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

Abstract

This study describes new lectin-decorated or protein-loaded nanoparticles with a hydrophobic poly(ε-caprolactone) (PCL) core and a hydrophilic dextran (Dex) corona. In this view, a family of block Dex–PCL n 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–PCL n 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-PCL n nanoparticles, even at concentrations as high as 660 μg/ml.