Photochemical Tissue Bonding: Photons for Healing

摘要

Tissue adhesion can be achieved using lasers in a non-thermal process called photochemical tissue bonding (PTB) as well as by the better known processes in which the tissue is heated to achieve welding or soldering. In PTB the energy of the absorbed photons is used to drive photochemical reactions via activated chemical species. Covalent bonds (nanosutures) formed between protein molecules bind the tissue surfaces together. In our PTB approach the photosensitizer used superficially stains the tissue such that effects are limited to the tissue interface. The overall temperature rise and concomitant thermal damage is negligible and structural integrity of the tissue is retained. This technology is generally applicable, but not limited to, collagenous tissues. In recent years we have used PTB for corneal repair, skin incision repair and skin grafts, tendon repair, nerve repair and blood vessel repair. In most cases, in vitro results have been followed by promising in vivo studies in appropriate animal models. Immediate repair strength, long term wound healing and functional recovery are all important factors governing the applicability of PTB in any given tissue and have been a focus of our work. This contribution will summarize our experience in mechanisms behind PTB, factors that influence the efficacy of PTB in various tissues and a comparison to other modalities for tissue adhesion and repair.