Novel core(polyester)-shell(polysaccharide) nanoparticles: protein loading and surface modification with lectins.

This study describes new lectin-decorated or protein-loaded nanoparticles with a hydrophobic poly(epsilon-caprolactone) (PCL) core and a hydrophilic dextran (Dex) corona. In this view, a family of block Dex-PCLn copolymers was first synthesized, consisting of a Dex backbone to which n preformed PCL blocks were grafted. The ability of these new copolymers to form nanoparticles was evaluated in comparison with a series of PCL homopolymers of various molecular weights (2000, 10,000 and 40,000 g/mole). Two different nanoparticle preparation methods have been developed and tested for their efficacy to incorporate proteins. For this, three proteins were used: a model protein, bovine serum albumin (BSA), a lectin from leaves of Bauhinia monandra (BmoLL) and Lens culinaris (LC) lectin. All these proteins were successfully incorporated in nanoparticles with a mean diameter around 200 nm. Lectins could also be adsorbed onto the surface of Dex-PCLn nanoparticles. Surface-bound BmoLL conserved its hemagglutinating activity, suggesting the possible application of this type of surface-modified nanoparticles for targeted oral administration. Caco-2 cellular viability was higher than 70% when put in contact with Dex-PCLn nanoparticles, even at concentrations as high as 660 microg/ml.