nanoparticles (Fe₃O₄@SiO₂@Apt) were formed by modifying with nucleic acids. In the presence of BPA in a MSPE system, the nucleic acid aptamer can specifically capture the target BPA. After magnetic separation, the Apt/BPA composite was eluted, and we observed enhanced fluorescence with the Apt/BPA composite that was formed. Our results showed that this method allowed a limit of detection of 0.05 ng mL^-1.

CRISPR-Mediated Isogenic Cell-SELEX Approach for Generating Highly Specific Aptamers Against Native Membrane Proteins

Introduction

The generation of affinity reagents that bind native membrane proteins with high specificity remains challenging. Most in vitro selection paradigms utilize different cell types for positive and negative rounds of selection (where the positive selection is against a cell that expresses the desired membrane protein and the negative selection is against a cell that lacks the protein). However, this strategy can yield affinity reagents that bind unintended membrane proteins on the target cells. To address this issue, we developed a systematic evolution of ligands by exponential enrichment (SELEX) scheme that utilizes isogenic pairs of cells generated via CRISPR techniques.

Methods

Using a Caco-2 epithelial cell line with constitutive Cas9 expression, we knocked out the SLC2A1 gene (encoding the GLUT1 glucose transporter) via lipofection with synthetic gRNAs. Cell-SELEX rounds were carried out against wild-type and GLUT1-null cells using a single-strand DNA (ssDNA) library. Next-generation sequencing (NGS) was used to quantify enrichment of prospective binders to the wild-type cells.

Results

10 rounds of cell-SELEX were conducted via simultaneous exposure of ssDNA pools to wild-type and GLUT1-null Caco-2 cells under continuous perfusion. The top binders identified from NGS were validated by flow cytometry and immunostaining for their specificity to the GLUT1 receptor.

Conclusions

Our data indicate that highly specific aptamers can be isolated with a SELEX strategy that utilizes isogenic cell lines. This approach may be broadly useful for generating affinity reagents that selectively bind to membrane proteins in their native conformations on the cell surface.

Identification of a DNA Aptamer That Binds to Human Monocytes and Macrophages

As cancer strategies shift toward immunotherapy, the need for new binding ligands to target and isolate specific immune cell populations has soared. Based on prior work identifying a peptide specific for murine M2-like macrophages, we sought to identify an aptamer that could bind human M2-like macrophages. Tumor-associated macrophages (TAMs) adopt an M2-like phenotype and support tumor progression and dissemination. Here, we employed cell-SELEX to identify an aptamer ligand that targets this cell population over tissue resident (M0-like) or tumoricidal (M1-like) macrophages. Instead, we identified an aptamer that binds both human M0- and M2-like macrophages and monocytes, with highest binding affinity to M2-like macrophage (K_d ∼ 20 nM) and monocytes (K_d ∼ 45 nM) and minimal binding to other leukocytes. The aptamer binds to CD14⁺ but not CD16⁺ monocytes, and is rapidly internalized by these cells. We also demonstrate that this aptamer is able to bind human monocytes when both are administered in vivo to mice. Thus, binding to these cell populations (monocytes, M0-like and M2-like macrophages), this aptamer lends itself toward monocyte-specific applications, such as monocyte-targeted drug delivery or column selection.

Aptamers Against Live Targets: Is In Vivo SELEX Finally Coming to the Edge?

Targeted therapeutics underwent a revolution with the entry of monoclonal antibodies in the medical toolkit. Oligonucleotide aptamers form another family of target agents that have been lagging behind in reaching the clinical arena in spite of their potential clinical translation. Some of the reasons for this might be related to the challenge in identifying aptamers with optimal in vivo specificity, and the nature of their pharmacokinetics. Aptamers usually show exquisite specificity, but they are also molecules that display dynamic structures subject to changing environments. Temperature, ion atmosphere, pH, and other variables are factors that could determine the affinity and specificity of aptamers. Thus, it is important to tune the aptamer selection process to the conditions in which you want your final aptamer to function; ideally, for in vivo applications, aptamers should be selected in an in vivo-like system or, ultimately, in a whole in vivo organism. In this review we recapitulate the implementations in systematic evolution of ligands by exponential enrichment (SELEX) to obtain aptamers with the best in vivo activity.

