Figure 1.

Evolution of fragmin and protamine in tissue engineering and regenerative medicine under the concept of drug repositioning. In the mid-1990s, F/P have been primarily used as antagonists of the circulating heparin. By the year of 2000, these drugs have been repurposed as biomaterials that control growth factor release, cell carriers, and cytokine attractant or immobilizer. Lately, more repositioning strategies have been emerging including DNA injectable complex, collagen and mRNA suppressor, protein carriers, and microencapsulation agents.