Amino acids and peptides. XXV. Preparation of fibronectin-related peptide poly(ethylene glycol) hybrids and their inhibitory effect on experimental metastasis.

Hybrids of fibronectin-related peptides [Arg-Gly-Asp (RGD), Arg-Gly-Asp-Ser (RGDS)] and poly(ethylene glycol) (PEG) were prepared and their inhibitory effects on experimental metastasis in mice were examined. The inhibitory effect of RGD was markedly potentiated by hybrid formation with poly(ethylene glycol) #6000. As to inhibitory effect, RGD was more potent than RGDS and RGD PEG hybrids were superior to RGDS PEG hybrids. Hybrid formation with PEG #6000 was more effective than that with PEG #4000.