Abstract
Hydrogels for drug delivery, particularly for the delivery of potent protein therapeutics, have been extensively studied across various biomedical applications. Because hydrogels act as reservoirs for localized drug release, this delivery approach is generally not expected to cause the same severe systemic toxicity observed with systemic drug administration. However, the current study has shown for the first time that the implantation of native hydrogels loaded with vascular endothelial growth factor (VEGF) induced acute severe hemorrhage and animal mortality in a femoral vessel micropuncture (MP) surgery model. In contrast, no side effects were observed when hydrogels functionalized with anti-VEGF aptamers and loaded with the same amount of VEGF were implanted. Furthermore, the presence of the aptamers in the hydrogels did not compromise the ability of VEGF to promote new blood vessel growth.