Injectable thermosensitive PEG-PCL-PEG hydrogel/acellular bone matrix composite for bone regeneration in cranial...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Injectable biomaterials are crucial for bone defect repair.
• Acellular bone matrix (ABM) possesses intrinsic osteoinductive properties.
• Thermosensitive hydrogels offer minimally invasive delivery for bone regeneration.

Purpose of the Study:

• To evaluate the bone regeneration potential of an injectable ABM/PECE composite.
• To compare the efficacy of ABM/PECE composite against a pure PECE hydrogel in cranial defects.
• To assess the healing process over 20 weeks using various imaging and histological techniques.

Main Methods:

• Creation of 12 mm × 8 mm × 2 mm cranial defects in New Zealand white rabbits.
• Injection of ABM/PECE composite or pure PECE (control) into the defects.
• Evaluation of bone regeneration at 4, 12, and 20 weeks via X-ray, micro-CT, and histology.

Main Results:

• The ABM/PECE group showed new bone formation from defect margins and center, with complete healing by 20 weeks.
• Newly formed bone in the ABM/PECE group achieved density comparable to host cortical bone.
• The control group exhibited limited, low-density new bone formation solely from the defect periphery.
• Histomorphometry confirmed superior bone regeneration in the ABM/PECE composite group.

Conclusions:

• The injectable ABM/PECE composite demonstrates significant potential for enhancing bone regeneration.
• The composite effectively guides bone formation in critical-sized cranial defects.
• ABM/PECE represents a promising therapeutic strategy for orthopedic bone repair applications.