Additionally, the band at around 953 cm -1 , which is linked to the vibration of C-O-C in PEG, completely vanishes after 4 weeks. Incorporation of hydrophilic PEGylated fibrinogen (Figure ) revealed discernible variances within two regions at the FT-IR spectra, namely 3500-3200 cm -1 and 1637 cm -1 . The absence of a band at 1650cm -1 after 4 and 7 weeks of experiment suggest successful degradation of peptide bond. Furthermore, the disappearance of bands at 3212 and 3450 cm -1 attributed to the hydrogen bonding between the amine (-NH) and carbonyl (-C=O) groups of the peptide backbone, further corroborates this observation during degradation, aligning with previous statement. Incorporation of catechol units (Figure ) revealed significant differences in the range of 3500-3200 cm-1 indicative of the changes taking place in the ester and amide groups. The presence of bands at 1660 cm -1 and 1530 cm -1 might be attributed to -NH bending vibration of degradation product (primary and secondary amine). The FTIR spectra of the polymer hybrids are presented in SI (Figure ). However, in order to have deeper insights into the changes of polymer network structure during the degradation , the 2D-COS analysis of ATR-FTIR spectra has been performed.