Biomaterial Strategies of Macrophage Behaviour in Bone Regeneration

Macrophages are essential mediators in the immune response to biomaterials, significantly influencing the success and longevity of bone tissue implants and engineered scaffolds. Their ability to transition between pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes offers unique opportunities for modulating tissue healing processes. This review examines current biomaterial strategies that harness macrophage plasticity to enhance bone regeneration, with a focus on surface modifications, mechanical properties, and scaffold biodegradability. We discuss the interactions between macrophages and various biomaterials used in bone tissue engineering, highlighting methods to promote M2 polarization and mitigate chronic inflammation. The findings underscore the importance of designing biomaterials that not only support structural integrity but also actively participate in immune modulation, aiming to improve scaffold integration, tissue regeneration, and overall therapeutic outcomes in bone repair.