In situ functionalization of poly(hydroxyethyl methacrylate) cryogels with oligopeptides via β-cyclodextrin-adamantane complexation for studying cell-instructive peptide environment

Oligopeptides are versatile cell modulators resembling pleiotropic activities of ECM proteins and growth factors. Studying the role of cell-instructive peptide signals within 3D scaffolds, yet poorly known, requires effective approaches to introducing bioactive sequences into appropriate materials. We synthesized RGD and GHK motif based peptides 1 and 2 linked to the terminal adamantyl group (Ada) and their fluorescent derivatives 3 and 4, respectively. Poly(hydroxyethyl methacrylate) (pHEMA) cryogels with additional PEG/β-cyclodextrin (CD) units were prepared as an inert macroporous scaffold capable to bind the adamantylated peptides via affinity CD-Ad complexation. According to toluidine blue staining, the CD moieties were effectively and stably incorporated in the pHEMA cryogels at nanomolar amounts per mg of material. The CD component gradually increased the thickness and swelling ability of the polymer walls of cryogels, resulting in noticeable decrease in macropore size and modulation of their visco...