Background-Activated macrophages have a significant role in wound healing and damaged tissue repair. We sought to explore the ability of ex vivo activated macrophages to promote healing and repair of the infarcted myocardium. Methods and Results-Human activated macrophage suspension (AMS) was prepared from a whole blood unit obtained from young donors in a closed sterile system and was activated by a novel method of hypo-osmotic shock. The AMS (Ϸ4ϫ10 5 cells) included up to 43% CD14-positive cells and was injected into the ischemic myocardium of rats (nϭ8) immediately after coronary artery ligation. The control group (nϭ9) was treated with saline injection. The human cells existed in the infarcted heart 4 to 7 days after injection, as indicated by histology, human growth hormone-specific polymerase chain reaction, and magnetic resonance imaging (MRI) tracking of iron oxide-nanoparticle-labeled cells.

While additional research is required to allow efficient and facile solutions to low oral bioavailability of guanidino-containing compounds, novel and exciting strategies have been developed in recent years. Although challenging, the development of a potent guanidino-containing compound into an orally administered drug is becoming an achievable target.