Liposomes as vehicles for cellular incorporation of biologically active macromolecules

Summary Lipid vesicles (liposome) have recently been shown to be a useful vehicle for the delivery of a variety of compounds to cultured cells. Using large unilamellar vesicles composed of phosphatidylserine [LUV(PS)] we were able to encapsulate poliovirus and purified poliovirus ribonucleic acid (RNA) and show that it can be delivered efficiently to cells in an infectious form. LUV-entrapped poliovirus RNA produced infectious titers 100-fold higher than comparable RNA preparations delivered to cells by other techniques. We have made a quantitative analysis of the uptake and infectivity of the vesicle-encapsulated RNA by using various ratios of RNA copies per vesicle and by determining the percentage uptake of labelled lipid and RNA by HeLa cells. Presented in the symposium on Gene Transfer, Differentiation and Neoplasia in Plant and Animal Cells at the 30th Annual Meeting of the Tissue Culture Association, Seattle, Washington, June 10–14, 1979. This symposium was supported in part by Grant CA 26748 from the National Cancer Institute, DHEW, and Grant RD-67 from the American Cancer Society. The research described here was supported by Grants AI-14042, CA-18527 and GM-18921 from the National Institute of Health and IN-54P-16 from the American Cancer Society.