Evaluation of pleurodesis by poly-ε-caprolactone (PCL) gel in an animal model using New Zealand white rabbits

Summary: Background/Purpose: Pleurodesis with biomaterial implant is an emerging treatment method for pleural diseases. However, the ideal biomaterial or the optimal form for the common diseases is still under investigation. In our previous study, Poly-ε-caprolactone (PCL) membrane produces significant pleurodesis in New Zealand White rabbit animal models. Methods: We investigate the Poly-ε-caprolactone (PCL) gel pleurodesis by animal models using New Zealand White rabbits, which were sacrificed for examination after one month. Thirty-Six New Zealand White rabbits were randomized into three groups equally to undergo procedures. Gross pleurodesis scoring was evaluated. Additionally, inflammation and fibrosis scoring were done under microscopic evaluation, as well as Western blot analysis. Results: Gross evaluation of pleurodesis score revealed that lower concentrated PCL gel (10%) produced moderate pleural adhesion, while higher concentrated PCL gel (25%) showed significantly higher pleurodesis scores. (P < 0.05) Control group with thoracostomy alone produced almost no pleurodesis (P < 0.05). Western blot showed fibronectin expression was more evident in the 25% PCL gel than 10% one. Conclusion: PCL gel induced significant degree of pleurodesis in the rabbits. The 25% PCL gel produces more intensive adhesion than 10% one. Fibronectin plays an important role in the process of pleurodesis. Further study is required for the clinical application of the promising biomaterial with gel form. Keywords: Pleurodesis, Spontaneous pneumothorax, Pleural disease, Poly-ε-caprolactone (PCL) gel, Fibronecti