Breast tissue engineering: implantation and three-dimensional tissue test system applications

Abstract Breast tissue engineering may provide a biologically based method for reconstruction following breast cancer surgery (mastectomy or lumpectomy) or for cosmetic augmentation of breast tissue. Breast tissue engineering also may provide a method to develop a personalized benchtop tissue test system that can be used to study key aspects of normal processes, a disease, to assess integrated tissue and organ systems, to screen drugs or vaccines or test therapies. This chapter focuses on breast cancer–related tissue engineering. Regardless of the endpoint, in vitro or in vivo, certain common approaches and challenges exist in engineering breast tissue. The ability to construct three-dimensional (3D) tissue requires the appropriate selection of cells and biomaterials and the ability to perfuse the tissue. Although early tissue-engineering approaches focused largely on implantation of differentiated cells, equal emphasis has been placed on stem or stem-like cells. A wide variety of biomaterial chemistries have been assessed, including naturally derived and synthetic materials, as have a wide variety of formulations and presentations, including injectable and noninjectable ones. Breast tissue engineering for in vivo application has more design constraints than breast tissue engineering for benchtop use; indeed, 3D benchtop tissue systems can be built to replicate aspects of a complex disease state, including integration of multiple engineered tissues or organs. In addition, benchtop systems may be used to evaluate and improve tissue-engineering systems for reconstruction, or other medical implants. A large focus is on developing high-throughput, high-resolution means of building key aspects of these complex benchtop tissue systems. It is now widely recognized that 3D test systems may provide a missing bridge to the better design and understanding of implantable systems and disease states.