NANOTECHNOLOGY FOR BIOMATERIALS ENGINEERING - STRUCTURAL CHARACTERIZATION OF AMPHIPHILIC POLYMERIC NANOPARTICLES BY H-1-NMR SPECTROSCOPY

Nanoparticles composed of diblock poly(D,L-lactide-co-glycolide)-poly( ethylene glycol) (PLGA-PEG) or a branched, multiblock PLA-(PEG)(3) wer e prepared by the single emulsion technique. Results of previous studi es of these nanoparticles suggested that their structure is of the cor e-corona type with a polyester core and an outer PEG coating. In the p resent study, H-1 NMR spectroscopy was utilized to provide direct evid ence of the structure of these nanoparticles suspended in an aqueous e nvironment. The results confirm the existence of the core-corona struc ture under these conditions, and show that the PEG moieties extend out from the nanoparticle core into the aqueous environment, and exhibit chain mobility similar to that of PEG in solution. (C) 1996 Elsevier S cience Limited