Molecular Encryption and Reconfiguration for Remodeling of Dynamic Hydrogels

Development of a Dual-Functional Hydrogel Using RGD and Anti-VEGF Aptamer

Synthetic molecular libraries hold great potential to advance the biomaterial development. However, little effort is made to integrate molecules with molecular recognition abilities selected from different libraries into a single biomolecular material. The purpose of this work is to incorporate peptides and nucleic acid aptamers into a porous hydrogel to develop a dual-functional biomaterial. The data show that an anti-integrin peptide can promote the attachment and growth of endothelial cells in a 3D porous poly(ethylene glycol) hydrogel and an antivascular endothelial growth factor aptamer can sequester and release VEGF of high bioactivity. Importantly, the dual-functional porous hydrogel enhances the growth and survival of endothelial cells. This work demonstrates that molecules selected from different synthetic libraries can be integrated into one system for the development of novel biomaterials.

Molecularly Imprinted Polymers with DNA Aptamer Fragments as Macromonomers

Molecularly imprinted polymers (MIPs) are produced in the presence of a template molecule. After removing the template, the cavity can selectively rebind the template. MIPs are attractive functional materials with a low cost and high stability, but traditional MIPs often suffer from low binding affinity. This study employs DNA aptamer fragments as macromonomers to improve MIPs. The DNA aptamer for adenosine was first split into two halves, fluorescently labeled, and copolymerized into MIPs. With a fluorescence quenching assay, the importance of imprinting was confirmed. Further studies were carried out using isothermal titration calorimetry (ITC). Compared to the mixture of the free aptamer fragments, their MIPs doubled the binding affinity. Each free aptamer fragment alone cannot bind adenosine, whereas MIPs containing each fragment are effective binders. We further shortened one of the aptamer fragments, and the DNA length was pushed to as short as six nucleotides, yielding MIPs with a dissociation constant of 27 μM adenosine. This study provides a new method for preparing functional MIP materials by combining high-affinity biopolymer fragments with low-cost synthetic monomers, allowing higher binding affinity and providing a method for signaling binding based on DNA chemistry.