An injectable APAG/CGF biomaterial orchestrates gingival black triangle reconstruction via biomimetic microenvironment for cellular regulation.

The presence of gingival black triangles in the anterior dentition poses significant esthetic and functional concerns. Conventional surgical interventions, despite being the most widely employed techniques, are hampered by inherent invasiveness, technique sensitivity, and unpredictable regenerative outcomes. These limitations drive the need for effective and predictable non-surgical alternatives. Herein, we develop an injectable biomaterial through the self-assembly and self-crosslinking of activated plasma albumin gel (APAG) with concentrated growth factors (CGF), effectively encapsulating bioactive components within a stable network. The APAG/CGF biomaterial exhibits a hierarchical microstructure with uniform porosity and nanofibers, controlled biodegradability, and rich growth factors, collectively constituting a biomimetic microenvironment. Notably, this matrix enables the sustained release of growth factors, which enhance the viability, proliferation, and migration of human periodontal ligament stem cells (PDLSCs) for at least 14 days in vitro. In clinical application, the injection of APAG/CGF into anterior gingival black triangle regions successfully promotes excellent reconstruction of the gingival papillae, with outcomes maintained over a 6-month follow-up period. In conclusion, this study introduces an injectable APAG/CGF biomaterial as a promising non-surgical strategy for gingival black triangle reconstruction by leveraging a biomimetic microenvironment to potentiate essential cellular functions.