A Bioprinting-Driven Paradigm Shift In Periodontal Soft Tissue Augmentation

Investigate the effect of bio-printed hydrogel on periodontal soft tissue augmentation. Bio-ink was constructed using rat gingival fibroblasts (rGFs), gelatin methacrylate (GelMA) and chondroitin sulfate methacrylate (ChsMA). Subsequently, rGFs loaded hydrogels were fabricated by bioprinting technology (GC@F). The mechanical and physical properties were evaluated through scanning electron microscope (SEM), rheometer, etc. In the cell experiment, gingival fibroblasts and gingival epithelial cells were used. The effects of GC@F were explored on cell proliferation, migration and related molecular mechanisms through fluorescence immunohistochemistry staining (IF), western blot (WB), polymerase chain reaction (PCR), etc. Rat gingival thickening model were constructed and the in vivo effects of GC@F were evaluated through magnetic resonance imaging (MRI), hematoxylin-eosin staining (HE), masson's staining, immunohistochemistry staining, etc. GC@F demonstrated superior rheology, printability, and microstructure, supporting rGFs proliferation, migration and elevated COL1/FN expression via Wnt/β-catenin and Smad activation. After co-culture with GC@F, the KRT10 and KRT14 in gingival epithelial cells were higher expressed than those in the control group. MRI examination detected a significant thickening of the buccal gingiva of incisors in rats transplanted with GC@F, Histological analysis revealed the GC@F group showed reduced inflammation, enhanced collagen deposition and superior angiogenesis compared to GC hydrogel and pseudoflux controls. The bio-printed hydrogel that can stably and effectively thicken the gingiva was successfully produced, which has the potential to replace autologous connective tissue for periodontal/perimplant soft tissue augmentation.