Solubilization and stabilization of carotenoids using micelles: Delivery of lycopene to cells in culture

The use of the organic cosolvents tetrahydrofuran and dimethylsulfoxide was found to be unsuitable for prostate tumor cell cultures because of solvent cytotoxicity and the poor solubility and instability of lycopene. For exam ple, the half-life of lycopene in organic/aqueous solution was found to be less than 2 h. Therefore, a micellar preparation of lycopene was developed for the solubilization and stabilization of lycopene in cell culture media. Neither the micelles themselves nor lycopene solubilized in micelles at co ncentrations up to 10 mu g/mL in the cell culture media produced cytotoxici ty or inhibition of cell proliferation in either LNCaP human prostate cells or Hs888Lu human lung cells. Lycopene solubilized in micelles was stable f or at least 96 h under standard cell culture conditions so that a constant lycopene supply could be provided to the cells. During the culture process, lycopene was taken up by LNCaP cells and reached a plateau at approximatel y 12 h. Micelles provide a convenient, inexpensive, and nontoxic vehicle fo r dissolving and stabilizing carotenes such as lycopene in tissue culture m edia and then delivering them to cells growing in culture.