# Effect of Poly (Lactic Acid/ε-Caprolactone) Bilayer Membrane on Tooth Extraction Socket Wound Healing in a Rat Model

## TL;DR

A new biodegradable membrane improved wound healing in rat tooth sockets, preserving bone-soft tissue boundaries better than existing options.

## Contribution

A novel bilayer membrane with prolonged degradability and elasticity was developed and tested for guided bone regeneration.

## Key findings

- PBM preserved a clear bone-soft tissue boundary in rat extraction sockets.
- PBM supported greater oral epithelial cell adhesion compared to its reverse side.
- PBM showed better protein permeability than PLGA membranes.

## Abstract

Guided bone regeneration membranes are essential for bone formation. While non-resorbable membranes require removal surgery, resorbable membranes such as poly (lactic-co-glycolic acid) PLGA are widely used; however, issues with animal-derived components and degradation control have been identified. A novel bilayer membrane composed of synthetic poly (L-lactic acid-co-ε-caprolactone) (PBM) was developed, offering prolonged degradability and elasticity. This study compared the wound-healing effects of PBM and PLGA membranes in vivo and in vitro experiments. In vivo, maxillary molars were extracted from rats, and membranes were placed over the sockets. Healing was evaluated histologically at 1, 2, 3, 4 and 8 weeks. In vitro, oral epithelial cells and fibroblasts were seeded on both sides of PBM. Adhesion and permeability of the membranes were assessed. In vivo, both groups displayed similar mucosal healing. However, PBM preserved a clear bone-soft tissue boundary. In vitro, the surface of PBM supported significantly greater oral epithelial cell adhesion than the reverse side, with no differences for fibroblasts. Both sides of PBM exhibited better protein permeability compared to PLGA. PBM maintained distinct bone-soft tissue separation in rat extraction sockets, suggesting its potential as an effective space maintainer in guided bone regeneration. Further studies are warranted to investigate the mechanisms underlying these favorable properties.