A novel BMP-2-loaded hydroxyapatite/beta-tricalcium phosphate microsphere/hydrogel composite for bone regeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Bone morphogenetic protein (BMP) exhibits potent osteoinductivity but its clinical use is limited by adverse events from burst release.
• Effective BMP delivery systems are crucial for maximizing bone regeneration while mitigating risks.

Purpose of the Study:

• To evaluate the bone-regenerating potential of NOVOSIS putty (NP), a novel composite hydrogel delivery system for recombinant human bone morphogenetic protein-2 (rhBMP-2).
• To compare the release kinetics and osteogenic efficacy of NP with conventional collagen sponge (CS) delivery.

Main Methods:

• In vitro release kinetics of rhBMP-2 from NP and CS assessed using ELISA.
• In vivo rhBMP-2 release and biological half-life tracked using fluorescently labeled rhBMP-2.
• Osteogenic gene expression in MC3T3-E1 cells co-cultured with NP and CS.
• Evaluation of bone regeneration in a rat spinal fusion model.

Main Results:

• NP demonstrated sustained in vitro release of rhBMP-2, contrasting with burst release from CS.
• In vivo studies showed a longer biological half-life of rhBMP-2 with NP compared to CS.
• Co-culture with NP significantly increased osteogenic gene expression in MC3T3-E1 cells.
• The NP group exhibited superior bone volume and quality in the rat spinal fusion model.

Conclusions:

• NOVOSIS putty facilitates efficient bone regeneration via sustained rhBMP-2 release.
• NP improves the quality of BMP-induced bone formation and enhances osteoblast differentiation.
• NP represents a promising delivery system for bone regenerative applications, overcoming limitations of burst release.