Effects of bone surface topography and chemistry on macrophage polarization

• Published in: Scientific reports Vol. 14; no. 1; p. 12721
• Main Authors: Özcolak, Birgün, Erenay, Berkay, Odabaş, Sedat, Jandt, Klaus D., Garipcan, Bora
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.06.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/61/2049; 639/301/54/2295; Animals; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Biomaterials; Biomedical materials; Biomimetic; Bone and Bones - cytology; Bone biomaterials; Bone surface topography; Bones; Cattle; Cell adhesion; Cell Adhesion - drug effects; Cell differentiation; Cell Differentiation - drug effects; Cell morphology; Cell Polarity - drug effects; Cell proliferation; Collagen Type I - metabolism; Cytokines - metabolism; Cytology; Durapatite - chemistry; Femur; Humanities and Social Sciences; Hydroxyapatite; Macrophage Activation - drug effects; Macrophage polarization; Macrophages; Macrophages - drug effects; Macrophages - immunology; Macrophages - metabolism; Mice; Microenvironments; Mimicry; multidisciplinary; Polarization; Polyesters - chemistry; Polylactic acid; RAW 264.7 Cells; Science; Science (multidisciplinary); Soft lithography; Surface modification osteoimmunomodulation; Surface Properties; Tissue engineering; Tissue Engineering - methods; Topography; Bone surface topography; Soft lithography; Surface modification osteoimmunomodulation; Biomimetic; Macrophage polarization; Macrophages
• ISSN: 2045-2322
• DOI: 10.1038/s41598-024-62484-3

Surface structure plays a crucial role in determining cell behavior on biomaterials, influencing cell adhesion, proliferation, differentiation, as well as immune cells and macrophage polarization. While grooves and ridges stimulate M2 polarization and pits and bumps promote M1 polarization, these structures do not accurately mimic the real bone surface. Consequently, the impact of mimicking bone surface topography on macrophage polarization remains unknown. Understanding the synergistic sequential roles of M1 and M2 macrophages in osteoimmunomodulation is crucial for effective bone tissue engineering. Thus, exploring the impact of bone surface microstructure mimicking biomaterials on macrophage polarization is critical. In this study, we aimed to sequentially activate M1 and M2 macrophages using Poly- l -Lactic acid (PLA) membranes with bone surface topographical features mimicked through the soft lithography technique. To mimic the bone surface topography, a bovine femur was used as a model surface, and the membranes were further modified with collagen type-I and hydroxyapatite to mimic the bone surface microenvironment. To determine the effect of these biomaterials on macrophage polarization, we conducted experimental analysis that contained estimating cytokine release profiles and characterizing cell morphology. Our results demonstrated the potential of the hydroxyapatite-deposited bone surface-mimicked PLA membranes to trigger sequential and synergistic M1 and M2 macrophage polarizations, suggesting their ability to achieve osteoimmunomodulatory macrophage polarization for bone tissue engineering applications. Although further experimental studies are required to completely investigate the osteoimmunomodulatory effects of these biomaterials, our results provide valuable insights into the potential advantages of biomaterials that mimic the complex microenvironment of bone surfaces.