麻豆淫院

During the COVID-19 pandemic, pharmaceutical companies produced unprecedented quantities of vaccines. This helped save millions of lives, but on the other hand, many vaccines remained unused, expired, and had to be thrown away. To avoid such problems in the future, Lithuanian researchers at the Center for 麻豆淫院ical Sciences and Technology (FTMC) are proposing an environmentally friendly solution as part of a project. Perhaps expired vaccines could be repurposed for another task: the development of new biosensors?

A group of scientists successfully demonstrated this possibility for the first time in the world in their article, which in Talanta.

The authors of the article are researchers from the FTMC Department of Nanotechnology: Dr. Vincentas Mindaugas Ma膷iulis, Dr. Asta Lu膷i奴nait臈, Dr. Mantvydas Usvaltas, Dr. Silvija Juci奴t臈, and Prof. Dr. Ieva Plikusien臈, as well as Dr. Almira Ramanavi膷ien臈, professor at the Faculty of Chemistry and Geosciences at Vilnius University.

Out-of-date preparations, but useful spikes

At the height of the pandemic, we heard stories from the media about how governments purchased large quantities of vaccines鈥攂ut like all products, they have an expiration date. Many of these vaccines remained unused and had to be thrown away. So FTMC scientists came up with an idea鈥攖o give expired preparations a second life.

"We focused our attention on the vaccines with virus-like particles (VLP). VLPs are protein structures that resemble real viruses but do not contain their genetic material (DNA or RNA). Therefore, they cannot cause infection, but the immune system recognizes them as a threat and begins to produce antibodies, thus forming immunity," says Dr. Vincentas Mindaugas Ma膷iulis, the lead author of the study.

The Lithuanian team has set itself two tasks: to use expired COVID-19 VLP vaccines and adapt them for use in biosensors that would help determine immunity to the coronavirus.

The expired vaccines were donated from the laboratory of Dr. Aurelija 沤virblien臈, a professor at the Life Sciences Center of Vilnius University (VU GMC).

"In addition to spike protein, the vaccine contains extra components鈥攑harmaceutical substances that improve the stability of the drug, as well as adjuvants. The latter are molecules that stimulate the immune response so that the body recognizes the danger and begins to protect itself.

"There are a lot of these additional substances in the vaccine. We needed to purify and obtain only spike proteins in order to get 'clean, concentrated' vaccines. This work was done by my colleague Dr. Asta Lu膷i奴nait臈 from VU GMC, who is also currently a research intern at the FTMC Department of Nanotechnology. She also conducted comparative studies to see whether the 'cleaned' spike proteins react with antibodies. That was our initial task," explains Dr. Ma膷iulis.

Greener and cheaper disease prevention

What happened next? Simply put, the spike proteins from the vaccines were "attached" (immobilized) to the gold surface using chemical bonds. This surface was thus designed to detect antibodies.

For this purpose, Ma膷iulis's team used specially prepared blood sera containing different amounts of antibodies. They were tested using three different sensor surfaces. One contained previously mentioned isolated spike proteins, another contained commercially available spike proteins from the virus strain that circulated at the beginning of the pandemic, and the third contained spike proteins from the omicron variant of the coronavirus.

The scientists observed how each spike of proteins bound to antibodies in blood serum鈥攚hether these spikes with different mutations would recognize a person's immunity to the coronavirus.

"As we described in the paper, these first experiments were very successful. In this way, biosensors recognized antibodies using spike proteins obtained from outdated vaccines and provided reliable results. Compared to commercial 'fresh' proteins, this interaction is not yet as accurate, but this is only the beginning. The overall result is encouraging鈥攁t this stage, the use of old vaccines is proving worthwhile.

"We are trying to be environmentally friendly so that vaccines no longer need to be discarded鈥攁nd so that vaccine production itself becomes more sustainable. In addition, if we succeed in refining our method into biosensor technology, it will be a much cheaper way to detect specific antibodies. Every scientist working in this field will tell you that buying specially designed proteins is expensive鈥攁nd in our case, laboratories could obtain expired vaccines much more cheaply," remarks the scientist.

After the successful demonstration that such a model system works, the FTMC team aims to continue its experiments, and it would also be useful to conduct immunity tests with other non-COVID-19 vaccines. For example, VLP vaccines against human papillomavirus or hepatitis B are developed using the same technologies. So, there is a good chance to adapt the method to prevent other diseases.

"It is likely that the method would work in a very similar way, but we would need to make sure that it is possible to obtain the same results. We also plan to improve the process of extracting spike proteins from old vaccines to strengthen their interaction with antibodies," says Ma膷iulis.