Assistant Professor Division of Periodontology, Department of Oral Biological Science, Graduate School of Medical and Dental Sciences, Niigata University
Background and objective: Proinflammatory M1 macrophages are the predominant type in periodontitis. It was demonstrated that inducing anti-inflammatory M2 macrophages prevented the disease progression in a mouse periodontitis model. Cellular immunotherapy, transfer immune cells, is expected to have a more direct and specific effect than using drugs; however, adopted immune cells can alter their function in undesirable directions in response to environmental conditions. Herein, we developed micro particles referred to as a “backpack(BP)” that adhered to macrophage helping the cells to maintain M2 phenotype in the disease site and tested its efficacy against experimental periodontitis. Materials and
Methods: BPs are fabricated with spin-coating method. IL-4 (200fg/BP) loaded BPs were attached to bone marrow–derived macrophages (BMDMs, C57BL/6) by incubation on dishes. Polarization of BP-bound MBDMs to M2 was observed by flow cytometry. The BP-bound M2 cells (BP-M2), BPs or M2 cells were injected to the periodontal region that induced by ligation and inoculation of Porphyromonas gingivalis W83, and therapeutic efficacy was assessed by alveolar bone loss measurement. Additionally, localization and phenotype of the macrophages in the disease sites were observed by immunohistology.
Results: BPs polarized BMDMs to M2 in vitro. Injected BP-M2 cells were localized in the disease sits over 5days and high ratio of M2 to total macrophages was observed only in BP-M2 injection group. Alveolar bone loss was significantly reduced in the BP-M2 group when compared with the other groups.
Conclusion: Transferred BP-bound macrophages localized and maintained M2 phenotype in periodontal region, and thereby prevent the disease progression.
