The life span of cells is limited and dying cells are replaced with new ones, differentiated cells derived from stem . Stem cells in the adult organism can be detected markers present in both embryonic stem cells and stem cells in the tissues. Examples of the protein markers are : Oct3 / 4 , CXCR4 , Nanos , CD133 , CD34 . Common features of stem cells include: 1) the ability for self-renewal ( division created after the new stem cells ), 2 ) the ability to differentiate into specialized cells of tissues and organs, 3 ) resistance to stress and radiation toxicity .

SCID mice ability to accept grafts ksengenicznch, allows the study of human stem cells share tissue regeneration. Regeneration of skeletal muscle is a good model for the study of stem cell involvement in the process. Regeneration of skeletal muscles depends on the presence of satellite cells (muscle precursor cells). Apart from them can participate in the regeneration of stem cells from other tissues. The aim of the project is to investigate what might be involved in the regeneration of stem cells in a xenograft system.

One of the immune surveillance mechanisms to protect the human body against the development of cancer is the presence of monoclonal IgM natural antibodies in the circulation. Routine immunosuppression is a wonderful occasion to carcinogenesis. Such a situation occurs for example after viral infections or is caused by smoking cigarettes. In addition, a growing cancer induces immunological tolerance.

Biotechnology deals with the use of biological systems for the production of biologically active substances or modifications of cellular products. Among the various applications is used in the development of artificial organs and drug delivery systems, which are described below, taking into account the materials used for these purposes.