A team led by the Massachusetts Institute of Technology (MIT) has developed microparticles that can be adjusted to deliver their payload at different timesaccording to a study published by Science Advances.
The team describes how these particles degrade over time and offers insight into how the content can be protected from losing its stability while waiting to be released.
According to the researchers, this method could also be used to deliver other therapiessuch as anticancer drugs, hormonal therapies, and biologic drugs.
Shaped like a cup of coffee closed with a lid, these microparticles they can stay under the skin until the vaccine is released and then break down.
The authors consider that this way of supplying vaccines could be especially useful for children in regions where the population does not have frequent access to medical care.
The first author of the research, Ana Jaklenec, from MIT, indicated that it is a platform that can be widely used. applicable to all types of vaccinesincluding those based on recombinant proteins, DNA or RNA.
The article describes the process of how vacuas are released, which “has allowed us to work on formulations that address some of the instability that could be induced over time,” he added.
The researchers first described their new technique microfabrication to manufacture these hollow microparticles in 2017.
The particles are made from PLGA, a biocompatible polymer which has already been approved for use in medical devices such as implants, sutures and prosthetics.
In this new study, they deepened their understanding of how the particles degrade over time, what causes them to release their content, and whether it is possible to improve the stability of the drugs or vaccines they carry.
The researchers found that parameters such as the size and shape of the particles hardly affected the kinetics of drug release and that when they release their charge is related to differences in polymer composition and the chemical groups attached to their ends.
“If we want the particle to be released after six months for a certain application, we use the corresponding polymer, or if we want it to be released after two days, we use another polymer,” explained another of the authors Morteza Sarmadi.
In addition, they studied how changes in the environmental pH affect the particles, since if it is more acidic it can damage the drugs they transport.
The researchers are now working on ways to counteract this increased acidity, which they hope will improve the stability of the payload carried within the particles.
To help design future particles, they developed a computational model that can take into account many design parameters and predict how a particular particle will degrade in the body.
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The research team has already used this strategy to design a self-boosted polio vaccine, which is now being tested on animals. Normally, the polio vaccine has to be given in a series of two to four separate injections.
This single injection approach also has the potential to increase cellular and humoral immune responses to the vaccineaffirmed Robert Langer, of MIT and also a signatory.