Regenerative Biomaterials, 2017, 55–68 doi: 10.1093/rb/rbw041 Review An overview of the role of neutrophils in innate immunity, inflammation and host-biomaterial integration Gretchen S. Selders1, Allison E. Fetz1, Marko Z. Radic2 and Gary L. Bowlin1,* 1Department of Biomedical Engineering, University of Memphis, Memphis, TN, USA and 2Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center (UTHSC), Memphis, TN, USA, 858 Madison Ave, Room 201 Molecular Science Building, Memphis, TN 38163, USA *Correspondence address. Department of Biomedical Engineering, 330 Engineering Technology Building, 3806 Norriswood Ave. Memphis, TN 38152, USA. Tel: (901)678-2670; Fax: (901) 678-5281; E-mail:
[email protected] Received 26 September 2016; revised 14 October 2016; accepted on 19 October 2016 Abstract Despite considerable recent progress in defining neutrophil functions and behaviors in tissue re- pair, much remains to be determined with regards to its overall role in the tissue integration of bio- materials. This article provides an overview of the neutrophil’s numerous, important roles in both inflammation and resolution, and subsequently, their role in biomaterial integration. Neutrophils function in three primary capacities: generation of oxidative bursts, release of granules and forma- tion of neutrophil extracellular traps (NETs); these combined functions enable neutrophil involve- ment in inflammation, macrophage recruitment, M2 macrophage differentiation, resolution of in- flammation, angiogenesis, tumor formation and immune system activation. Neutrophils exhibit great flexibility to adjust to the prevalent microenvironmental conditions in the tissue; thus, the bio- material composition and fabrication will potentially influence neutrophil behavior following con- frontation. This review serves to highlight the neutrophil’s plasticity, reiterating that neutrophils are not just simple suicidal killers, but the true maestros of resolution and regeneration.