(P 273) Nanostructured Polymeric Constructs as Blood Substitutes

The present work is aimed at the development of biopolymeric nanoparticles to be used as blood substitutes. Developing alternative strategies to commonly used blood transfusion is essential because of the fewness of donor, the short time storage of blood samples and the presence of blood antigens. Two alternative polymeric matrices were used, the synthetic 2-methoxyethanol hemiesters of poly(maleic anhydryde-alt-butylvinylether) grafted with polyethylen glycol (PEG) VAM41-PEG and the natural derived polymer Alginate. Hemoglobin loaded nanoparticles based on VAM41-PEG were prepared by means of the co-precipitation technique. The process was performed under controlled conditions (N2 atmosphere, 4 degree C), in the presence of reducing agents (such as ascorbic acid and methylene blue).The prepared nanoparticles have shown a spherical morphology and a diameter distribution of about 140 nm, detected by means of Scanning Electron Microscopy (SEM) and light scattering analysis, while the quantification of loaded haemoglobin, performed by means of Drabkin's assay, revealed a protein loading of about 50%. Zeta potential measurements confirmed PEG chains exposure on nanoparticles surface giving these structures stealth properties once in-vivo. Alginate beads loaded with Hemoglobin were obtained via ionical gelation with a diameter of about 2 mm. UV-Vis analysis revealed that the protein maintain its functionality when loaded inside these structures. Although further investigation aimed at testing alternative reducing agents, modifying the starting polymeric matrix and reducing Alginate beads size are currently ongoing, these results appear promising in order to produce polymeric nanoparticles to be used as blood substitutes.