Degradation Pattern of a Biodegradable and Photocurable Sealants Based on Hyaluronic Acid : A Serial Magnetic Resonance Imaging Observational Study in Rat Craniectomy Model

The aim of this study is evaluating in vivo degradation of photocrosslinkable hyaluronic acid (HA)-based dural sealant (HA photosealant) using magnetic resonance imaging (MRI) and histopathological analysis to assess its biodegradability and effectiveness in preventing cerebrospinal fluid (CSF) leakage. HA photosealants were applied to the incised dura in a rat craniectomy and durotomy. The HA photosealant quickly seal the wound upon low-energy visible light exposure (405 nm, < 5 s, < 1 J/cm2). The degradation of HA photosealants was tracked through serial MRI scans at 1, 2, and 4 weeks post-application. The remaining area of HA photosealants on the dura was measured using image processing program for volumetric analysis. Additionally, histopathological analyses were performed to evaluate the biocompatibility and effectiveness of the dural repair. The MRI and histopathological analyses showed that the HA photosealants achieved progressive degradation while successfully preventing CSF leakage without any adverse tissue reactions. The residual area of HA photosealants measured at 2 weeks ranged from 41.36% to 94.88%, with an average of 66.57%. At 4 weeks, a more distinct degradation pattern was observed compared to 2 weeks, showing a residual area of 10.28% to 56.12%. The HA photosealants maintained structural integrity until dural regeneration was complete. HA photosealant showed gradual degradation in vivo while maintaining mechanical strength until the dura was repaired for preventing CSF leakage without inflammation and toxicity. HA photosealant has great potentials for clinical application for dural repair with biodegradable properties and biocompatibility.