Ahmed N.E.-M.B.El Azeem A.F.A.Bayoumi F.S.Department of Oro-Dental GeneticsMedical Research Centre of ExcellenceNational Research CentreCairoEgypt; Stem Cell LaboratoryCenter of Excellence for Advanced SciencesNational Research CentreCairoEgypt; Department of Microbiology and ImmunologyFaculty of PharmacyOctober University of Modern Sciences and Arts (MSA)CairoEgypt; Department of ImmunogeneticsNational Research CentreCairoEgypt2020-01-092020-01-09201815568539https://doi.org/https://t.ly/JXK7YScopusBiomaterials have allowed many advances in the field of bone tissue engineering (BTE). Polycaprolactone (PCL) is an FDA degradable polymer that has been used for manufacturing scaffolds in bone tissue engineering. Different modifications have been made to PCL scaffold in order to improve its surface properties and osteoinductive abilities. It is essential that any modification of the engineered scaffold should avoid altering the properties of the seeded cells. Stem cells isolated from human exfoliated deciduous teeth (SHED)-similar to all other mesenchymal stem cells (MSCs)-do not express costimulatory molecules on their surface. These molecules are essential for the completion of T cell activation and therefore the lack of their expression accounts for the low immunogenicity of MSCs. In this study, SHED were isolated and seeded on 3D-printed PCL scaffolds which were either non-coated or coated with either nanohydroxyapatite (N-HAp) or multiwalled carbon nanotubes (MWCNTs). Cells cultured without scaffolds were used as a control. After three-day culture, all cells were collected and analyzed by flow cytometry for the expression of surface co-stimulatory molecules; CD40, CD80, and CD86. Results showed that different coating materials evidently affected the immune-genicity of the seeded SHED. The expression of CD40, CD80, and CD86 markers was significantly higher in cells seeded on MWCNTs/PCL scaffolds, followed by cells seeded on N-HAp/PCL scaffolds when compared to cells seeded on non-coated PCL scaffolds. On the other hand, cells seeded on non-coated PCL scaffolds showed no significant difference in their expression to the specified markers when compared to the control group. The data presented in this study are significant when considering allogeneic MSCs treatments in order to avoid immune rejection. � Nova Science Publishers, Inc.English3D printingImmunogenicityPolycaprolactoneScaffoldsStem cellsB7 antigenCD40 antigenCD86 antigenfluorochromemulti walled nanotubepolycaprolactoneArticledeciduous toothflow cytometryhumanimmunogenicityin vitro studymesenchymal stem cellprotein expressionthree dimensional printingArticlehttps://doi.org/