  In order to establish defined biomimetic systems, type I collagen was
functionalised with 1,3-Phenylenediacetic acid (Ph) as aromatic, bifunctional
segment. Following investigation on molecular organization and macroscopic
properties, material functionalities, i.e. degradability and bioactivity, were
addressed, aiming at elucidating the potential of this collagen system as
mineralization template. Functionalised collagen hydrogels demonstrated a
preserved triple helix conformation. Decreased swelling ratio and increased
thermo-mechanical properties were observed in comparison to state-of-the-art
carbodiimide (EDC)-crosslinked collagen controls. Ph-crosslinked samples
displayed no optical damage and only a slight mass decrease (~ 4 wt.-%)
following 1-week incubation in simulated body fluid (SBF), while nearly 50
wt.-% degradation was observed in EDC-crosslinked collagen. SEM/EDS revealed
amorphous mineral deposition, whereby increased calcium phosphate ratio was
suggested in hydrogels with increased Ph content. This investigation provides
valuable insights for the synthesis of triple helical collagen materials with
enhanced macroscopic properties and controlled degradation. In light of these
features, this system will be applied for the design of tissue-like scaffolds
for mineralized tissue formation.
