Conventional implants made of inert material can correct only physical and mechanical defects of damaged tissues. The aim of tissue engineering is to restore biological (metabolic) functions, i.e., tissue regeneration rather than simply replacing it with synthetic material.

Developing a tissue-engineered implant (graft) involves several steps:

1. isolation and culturing of autologous or donor cell material,

2. engineering of a special cell carrier (the matrix) using biocompatible materials,

3. placement of cells onto the matrix and cell proliferation in a bioreactor at special culture conditions,

4. introduction of the graft into the affected organ area or its pre-placement in the body area with optimal blood supply for maturation and formation of a microcirculatory network within the graft (prefabrication).

Differentiated cells of the tissue or stem cells may be used. To create a graft matrix, the following materials can be used: biologically inert synthetic materials, natural polymer-based materials (chitosan, alginate, collagen), and biocomposite materials. For example, the equivalent bone tissue is produced by the controlled differentiation of stem cells from bone marrow, umbilical cord blood or adipose tissue. Then the resultant osteoblasts (cells responsible for bone growth) are placed onto various cell growth supporting materials: donor bones, collagen matrices, porous hydroxyapatites, etc. Living skin equivalents containing donor or autologous dermal cells are widely used now in the U.S., Russia and Italy. They are used to improve the healing of extensive burn wounds. Grafts are being developed in cardiovascular therapy (artificial heart valves, reconstruction of blood vessels and capillaries), as well as to restore the functions of the respiratory system (larynx, trachea and bronchi), small intestine, liver, urinary organs, endocrine glands and neurons. Metal nanoparticles are used in tissue engineering to control cell growth through their exposure to multidirectional magnetic fields. This approach made it possible to create not only miniature livers but also such complex structures as retinal elements. that were fabricated by Electron beam lithography enables the manufacture of nanocomposites with nanoscale surface roughness promoting efficient bone implant formation. Artificial tissues and organs will circumvent the need for donor organ transplantations and improve survival rates and quality of life.