COMPLEMENT CONSUMPTION BY POLY(ETHYLENE GLYCOL) IN DIFFERENT CONFORMATIONS CHEMICALLY COUPLED TO POLY(ISOBUTYL 2-CYANOACRYLATE) NANOPARTICLES

There is an increasing interest to develop injectable drug polymeric c arriers not recognizable by the body as foreign particles and eliminat ed very quickly from the bloodstream. A polyethylene glycol (PEG)-coat ing onto injectable particles showed to reduce either protein adsorpti on and complement consumption, as a function of the PEG density. In th is work we compared the complement rejecting ability of PEG in differe nt conformations coupled to polyisobutylcyanoacrylate (PIBCA) nanopart icles, through the analysis of the residual hemolytic capacity of the human serum after contact with the particles. Nanoparticles were forme d by chemical coupling of PEG during emulsion/polymerization of isobut ylcyanoacrylate (IBCA). Nanoparticles characterization included an inv estigation of their surface properties, such as hydrophilicity and con formational mobility of the PEG chains grafted on the nanoparticles su rface, and PEG total content. The polymerization kinetics of IBCA in p resence of PEG or MePEG were also studied. Complement consumption was observed to be very sensitive to the number of particles in contact wi th human serum, as well as to the PEG conformation, suggesting PEG con figuration could affect the particle exposed surface.