Macrophages of Different Phenotypes Influence the Migration of BMSCs in PLGA Scaffolds with Different Pore Size.

Immune modulation of the scaffolds not only reduces the host immunological rejection response, but also improves the regenerative cell migration into the scaffolds. Herein a convenient immune modulation of poly(lactide-co-glycolide) (PLGA) scaffold is applied with macrophages of different phenotypes to evaluate its influence on the migration behavior of bone marrow mesenchymal stem cells (BMSCs). With pro-inflammatory macrophages (M1) pre-loading, BMSCs migrate significantly faster into the PLGA scaffold, compared with those in the control scaffold or pre-seeded with inactivated macrophages (M0). The pore size of PLGA scaffolds is found to take a more important role, as the one with a larger pore size significantly enhance migration of BMSCs no matter the pre-seeding of macrophages. The enhanced cell migration in the macrophage-modulated scaffold can provide a new protocol for in situ tissue regeneration by recruiting endogenous cells.