Polymer-coated nanoparticles to promote drug delivery to the brain


Date:
November 5, 2021
Source:
Institut national de la recherche scientifique - INRS
Summary:
Researchers are optimizing polymer-coated nanoparticles to increase
their permeability across this barrier and consequently the delivery
of encapsulated drugs in the brain.



FULL STORY ========================================================================== Treating diseases such as Alzheimer's or Parkinson's is a challenge
because drugs have to be able to cross the blood-brain barrier. As a
result, the doses administered must be high and only a small fraction
reaches the brain, which can lead to significant systemic side effects. To solve this issue, the postdoctoral researcher Jean-Michel Rabanel,
under the supervison of Professor Charles Ramassamy, at the Institut
national de la recherche scientifique (NRS), is optimizing polymer-coated nanoparticles to increase their permeability across this barrier and consequently the delivery of encapsulated drugs in the brain.


==========================================================================
In their recentstudy, the team demonstrated the effectiveness of a
specific polymer with zwitterion properties. These molecules are neutral overall, and have an equal number of positive and negative charges to
mimic the molecules on the cell's surface. The researchers compared the characteristics of two polymer coatings on the polylactic acid (PLA) nanoparticles, a biocompatible material easily cleared by the body.

Promising coatings The first coating, made of polyethylene glycol (PEG),
had already been tested on the zebrafish, whose transparent body makes
it possible to see the distribution of nanoparticles virtually in real
time. The second coating, made of zwitterionic polymer, was compared
under the same conditions.

"With this type of experiment, we demonstrated that the zwitterionic
polymer, which in theory is more biocompatible since it's similar
to molecules at the cell's surface, have a better access to the
brain. However, it is more rapidly absorbed by blood vessel walls,
which reduces their circulation time," explained Professor Ramassamy.

Thus, PEG remains the most attractive coating polymer with respect to
the bloodstream, while the zwitterionic polymer would potentially result
in a weaker immune system response. Professor Ramassamy pointed out that
a mixture of both polymers could be considered to leverage the benefits
of each.

"Our findings demonstrate that the drug coating is a very important factor
in the therapeutic use of nanoparticles. It's an interesting avenue for delivering drugs directly to the brain and improving the treatment for neurodegenerative diseases," said the researcher, who also holds the
Louise and Andre' Charron Research Chair on Alzheimer's Disease at the Armand-Frappier Foundation.

According to Socie'te' Alzheimer de Que'bec, neurodegenerative diseases currently affect more than 565,000 Canadians, including 152,121 in
Que'bec.

========================================================================== Story Source: Materials provided by Institut_national_de_la_recherche_scientifique_-_INRS.

Original written by Audrey-Maude Ve'zina. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Jean-Michel Rabanel, Jimmy Faivre, Charlotte Zaouter, Shunmoogum A.

Patten, Xavier Banquy, Charles Ramassamy. Nanoparticle shell
structural cues drive in vitro transport properties, tissue
distribution and brain accessibility in zebrafish. Biomaterials,
2021; 277: 121085 DOI: 10.1016/ j.biomaterials.2021.121085 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/11/211105084058.htm

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