Monitoring neovascularization and integration of decellularized human scaffolds using photoacoustic imaging

摘要： Tissue engineering is a branch of regenerative medicine that aims to manipulate cells and scaffolds to create bioartificial tissues and organs for patients. A major challenge lies in monitoring the blood supply to the new tissue following transplantation: the integration and neovascularization of scaffolds in vivo is critical to their functionality. Photoacoustic imaging (PAI) is a laser-generated ultrasound-based technique that is particularly well suited to visualising the microvasculature due to the high optical absorption of haemoglobin. Here, we describe an early proof-of-concept study in which PAI in widefield tomography mode is used to image biological, decellularized human tracheal scaffolds. We found that photoacoustic imaging allowed the longitudinal tracking of scaffold integration into subcutaneous murine tissue with high spatial resolution at depth over an extended period of time. The results of the study were consistent with post-imaging histological analyses, demonstrating that photoacoustic imaging can be used to non-invasively monitor the extent of vascularization in biological tissue-engineered scaffolds. We anticipate that this technique could find application in tissue-engineering studies aimed at improving the speed and extent of scaffold neovascularization. With technological development, it could also be used to inform the clinical timing of surgical procedures following heterotopic transplantation to establish vasculature.