Ultra-deformable liposomes containing bleomycin: In vitro stability and toxicity on human cutaneous keratinocyte cell lines

In vitro data revealed that the LD50 of bleomycin encapsulated in Bleosome™ was approximately three-fold higher than free bleomycin solution for SCC cells, and nearly 30 times higher for NEB-1 cells. However, Bleosome™ containing 30 μg/ml of active bleomycin killed more than twice as many SCC cells than NEB-1 cells. At that concentration, the potency of liposomal bleomycin on causing cell death of SCC cells was found to be similar to that of free bleomycin solution. This effect was not seen on NEB-1 cells. It seems that SCC cells were particularly susceptible to Bleosome™ containing high levels of bleomycin. Results from these experiments promote the development of a novel product for the topical treatment of skin cancer.