A novel 3D-assembled NIR-responsive scaffold create a bone-mimicking niche for infectious bone regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Engineering

Background:

• Natural bone grafts face limitations like donor-site morbidity and immune rejection.
• Bioactive scaffolds are promising alternatives but struggle with mechanical strength, porosity, and osteogenic/angiogenic properties.
• Infectious bone defects require effective infection control strategies.

Purpose of the Study:

• To develop a 3D-assembled, near-infrared (NIR)-responsive biomimetic scaffold for enhanced bone regeneration.
• To address challenges in mechanical strength, biocompatibility, osteogenesis, and angiogenesis in critical-sized bone defects.
• To incorporate infection control mechanisms within the scaffold for treating infectious defects.

Main Methods:

• Fabrication of a 3D printed polylactic acid framework mimicking trabecular bone.
• Loading the porous network with collagen-encapsulated graphene oxide (GO) and black phosphorus (BP) for enhanced properties.
• Utilizing collagen to improve dispersion, mimic extracellular matrix (ECM), and boost biocompatibility.

Main Results:

• The scaffold demonstrated excellent biocompatibility and resisted inflammation and infection under NIR modulation.
• BP release promoted calcium recruitment, while GO enhanced in situ mineralization.
• The scaffold successfully recruited host-derived cells, promoting proliferation, angiogenesis, and osteogenesis for vascularized bone regeneration.

Conclusions:

• The developed bone niche scaffold offers a promising strategy for bone regeneration by mimicking the native bone microenvironment.
• NIR responsiveness provides effective infection control, a critical factor in treating bone defects.
• The scaffold design supports vascularized bone regeneration, addressing key challenges in current treatments.