Smart Nanocarriers Bearing Docetaxel for Improved Chemotherapy Cancer

Cancer is a term used for a collection of diseases in which some of the normal and somatic body cells start dividing and re-dividing out of control . It is a leading cause of  the  morbidity  and  mortality  worldwide,  second  only  to  the  cardiovascular  diseases . The occurrence of cancer is not new to human kind and the world's oldest recorded case of breast cancer dates back to 1500 BC from ancient Egypt.
Some evidences of human  osteosarcoma  were  also  found  in  mummies  in  ancient  Egypt  which  have  been recorded  in  the  manuscripts  dated  about  1600  B. C  .  The  word  cancer, however, was first used by a physician Hippocrates  which finds its origin in a Greek word 'karkinos' to describe carcinoma tumors . Our body is made up of the trillions of cells and any one of them could be the site of cancer initiation.
During the normal physiological course, the human cells grow and divide to form new   cells   as   and   when   the   need   arises   (McDonald,   Fielding,   &   Dedhar,   2008). Simultaneously,  the  old  and  damaged  cells  die  and  new  cells  replace  them.  This  process operates  in  a  checked  manner.  But  this  methodical  operation  breaks  down  when  cancer develops  and  cells  grow  in  an  unchecked  manner.
 These  abnormal  cells  then  form  solid growths called tumors  . Some cancers like that of blood cells and known as leukemias do not form solid tumors and remain floating in the blood stream and may reach other  distal  organs.  The  DNA  damage  repair,  which  is  an  inherent  mechanism  in  normal cells, is compromised in cancerous cells. This damaged DNA can often be inherited leadingto a genetic predisposition to cancer. Cancer  can  be  classified  according  to  the  organ  of  origin  or  according  to  the  cells  of  the origin of cancer .
On the basis of the cells of origin,  major  types  of  clinically  identified  cancer  are  carcinomas,  sarcomas,  leukaemias, lymphomas, myelomas, and brain and spinal cord cancer. Carcinomas are the most common type of cancer begins in the skin or in epithelial cells which lines the external body surface and covers the internal organs. These have been further classified into the subtypes such as, transitional     cell     carcinoma,     basal     cell     carcinoma,     squamous     cell     carcinoma and adenocarcinoma etc.
depending upon the epithelial layer of origin  .