Assembly of Bifunctional Aptamer-Fibrinogen Macromer for VEGF Delivery and Skin Wound Healing.

Macromolecular assembly has been studied for various applications. However, while macromolecules can recognize one another for assembly, their assembled structures usually lack the function of specific molecular recognition. We hypothesized that bifunctional aptamer-protein macromers would possess dual functions of molecular assembly and recognition. The data show that hybrid aptamer-fibrinogen macromers can assemble to form hydrogels. Moreover, the assembled hydrogels can recognize vascular endothelial growth factor (VEGF) for sustained release. When the VEGF-loaded hydrogels are implanted in vivo, they can promote angiogenesis and skin wound healing. Thus, this work has successfully demonstrated a promising macromolecular system for broad applications such as drug delivery and regenerative medicine.

Dual Aptamer-Functionalized in Situ Injectable Fibrin Hydrogel for Promotion of Angiogenesis via Codelivery of Vascular Endothelial Growth Factor and Platelet-Derived Growth Factor-BB.

In situ injectable hydrogels hold great potential for in vivo applications such as drug delivery and regenerative medicine. However, it is challenging to ensure stable sequestration and sustained release of loaded biomolecules in these hydrogels. As aptamers have high binding affinities and specificities against target biomolecules, we studied the capability of aptamers in functionalizing in situ injectable fibrin (Fn) hydrogels for in vivo delivery of two growth factors including vascular endothelial growth factor (VEGF) and platelet-derived growth factor-BB (PDGF-BB). The results show that aptamer-functionalized fibrinogen (Fg) could form in situ injectable Fn hydrogels with porous structures. The aptamer-functionalized Fn hydrogels could sequester more VEGF and PDGF-BB than the native Fn and release these growth factors in a sustained manner with high bioactivity. After the aptamer-functionalized Fn hydrogels were subcutaneously injected into mice, the codelivery of VEGF and PDGF-BB could promote the growth of mature blood vessels. Therefore, this study has successfully demonstrated that aptamer-functionalized in situ injectable hydrogels hold great potential for in vivo codelivery of multiple growth factors and promotion of angiogenesis .