Abstract: The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities. This investigation focused on the preparation of Three-Dimensional (3D)- printed Polycaprolactone (PCL) scaffolds with varying proportions of Nanohydroxyapatite (NHA) and Nanoclay (NC), and their physiochemical and biological properties were assessed. The mechanical properties of PCL are satisfactory; however, its hydrophobic nature and long-term degradation hinder its use in scaffold fabrication. NHA and NC have been employed to improve the hydrophilic characteristics, mechanical strength, adhesive properties, biocompatibility, biodegradability, and osteoconductive behavior of PCL. The morphology results demonstrated 3D-printed structures with interconnected rectangular macropores and proper nanoparticle distribution. The sample containing 70 wt% NC showed the highest porosity (65.98 ±2.54%), leading to an increased degradation rate. The compressive strength ranged from 10.65 ± 1.90 to84.93±9.93 MPa, which is directly proportional to the compressive strength of cancellous bone (2–12 MPa). The wettability, water uptake, and biodegradability of PCL scaffolds considerably improved as the amount of NC increased. Theresults of the cellular assays exhibited increased proliferation, viability, and adhesion of MG-63 cells due to the additionof NHA and NC to the scaffolds. Finally, according to the in vitro results, it can be concluded that 3D-printed sampleswith higher amounts of NC can be regarded as a suitable scaffold for expediting the regeneration process of bone defects.

Key words: Polycaprolactone')">Polycaprolactone, Hydroxyapatite, Nanoclay, 3D printing, Bone tissue engineering