Calcium phosphate coating enhances osteointegration of melt electrowritten scaffold by regulating macrophage polarization

• Published in: Journal of nanobiotechnology 2024-01, Vol.22 (1), p.47-21, Article 47
• Main Authors: Shi, Yubo, Tao, Weidong, Yang, Wenjing, Wang, Lei, Qiu, Zhennan, Qu, Xiaoli, Dang, Jingyi, He, Jiankang, Fan, Hongbin
• Format: Article
• Language: English
• Subjects: 1-Phosphatidylinositol 3-kinase; 3-D printers; AKT protein; Biocompatibility; Biomedical materials; Bone growth; Bone healing; Bone implants; Bone marrow; Bone Regeneration; Calcium ions; Calcium phosphate; Calcium phosphates; Calcium Phosphates - chemistry; Cell growth; Coatings; Contact angle; Cytokines; Differentiation (biology); Ethanol; Evaluation; Foreign bodies; Fourier transforms; Immunomodulation; Macrophage polarization; Macrophages; Macrophages - metabolism; Melt electrowritten; Mesenchymal stem cells; Microenvironments; Morphology; Osseointegration; Osteogenesis; Osteointegration; Phenotypes; Phosphate coatings; Phosphates; Phosphatidylinositol 3-Kinases - metabolism; Physiochemistry; Polarization; Polycaprolactone; Properties; Protective coatings; Protein kinase A; Regeneration; Regeneration (physiology); Scaffolds; Scanning electron microscopy; Stem cells; Surgical implants; Tissue engineering; Tissue Scaffolds - chemistry; Tumor necrosis factor-TNF
• ISSN: 1477-3155; 1477-3155
• DOI: 10.1186/s12951-024-02310-0

The osteoimmune microenvironment induced by implants plays a significant role in bone regeneration. It is essential to efficiently and timely switch the macrophage phenotype from M1 to M2 for optimal bone healing. This study examined the impact of a calcium phosphate (CaP) coating on the physiochemical properties of highly ordered polycaprolactone (PCL) scaffolds fabricated using melt electrowritten (MEW). Additionally, it investigated the influence of these scaffolds on macrophage polarization and their immunomodulation on osteogenesis. The results revealed that the CaP coated PCL scaffold exhibited a rougher surface topography and higher hydrophilicity in comparison to the PCL scaffold without coating. Besides, the surface morphology of the coating and the release of Ca from the CaP coating were crucial in regulating the transition of macrophages from M1 to M2 phenotypes. They might activate the PI3K/AKT and cAMP-PKA pathways, respectively, to facilitate M2 polarization. In addition, the osteoimmune microenvironment induced by CaP coated PCL could not only enhance the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) in vitro but also promote the bone regeneration in vivo. Taken together, the CaP coating can be employed to control the phenotypic switching of macrophages, thereby creating a beneficial immunomodulatory microenvironment that promotes bone regeneration.