In this study, multifunctional polysaccharide-based injectable hydrogels were developed using chitosan (CS) and dialdehyde bacterial cellulose (D-BC), interpenetrated with pectin (PT). The hydrogels exhibited rapid gelation, good water retention, and injectability under physiological conditions. Comprehensive characterization was performed to assess their chemical structure, internal morphology, thermal stability, and rheological behavior. The formation of dynamic Schiff base bonds between amine groups of CS and aldehyde groups of D-BC facilitated efficient crosslinking, resulting in rapid gelation and favorable swelling properties. The hydrogels also demonstrated shear-thinning behavior, contributing to their injectable and self-supporting characteristics. In vitro biocompatibility was evaluated over 21 days using gingival mesenchymal stem cells (GMSCs), with all formulations maintaining over 80% cell viability, confirming their cytocompatibility. Antibacterial assays revealed significant inhibition of Staphylococcus aureus, indicating promising antimicrobial performance. The 3D hydrogel networks provided a porous and stable structure suitable for cellular infiltration and tissue integration. Overall, this work presents a green, bio-based approach for fabricating injectable hydrogels with tunable physicochemical and biological properties, offering a potential platform for soft tissue repair applications, particularly in maxillofacial regeneration.