Janus fibre/sponge composite combined with IOPNs promotes haemostasis and efficient reconstruction in oral guided bone regeneration

Scheme 1. Schematic illustration of the fabrication and utilisation of γ-Fe2O3-loaded fibre/sponge scaffolds in a tooth-extraction model. The γ-Fe2O3-loaded scaffold has a dense-loose structure for oral guided bone regeneration. The dense part of the electrospun fibre sheet functions as a barrier membrane; the loose part of the chitosan sponge loaded with γ-Fe2O3 promotes haemostasis and bone regeneration. [Display omitted] •A Janus fibre/sponge composite combining iron oxide nanoparticles (IONPs, γ-Fe2O3) was successfully fabricated for oral guided bone regeneration.•The scaffold had a Janus structure and was superparamagnetic.•The scaffold showed superior hemostatic ability.•The Janus scaffold can work as barrier membrane and bone-forming substitute. Placing a barrier membrane between an alveolar bone wound and gingival soft tissue is a common and effective method to prevent fibroblast invasion and promote new bone formation. However, the combined use of a barrier membrane with bone-forming substitutes remains a challenge for dentists during surgery. Thus, a Janus fibre/sponge composite combining iron oxide nanoparticles (IONPs, γ-Fe2O3) was fabricated to prevent epithelial invasion and promote alveolar reconstruction. In the scaffold, a poly (lactic-co-glycolic acid)/polycaprolactone (PP) electrospun layer was covalently bound with a chitosan sponge containing γ-Fe2O3 by polydopamine. The resilient chitosan sponge can easily adhere to the wound surface and encompass haemostatic capability by swelling and forming blood clots to block bleeding. The introduction of IONPs promoted the osteogenesis of rBMSCs, as shown by ALP analysis and cytokine assay. The PP layer maintained its structure integrity and prevented epithelial cells from invading into blood clots or fibroblasts from penetrating through the critical pore size. Assessment with a rat model having one-sided calvarial bone injury further confirmed the effectiveness of Janus scaffolds in facilitating the bone regeneration in the postoperative areas.