Experimental investigation of pre-crosslinking methods and employing nano-hydroxyapatite powder on alginate/carboxymethyl cellulose hydrogel printability via 3D bioprinting

Purpose Three-dimensional bioprinting (3D bioprinting) is used for repairing and regenerating living tissues due to its ease of use, cost-effectiveness and high precision in fabricating. Owing to their high biocompatibility, natural hydrogels are widely used as scaffold materials in bioprinting. However, the mechanical properties and low printability of hydrogels present a challenge. This study aims to introduce a composite hydrogel that exhibits excellent mechanical, biological and printability properties simultaneously. Design/methodology/approach Alginate (Alg), carboxymethyl cellulose (CMC) and nanohydroxyapatite (nHA) as suitable materials for 3D printing were used. Effect of material content and pre-crosslinking on various properties of these materials were investigated. Both quantitative and qualitative experiments were conducted to validate the biomaterial ink’s printability, its rheological characteristics, as well as its biological and mechanical properties. Findings Based on the analysis of the obtained experimental results from all mentioned tests, a hydrogel with a composition of 4% Alg, 2% CMC and 2% nHA with the pre-crosslinking process was selected as the preferred option. The results demonstrated that the selected material has good cell adhesion, wettability, degradation rate and 93% cell viability. Furthermore, compared to the composition of 4% Alg–2% CMC, the chosen material exhibited a 52% improvement in printability and a 55% improvement in compressive modulus. Originality/value A significant challenge in the field of 3D bioprinting is the development of scaffolds that possesses optimal mechanical, biological and printability characteristics simultaneously, essential for attaining tissue-like properties. Hence, this paper explores a novel nanocomposite hydrogel that demonstrates promising outcomes across all these aspects simultaneously.