Bone matrix

The bone matrix, also known as the extracellular matrix of bone, is a complex and dynamic tissue that provides support, protection, and mineral storage to the body. It primarily comprises collagen fibers and hydroxyapatite crystals, which give bone strength and rigidity. The bone matrix also contains various types of cells, such as osteoblasts, osteoclasts, and osteocytes, that work together to maintain bone structure and function. The composition and organization of the bone matrix can be influenced by various factors, such as hormones, mechanical stress, and disease.

Integrating a biomimetic extracellular matrix to improve the microenvironment of 3D printing scaffolds is an emerging strategy for bone substitute design.

A “soft-hard” bone implant (BM-g-DPCL) consisting of a bioactive matrix chemically integrated on a polydopamine (PDA)-coated porous gradient scaffold by polyphenol groups is constructed. The PDA-coated “hard” scaffolds promoted Ca2+ chelation and mineral deposition; the “soft” bioactive matrix is beneficial to the migration, proliferation, and osteogenic differentiation of stem cells in vitro, accelerated endogenous stem cell recruitment and initiated rapid angiogenesis in vivo. The results of the rabbit cranial defect model (Φ = 10 mm) confirmed that BM-g-DPCL promoted the integration between bone tissue and implant and induced the deposition of bone matrix. Proteomics confirmed that cytokine adhesion, biomineralization, rapid vascularization, and extracellular matrix formation are major factors that accelerate bone defect healing. This strategy of highly chemically bonded soft-hard components guided the construction of the bioactive regenerative scaffold ¹⁾.