An Injectable ROS-Sensitive Hydrogel for Bone Regeneration in Periodontitis

Objectives: Bone repair in periodontitis remains a big challenge since the injury sites are often accompanied by an abnormal level of reactive oxygen species (ROS), which hinders new bone regeneration. This study aimed to synthesize an injectable hydrogel (PeMA_GSH-SF@h-BN) with acceptable mechanical properties and high anti-ROS sensitivity to promote bone regeneration in the periodontitis environment.
Methods: The injectable hydrogel contained pectin methacrylate (PeMA), glutathione-modified silk fibroin (GSH-SF), hexagonal boron nitride (h-BN) and photo-initiator (LAP) was photo-crosslinked under UV light (405 nm) for 30 s. The hydrogel system's rheology, mechanical properties, swelling behaviour, biocompatibility, and osteogenic and antioxidant capabilities were evaluated. BMSCs isolated from SD rats' bone marrow were used for in vitro experiments. Moreover, an in vivo periodontal ligature rat model was used to demonstrate the periodontal bone regeneration ability of the hydrogel. Statistical analyses were performed using the Student T-test (α=0.05).
Results: FTIR analysis confirmed the synthesis of PeMA and GSH-SF, in which highly methacrylated pectin and GSH-modified 8% SF were selected as the hydrogel components. The incorporation of GSH and PeMA did not adversely alter the physico-mechanical properties of the hydrogel. The addition of 10 μg/mL h-BN significantly improved the mechanical properties and osteogenic and antioxidant capabilities of the hydrogel, without compromising biocompatibility. Furthermore, in vivo experiments demonstrated that the PeMA_GSH-SF@h-BN hydrogel has the potential to promote bone regeneration in the periodontitis environment.
Conclusions: The injectable PeMA_GSH-SF@h-BN hydrogel has been successfully designed and synthesized. H-BN has beneficially enhanced the hydrogel’s anti-ROS ability. The remarkable anti-ROS sensitivity of the fabricated hydrogel makes it a promising candidate for bone regeneration in a periodontitis environment.