PREPARATION OF SURFACE-MODIFIED ALBUMIN NANOSPHERES

Surface-modified human serum albumin (HSA) nanospheres with a size of around 100 nm in diameter were prepared from poly(amidoamine)-poly(eth ylene glycol) copolymer grafted human serum albumin (HSA-PAA-PEG) and poly(thioetheramido acid)-poly(ethylene glycol) copolymer grafted huma n serum albumin (HSA-PTAAC-PEG). The nanospheres were produced using a pH-coacervation method and cross-linked with glutaraldehyde. The cros s-linking efficiency was affected by the type of albumin conjugate use d. The zeta potential of the surface-modified nanospheres was signific antly lower than that of unmodified particles. The existence of a hydr ated steric barrier surrounding the nanospheres was confirmed by elect rolyte- and pH-induced flocculation tests. The surface-modified nanosp heres showed a reduced plasma protein adsorption on the particle surfa ce compared with unmodified particles. (C) 1997 Elsevier Science Limit ed.