Citric Acid-Crosslinked PVA/CMC Composite Membranes with Enhanced Wet-State Stability for Prevention of Postoperative Pericardial Adhesions

Abstract Maintaining sufficient barrier integrity under wet physiological conditions remains a key challenge for membranes used to prevent postoperative pericardial adhesions. Citric acid content was investigated as a crosslinking parameter to regulate the wet-state stability of PVA/CMC (PCC) composite membranes. Increasing CA content progressively reduced water absorption, volumetric swelling, and mass loss, while substantially improving wet mechanical performance. Among the formulations, PCC15 exhibited the best overall performance, with a swelling ratio of 93%, a wet tensile strength of 6.7 MPa, and an elongation at break of 190%. After 30 days in PBS, PCC15 retained a wet tensile strength of 5.7 MPa, demonstrating sustained mechanical integrity under prolonged wet conditions. All PCC membranes showed hemolysis ratios below 5% and cell viabilities above 70%, with lower fibroblast attachment than the tissue-culture plate control. In a rabbit pericardial adhesion model, PCC15 markedly reduced heart-to-sternum adhesion and collagen deposition without obvious local inflammation. Overall, increasing CA crosslinking effectively improved the wet-state stability of PCC membranes while maintaining favorable flexibility and biocompatibility, supporting their potential as physical barriers for postoperative pericardial adhesion prevention.