Cutting Edge Targeting Strategies Utilizing Nanotechnology in Breast Cancer Therapy

Breast cancer is one of the major reasons for mortality and trauma amongst women. Therapy for breast cancer has various options such as, chemotherapy, hormone therapy, gene therapy, immunotherapy, and radiation therapy. Chemotherapy is the choice in most cases but is often associated with side/adverse effects. These side/adverse effects can be eliminated by delivering the drug to the target site. With the help of nanotechnology and drug delivery through a suitable carrier, targeting has become achievable. Targeting includes both, the active as well as the passive approach. Passive targeting is based on the accumulation of the drug over tumor tissues whereas active targeting is done by means of an interaction with the receptor/antigen and the targeting moiety. Nowadays, the focus is on the active targeting of drugs in which an approach to target the drug directly to the diseased cells is taken. The approaches can be broadly classified mainly into antigen-antibody, aptamers, ligand-receptors and lectin-carbohydrate based, respectively. Every targeting strategy is based on one basic concept, i.e. an overexpression of a biomarker on a specific diseased cell type. Hence, a suitable moiety is utilized to carry out the active targeting of drugs. Apart from chemotherapeutic agents, hormonal drugs, gene silencing molecules can also be successfully delivered through nanotechnology. Some of the nano based medicines are already in the market and there is a constant enhancement in the success of the systems. Some are in the trial phase and some approaches have been patented. However, the translational challenge yet exists and there is a need to overcome it. Thus, this chapter discusses the various delivery systems, different materials and various approaches for the active targeting of the drug, recent clinical trials, challenges and some recent patents.

Keywords: Active targeting, Aptamers, Breast cancer cells, Chemotherapy, Drug delivery, Ligand based targeting, Monoclonal antibodies, Nanomedicine, Over expression, Patents, Trials.