Anticancer metallotherapeutics in preclinical development.

This article reviews recent studies of platinum and other metal-containing antitumor drugs in preclinical development. A short overview of the development of cisplatin-based drug generations is given. Some pioneering strategies towards unconventional drugs, such as platinum complexes with biomolecules and carrier ligands, organoplatinum and multinuclear platinum complexes developed in recent years are outlined. Furthermore, nonplatinum-based antitumor drugs containing ruthenium(II/III), gallium(III), titanium(IV) or tin(IV) that illustrate the prominent strategies are presented with an emphasis on recent developments. In addition, alternatives for water insoluble drugs will be discussed. A brief overview of development of nanodrug delivery systems and their potential as alternative cancerostatic carriers are discussed.