The main objective of this book has been to analyze in depth and discuss the different aspects related to the design and elaboration of cell-enclosing microcapsules, even the regulatory features and clinical trials under development. These improvements will lead to progression in this therapeutic approach which may become one day closer to a realistic proposal for clinical application. The advances in drug delivery technology have enabled a new era of drug discovery and development. In this regard, cell microencapsulation is a technology that opens new venues and possibilities to the administration of new active principles and may be the key to solve several issues related to the correct administration of new therapeutic agents to finally success in the clinical setting. The editors believe that this technology may have important applicability not only in the field of drug delivery (to treat diseases such as cancer, neurodegenerative disorders, metabolic diseases etc) but also in cellular therapy and tissue regeneration among others. Due to the organization of the chapters, this book can be read at different levels and readers may analyze from basic aspects of encapsulation, biomaterials, clinical applications and regulatory and industrial issues of this technology. Due to this, the book could be useful for both graduate and PhD students belonging to the pharmaceutical, engineering and biomedical fields. Nevertheless, we hope that this book is also useful to expert researchers who may find information and new ideas about the cell microencapsulation area.