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Browsing by Author "Ferreira, Sara Ataíde"

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  • Development of fucoidan/chitosan nanoparticulate systems for protein administration through mucosal routes
    Publication . Ferreira, Sara Ataíde; Grenha, Ana
    Presently, the administration of therapeutic proteins through non-parenteral routes poses a challenge due to stability problems, mainly attributed to pH and high enzymatic content present in mucosal surfaces. Therefore, the administration of proteins through mucosal routes requires the development of suitable carriers which confer stability and protection against harsh environments of the organism and that further facilitate macromolecule permeation. Polymeric nanoparticles have been proposed as valuable systems to overcome these biological barriers, showing, in some cases, useful properties of controlled release and cellular internalization. In this context, there is also a growing tendency towards the use of natural polymers such as polysaccharides, because of their unique properties and high biocompatibility and biodegradable profile. In this work, fucoidan/chitosan (FUC/CS) nanoparticles were prepared by polyelectrolyte complexation. The aim lying in the development of these carriers is the expectation that they confer stability and protection to the biomolecules against mucosal environments, such as pH and enzymatic contents, providing a non-parenteral route for the administration of protein-based drugs. In this study, bovine albumin serum, insulin and ovalbumin were used as model proteins. Several FUC/CS mass ratios (4/1 to 1/4) were tested, resulting in nanoparticles with different sizes (338-676 nm) and zeta potentials (+41 a -49 mV). Nanoparticles FUC/CS = 1/4 and 4/1 were proposed for BSA encapsulation and variables such as order of polymer addition over each other and the polymeric solution with which the protein was mixed at first, were tested for their ability to affect the nanoparticles encapsulation efficiency. Efficiencies as high as 100% were registered (FUC/CS = 4/1) and the tested variables were found to have a stronger effect on the formulation FUC/CS = 1/4. The small sizes and high negative and positive charges displayed by the developed nanoparticles, in addition of their ability to associate macromolecules, were considered to hold potential for an application in mucosal delivery.
    2012Master thesis Open access Show more