The Scaffold Immune Microenvironment: Biomaterial-Mediated Immune Polarization in Traumatic and Nontraumatic Applications

Tissue Eng Part A. 2017 Oct;23(19-20):1044-1053. doi: 10.1089/ten.TEA.2016.0304. Epub 2016 Nov 9.

Abstract

The immune system mediates tissue growth and homeostasis and is the first responder to injury or biomaterial implantation. Recently, it has been appreciated that immune cells play a critical role in wound healing and tissue repair and should thus be considered potentially beneficial, particularly in the context of scaffolds for regenerative medicine. In this study, we present a flow cytometric analysis of cellular recruitment to tissue-derived extracellular matrix scaffolds, where we quantitatively describe the infiltration and polarization of several immune subtypes, including macrophages, dendritic cells, neutrophils, monocytes, T cells, and B cells. We define a specific scaffold-associated macrophage (SAM) that expresses CD11b+F4/80+CD11c+/-CD206hiCD86+MHCII+ that are characteristic of an M2-like cell (CD206hi) with high antigen presentation capabilities (MHCII+). Adaptive immune cells tightly regulate the phenotype of a mature SAM. These studies provide a foundation for detailed characterization of the scaffold immune microenvironment of a given biomaterial scaffold to determine the effect of scaffold changes on immune response and subsequent therapeutic outcome of that material.

Keywords: T cells; biomaterial implant; extracellular matrix; immune polarization; macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / pharmacology*
  • CD4-Positive T-Lymphocytes / metabolism
  • Cellular Microenvironment* / drug effects
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism
  • Female
  • Flow Cytometry
  • Mice, Inbred C57BL
  • Muscles / pathology
  • Myeloid Cells / metabolism
  • Subcutaneous Tissue / metabolism
  • Sus scrofa
  • Tissue Scaffolds / chemistry*
  • Wound Healing / drug effects
  • Wounds and Injuries / immunology*
  • Wounds and Injuries / pathology*

Substances

  • Biocompatible Materials