Injectable hydrogel could someday lead to more effective vaccines

September 16, 2020

Vaccines have curtailed the spread of several infectious diseases, such as smallpox, polio and measles. However, vaccines against some diseases, including HIV-1, influenza and malaria, don't work very well, and one reason could be the timing of antigen and adjuvant presentation to the immune system. Now, researchers reporting in ACS Central Science developed an injectable hydrogel that allows sustained release of vaccine components, increasing the potency, quality and duration of immune responses in mice.

To confer resistance to infectious diseases, vaccines display parts of a pathogen -- known as antigens -- to cells of the immune system, which develop antibodies against these molecules. If a vaccinated person later becomes infected with the same pathogen, their immune system can quickly deploy antibodies to destroy the invader. Vaccines usually contain an additional component, called an adjuvant, that helps stimulate the immune system. In natural infections, the body is typically exposed to antigens for 2-3 weeks, compared with only 1-2 days for vaccines. Eric Appel and colleagues wondered whether they could develop an injectable hydrogel that would slowly release vaccine components over a longer period of time, more similar to what the body is used to, which might boost the immune response.

The researchers developed a polymer-nanoparticle hydrogel that could be mixed with vaccine components. When injected under the skin of mice, the material formed a localized area of inflammation that attracted certain types of immune cells, while slowly releasing the antigen and adjuvant over a period of several days. As a result, the mice injected with the hydrogel produced more antibodies over a longer period of time than mice treated with a traditional vaccine. Importantly, the antibodies produced by the hydrogel-vaccine-treated mice had about 1,000-fold higher affinity for the antigen than those made by mice receiving the standard immunization. Although the new system still needs to be tested to see if it improves vaccine protection from specific diseases, this study demonstrates a simple, effective vaccine delivery platform that enhances the potency and duration of antibody-mediated immunity in mice, the researchers say.
-end-
The authors acknowledge funding from the Bill and Melinda Gates Foundation; the Stanford School of Medicine Immunity, Transplantation and Infection Seed Grant; and the National Science Foundation Graduate Research Fellowship.

The paper's abstract will be available on September 16 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acscentsci.0c00732

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS' main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Follow us: Twitter | Facebook

American Chemical Society

Related Immune System Articles from Brightsurf:

How the immune system remembers viruses
For a person to acquire immunity to a disease, T cells must develop into memory cells after contact with the pathogen.

How does the immune system develop in the first days of life?
Researchers highlight the anti-inflammatory response taking place after birth and designed to shield the newborn from infection.

Memory training for the immune system
The immune system will memorize the pathogen after an infection and can therefore react promptly after reinfection with the same pathogen.

Immune system may have another job -- combatting depression
An inflammatory autoimmune response within the central nervous system similar to one linked to neurodegenerative diseases such as multiple sclerosis (MS) has also been found in the spinal fluid of healthy people, according to a new Yale-led study comparing immune system cells in the spinal fluid of MS patients and healthy subjects.

COVID-19: Immune system derails
Contrary to what has been generally assumed so far, a severe course of COVID-19 does not solely result in a strong immune reaction - rather, the immune response is caught in a continuous loop of activation and inhibition.

Immune cell steroids help tumours suppress the immune system, offering new drug targets
Tumours found to evade the immune system by telling immune cells to produce immunosuppressive steroids.

Immune system -- Knocked off balance
Instead of protecting us, the immune system can sometimes go awry, as in the case of autoimmune diseases and allergies.

Too much salt weakens the immune system
A high-salt diet is not only bad for one's blood pressure, but also for the immune system.

Parkinson's and the immune system
Mutations in the Parkin gene are a common cause of hereditary forms of Parkinson's disease.

How an immune system regulator shifts the balance of immune cells
Researchers have provided new insight on the role of cyclic AMP (cAMP) in regulating the immune response.

Read More: Immune System News and Immune System Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.