Fig. 4

Morphological analysis of microspheres by scanning electron microscopy. Blank silica gel microspheres a; peptide-modified microspheres b; M3R-coated microspheres c; microspheres incubated with N,N-dimethylformamide d; microspheres incubated with CH₂Cl₂ containing EDTA e; microspheres incubated with phosphate buffer (20 mM, pH 7.4) (f)