Constructing highly bioactive and tough polyurethane bone adhesives by covalently integrating nanohydroxyapatite.

Tong, Lei; Cheng, Yaling; Wang, Yuxiang; Li, Na; Liang, Jie; Sun, Yong; Fan, Yujiang; Zhang, Xingdong · Biomaterials · 2026

basic_science · Level V

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Abstract

Achieving both robust mechanical and osteogenic properties of bone adhesives remains challenging. Here, we developed a novel polyurethane-based bone adhesive (PCLU-g-nHA) by covalently incorporating aminated nanohydroxyapatite (nHA-NH<sub>2</sub>) into a biodegradable poly (ε-caprolactone) urethane (PCLU) network. This design promoted uniform nHA dispersion and strong organic-inorganic integration through urea linkages, significantly enhancing compressive modulus (4.91 ± 0.10 MPa) and adhesive strength (3.41 ± 0.24 MPa in lap-shear). The adhesive cured rapidly under mild conditions with minimal heat release. PCLU-g-nHA showed improved biocompatibility and stimulated bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation in vitro. Transcriptomics revealed upregulation of extracellular matrix remodeling and collagen synthesis pathways. In vivo, PCLU-g-nHA enhanced bone regeneration and osseointegration in rabbit femoral condyle defect and tibial fracture models, outperforming a commercial PMMA bone cement. This study offers a scalable strategy for developing highly bioactive and tough bone adhesives with clinical translational potential.

Medical subject headings