Nanoparticle mediated targeting of VEGFR and cancer stem cells for cancer therapy

Tumours are now understood to contain different types of cells, and it is the cancer stem cells that retain the ability to drive the tumour's growth. They are called cancer stem cells because, like stem cells present in normal tissues of the body, they can self-renew and differentiate. These cancer stem cells are responsible for the relapse of cancer as they are found to be resistant to conventional modes of cancer therapy like chemotherapy and radiation.In this review, a novel mode of treatment of cancer is proposed, which utilizes the twin nanoparticle to target endothelial cells in the niche of cancer stem cell. The nanoparticle discussed in this review, is a twin nanoparticle of iron coated with gold, which targets VEGF positive cell in the vicinity of cancer stem cell. In the twin nanoparticle, one particle will recognize cancer stem cell, and another conjugated nanoparticle will recognize VEGF positive cells, thereby inhibiting endothelial cells in the proximity of cancer stem cell. This novel strategy will inhibit angiogenesis near cancer stem cell hence new tumour cannot grow and old tumour will be unable to metastasize.Angiogenesis is the formation of new blood vessels from the pre-existing vasculature. It is an important process as the blood delivers oxygen and nutrients for the survival of cells and their functioning. It has been reported that in the absence of blood vessel formation, the tumor mass does not grow more than 1-2 mm in size and also the cells from the primary tumor cannot escape and metastasize.Angiogenesis is controlled by pro-angiogenic and anti-angiogenic factors in the body. The regulatory factors may be several growth factors like VEGF, FGF, PDGF, EGF, placental growth factor, Angiopoietin-1, Angiogenin, Interleukin 8 etc. The natural anti-angiogenic factor presents in the body are Angiostatin, Endostatin, Vasostatin, Prolactin, Angiopoietin-2, Interferon, -α and γ Interleukin 12, Fibronectin, Platelet factor-4, etc. A finely tuned equi