FIG. 2.

Characterization of the dynamics of PDL-mediated biofunctionalization. Representative top-view (A) and cross-sectional views (B) of PDL-BF hydrogel functionalized with fluorescent collagen IV. Surface enrichment of fluorescence due to immobilized collagen IV is only present in hydrogels that contain excess norbornene moieties. Dashed line boxes indicate the surface region of the hydrogels in (B). (C) Adsorbed collagen IV varies linearly (r² = 0.909) with the concentration of excess norbornene present in the PEG hydrogel. (D) The relationship between adsorbed collagen IV and PDL concentration reveals a threshold effect: collagen IV levels increase significantly between 0 and 0.1 mg mL⁻¹ (***p < 0.005) but are not significantly different thereafter. (E) The amount of adsorbed collagen IV is positively and linearly correlated with the concentration of collagen IV applied to the hydrogel (r² = 0.996).