Figure 2.

(a) Flowchart of types of collagen networks specimens as a result of different enzymatic treatments and the types of aqueous solutions for aggrecan–collagen adhesion test. (b) Schematics of colloidal force spectroscopy using microspherical tips (end radius R ≈ 2.5 μm) functionalized with hydroxyl-terminated self-assembled monolayer (OH-SAM) and aggrecan. (c) Typical force vs depth (F–D) curves measured via OH-SAM and aggrecan tips (PBS, [Ca²⁺] = 0 mM, surface dwell time t_d = 30 s). Curves shown are from three different locations for each tip. (Inset) Definitions of the maximum adhesion force, F_ad, total adhesion energy, E_ad, and maximum adhesion interaction distance, D_ad, for each F–D curve.