Structure-property-function relationships in triple helical collagen hydrogels

TL;DR

This study develops and characterizes collagen hydrogels functionalized with 1,3-Phenylenediacetic acid, demonstrating improved mechanical properties, controlled degradation, and mineralization potential for tissue engineering applications.

Contribution

It introduces a novel Ph-crosslinked collagen hydrogel system with enhanced stability and bioactivity compared to traditional EDC-crosslinked controls.

Findings

Preserved triple helix conformation in Ph-crosslinked hydrogels

Reduced swelling and increased thermo-mechanical strength

Enhanced mineralization potential with increased calcium phosphate deposition

Abstract

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.