10.6084/m9.figshare.3823905.v1 Hugo R. Caires Hugo R. Caires Tiago Esteves Tiago Esteves Pedro Quelhas Pedro Quelhas Mário A. Barbosa Mário A. Barbosa Melba Navarro Melba Navarro Catarina R. Almeida Catarina R. Almeida Supplementary Figure S1, Figure S2 and Figure S3 from Macrophage interactions with poly-lactic acid and chitosan scaffolds lead to improved recruitment of human mesenchymal stem/stromal cells: a comprehensive study with different immune cells The Royal Society 2016 biomaterials inflammation regeneration mesenchymal stem cell recruitment human 2016-09-13 10:42:25 Online resource https://rs.figshare.com/articles/online_resource/Supplementary_Figure_S1_Figure_S2_and_Figure_S3_from_Macrophage_interactions_with_poly-lactic_acid_and_chitosan_scaffolds_lead_to_improved_recruitment_of_human_mesenchymal_stem_stromal_cells_a_comprehensive_study_with_different_immune_cells/3823905 Despite the importance of immune cell–biomaterial interactions for the regenerative outcome, few studies have investigated how distinct three-dimensional biomaterials modulate the immune cell-mediated mesenchymal stem/stromal cells (MSC) recruitment and function. Thus, this work compares the response of varied primary human immune cell populations triggered by different model scaffolds and describes its functional consequence on recruitment and motility of bone marrow MSC. It was found that poly-lactic acid (PLA) and chitosan scaffolds lead to an increase in the metabolic activity of macrophages but not of peripheral blood mononuclear cells (PBMC), natural killer (NK) cells or monocytes. PBMC and NK cells increase their cell number in PLA scaffolds and express a secretion profile that does not promote MSC recruitment. Importantly, chitosan increases IL-8, MIP-1, MCP-1 and RANTES secretion by macrophages while PLA stimulates IL-6, IL-8 and MCP-1 production, all chemokines that can lead to MSC recruitment. This secretion profile of macrophages in contact with biomaterials correlates with the highest MSC invasion. Furthermore, macrophages enhance stem cell motility within chitosan scaffolds by 44% but not in PLA scaffolds. Thus, macrophages are the cells that in contact with engineered biomaterials become activated to secrete bioactive molecules that stimulate MSC recruitment.