Polysaccharide-based hydrogels for alveolar socket healing: biological functions and material design strategies.

Tooth extraction sockets undergo a tightly regulated sequence of hemostasis, inflammation, angiogenesis and bone remodeling within a confined bony cavity that is directly exposed to the oral environment. Conventional socket dressings mainly act as passive fillers or barriers and provide little control over the local immune and regenerative microenvironment. Polysaccharide based hydrogels, derived from chitosan, hyaluronic acid, alginate, cellulose and related macromolecules, offer a structurally tunable platform in which macromolecular parameters and network architecture can be engineered to match phase specific healing requirements. In this review, we summarize how degree of deacetylation, molecular weight, substitution pattern and block sequence, together with crosslinking chemistry and degradation behavior, govern clot stabilization, antimicrobial activity, immunomodulation, angiogenesis and osteogenesis in extraction sockets. We highlight representative systems in which charge density and dynamic covalent or ionic crosslinks are exploited to program hemostatic and antibacterial responses, and discuss polysaccharide networks that deliver ions, growth factors or cells to restore angiogenic and osteogenic signaling in compromised sockets. Emerging architectures, including hybrid and multi network gels, in situ gelling formulations, bilayer and Janus constructs, microsphere hydrogel composites and microneedle platforms, are examined from a structure property function perspective, emphasizing how network design improves mechanical robustness, degradation kinetics and spatiotemporal release profiles under intraoral loading. Finally, we outline opportunities for stimuli responsive and patient tailored polysaccharide hydrogels that dynamically respond to pH, oxidative stress or inflammatory cues, aiming at predictable and clinically practical regeneration of both soft and hard tissues after tooth extraction.