We have reported previously that daily
intravenous infusions of a soluble nanobiotechnological complex,
polyhemoglobin-tyrosinase [polyHb-Tyr], can suppress the growth of murine B16F10
melanoma in a mouse model. In order to avoid the need for daily
intravenous injections, we have now extended this further as follows. We have prepared two types of biodegradable
nanocapsules containing [polyHb-Tyr]. One type is to increase the circulation time and decrease the frequency of injection and is based on polyethyleneglycol-
polylactic acid (
PEG-PLA)
nanocapsules containing [polyHb-Tyr]. The other type is to allow for intratumoural or local injection and is based on
polylactic acid (PLA)
nanocapsules containing [polyHb-Tyr]. Cell culture studies show that it can inhibit the proliferation of murine B16F10
melanoma cells in the "proliferation model". It can also inhibit the attachment of murine B16F10
melanoma cells in the "attachment model." This could be due to the action of
tyrosinase on the depletion of
tyrosine or the toxic effect of
tyrosine metabolites. The other component,
polyhemoglobin (polyHb), plays a smaller role in
nanocapsules containing [polyHb-Tyr], and this is most likely by its depletion of
nitric oxide needed for
melanoma cell growth.