Metal-Organic Framework Nanocarriers for Drug Delivery in Biomedical Applications

Investigation of metal-organic frameworks (MOFs) for biomedical applications has attracted much attention in recent years. MOFs are regarded as a promising class of nanocarriers for drug delivery owing to well-defined structure, ultrahigh surface area and porosity, tunable pore size, and easy chemical functionalization. In this review, the unique properties of MOFs and their advantages as nanocarriers for drug delivery in biomedical applications were discussed in the first section. Then, state-of-the-art strategies to functionalize MOFs with therapeutic agents were summarized, including surface adsorption, pore encapsulation, covalent binding, and functional molecules as building blocks. In the third section, the most recent biological applications of MOFs for intracellular delivery of drugs, proteins, and nucleic acids, especially aptamers, were presented. Finally, challenges and prospects were comprehensively discussed to provide context for future development of MOFs as efficient drug delivery systems.

Functional Applications of Nucleic Acid-Protein Hybrid Nanostructures

Combining the diverse chemical functionality of proteins with the predictable structural assembly of nucleic acids has enabled the creation of hybrid nanostructures for a range of biotechnology applications. Through the attachment of proteins onto or within nucleic acid nanostructures, materials with dynamic capabilities can be created that include switchable enzyme activity, targeted drug delivery, and multienzyme cascades for biocatalysis. Investigations of difficult-to-study biological mechanisms have also been aided by using DNA-protein assemblies that mimic natural processes in a controllable manner. Furthermore, advances that enable the recombinant production and intracellular assembly of hybrid nanostructures have the potential to overcome the significant manufacturing cost that has limited the use of DNA and RNA nanotechnology.

Advances of aptamers screened by Cell-SELEX in selection procedure, cancer diagnostics and therapeutics

Aptamers are a class of short artificial single-stranded oligo(deoxy) nucleotides that can bind to different targets, which generated by Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Due to excellent selectivity and high affinity to targets, aptamers hold considerable potential as molecular probe in diverse applications ranging from ensuring food safety, monitoring environment, disease diagnosis to therapy. This review highlights recent development and challenges about aptamers screened by Cell-SELEX, and its application about cancer diagnostics and therapeutics. Advances about some operation methods such as seperation method and culture method in aptamers selection procedure were summarized in this paper. Some common challenges and technological difficulties such as nonspecific binding and biostability were discussed. Up to now, the recent endeavors about cancer diagnostic and therapeutic applications of aptamers are summarized and expatiated. Most of aptamers screened by Cell-SELEX took tumor cells as target cells, and such aptamers have been assembled to various aptasensor for cancer diagnosis. Aptamers conjugated various drugs or nanomaterials are functioned for cancer target therapy to improve drugs delivery efficiency and reduce side effects. Furthermore, the duplexed aptamer is discussed to be applied for cancer cells detection and some conflicts of theories about duplexed aptamer designs are analyzed.

FRET-Based Aptasensor for the Selective and Sensitive Detection of Lysozyme

Lysozyme is a conserved antimicrobial enzyme and has been cited for its role in immune modulation. Increase in lysozyme concentration in body fluids is also regarded as an early warning of some diseases such as Alzheimer’s, sarcoidosis, Crohn’s disease, and breast cancer. Therefore, a method for a sensitive and selective detection of lysozyme can benefit many different areas of research. In this regard, several aptamers that are specific to lysozyme have been developed, but there is still a lack of a detection method that is sensitive, specific, and quantitative. In this work, we demonstrated a single-molecule fluorescence resonance energy transfer (smFRET)-based detection of lysozyme using an aptamer sensor (also called aptasensor) in which the binding of lysozyme triggers its conformational switch from a low-FRET to high-FRET state. Using this strategy, we demonstrated that the aptasensor is sensitive down to 2.3 picomoles (30 nM) of lysozyme with a dynamic range extending to ~2 µM and has little to no interference from similar biomolecules. The smFRET approach used here requires a dramatically small amount of aptasensor (~3000-fold less as compared to typical bulk fluorescence methods), and it is cost effective compared to enzymatic and antibody-based approaches. Additionally, the aptasensor can be readily regenerated in situ via a process called toehold mediated strand displacement (TMSD). The FRET-based aptasensing of lysozyme that we developed here could be implemented to detect other protein biomarkers by incorporating protein-specific aptamers without the need for changing fluorophore-labeled DNA strands.

Discovery of tumoricidal DNA oligonucleotides by response-directed in vitro evolution

Drug discovery is challenged by ineffectiveness of drugs against variable and evolving diseases, and adverse effects due to poor selectivity. We describe a robust platform which potentially addresses these limitations. The platform enables rapid discovery of DNA oligonucleotides evolved in vitro for exerting specific and selective biological responses in target cells. The process operates without a priori target knowledge (mutations, biomarkers, etc). We report the discovery of oligonucleotides with direct, selective cytotoxicity towards cell lines, as well as patient-derived solid and hematological tumors. A specific oligonucleotide termed E8, induced selective apoptosis in triple-negative breast cancer (TNBC) cells. Polyethylene glycol-modified E8 exhibited favorable biodistribution in animals, persisting in tumors up to 48-hours after injection. E8 inhibited tumors by 50% within 10 days of treatment in patient-derived xenograft mice, and was effective in ex vivo organ cultures from chemotherapy-resistant TNBC patients. These findings highlight a drug discovery model which is target-tailored and on-demand.

Noam Mamet et al. describe a platform for rapid de novo discovery of DNA oligonucleotides that directly and selectively induce apoptosis in cancer cells. They report target-tailored discovery of tumoricidal oligonucleotides against tumor cell lines as well as patient-derived tumors.

Cell-SELEX, an Effective Way to the Discovery of Biomarkers and Unexpected Molecular Events

Cell-SELEX can not only generate aptamers for specific cell isolation/detection, diagnosis, and therapy, but also lead to the discovery of biomarkers and unexpected molecular events. However, most cell-SELEX research is concentrated on aptamer generation and applications. In this progress report, recent research progress with cell-SELEX in terms of the discovery of biomarkers and unexpected molecular events is highlighted. In particular, the key technical challenges for cell-SELEX-based biomarker discovery, namely, the methods for identification and validation of target proteins of aptamers, are discussed in detail. Finally, the prospects of the applications of cell-SELEX in this field now and in the near future are described. It is expected that this report will attract attention to the benefit of cell-SELEX and provide a practical reference for biomedical researchers.

Digitizable therapeutics for decentralized mitigation of global pandemics

When confronted with a globally spreading epidemic, we seek efficient strategies for drug dissemination, creating a competition between supply and demand at a global scale. Propagating along similar networks, e.g., air-transportation, the spreading dynamics of the supply vs. the demand are, however, fundamentally different, with the pathogens driven by contagion dynamics, and the drugs by commodity flow. We show that these different dynamics lead to intrinsically distinct spreading patterns: while viruses spread homogeneously across all destinations, creating a concurrent global demand, commodity flow unavoidably leads to a highly uneven spread, in which selected nodes are rapidly supplied, while the majority remains deprived. Consequently, even under ideal conditions of extreme production and shipping capacities, due to the inherent heterogeneity of network-based commodity flow, efficient mitigation becomes practically unattainable, as homogeneous demand is met by highly heterogeneous supply. Therefore, we propose here a decentralized mitigation strategy, based on local production and dissemination of therapeutics, that, in effect, bypasses the existing distribution networks. Such decentralization is enabled thanks to the recent development of digitizable therapeutics, based on, e.g., short DNA sequences or printable chemical compounds, that can be distributed as digital sequence files and synthesized on location via DNA/3D printing technology. We test our decentralized mitigation under extremely challenging conditions, such as suppressed local production rates or low therapeutic efficacy, and find that thanks to its homogeneous nature, it consistently outperforms the centralized alternative, saving many more lives with significantly less resources.

