Fabrication and characterization of 3D printing biocompatible crocin-loaded chitosan/collagen/hydroxyapatite-based scaffolds for bone tissue engineering applications

Introduction: Crocin (Cro) is a bioactive biomaterial with properties that promote osteoconduction, osteoinduction, and osteogenic differentiation, making it an ideal candidate for developing mechanically enhanced scaffolds for bone tissue engineering (BTE). Present study focused on a 3D printing matrix loaded with Cro and featuring a composite structure consisting of Chitosan (CH), collagen (Col), and hydroxyapatite (HA). Method: The scaffolds' structural properties were analyzed using FESEM, and FTIR DSC, while the degradation rate, swelling ratio, cell viability were examined to determine their in vitro performance. Additionally, the scaffolds' mechanical properties were calculated by examining their force, stress, elongation, and Young's modulus. Results: The CH/Col/nHA scaffolds demonstrated interconnected porous structures. The cell study results indicated that the Cro-loaded in scaffolds cause to reduce the toxicity of Cro. Biocompatibility was confirmed through degradation rate, swelling ratio parameters, and contact angle measurements for all structures. The addition of Cro showed a significant impact on the strength of the fabricated scaffolds. By loading 25 and 50 mu l of Cro, the Young's modulus improved by 71 % and 74 %, respectively, compared to the free drug scaffold. Conclusion: The obtained results indicated that the 3D printing crocin-loaded scaffolds based chitosan/collagen/ hydroxyapatite structure can be introduced as a promising candidate for BTE applications.