What is an aptamer ?

The selective binding capacity of aptamers has major implications in research and medicine.
They are used in a variety of fields, from the specific detection of biomarkers to the design of targeted drugs.
Aptamers are also of interest in analytical chemistry/biochemistry for the quantitative detection of biomarkers or contaminants.

Origin and discovery of aptamers

The history of aptamers dates back to the 1990s, when researchers began exploring new alternatives to traditional antibodies for the recognition of targets.
The discovery and development of aptamers has been hailed as a major breakthrough in biotechnology. Jack Szostack and Larry Gold were pioneers in this field, and in particular helped define the foundations of the SELEX technology.

Comparison with other probes and ligands

Compared to other ligands such as antibodies, aptamers offer several advantages. They are more stable, less costly to produce in large quantities, and their in vitro selection process is faster and more versatile.
Aptamers can be developed to target specific molecules without the need for animal breeding or cell culture, making them particularly attractive for applications in research and medicine.

How do aptamers work ?

The aptamer selection process is the cornerstone of the creation of specific aptamers. It begins with the generation of an initial library of random oligonucleotides. This library contains a multitude of DNA or RNA sequences, each with a unique three-dimensional structure.
This library is then subjected to selection cycles in which aptamers with a high affinity for the desired target are isolated. These cycles consist of a series of steps that include binding to the target, washing to remove unbound sequences, and finally, elution of target-bound aptamers.
This process is repeated several times iteratively until the aptamers with high specificity and affinity are selected by Novaptech.

The specific binding mechanism of aptamers to their target

Aptamers use a variety of molecular interactions to bind to their target hydrogen bonds, electrostatic or/and stacking interactions, between the aptamer nucleotides and the target residues. This interaction is highly specific, depending on the precise molecular characteristics of the target.
Moreover, the aptamer three-dimensional conformation is essential for its specificity. The aptamer adopts a particular folded structure that perfectly matches the shape of the target. This ensures tight, specific binding.

Examples of targets commonly studied with aptamers

Aptamers have become the tools of choice for the recognition and study of a variety of biomolecular targets. Commonly studied examples include proteins, peptides, viruses, bacteria, cells, drugs and chemical compounds.
For example, aptamers have been developed to specifically target proteins such as thrombin, EGFR (epidermal growth factor receptor) and vascular endothelial growth factor (VEGF).
These aptamers are used in biomedical research for applications ranging from biomarker to drug analysis.

Use of aptamers in molecular biology

Today, aptamers are essential tools in molecular biology for studying various cellular and molecular processes.
They can be used to analyze the structure and function of proteins by binding specifically to them. For example, aptamers are used to study protein-protein interactions, to target specific regions of proteins or to selectively inhibit their activity.
These applications are essential for understanding the biological mechanisms underlying many diseases and for developing new therapies.

Applications in diagnostics and detection

Thanks to their high specificity, aptamers are able to detect specific biomarkers associated with diseases, such as proteins or metabolites.
This capability enables Novaptech to create accurate, rapid and sensitive diagnostic tests for diseases such as cancer, viral infections or neurodegenerative diseases.
Aptamers are also used to detect toxic substances or contaminants in the environment (pesticides, endocrine disruptors, drug residues…).

Aptamers in pharmacology

In the pharmaceutical industry, aptamers are playing an increasingly important role in drug discovery. They can be designed to specifically target proteins involved in disease, paving the way for the development of more specific and less toxic drugs.
For example, aptamers are being studied to target cell receptors involved in cancer or autoimmune diseases. 

In addition, aptamers can be used to deliver drugs directly to target cells, thus minimizing undesirable side effects.

Detection of small molecules in medicine and environment

– Companion test
– Point of care or in the field analysis
– Food safety
– Pollution analysis

Diagnostic applications

– Metabolite monitoring
– Biomarker detection

Therapy with aptamers

Aptamers and Novaptech are revolutionizing the field of medicine by offering the possibility
of developing targeted therapies.
This approach enables drugs to be delivered specifically to diseased cells or tissues, thereby
reducing the risk of adverse effects on healthy tissue. Aptamers can be designed to target
specific receptors on the surface of cancer cells, virus-infected cells or cells involved in
autoimmune diseases.
This high-precision drug delivery enhances treatment efficacy while reducing side effects.

Aptamers in cancer treatment

One of the applications of aptamers in medicine is in cancer treatment.
In this context, aptamers are designed to specifically target proteins overexpressed on the
surface of cancer cells, making them precise binding agents for the delivery of anti-cancer
drugs.
In addition, aptamers are used to block cancer cell growth signals or inhibit tumor
vascularization, representing a brake on cancer progression.

The advantages of aptamers are numerous, reinforcing their position as an innovative solution in the development of new therapies, innovative diagnostic probes and robust analytical tools :
1. High binding specificity : aptamers are designed to bind highly specifically to their target, be it a protein, a virus or a small molecule. This specificity ensures that the aptamer interacts only with the intended target, minimizing undesirable side effects. This precision and affinity in binding is essential for the creation of tools in many applications.
2. Modifiability to improve their binding properties and function : Aptamers can be chemically modified to improve their stability in the biological environment, for their detection through their conjugation to a dye or for their grafting on a support.
3. Less immunogenic than antibodies : Unlike antibodies, are not or poorly immunogenic, less likely to trigger an immune response in the patient’s body.
This characteristic is particularly important during repeated use of a drug, as an undesirable immune response is likely to lead to a reduction in treatment efficacy.

Although aptamers have already demonstrated their potential in numerous applications, challenges remain in the field of aptamer research.
Novaptech researchers are actively working on chemical modifications to improve their properties (affinity, lifetime…).
Another challenge facing Novaptech teams is to develop even more efficient large-scale screening methods. Efforts are underway to automate and optimize the SELEX selection process to make our aptamer identification more efficient and cost-effective.