Vitamin-anticancer drug conjugates: a new era for cancer therapy

Background: Following cardiovascular diseases, cancer is the world's second leading cause of death. Chemotherapy is the conventional gold technique for successful treatment of cancer. There are some drawbacks associated with traditional chemotherapy, namely, low aqueous solubility, limited biological half-life, production of multidrug resistance and non-specificity (lack of targeting ability) or dose-limiting cellular toxicity. To develop a targeted drug delivery for its anticancer effect is still a challenging task. Methods: We developed literature review methods which included inclusion and exclusion criteria for identifying potentially relevant articles, articles search strategies, abstract review protocols and a comprehensive scoring system for published studies. This study contains a detailed survey of various reported methods such as folic acid-drug conjugates, Cobalamin- Drug Conjugate, Vitamin B12-Conjugated and Paclitaxel-Loaded Micelles etc., all of which were studied for their methods of preparation and possible impact on biological activity. Results: Due to its specific ability to carry anticancer drugs directly to tumours, vitamin-mediated drug targeting has recently emerged as a novel concept. Solid tumour cancer has an unquenchable appetite for various essential vitamins, resulting in over-expression of the receptors involved in cell internalization of vitamins on the surface of cancer cells. So, the vitamin drug conjugates are specifically important for carrying the anticancer drugs directly to the tumour cells. Biotin, folic acid, vitamin B12 and riboflavin, the vitamin necessary for the division of all cells, especially cancer cells, have recently been examined as targeting agents. Conclusion: Vitamin-Drug Conjugate methods were found to be the most suitable methods amongst all the other reported methods and they can be applied for current therapy against cancer.