Metal-Containing Proteins, Macrocycles, and Coordination Complexes in Therapeutic Applications and Disease

Treatment of diseases with natural and synthetic materials has been an aspiration of mankind since the dawn of human development. From the use of willow-bark to the marketing of aspirin, a steady move from folk remedies to the use of chemistry and biology to develop new therapies has been observed. In terms of metal-containing drugs, the platinumcontaining drug cisplatin has long been the most effective metal-containing anticancer drug on the market. However, severe side effects of conventional drugs are associated with the inability to distinguish between healthy and cancer cells. Hence, a concerted world-wide effort is in progress to discover and characterise new drugs that may distinguish between healthy and cancer or other diseased cells. New techniques of drug delivery are sought and the use of natural products, proteins, antibodies, and synthetic polymers as drug delivery devices capable of targeting a diseased site is being investigated. These issues are nicely illustrated by macrocycles such as porphyrins, phthalocyanines, and related systems. Some of these compounds exhibit selective absorption by cancer cells and have the ability to photosensitize formation of singlet oxygen. These attributes have led to the development of alternative cancer treatments known as photodynamic therapy. Sadly, many potentially good new therapeutic agents often never leave the designers’ laboratory due to some pharmacological problems associated with its in vivo use. The use of drug delivering devices, including watersoluble synthetic polymeric drug delivery systems, may help overcome many pharmacological drug-related problems, including those of solubility, specificity, and biocompatibility, factors that currently prevent many potentially good therapeutic agents from reaching clinics. The focus of this special issue is the synthesis, characterisation, physical studies, and application of synthetic metalcontaining complexes and natural occurring proteins in serious human diseases such as cancer, diabetes, arthritis, viral disease, malaria, and tuberculosis with special focus on the following: