Asymmetric Janus fiber membrane for preventing cerebrospinal fluid leakage and promoting bone regeneration

Repairing skull base defects caused by pituitary tumor surgery remains challenging as it is difficult to restore its structural integrity and avoid cerebrospinal fluid leakage. To address this issue, this study aimed to prepare a Janus bilayer membrane with asymmetric wetting properties (hydrophobicity/super hydrophilicity) using polycaprolactone (PCL), gelatin (Gel), and polydopamine (PDA) through a layer-by-layer electrospinning technique. Randomly stacked hydrophobic PCL fibers were designed as the upper layer to control leakage of cerebrospinal fluid. Meanwhile, the bottom layer composed of hydrophilic PG-PDA nanofibers was utilized to promote the skull base bone repair. The experimental results showed that under a pressure of 200 mm water column, the Janus bilayer membrane could efficiently prevent leakage for several days. The prepared Janus PCL/PG-PDA membrane revealed excellent mechanical properties to mimic bone ECM and showed surface bioactivity to accelerate mineralization. The results of in vitro cell experiments indicated that the Janus membrane prepared in this study displays exceptional biocompatibility, with the PCL/PG-0.5%PDA fiber membrane demonstrating the highest capacity to promote osteogenic differentiation. These observations suggest that the asymmetric Janus fiber membrane (PCL/PG-PDA) has the potential to serve as a promising candidate for skull base repair.