The use of polymeric carriers containing dispersed magnetic nanocrystalline particles has attracted considerable interest in the medical field. In this paper, we propose an innovative nanotechnological platform for cancer therapy, based on highly magnetized, biodegradable, and biocompatible polymeric nanoparticles. Alginate magnetic nanoparticles were prepared by our group by an efficient emulsion/reticulation technique and tested as drug delivery system. Here, we present a potential application that combines, in a single nanovector, efficient targeting, overcoming of bio-barriers, drug delivery, and physical disruption of tumor tissues.