Advances in the Development of Tissue Engineering Applied to the Skin Using 3D Bio-Printers for the Treatment of Burn Patients

In 1975, Dr. Burke and Dr. Yahanas (at MGH and MIT) were the first to develop an idea and prototype of an artificial dermis. In the year of 1976, Dr. Green (at MGH) got a sheet of keratinocytes <i>in vitro</i>. In the year of 1980, there is the clinical use and improvement of the technique. In the year of 1982, a laminar system of cells is achieved. In 2000, the development <i>in vitro</i> of the dermis and epidermis is achieved. In 2010, the development of 3D skin printers with the ability to print the dermis and epidermis with the cells of the patient with thickness control and printing área is produced.<br><br>The concept of 3D printing was developed in 1980. The idea of 3D printing to manufacture objects was established by Charles Hull in the year of 1986. His idea was that successive layers of a base material could be added at the top of each to manufacture (print) objects. The first 3D printing was designed by Sachs in 1993 to print plastics and metals. Then, a series of 3D printers have been developed with different applications. Besides, in 2002 (Italy), another dermal regeneration matrix (hyalomatrix) was developed with hyaluronic acid and silastic fibers, mimicking the epidermis. In 2003 (Mexico) an allogeneic keratinocyte culture is developed as a system for the release of growth factors in skin lesions. In the last 10 years, 15 matrices of dermal regeneration have appeared.<br><br>It has had a great impact in engineering and medicine. In the medical field, a very important application is the tissue engineering, not only for the manufacture of skin and grafting but also for conducting scientific experimentation in the evaluation and discovery of drugs. Bio-printing of tissues can also help to the study of skin disorders and diseases. By using 3D bio-printing, the respective aggregation layer by layer of the cells is obtained. It allows the organization of multiple cell types in a desired structure. Then, the respective cell culture is performed0 <i>in vitro</i> (3 to 4 weeks), allowing the respective growth and maturation to achieve the desired tissue. Thus, the tissue implantation is performed.<br><br>The conventional methods of tissue engineering (without 3D bio-printers) have little spatial relationship between the individual elements (cells) of the desired tissue. For other hand, the 3D bio-printing technique improves both spatial resolution and reproducibility. Therefore, it is possible to obtain the optimal conditions for cell incubation and maturation.<br><br>Besides, organ transplantation is one of the biggest treatments in medicine for many organ disorders. However, the supply of donors is limited and thus, the bio-fabrication of organs and tissues can help for the respective transplant.