©  Copyright 2013 Exercitation One application of nanotechnology in medicine currently being developed involves  employing nanoparticles to deliver drugs, heat, light or other substances to specific types of cells (such  as cancer cells). Particles are engineered so that they are attracted to diseased cells, which allows  direct treatment of those cells. This technique reduces damage to healthy cells in the body and allows  for earlier detection of disease.   For example, nanoparticles that deliver chemotherapy drugs directly to cancer cells are under  development. Tests are in progress for targeted delivery of chemotherapy drugs and their final approval  for their use with cancer patients is pending.  Another technique delivers chemotherapy drugs to cancer cells and also applies heat to the cell.  Researchers are using gold nanorods to which DNA strands are attached. The DNA strands act as  a scaffold, holding together the nanorod and the chemotherapy drug. When Infrared light  illuminates the cancer tumor the gold nanorod absorbs the infrared light, turning it into heat. The  heat both releases the chemotherapy drug and helps destroy the cancer cells.  Reserchers are developing a method to release insulin that uses a sponge-like matrix that contains  insulin as well as nanocapsules containing an enzyme. When the glucose level rises the  nanocapsules release hydrogen ions, which bind to the fibers making up the matrix. The hydrogen  ions make the fibers positively charged, repelling each other and creating openings in the matrix  through which insulin is released.  Chemical Engineering & Gas Processing