Safety of Light-Targeted Drug Delivery

The information available so far indicates that LTD is safe. Intravenously administered liposomes are in use today in humans for cancer chemotherapy, as vehicles for delivery of immunomodulators, and for gene therapy (31). The liposomes used in our preparation are composed of phospholipids such as DPPC, DPPG, and 

All the tests in humans have indicated so far that liposomal delivery does not introduce side effects other than those linked to the specific drug, which is encapsulated. We have performed a pilot toxicology test of our preparation in rats with a fluorescent dye and have not found any morbidity or mortality, or any change in biochemical parameters or histology of the liver, spleen, and kidneys (37). A formal toxicology study in the dog, using 10 times the dose intended for humans, showed no systemic side effect of clinical significance (unpublished data). 

There is a need for tight control of manufacturing parameters, particularly liposome size, uniformity of liposomes, stability of bioactive drugs during the encapsulation process, sterility and endotoxin control. Hydrophilic drugs are easily encapsulated, but lipophyllic drugs may need to be modified to render them encapsulate. 

Supported by Research Grants EY 07768, EY 10017 and Core Grant EY 1765 (JHU) from the National Institutes of Health, Bethesda, Maryland, the Lew R. Wasserman Merit Award, an Alcon Research Institute Award, a Biomedical Research Award from the Whitaker Foundation, an unrestricted research grant from Research to Prevent Blindness, Inc., New York, NY and gifts from the McGraw family and the McDuffie family. 

The material presented here is the product of efforts by the many collaborators who appear as authors in the cited references. 

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