Differentiating breast cancer molecular subtypes using a DNA aptamer selected against MCF-7 cells

Aptamers are single-stranded DNA or RNA oligonucleotides selected by systematic evolution of ligands by exponential enrichment (SELEX), which show great potential in the diagnosis and personalized therapy of cancers, due to their specific advantages over antibodies. In the past years, though great progress has been made in molecular subtyping of breast cancer, it remains a challenge in clinical medicine, which plays a crucial role in the treatment. In this study, a ssDNA aptamer MF3 against MCF-7 breast cancer cells was developed by Cell-SELEX for differentiating breast cancer molecular subtypes, which showed favorable specificity and binding affinity towards MCF-7 cells with a Kd value of 82.25 ± 25.14 nM. The aptamer could not only successfully distinguish MCF-7 breast cancer cells from MDA-MB-231 and SK-BR-3 breast cancer cells and MCF-10A human normal mammary epithelial cells, but also could differentiate MCF-7 cells from other cancer cells or normal cells. Moreover, both in vivo and in vitro fluorescence imaging studies demonstrated that aptamer MF3 was able to distinguish tumor-bearing mice and xenograft tissue sections of MCF-7 breast cancer cells from that of MDA-MB-231 and SK-BR-3 breast cancer cells. All these results suggested that aptamer MF3 is a potential tool for differentiating molecular subtypes and diagnosis of breast cancer.

Selection and preliminary application of a single stranded DNA aptamer targeting colorectal cancer serum

Colorectal cancer is one of the common causes of malignant tumors in recent years, thus the discovery of potential compounds that detect the occurrence of colorectal cancer by efficient approaches is necessary. In this study, the method of systematic evolution of ligands by exponential enrichment (SELEX) was used for recognizing serum from colorectal cancer patients by a single-stranded DNA library of aptamers assisted by single-walled carbon nanotubes (SWCNTs) to remove single-stranded DNA with low affinity. Ten rounds of selection were applied using colorectal cancer serum as a target with the serum of healthy individuals as a control. As the result, we have successfully identified four candidate aptamers after high-throughput genome sequencing analysis, comparison analysis and secondary structure prediction. Among them, aptamer Seq-2 exhibited the highest affinity and the strongest selectivity with an equilibrium dissociation constant (K_d) of 11.31 ± 3.25 nM and a C_t difference value of 4.25 ± 0.38 between the colorectal cancer group and the healthy group. Moreover, with fifty negative control serum samples, the positive detection rate of fifty positive serum samples tested by aptamer Seq-2 was over 90%. In particular, aptamer Seq-2 can strongly bind the colorectal cancer serum, less strongly bind the non-colon cancer serum and hardly bind the healthy serum. Therefore, aptamer Seq-2 presents enormous potential for exploring as a tumor diagnostic kit and detecting unknown tumor markers in serum to reflect colorectal cancer.

Aptamer Seq-2 with high affinity and selectivity was screened against colorectal cancer serum directly for clinical application.

Application of Aptamer-based Hybrid Molecules in Early Diagnosis and Treatment of Diabetes Mellitus: From the Concepts Towards the Future

Aptamers have several positive advantages that made them eminent as a potential factor in diagnosing and treating diseases such as their application in prevention and treatment of diabetes. In this opinion-based mini-review article, we aimed to investigate the DNA and RNA-based hybrid molecules specifically aptamers and had a logical conclusion as a promising future perspective in early diagnosis and treatment of diabetes.

Recent developments in cell-SELEX technology for aptamer selection

BACKGROUND

SELEX technique is employed to select aptamers against wide range of targets. The in vitro method of aptamer selection using live cells as the target is referred as cell-SELEX.

SCOPE OF THE REVIEW

The review provides a comprehensive description on the development of aptamers through various cell-SELEX methods and list of aptamers identified through this method. In addition, it pinpoints the advantages and limitations of the cell-SELEX process and its variants.

MAJOR CONCLUSIONS

The use of aptamers as therapeutic and diagnostic agents is rapidly evolving, selection techniques such as Cell-SELEX could be beneficial in identifying aptamers when the target is in its native conformation and without prior information of the cognate target, thereby bringing the aptamer development one step closer to the clinic.

GENERAL SIGNIFICANCE

The information in this review can serve as a database for the design and development of futuristic oligonucleotide based diagnostics and therapeutics work.