Layered Double Hydroxide Modified Bone Cement Promoting Osseointegration via Multiple Osteogenic Signal Pathways

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Tissue Engineering

Background:

• Poly(methyl methacrylate) (PMMA) bone cement is widely used in orthopedic surgery but prone to aseptic loosening.
• Improving osseointegration of PMMA bone cement is crucial for long-term implant success.
• Current modifications aim to enhance bone-to-cement integration and reduce adverse effects.

Purpose of the Study:

• To synthesize and evaluate MgAl-layered double hydroxide (LDH) microsheet-modified PMMA (PMMA&LDH) bone cement.
• To assess the osseointegration, mechanical properties, and osteogenic potential of the modified PMMA.
• To elucidate the molecular pathways involved in the enhanced bone growth induced by PMMA&LDH.

Main Methods:

• Synthesis of MgAl-LDH microsheets and their incorporation into PMMA bone cement.
• Characterization of polymerization temperature and mechanical properties of PMMA&LDH.
• In vivo studies to evaluate bone growth and osseointegration.
• Transcriptome sequencing, IPA, qPCR, and Western blot to identify osteogenic pathways.

Main Results:

• PMMA&LDH exhibited reduced maximum polymerization temperatures compared to PMMA and PMMA&COL-I.
• Slightly decreased mechanical performance of PMMA&LDH, potentially alleviating stress-shielding.
• Significant enhancement of bone growth in vivo, with 2.17- and 18.34-fold increases compared to PMMA&COL-I and PMMA groups, respectively.
• Identification of p38 MAPK, ERK/MAPK, FGF, and TGF-β pathways as key mediators of osteogenesis.

Conclusions:

• LDH-modified PMMA bone cement (PMMA&LDH) demonstrates superior osseointegration and osteogenic ability.
• The reduced polymerization temperature and favorable mechanical properties contribute to improved clinical outcomes.
• PMMA&LDH is a promising biomaterial for orthopedic applications, enhancing bone growth and potentially reducing aseptic loosening.