Lysozyme – alginate nanocomplex: Effect of alginate composition

J.P. Fuenzalida, P.K. Nareddy, I. Moreno-Villoslada, B. Moerschbacher, M.J. Swamy, F.M.A. Goycoolea
Westfälische Wilhelms-Universität Münster, DE

Keywords: lysozyme, alginate, nanocomplex, isothermal titration calorimetry

Summary:

In the present work we investigated the electrostatic self-assembly of nanoparticles of Lyz and different alginates (Alg A Mw~4kD and M/G~1.42 or Alg B Mw~7kD and M/G~5.00)to establish a relationship between the alginate structure and the biophysical (size, zeta potential, optical density, thermodynamic and SAXS) properties of the systems. The NCXs were formed at varying charge ratio between of positive in Lyz and negative charge in Alg [n+]/[n-].Alg B is able to retain ~3-fold more Lyz than Alg A, a result that is in line with the larger size of NCXs formed by Alg B (168±1 and 101±3 nm, respectively). This fact could be associated to the more extended structure of Alg B, which facilitates greater Lyz association than do Alg A the self-assembly process is enthalpically driven in the three system corresponding with an electrostatic interaction in which the negative entropy is due to the structural fixation of both highly hydrated molecules. It is possible to observe a relationship between increasing size and percentage of loaded Lyz with the number of alginate monomers bound per Lyz. The Lyz-Alg NCXs have been loaded with voriconazole and naproxen an the permeability across a model cell epithelium (MDCK)is currently being evaluated.