A unidirectional drug‐release Janus membrane based on hydrogen bonding barrier effect for preventing postoperative adhesion and promoting tissue repair

Abstract Barrier membranes incorporated with anti‐adhesion drugs have been widely used for preventing postoperative adhesion. However, the bidirectional release of drugs may interfere with internal tissue healing. Herein, a unidirectional Janus membrane composed of two functional layers is prepared by sequential electrospinning. The outer layer is designed as random polycaprolactone fibers incorporated with tannic acid/Fe 3+ particles to prevent tissue adhesion, while the inner layer is designed as oriented gelatin fibers to promote tissue repair. Hydrogen bonding was employed to act as a barrier for preventing the diffusion of the tannic acid to the inner side, and thus the release of tannic acid occurs in a unidirectional manner. As a result, asymmetric biological performances of the Janus membrane are achieved. The outer face can provide anti‐inflammatory capability to the membrane and inhibit the viability of fibroblasts, while the inner face can promote the proliferation and differentiation of tendon stem cells. Tendon injured model confirms the prominent inflammation modulation, adhesion prevention, and repair promotion capabilities of the Janus membrane in vivo. This study provides a new strategy to develop advanced functional barrier membranes for postoperative adhesion prevention and internal tissue repair promotion.