Design and Development of <scp>3D</scp> Printed Scaffolds Using Polysaccharide‐Based Hydrogels via Quality‐by‐Design Approach

ABSTRACT The development of advanced bioinks is critical for the successful fabrication of tissue‐engineered scaffolds via three‐dimensional (3D) printing. In this study, we have reported the synthesis and characterization of a novel Hyaluronic Acid–Chitosan (HA‐CH) co‐polymer hydrogel specifically engineered for extrusion‐based 3D bioprinting. The HA‐CH conjugate was synthesized via carbodiimide‐mediated coupling and comprehensively characterized through UV–Vis spectroscopy, FT‐IR, DSC, XRD, 1 H NMR, and SEM analyses, confirming successful conjugation, enhanced thermal stability, and favorable morphological features with interconnected porosity. Employing a Quality‐by‐Design (QbD) approach, CMAs and process parameters were identified and optimized via a Box Behnken design (BBD), achieving hydrogels with tailored viscosity (2366.6 mPa s), storage modulus (232 Pa), and loss modulus (236 Pa). The optimized batch of hydrogel was successfully 3D printed into scaffolds exhibiting excellent physical uniformity, 100% flatness, high folding endurance (&gt; 100 folds), and physiologically compatible surface pH. Comprehensive evaluation demonstrated ideal moisture content, swelling indices up to 1850% in PBS, pore sizes conducive to cellular infiltration (average ~403.9 μm), and a sustained biodegradation profile (48% mass loss over 14 days). Texture profile analysis confirmed adequate mechanical resilience and elasticity suitable for biomedical applications. The MTT assay confirmed the excellent biocompatibility of the HA‐CH hydrogel, with L929 fibroblast viability remaining high at 92.2%—showing no significant cytotoxicity. Collectively, the engineered HA‐CH conjugate hydrogel demonstrates exceptional potential as a biocompatible, tunable, and printable material platform for future applications in regenerative medicine, wound healing, and customized tissue engineering constructs.