Revealing the aggregation behaviors of mesostructured collagen by the evaluation of reconstituted collagen performance

Mesostructured collagen as a building block has been widely applied to construct materials for food packing, wound dressing and flexible sensors. Collagen aggregation at the mesostructured level has great influence on material performance and provides critical details for understanding structure property relationships. In this work, by varying the factors of pH, ionic strength, temperature, and solvent, the aggregation behaviors of exfoliated collagen fibrils with both high and low aspect ratios in suspension were studied by optical and turbidity tests. The absorbance and turbidity increased with increasing ionic strength and temperature, as well as near the isoelectric point. Collagen fibrils with high aspect ratios tended to form more aggregation and entanglement. Reconstituted collagen films with mesostructured fibrils as building blocks were fabricated by a vacuum-assisted filtration method. Under the induction of external factors (pH, ionic strength, temperature, and solvent), the formation of electrostatic, hydrophobic, and hydrogen-bonding interactions between collagen fibrils induced changes in the optical, swelling and mechanical properties of the reconstituted collagen films. This research provides a comprehensive understanding of and guidance for the aggregation behaviors of mesostructured collagen for practical applications. • Properties of reconstituted collagen depend on the assembly behaviors of the collagen fibrils. • Assembly behaviors of mesostructured collagen are revealed. • Collagen fibrils with high aspect ratios tend to form aggregation and entanglement. • Electrostatic, hydrophobic, and hydrogen bonding interactions induce assembly behaviors. • Relationship is established between reconstituted collagen and mesoscopic building blocks.