Synthetic blood substitutes

Abstract

In damage control resuscitation (DCR) management of traumatic hemorrhage and coagulopathy, timely transfusion of whole blood (WB) or blood components (platelets, RBCs, plasma in controlled ratios) can significantly reduce mortality. WB or component transfusion is also clinically important in managing bleeding dysfunctions and risks in surgery, myelosuppression, and congenital coagulation defects. However, donor-derived blood products suffer from many logistical challenges including shortage in supply due to limited donor availability, need for type matching, high risks of pathogenic contamination, limited portability and shelf-life, and various biological side effects. A robust volume of research is being directed to resolve these issues, including pathogen reduction technologies (PRT), low temperature storage, and bioreactor-based technologies to produce blood cells from stem cells in vitro. In parallel, significant clinical interest has developed toward bioengineering of synthetic blood substitutes that can provide blood's functions while circumventing the above logistical challenges associated with natural blood products. Research in this field over the last few decades have primarily focused on the development of semisynthetic and synthetic RBC substitutes for enabling oxygen transport and platelet substitutes for enabling rapid hemorrhage control. This chapter provides a comprehensive review of the various "synthetic blood substitute" approaches, along with a critical discussion of successes, challenges, and current state-of-the-art and future opportunities in this field.