Dual stimuli activation for tougher diazirine-grafted polycaprolactone bioadhesive

• Main Authors: Ang, Elwin Wei Jian, Steele, Terry W. J.
• Other Authors: School of Materials Science and Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2024
• Subjects: Engineering; Dual stimuli; Bioadhesive; Carbene
• Online Access: https://hdl.handle.net/10356/174202; https://wbc2024.com/
• Institution: Nanyang Technological University

Carbene based bioadhesives are developmental tissue adhesive, where photolysis creates carbenes that indiscriminately insert into amino acids. However, the nitrogen side product generates internal pores, creating a relatively weak cohesive matrix. To further improve cohesive toughness, photo-curing at elevated temperatures hypothesizes higher nitrogen solubility and lower apparent viscosity in order to generate higher crosslinking density. Real-time crosslinking kinetics of storage (G’) and loss (G”) moduli and adhesive properties post-activation (viscosity, yield stress and modulus of toughness) are characterised through a custom photorheometer setup with a high thermal-conductivity, temperature-controlled diamond plate. Dual activation improved elongation at break and toughness up to three-fold under photolysis at elevated temperature of 70°C. The resultant adhesive attaches low-surface energy silicon rubber substrates onto tissue, supporting up to 1 kg loads. The hybrid modes of activation (light/temperature) could improve control over crosslinking kinetics and material properties using other types of polymers such as polyacrylates and polyolefins.