G-quadruplex-based antiviral hydrogels by direct gelation of clinical drugs

Supramolecular hydrogels made from guanine derivatives have attracted great interest for various applications. The gelation of guanine analogues usually involves the formation of guanine/K⁺ quartets. Functional cargoes such as fluorophores and drugs are usually decorated onto the guanine quartet gels via non-covalent π-π interactions or dynamic covalent linkages to render the gel with new functionalities. Here, a class of antiviral guanine quartet hydrogels have been developed via direct gelation of clinically available antiviral drugs such as entecavir, penciclovir, and ganciclovir in the presence of K⁺ ions. The prepared gels were stable at ambient temperature, non-toxic to normal cell lines, and maintained their inherent antiviral activities against hepatitis B virus and Herpes simplex virus, respectively. This study expands the function of guanine-based supramolecular gels and permits the development of a new class of antiviral gels.