• Polymer-coated nanoparticles to promote

    From ScienceDaily@1:317/3 to All on Fri Nov 5 21:30:44 2021
    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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