Macromolecules as taxane delivery systems

Importance of the field: Taxanes have received considerable attention owing to their significant activity against a variety of tumors. Nevertheless, many different approaches have been developed to improve their safety profile and water solubility, in terms of both dosing schedules and delivery strategies. Areas covered in this review: Among the different taxane delivery systems, macromolecule conjugates have been widely explored; this review collects and summarizes such systems from reports after 1990. Natural and synthetic polymers, proteins and polysaccharides have been covalently coupled with taxanes; immunoconjugates have also been developed for targeted delivery. In-depth descriptions, from synthesis to preclinical or clinical data, are given. What the reader will gain: The choice of macromolecule, the spacer, the chemistry of the linkage with taxane, as well as other cytotoxic drugs, are key points to obtain effective conjugates with higher activity than that of the free drug, reducing side effects. Critical evaluation of the different approaches may help in comprehending and comparing the results and may elucidate the role of individual components. Take home message: Taxane covalently-bound to macromolecules shows advanced properties, and although only one compound is in advanced clinical trials, this area deserves attention and seems a promising route to achieve effective new anticancer compounds.