Abstract Tissue engineering uses biological scaffolds and stem cells to repair and regenerate damaged tissues such as bones and nerves. Engineered scaffolds for bone provide a suitable environment for cell growth and should have appropriate porosity, favorable mechanical properties, and biodegradability. In this context, 3D printing enables the production of scaffolds with precise and complex structures, and by controlling porosity and shape, it helps to improve cell growth and tissue regeneration, and accelerates the optimization of restorative treatments. In this research, biological scaffolds were produced using three main components with different percentages, including polycaprolactone as a polymer base and bioglass with high entropy oxide nanoparticles containing silver, and then the mechanical and biological properties of these scaffolds were investigated for bone tissue engineering applications. . was investigated. The purpose of this research is to investigate the effect of composition and percentage of components on the porosity, mechanical properties and biocompatibility of the scaffold. For this purpose, nanoparticles of high entropy oxides (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 were synthesized by mechanical alloy method and silver was doped in it, the antibacterial properties of prepared nano powders were investigated and the results showed that the presence of silver makes it have antibacterial properties. After that, bio glass was produced using three compounds of calcium nitrate tetrahydrate, diammonium hydrogen phosphate and soluble sodium silicate using ultrasonic and centrifuge devices. Then the scaffolds in two groups containing silver and without silver with 20% by weight of biological glass and respectively with 20-60, 70-10 and 5-75% by weight of polycaprolactone and high entropy oxides in three dimensions. Printing Method They were then produced by FDM. Based on the results obtained from the wettability and mechanical properties test, scaffolds containing 10% of high entropy oxides containing silver and without silver have better results compared to other production scaffolds that were selected as optimal samples. . After eva‎luating the porosity percentage of the samples of both groups of scaffolds, their degradability was checked for 91 days in phosphate buffer salt solution and it was observed that the percentage of scaffold degradability increased slightly with the addition of silver nanoparticles. And bioactivity was observed in both scaffold samples. L929 cell adhesion was checked in both scaffolds and based on DAPI test results, it was observed that there is cell density on the samples. Also, in both scaffold samples, the lack of MTT cytotoxicity was proven within 24, 48 and 120 hours, and it was observed that the cell viability was higher in the sample with silver, which shows that the antibacterial properties of silver are effective in implantation. Then, drug release was checked using Vancomycin 500 in both scaffold samples, and the cumulative release in both samples was suitable and equal to 95% ± 0.5, and the release rate in the sample containing silver was more continuous and with a more uniform rate. done At the end, filled scaffolds without voids were produced from the two optimal samples that were previously determined, and vancomycin was loaded on them, and their antibacterial properties were investigated, and the results showed that considering the diameter The area where the bacteria are inhibited, there are antibacterial properties in two samples, especially in the scaffold containing silver. Based on the results obtained in this research, the use of nanocomposite scaffold produced by FDM 3D printing method and containing 70% polycaprolactone, 20% bio glass and 10% high entropy oxide doped with silver nanoparticles (with a structure that was previously mentioned), it is suggested for use in bone tissue engineering

تقي اصفهاني

مهدي مهدي خاني , وحيده السادات صادقي