Critical size bone defect caused by various reasons repairing is still a major clinical challenge and requires bone grafts or bone substitutes. In recent year, polymer-cermic composits have been of great interest as replacements for damaged bone tissues due to their similarity with the natural bone tissue. Therefore, the aim of the current research, is to fabrication and characteriztion of Polycaprolactone-Hardystonite composite scaffold by melt layering method by 3D printing bone tissue engineering applictions. In this regard, first hardystonite particles were made by sol-gel method. Then, poly-caprolactone-hardystonite scaffolds with different percentages of hardystonite (0, 10, 20 and 30% weight) were prepared by 3D printing by fused deposition modeling (FDM). In order to confirm the presence of desired phases in the composition of the studied scaffolds, X-ray diffraction test was used and scanning electron microscope (SEM) was used to check the shape and distribution of porosity. A water contact angle measuring device was used to check the level of hydrophilicity of the scaffolds. Compressive mechanical properties were performed by performing a uniaxial compression test. The ability to form bone-like apatite by immersing the scaffolds in simulated blood solution for 28 days and the biodegradability rate by immersing the scaffolds in phosphate buffered saline solution for 28 days. were eva‎luated.cell viability, cell proliferation, adhesion and non-toxicity of pure PCL scaffolds and optimal scaffolds were determined by MTT test. The pore size of scaffolds varied from 394 to 564 micrometers and the diameter struts varied from 351 to 517 micrometers. The percentage of porosity scaffolds increased with the increase of hardystonite percentage from 56% for pure polycaprolactone scaffold to 66% for scaffold containing 20% weight of harydstonite. The results of the water contact angle showed a decrease in the water contact angle from 75° to 59° with the increase of hardstonite content, which indicates the improvement of the hydrophilicity of the scaffolds by adding hardstonite particles to poly-caprolactone. The results of the compressive mechanical test showed that with the increase of hardstonite content, the compressive strength of the scaffold increased from 8 MPa to 19.33 MPa and reached 18 MPa in the scaffold containing 30% by weight of hardstonite. The elasticity coefficient also increased from 19 MPa to 76 MPa following the same process of increasing the compressive strength, and then reached 24 MPa for the scaffold containing 30% by weight of hardstonite. The scanning electron microscope images after being placed in the simulated blood solution showed an increase in the ability to form a bone-like apatite layer on the surface of the composite scaffolds compared to the pure polycaprolactone scaffold. The degradability rate of poly-caprolactone-hardystonite scaffolds with percentages of 0, 10, 20 and 30% by weight were 2.16, 5.12, 5.66 and 5.4%, respectively. The results showed an increase in the degradability of scaffolds containing hardystonite compared to pure polycaprolactone scaffolds. Also, the results of cell biocompatibility by MTT test showed that by adding 20% hardystonite, the cell viability reached more than 95% after one day of cultivation against osteoblast cells (MG63), which indicates the absence of The toxicity of the scaffold is desired. Also, the results of cell adhesion indicate that the addition of 20% hardystonite has increased the number of cells and the connection and adhesion of osteoblast cells. Based on the results, it seems that 3D printing of poly-caprolactone-hardystonite scaffold containing 20% of hardystonite is a suitable option for use in bone tissue engineering.

رحمت اله عمادي , رضا مرتضوي

محمد خدائي

مهدي رفيعائي , مريم كرباسي