Fig. 3: In vitro characterization and drug delivery mechanism of the MN materials.

A UV-Vis spectra of HA-DA, HA-DA + Z-GCN, HA-DA + AFBA, and HA-DA + Z-GCN + AFBA in the presence and absence of glucose. B A schematic illustration of the Z-GCN, catechol and AFBA interactions in the presence of high/low glucose concentrations. C Reaction energy profile of reactants (Zn-catechol and glucose-AFBA complexes) and products (zinc ion, glucose, and AFBA-catechol). D Radial distribution function (RDF) as a function of distance between zinc ion and Phe 6 from GCN. E Reaction energy profile of reactants (Phe-Zn-catechol and glucose-AFBA complexes) and products (Phe-Zn, glucose, and AFBA-catechol). F Depiction of the interaction mode among zinc ion, solvent molecules, polymer, and GCN. In this illustration, the water molecules are denoted by ‘W.’ Interacting residues are represented using a stick model, while the non-interacting portions of the polymer and glucagon are shown through a ball model and cartoon presentation, respectively. G The density surface plots for the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of glucose-AFBA, Phe-Zn-catechol, and catechol-bound AFBA.