Surgical adhesive activated by visible light

• Main Author: Hafiz Mohamad Hamzah
• Other Authors: Terry W.J. Steele
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/156283
• Institution: Nanyang Technological University

Surgical adhesives have been utilized to replace conventional wound sealants such as sutures and staples to prevent the risk of infection and chronic inflammation at the healing site. One beneficial impact of bioadhesives in the surgical field is their on-site application through different stimuli such as heat, light and the use of chemicals. UV light serves as the primary mode of photoactivation for stimuli-sensitive bioadhesives given its fast application and better control over mechanical properties through its UV energy dosage. However, excessive exposure to UV may impose many negative side effects on the human body. This drives the necessity to research deeper on alternative photoactivation methods to fulfil the unmet clinical needs of using less harmful light for the activation of surgical adhesives. In this project, the activation of photo-crosslinkable diazirine-grafted polycaprolactone bioadhesive (CaproGlu) was extensively investigated using sunlight and visible (blue) light to replace unfavourable UV light. Photorheometry measurements are conducted to study the effect of varying concentrations of iridium photocatalyst (IrPC) that mediates CaproGlu activation by visible light. Other factors such as heat, grafting concentration of diazirine groups and lastly, gamma sterilization were also incorporated to see any underlying effect on its rheological properties. Photorheometry results showed that favourable covalent crosslinking could be achieved when using visible light sources. Nearly similar mechanical properties as in UV light could be attained by blue light activation with the dissolution of 2.5% mol IrPC. The capability to tune specific properties could motivate further explorations in visible light-activated surgical adhesives.