Integrated Janus silk fibroin membranes for periodontal-guided tissue regeneration

Membrane materials containing dense and porous layers are greatly needed for periodontal-guided tissue regeneration (GTR) surgery. Silk fibroin (SF) has been widely used in medical biomaterials. However, conventional methods make it difficult to prepare suitable SF membranes for periodontal GTR. Here, an integrated Janus SF membrane (JSFM)-a membrane with two distinct sides-with dense and porous layers was directly prepared by unidirectional nanopore dehydration (UND) and freeze-drying. The effects of UND duration on the JSFM were examined. In addition, the biocompatibility of the membranes was examined in vitro and in vivo. Scanning electron microscopy showed that the resulting membrane had a Janus structure when the UND was performed for less than 4.5 h. With extended UND duration, the Janus structure disappeared, and the swelling ratio and water uptake abilities of the membranes decreased significantly while the mechanical properties were enhanced. Fourier transform infrared (FTIR) spectroscopy indicated that the crystalline structure of the porous layer gradually increased with increasing UND duration. The in vivo study indicated that the membrane could support the growth and proliferation of human periodontal ligament fibroblast cells (hPDLs), and the dense layer of the membrane effectively prevented the migration of hPDLs. The in vivo study performed in rats demonstrated that the membranes have good biocompatibility. Therefore, a new membrane type with a special Janus structure was developed. The membrane shows excellent biocompatibility and can intercept cells for exploitation in various biomedical applications, particularly in periodontal GTR.