Injectable Nanocomposite Hydrogels for Non-Critical Mandibular Fracture Repair

Injectable hydrogels are emerging material for the management of non-critical mandibular fractures. They have the capacity to enable minimally invasive interventions and conform to complex defect geometries. Within this framework, the present work focuses on the design of injectable nanocomposite hydrogels capable of avoiding soft-tissue collapse into mandibular bone defects, preserve geometry for later mineralization while delivering cues for bone regeneration. In particular, this work investigates injectable nanocomposite hydrogels based on k-carrageenan (kC) and guar gum (GG), reinforced with fluorapatite nanoparticles (FA NPs) as a biomimetic inorganic phase. FA NPs were synthesized via a sol–gel route and incorporated into the polysaccharide matrix at different loadings (0.5 % w/w, 1.0 % w/w), while the polymer composition was varied to modulate network properties. The resulting formulations were characterized in terms of rheological behaviour, morphology, and chemical structure. The hydrogels exhibited solid-like viscoelastic properties and a three-dimensional porous architecture, with FA NPs physically embedded within the polymer network. The results clearly demonstrate that the polymer ratio and nanoparticle content are key parameters governing the structural organization and viscoelastic response of the hydrogel, enabling tailored material properties.