Adhesion Prevention after Laminectomy Using Silk-Polyethylene Glycol Hydrogels.

Laminectomy is a common operation in spine surgery to reduce spinal cord and nerve pressure. However, scar tissues often form in the spinal canal and adhere to the dura surface, resulting in low back pain postsurgery. In the present study, biodegradable silk-polyethylene glycol (PEG) hydrogels are evaluated for adhesion prevention after laminectomies in New Zealand rabbits, with nondegradable expanded polytetrafluoroethylene (ePTFE) membranes and saline as controls. No significant difference among the three groups is observed within 2 weeks. Silk is fully degraded within 6 weeks, leaving a gap separating the scar tissue and the dura mater. Severe dural scar adhesion form in the saline control group after 8 weeks, while no or mild adhesion is observed in the ePTFE membrane and silk-PEG hydrogel samples. Human dermal fibroblasts (HS-865-SK cells) are cultured in the silk-PEG hydrogel extracts and on top of gel surfaces. Compared to the controls of tissue culture plate (no silk) and sonicated silk hydrogels (no PEG), the proliferation of fibroblasts in both conditions is significantly reduced initially but resumes after 120 h, suggesting the surface properties of the hydrogels and local, temporal release of PEG accounts for the adhesion prevention observed in vivo in this study.