Fluoropolymer based on a polyaspartamide containing 1,2,4-oxadiazole units:: A potential artificial oxygen(O2) carrier

In this preliminary work we have prepared a fluorinated polymer capable of solubilizing an appreciable amount of O-2 and, at the same time, maintaining a higher water solubility than perfluoroalkanes investigated as injectable O-2 carriers. In particular, we describe the synthesis and characterization of a new macromolecular conjugate obtained by derivatization of alpha, beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) with 5-pentafluorophenyl-3-perfluoroheptyl-1,2,4-oxadiazole, called PHEA-F. This new water soluble fluoropolymer was prepared in high yield using a simple procedure. It was characterized by FT-IR and UV-vis spectrophotometry, F-19-NMR and SEC measurements. O-2 solubility studies on PHEA-F aqueous solutions were carried out at 25 degrees C and 37 degrees C at atmospheric pressure and showed that PHEA-F conjugate, despite its low degree of derivatization in fluorine containing groups (2.60 mol-%), is capable of dissolving 13-15% more O-2 than non-fluorinated PHEA. Moreover, O-2 release in simulated physiological conditions is faster for PHEA-F than for PHEA. The biocompatibility of this conjugate has been evaluated by performing an in vitro viability assay on human chronic myelogenous leukaemia cells (K-562) chosen as a model cell line and in vitro haemolysis experiments on human RBCs. All these properties suggest the potential use of PHEA-F as an artificial O-2 carrier.