Figure 1. Design of a molecular-necklace system to create tunable, multifunctional hydrogels with independent control of mechanics, cell adhesion properties, and chemical functionality.
a, Alpha-cyclodextrin (α-CD), with its nanobead-like structure, forms an inclusion complex with poly(ethylene glycol)-diacrylate (PEGDA) (R = hydroxyl or other functional groups). After threading α-CD onto polymer chains, PEGDA is crosslinked to form a hydrogel. b, The mechanical properties of α-CD-PEG hydrogel can be varied independent of α-CD by manipulating the cross-linking density of PEG, which is directly related to the stiffness of the hydrogel. c, The α-CD can be substituted with cell adhesion peptides before threading and hydrogel formation. The concentration of cell integrin-binding peptide conjugated to α-CD can be varied independent of the cross-linking density. d, The chemical functionality of α-CD can be varied (i.e., hydrophobic, hydrophilic or charged groups) to create specific microenvironments.