Polysaccharide based anticancer prodrugs

So far, polysaccharides have been widely used in pharmaceutical technology as first choice excipients for production of traditional formulations. Nevertheless, in the recent years these natural and semisynthetic macromolecules have been addressed for new challenging applications as functional materials for innovative formulations. Their peculiar physicochemical and biological properties have been exploited to develop macromolecular prodrugs which can exhibit favourable biopharmaceutical properties and enforce the therapeutic performance of the parent drugs. These polymers display, in fact, high biocompatibility and biodegradability, multiple insertion points and biological properties that can be advantageously exploited in drug delivery. In particular, the multifunctional structure of these polymers are anchoring points for conjugation of several anticancer drugs, which usually suffer of poor physicochemical, biopharmaceutical and therapeutic properties that limit their therapeutic performance and proper use in anticancer treatment. Polysaccharide based anticancer prodrugs can be designed to endow derivatives with new bioresponse, targeting or environmental triggering properties or to combine molecules with synergistic therapeutic effect. Over the years, a variety of synthetic protocols have been set up to conjugate anticancer drugs to the polysaccharide backbone via specific linkages or through spacers which convey to the conjugates selective drug delivery properties. Furthermore, the intrinsic antitumor activity and cell targeting properties of few polysaccharides represent an additional value to the final therapeutic systems. Anticancer drugs with different pharmacodynamic, pharmacokinetic and physicochemical properties have been successfully conjugated to various natural and semisynthetic polysaccharides highlighting the interesting perspectives for exploitation of new promising anticancer polymer therapeutics