Skin responses to biomaterials

Abstract The skin is the largest body organ and it develops myriad of functions that allow the body to maintain homeostasis and to be protected from the environment. The skin maintains its homeostasis under physiological conditions, but its balance can be disturbed when attacked by an external environment. Biomaterials are powerful tools that modify the host microenvironment based on their properties obtained through the fabrication processes. Surface chemistry, topography, mechanical properties, and degradation products combined or not with biological signals can promote an efficient homeostasis regulation or regeneration, while biomaterials are foreign bodies to the skin which induce immune response or rejection from the recipient. To achieve the success of biomaterial transplantation, the responses should be accepted by the host without seriously harmful effects. In this article, we give a general description of the skin tissue and summarize the skin responses to biomaterials including inflammatory responses, hypersensitivity responses, and stimulation responses. The stimuli responses are explored from biomaterial physical properties, biomaterial bioactive strategies, biomaterial mechanical properties, and stimulus signal as well as metal ions and inorganic compounds. Finally, we summarize the applications of biomaterials in skin tissue engineering and the promise to develop better treatments for skin disorders.