Preparation and characterization of a novel acellular swim bladder as dura mater substitute

Objectives: This paper aimed to develop a novel dura mater substitute made from swim bladders. Methods: The swim bladders were decellularized by diverse methods. The physical structure, residual DNA amount, mechanical properties and hemolysis rate were tested. The in vitro mouse embryonic fibroblast cells (MEFs) co-culture and in vivo dural repair surgery were performed to evaluate the biocompatibility of acellular swim bladder (ASBs). Results: The characteristics of different ASBs were evaluated, and the materials prepared via 'freezing-thawing and DNase-I' method showed the most appropriate features as dura mater substitute. The loosen fiber layer structure and three-dimensional porous structure were formed after decellularization. The residual DNA content was low (9.2 +/- 2.0 ng/mg) and the mechanical properties could meet the clinical requirement (the maximum tensile strength was 34.77 +/- 4.28 N and the maximum stitch tear strength was 7.15 +/- 1.84 N). The hemolysis rate was up to 2.8 +/- 0.15%. In the MEFs co-culture test, ASBs could support the adhesion, migration and proliferation of cells. The dural repair experiment demonstrated ASBs could prevent the leak of cerebrospinal fluid, and the materials were gradually replaced by autologous connective tissue. The novel dura mater substitute improved dura repair and regeneration without causing adhesion or severe inflammation. Discussion: The ASBs prepared via 'freezing-thawing and DNase-I' method had the ideal physical and biological properties as a dura mater substitute for clinical application.