Entrapment of plasmid DNA by liposomes and their interactions with plant protoplasts

Abstract

Lecithin and lecithin/cholesterol liposomes formed in aqueous solutions of DNA entrap covalently closed circular, open circular and linear DNA molecules of size up to at least 13 kilobases. The sequestered DNA molecules are efficiently protected against exogenous deoxyribonuclease action although nicking and linearization of circular DNA can be observed. The size of these liposomes ranges from approximately 0.5 to 7.5 mu with an average of 2.5--4 mu. DNA filled liposomes strongly interact with plant protoplasts under conditions inducing protoplast fusion. Results suggest that sequestered plasmid DNA can be transferred to protoplast nuclei.

Stabilized plasmid-lipid particles: construction and characterization

“…Plasmid DNA has been encapsulated by a variety of methods, including reverse phase evaporation, [18][19][20] ether injection, 21,22 detergent dialysis in the absence of PEG stabilization, 20,21 lipid hydration and dehydration-rehydration techniques [25][26][27] and sonication, [28][29][30] among others. The characteristics of these protocols are summarized in Table 1.…”

Neutral Liposomes and DNA Transfection

“…It was in those years that the entrapment of synthetic polynucleotides (Magee et al, 1976), as well as natural ones (Hoffman et al, 1978;Lurquin, 1979), was undertaken. Large unilamellar liposomes were obtained (Dimitriadis, 1978) by adding ribonucleic acid (globin mRNA) to PS and it was demonstrated that mRNA is really entrapped and not simply adhering to the surface.…”

Liposome-mediated Transfer of Simian Virus 40 DNA and Minichromosome into Mammalian Cells

“…The technique of liposome preparation we used, reverse-phase evaporation (Szoka & Papahadjopoulos, 1978), has been reported to produce large, unilamellar vesicles. These entrap greater quantities of input DNA than multilamellar vesicles (Hoffman et al, 1978;Lurquin, 1979) or unilamellar vesicles produced by other methods (Dimitriadis, 1979). Additionally, DNA molecules as large as bacteriophage lambda (approx.…”

“…In addition, liposome-entrapped mitotic chromosomes have been used to transfer the hypoxanthine-guanine phosphoribosyltransferase gene into cells at a significantly higher rate than with free mitotic chromosomes (Mukherjee et al, 1978). Although several reports have described methods to entrap 'naked' DNA in liposomes (Hoffman et al, 1978;Dimitriadis, 1979;Lurquin, 1979), transfer and subsequent expression of such DNA in mammalian cells has only recently been demonstrated. Liposome-mediated transfer and expression of viral DNA (Fraley et al, 1980;Straus et al, 1981), E. coli plasmid/~-lactamase gene (Wong et al, 1980), and herpes simplex virus thymidine kinase gene (SchaeferRidder et al, 1982) have been reported.…”