Delivery of Pharmacological Agents in Tissue Engineering and Regenerative Medicine

Every tissue in the human body is subject to traumatic injury, disease, or age-based decay. Few diseases (including aging) can truly be “cured” and many traumatic injuries leave a permanent deficit to tissue function. Treatments for such injuries and diseases have traditionally followed two paths: devices (biomaterials) and/or pharmacological agents (drugs). Indeed, the U.S. Food and Drug Administration (FDA) has regulated treatment modalities as devices or drugs for decades. Man-made devices fail at a more rapid rate than native tissues while pharmacological agents are typically palliative and do not repair the underlying condition (e.g., at the genetic level). Further, pharmacological approaches often lead to the development of tolerance, thus requiring higher doses or more alternative drugs. As such, devices and pharmacological agents generally cannot be said to “cure” a disease or injury. Tissue engineering and regenerative medicine (TERM) is a field that has evolved rapidly to include aspects of biomaterial constructs (devices) and pharmacological agents, but in combination with cells. Unlike device and drug approaches, TERM strategies involving biomaterials, therapeutic agents, and cells (including or in particular, stem cells) seek to repair the biological or physiological deficit in order to achieve cure or longer-term functional recovery. In order to direct cells to behave properly when associated with a biomaterial “scaffold” system, chemical cues provided by exogenous pharmacological agents should be a key consideration. Pharmacological agents provide the potential to direct cell attachment, cell migration, differentiation of stem cells, maintenance of cell viability, and direction of cell function including production of important metabolic chemical products. The purpose of this Research Topic is to provide an overview of TERM approaches toward repair of several important tissue types by presenting a series of review articles that emphasize delivery aspects of exogenous pharmacological agents or production of therapeutically active agents from delivered cells, followed by relevant original research articles within these fields.