| abstract |
Conjugates are provided which comprise a membrane permeable drug linked to a moiety that is not membrane permeable. Attachment of the moiety that is not membrane permeable prevents the drug from crossing cell membranes and entering cells. However, exposure to light either i) breaks the linkage, releasing the drug and allowing it to enter cells; or ii) converts the non-membrane permeable moiety to a membrane permeable form, allowing the entire conjugate to enter the cell, where the drug is released from the conjugate by cleavage. The membrane permeable drugs are thus delivered to cells at locations of interest, e.g. cancer cells in a tumor, in a temporally and spatially controlled manner. |