Biomimetic nanoparticles based on polysaccharides-poly(alkylcyanoacrylates) copolymers were initially developed in view of drug delivery. Core-shell nanoparticles covered with a sufficiently long brush of polysaccharides were shown to be very low complement activators and have the potential for long circulation times in the bloodstream. Such nanoparticles bearing haemoglobin were envisaged as potential red cell substitutes. Different core-shell nanoparticles with a brush shell made of dextran, dextran-sulphate, or heparin were prepared and haemoglobin (Hb) could be adsorbed on their surface. Benzene tetracarboxylic acid (BTCA) was used as a coupling agent for Hb to dextran-coated nanoparticles; the Hb loading capacity of the dextran nanoparticles showed a 9.3 fold increased. The coupled Hb maintained the allosteric properties of free Hb. While modification of nanoparticles by BTCA slightly increased complement activation, the further addition of Hb totally reversed this effect providing Hb-loaded nanoparticles with a very low level of complement activation. Such nanoparticles could be a suitable alternative to haemoglobin solutions in the development of a blood substitute.
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