mRNA technology simply explained

New advances in mRNA technology are happening regularly and rapidly. The prevention and treatment of viruses and immunogenic diseases has become possible through new therapeutics that use messenger RNA to help the body produce the right proteins. Nevertheless, the heightened demand for mRNA drugs leads to challenges for its production.

In the following, we will take a closer look at those challenges and explain mRNA and its applications more generally. Further, an outlook is given on how to streamline the manufacturing process to achieve optimal results. 

mRNA - what is messenger RNA?

So what is mRNA, actually? mRNA is the abbreviation for messenger ribonucleic acid. As its name already suggests, mRNA functions as a messenger for genetic information that is needed to form a specific protein in a cell.

Messenger RNA is a single-stranded molecule, which is formed during the transcription process of DNA. An enzyme converts the genetic sequence into mRNA, which is transported from the nucleus of a cell to its cytoplasm, where it is read by the ribosome and a specific protein is formed.¹

In order to treat certain diseases, this method of the body is mimicked. In mRNA technology, the instructions for the production of specific proteins which are needed to accomplish an immune response are encoded into mRNA to help the immune system fight infectious diseases like the coronavirus and other pathogens, genetic diseases and various cancer types.

Due to the short-livety of mRNA, the cells only use it until the protein is produced. Afterwards, it is destroyed and removed from the body without changing the DNA.^1 2 

Applications of mRNA technology

The use of mRNA technology has changed the pharmaceutical sector completely. Its applications range from vaccines to gene therapy which made the treatment of complicated diseases possible and hold a lot of potential for the future. In the following, we explain how mRNA vaccines work and provide information on the topic of gene therapy.

mRNA vaccines and the way they work

With mRNA vaccines, mRNA is delivered to cells with the help of a delivery system in order to trigger the immune system to produce the right antibodies for the fight of certain diseases.

The most recent and known example for mRNA vaccine technology was the vaccine development in the fight against the SARS-CoV2 pandemic, as promoted by the centers for disease control and prevention. Both Moderna and Pfizer-Biontech developed mRNA Covid-19 vaccines, which are considered breakthroughs for international health care.³ 

The way these vaccines work is using mRNA to help cells produce a spike protein, which is also found on the surface of the virus. Once the immune system recognizes these foreign antigens on the outside of the cell, the body produces antibodies and T-cells. This mechanism is responsible for the normal side effects of the vaccination, like fever or headache.

Further, mRNA vaccines have shown good results as cancer vaccines and in the treatment of diseases like influenza or Ebola. The principle is also to help the immune system recognize cancer cells as a potential threat and destroy them.

Next to their important contribution in the handling of the pandemic, storing and shipping mRNA vaccines bear distinctive challenges. They require safe cold chain management and controlled production and distribution methods. To guarantee safe use for the patient, mRNA vaccines have to be stored between -50 and -15 degrees Celsius until their expiration date. Current good manufacturing practice (cGMPs) and Food and Drug Administration (FDA) guidelines have to be met.⁴ 

mRNA technology in gene therapy

In gene therapy, mRNA technology is used to replace faulty or non-functioning genes with healthy genes, which means that the genetic code is inherently altered.⁵

There are different approaches for gene therapy. One is to use silencing RNA, which binds to non-functioning mRNA and prevents it from making a specific protein. The other approach involves the delivery of fully functioning mRNA into cells to provide them with an example of healthy mRNA.

In terms of what’s next for mRNA technology in gene therapy, the future of gene therapies as predicted by investigators is bright.⁶ Many variants are currently in clinical trials and will help to cure diseases like hemophilia, sickle cell disease, certain cancers or infections.

As already established, messenger RNA vaccines like the Pfizer-Biontech or Moderna vaccines for Covid-19 do not alter the DNA and can therefore not be considered gene therapy.^5 6 7 

How does mRNA production work?

The process of mRNA manufacturing for therapeutics is multifaceted and has to be performed under ideal circumstances. Temperature control is an important factor because RNA degrades in the unfrozen state. Therefore, they are ideally stored between -80 and -60 degrees Celsius. As an example, RNA samples are completely destroyed within a few minutes at 40 degrees Celsius.

Further, contamination has to be prevented, which means skilled and well-trained staff is needed during the manufacturing process.  In the following, we have provided a simplified display of the five most important steps in mRNA production:

1. Target gene design and plasmid production
2. Plasmid purification and linearization
3. mRNA synthesis
4. mRNA purification
5. mRNA analytics

Lipid nanoparticles – genome carriers for mRNA

In the development of mRNA therapeutics like new vaccines or gene therapy, good effects have been achieved by using adjuvants like lipid nanoparticles as mRNA delivery systems. In comparison to other delivery systems like viral vectors or modified nucleosides, they pose an exceptionally lower toxic risk, are biodegradable and can easily be absorbed by cells due to their lipophilic qualities. In mRNA delivery, they function as a kind of security shield for the mRNA. They envelop it and transport it to the targeted cells.

Challenges related to mRNA technology

There are several challenges associated with mRNA technology that can make the production of mRNA therapeutics a laborious and risk prone process. As there are often many parties involved in the production of vaccines or gene therapeutics, safe transport and storage conditions have become an integral part in the successful manufacturing.

mRNA cold chain management – best practice in freezing and storing mRNA

As mRNA can only be stored safely under precise temperature ranges, mRNA cold chain management has to be as reliable and efficient as possible in order not to risk any alterations or product loss. Typically, the temperature of the substances during production is kept between -80 and -60 degrees Celsius.

There are different methods for freezing mRNA, one of the most efficient and controllable methods being plate freezing, which allows for even freezing and prevents crystallization or vacuums.

LNP manufacturing

mRNA therapeutics often involve LNP manufacturing as well, which poses its own challenges. As non-viral vectors, lipid nanoparticles show many advantages as drug delivery systems, however, lipid nanoparticle toxicity is still a field of research without enough data because they are relatively new to the market.

Nevertheless, it is essential to meet the requirements of LNPs all along the manufacturing process, as product loss and unwanted side effects in the product have to be avoided. For instance, they have to be stored frozen and are best kept at -20 degrees Celsius. Furthermore, an elaborate fluid management is necessary to deal with often large volumes of biopharmaceuticals.

Single-use solutions in mRNA technology

Usually, mRNA vaccines and gene therapy products are not immediately used after production, but have to be stored until they are due to be used. Single-use bags are an efficient and safe packaging solution which can be combined with a variety of storage systems from Single Use Support or other suppliers.

In order to prevent gaps in the cold chain that could lead to product loss, end-to-end solutions from Single-Use Support help to streamline the process from start to finish while minimizing contamination risks through human errors. Products like the freeze & thaw system Ross.pFTU allow for controlled freezing and thawing of temperature sensitive substances and make mRNA production safe and therefore more profitable.