Increased Osteoid Formation in BMP-2-Loaded Silk-Based Screws.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Conventional resorbable osteosynthesis materials can cause inflammation and hinder bone remodeling.
• Silk fibroin offers a promising alternative for resorbable fixation devices.
• Bone morphogenetic protein-2 (BMP-2) is investigated for its osteoinductive properties.

Purpose of the Study:

• To evaluate the biocompatibility and bone remodeling potential of silk fibroin screws loaded with BMP-2.
• To compare BMP-2 loaded silk screws with non-loaded controls in a rat femur model.

Main Methods:

• Resorbable silk screws were fabricated and loaded with BMP-2.
• Screws were implanted into the distal femora of Sprague-Dawley rats.
• Histological evaluation was performed at 1, 3, and 6 months post-implantation.

Main Results:

• Both BMP-2 loaded and non-loaded silk screws demonstrated biocompatibility with no significant inflammation.
• Organized mineralized collagen and osteoid deposition were greater around BMP-2 loaded screws.
• Increased osteoblast and osteoclast recruitment was observed around BMP-2 loaded screws at later time points.

Conclusions:

• Silk fibroin screws functionalized with BMP-2 exhibit comparable biocompatibility to non-loaded screws.
• BMP-2 loaded silk screws promote more organized bone and collagen deposition, enhancing remodeling potential.
• These findings suggest BMP-2 loaded silk screws may improve craniofacial fracture healing.