Gemcitabine delivered by fucoidan/chitosan nanoparticles presents increased toxicity over human breast cancer cells

Aim: To produce marine-origin nanoparticles (NPs) aiming to develop more effective and tolerated therapies for breast cancer. Materials & methods: NPs based in two marine-origin polymers (fucoidan and chitosan) were prepared by polyelectrolyte complexation, for the delivery of an antitumor drug model (gemcitabine [Gem]). Results: Final formulation resulted in stable NPs around 115–140 nm in size and with a polydispersity index less than 0.2. Gem was encapsulated at a maximum entrapment efficiency of 35–42%. Drug-release studies demonstrated that around 84% of Gem is released within 4 h. Cytotoxicity results of Gem-loaded NPs showed increased toxicity (around 25%) when compared with free Gem. Conclusion: The drug-loaded NPs present increased toxicity over human breast cancer cells without increasing toxic effects over endothelial cells.