Characterization, in vitro cytotoxicity studies and photoactive effect of gold nanorods on colorectal cancer cells

Abstract: Cancer is a disease formed from abnormal growth of cells affecting any part of the body. It is reported that cancer is the third leading cause of death after stroke and heart disease in developed countries. Colorectal cancer (CRC) incidence and mortality rates vary markedly around the world; according to the World Health Organization (WHO) colorectal cancer is the third most commonly diagnosed cancer as well as being the third leading cause of cancer death after lung and gastric cancer worldwide in both sexes. Thus each year over 1 million new patients develop colorectal cancer and over 600,000 patients die from it. The main problem in using most conventional cancer therapies such as anticancer drugs (chemotherapy); as well as radiation is their low selectivity for cancer cells coupled with their often high toxicity to non-targeted cells in the body and they often cause side effects that may be more unbearable than the disease at that particular point in time. In contrast with conventional cancer therapy’s photodynamic therapy (PDT) was developed to try and address the disadvantages caused by conventional therapy’s. Photodynamic therapy is a non-invasive method which yields satisfactory clinical results with fewer adverse side effects accompanied by higher selectivity. Although photodynamic therapy has significantly improved the quality of life and life expectancy of patients with cancer, further advances in therapeutic efficacy are required to overcome numerous side effects for example hydrophobicity and poor selectivity between deceased cells and healthy cells related to conventional PDT. Much attention has been directed to improving photosensitizers. Due to the highly desirable and tunable optical properties of light sensitive nanoparticles they are deemed resourceful in developing phototherapeutic agents for cancer therapy. Gold nanorods (GNRs) showing a surface plasmon resonance (SPR) band at the near infra-red (NIR) region are of great interest for the development of nanomedicine in particular phototherapy of cancer and drug delivery. The main concerns usually encountered when using metal nanoparticles for general bio-applications are their potential toxicity and biological interactions of the nanoparticles with the cells...M.Sc. (Nanoscience