2023, Vol. 27 ›› Issue (7): 1071-1079

Application of the interaction between biological scaffolds and macrophages in bone regeneration

Yang Yitian1, 2, Wang Lu1, 2, Yao Wei1, 2, Zhao Bin1, 2   

Abstract: BACKGROUND: In recent years, the way of repairing tissue defects with biological scaffolds has been widely concerned by scholars. As an external implant, the body inflammatory response is vital for the integration between materials and tissues, in which macrophages serve as important participants and regulators. It is necessary to understand the interaction between biological scaffolds and macrophages, which will have crucial guiding significance for the design of new scaffolds in the future.
OBJECTIVE: To review the researches on the interaction between biological scaffolds and macrophages as well as the regulation of this dynamic balance between them.
METHODS: PubMed, Web of Science, and CNKI were used to search the related articles published from 1971 to 2021. The search terms were “macrophage polarization, M2, foreign body, tissue engineering, scaffolds, mediation, bone, degradation” in English and Chinese. An inductive analysis was conducted in the 76 selected articles on the latest research progress in this field.
RESULTS AND CONCLUSION: (1) Immune response plays an indispensable role in tissue regeneration and repair. (2) Macrophage is an important regulator of inflammatory response. It will polarize into different phenotypes such as pro-inflammatory or anti-inflammatory according to different microenvironment stimuli. On one hand, the imbalance of macrophage polarization in different stages of inflammatory response will hinder the integration of biological scaffold materials and tissue repair. The high expression of pro-inflammatory macrophages in the early stage of biomaterial implantation is conducive to the integration of biomaterials. In the late stage of inflammation, however, the sustained high expression of pro-inflammatory macrophages will hinder the formation of new bone. On the other hand, the properties of biological scaffolds (composition, hardness, roughness, surface geometry, hydrophilicity, etc.) will affect the polarization direction of macrophages. For example, adjusting the surface morphology of scaffolds cannot change the ideal physical and chemical properties of scaffolds, but promote effectively the polarization of macrophages towards pro-regenerative phenotype and tissue repair. (3) At present, the effect of biological scaffolds on macrophages has been realized by changing the composition, preparation methods and adjusting the physical and chemical properties of scaffolds. However, how to efficiently regulate this dynamic balance is still the focus and our key direction in the future, In particular, how to successfully translate the ideal results of basic research in vitro into practical application in vivo is still under further exploration.
Key words: tissue engineering, scaffold, macrophage, polarization, immune response, mediation, microenvironment, foreign body reaction, degradation