Figure 1

AFM and contact angle analysis of dopamine polymerization on plasma treated PCL. (A1–D1) Representative AFM micrographs of PCL, plasma treated PCL (pPCL) and pPCL after 30 min and 60 min of dopamine polymerization, respectively. (A2–D2) Representative line analysis demonstrating the polydopamine on the surface as submicron- and nano-sized clusters. Longer dopamine polymerization time onto PCL increased the surface roughness (F) and hydrophilicity (E). FTIR analysis comparing PCL and PCL-PDA (60 min of functionalization) showing a small yet clear contribution of C = O stretching in quinone group in PDA (around 1721 cm⁻¹) group in PDA. Data = mean ± SEM.