Long term recovery of median nerve repair using laser‐activated chitosan adhesive films

Abstract

Sutures remain the standard peripheral nerve repair technique, whether applied directly or indirectly to nerve tissue. Unfortunately, significant postoperative complications can result, such as inflammation, neuroma formation and foreign body reactions. Photochemical-tissue-bonding (PTB) using rose Bengal (RB) integrated into a chitosan bioadhesive is an alternative nerve repair device that removes the need for sutures. Rats were arranged into three groups: RB-chitosan adhesives-repair, end-to-end epineural suture-repair (surgical standard) and sham laser-irradiated control. Groups were compared through histological assessment, electrophysiological recordings and grip motor strength. RB-chitosan adhesive repaired nerves displayed comparable results when compared to the standard suture-repair based on histological and electrophysiological findings. Functionally, RB-chitosan adhesive was associated with a quicker and more pronounced recovery of grip force when compared to the suture-repair.

A conducting polymer with enhanced electronic stability applied in cardiac models

“…Here, we introduced a new sutureless method for adhesion of patches onto heart tissue (movie S1), namely, using photoadhesion with a green laser (fig. S9 and movies S1 and S2) ( 54 , 55 ). Consequently, we conducted a preliminary in vivo study to investigate whether the sutureless C-Patch has any effect on cardiac function and whether it imposes a proarrhythmic risk.…”

Gecko-inspired chitosan adhesive for tissue repair

“…About 10% of the adhesive nanopillars presented some defects that can be corrected if the dry-casting technique is optimized, for example, exploring different materials for the master plate such as polydimethylsiloxane or Perspex. 6,37 The flat chitosan adhesive has been successfully used to repair rat median nerves in vivo, 18,19 showing repair strength comparable to sutures. Myelinated axons regenerated equally well either in rats operated with the flat chitosan adhesives or in sutured nerves; the laser-adhesive technique was nonetheless superior and less invasive than suturing when the functional recovery of nerves was tested 3 months postoperatively.…”

“…Myelinated axons regenerated equally well either in rats operated with the flat chitosan adhesives or in sutured nerves; the laser-adhesive technique was nonetheless superior and less invasive than suturing when the functional recovery of nerves was tested 3 months postoperatively. 19 Of relevance is the fact that the nanoscale modification of the flat chitosan adhesive did not alter its chemical composition and thus its excellent biocompatibility and biodegradability. 38 In this respect, a recent study has highlighted that the degradation of the flat chitosan adhesives can be modulated if a physiological amount of lysozyme is added during the fabrication process of the adhesive.…”

“…16 Our group has recently developed a biocompatible and sutureless adhesive for peripheral nerve repair; 17 this adhesive is based on chitosan and is bonded photochemically to tissue by a green laser without causing thermal damage. 18,19 In this study, we succeeded in modifying the adhesive surface with nanopillars to further enhance the strength of tissue bonding. A simple dry-casting technique is required to fabricate the nanostructured film and no coating is necessary to stabilize the bonding between adhesive and tissue in wet environment; this feature simplifies the fabrication process to a single step procedure.…”

Improving Outcomes in Immediate and Delayed Nerve Grafting of Peripheral Nerve Gaps Using Light-Activated Sealing of Neurorrhaphy Sites with Human Amnion Wraps

“…The technique has also been applied successfully to peripheral nerve repair using photochemically sealed chitosan adhesive films. 20 This study assesses whether photochemical sealing of nerve grafts remains efficacious following a clinically relevant surgical delay and, indeed, whether outcomes can be enhanced in comparison with conventional suture repair.…”