text: Cell encapsulation is a possible solution to graft rejection in tissue engineering applications.  Cell microencapsulation technology involves immobilization of cells within a polymeric semi-permeable membrane. It permits the bidirectional diffusion of molecules such as the influx of oxygen, nutrients, growth factors etc. essential for cell metabolism and the outward diffusion of waste products and therapeutic proteins.  At the same time, the semi-permeable nature of the membrane prevents immune cells and antibodies from destroying the encapsulated cells, regarding them as foreign invaders.
  Cell encapsulation could reduce the need for long-term use of immunosuppressive drugs after an organ transplant to control side effects.