Microfluidic 3D Printing Responsive Scaffolds with Biomimetic Enrichment Channels for Bone Regeneration

Tissue‐engineered scaffolds have been extensively explored for treating bone defects; however, slow and insufficient vascularization throughout the scaffolds remains a key challenge for further application. Herein, a versatile microfluidic 3D printing strategy to fabricate black phosphorus (BP) incorporated fibrous scaffolds with photothermal responsive channels for improving vascularization and bone regeneration is proposed. The thermal channeled scaffolds display reversible shrinkage and swelling behavior controlled by near‐infrared irradiation, which facilitates the penetration of suspended cells into the scaffold channels and promotes the prevascularization. Furthermore, the embedded BP nanosheets exhibit intrinsic properties for in situ biomineralization and improve in vitro cell proliferation and osteogenic differentiation. Following transplantation in vivo, these channels also promote host vessel infiltration deep into the scaffolds and effectively accelerate the healing process of bone defects. Thus, it is believed that these near‐infrared responsive channeled scaffolds are promising candidates for tissue/vascular ingrowth in diverse tissue engineering applications. A photothermal responsive scaffold with biomimetic enrichment channels is fabricated via a coaxial microfluidic 3D printing strategy. The incorporation of black phosphorus nanosheets endows the poly(N‐isopropylacrylamide) based channels with repeatable shrinkage/swelling performance controlled by near‐infrared irradiation, which facilitate vessel/tissue ingrowth into the scaffolds and accelerates bone regeneration in rat cranial defects.