Nano bone material exhibits high elasticity and strength to accelerate surgery and healing

A research team from the Department of Orthopedics and Traumatology at the University of Hong Kong’s LKS Faculty of Medicine (HKUMed) has successfully developed a novel elastic calcium phosphate material that mimics the structure of human bone.

The material, dubbed “nano bone cement,” offers a promising alternative to traditional bone grafts in orthopedic surgeries, which typically rely on harvesting tissue from the patient or a donor. Research and experimental results show that this innovative bone material provides robust mechanical support and accelerates healing in bone-defect cases.

The team plans to apply this technology to repair large segmental bone defects, potentially speeding up patient recovery and achieving optimal outcomes. The research findings are published in the journal Nature Communications.

Current challenges in large segmental bone defect surgery

Professor Kelvin Yeung Wai-kwok, Ng Chun-man Professor in Orthopedic Bioengineering, Department of Orthopedics and Traumatology, School of Clinical Medicine, HKUMed, and project leader of the research, said treating large segmental bone defects typically requires bone grafting, which often involves autografts (from the patient’s own bone) or allografts (donated bone), which are scarce and carry significant risks. Autografts may lead to complications and collapse at the donor site, while allografts carry the risk of infection and immune rejection.

Traditional calcium phosphate bone materials are formed by mixing powders containing calcium and phosphorus with a liquid solution, resulting in a hardened solid through a self-setting reaction.

Dr. Wu Jun of the Orthopedic Medical Center at the University of Hong Kong-Shenzhen Hospital explained, “This material closely resembles the composition of natural bone, offering excellent safety and biocompatibility. Moreover, it can be freely shaped before hardening, making it one of the most promising options for bone repair.”

While traditional calcium phosphate artificial bone materials provide rigidity, their compressive strength falls short of that of human cortical bone. Their lack of elasticity makes them prone to fracturing in clinical use, and they struggle to adapt to minor deformations during daily activities, potentially leading to structural collapse and treatment failure.

These limitations restrict the effectiveness and safety of existing bone graft technologies, underscoring the need to develop elastic bone materials to improve the success rate of large segmental bone repair.

Triple ‘high performance’ nano material

To address the shortcomings of existing calcium phosphate bone materials, the research team utilized nano-cluster anchoring technology to successfully integrate the mechanical properties of organic flexible materials and inorganic rigid materials. This breakthrough resulted in a new “nano-artificial bone material” (calcium phosphate cement (CPC)) that exhibits exceptional elasticity, toughness and strength.

Professor Yeung stated, “Our goal is to mimic the structure of natural bone, and this innovative nanomaterial closely resembles human bone. Its mechanical properties are closer to those of natural bone, thus enhancing patient comfort and mobility. It can be shaped into any form before the hardening stage, making it particularly suitable for repairing irregularly shaped or complex bone defects.”

Leveraging the material’s capacity to expand in volume after absorbing water, the team developed a new type of elastic microsphere capable of automatically filling bone defects. This innovation streamlines surgical procedures and improves treatment efficiency.

“The new nanomaterial maintains maximum compressive strength after absorbing water and exhibits excellent elasticity, a property not found in current bone material. It forms a porous structure that promotes cell adhesion and integration with the material, supporting bone tissue regeneration. This advancement will benefit more patients, offering them new hope for returning to a normal life,” added Professor Yeung.

Professor Wong Tak-man, clinical professor, Department of Orthopedics and Traumatology, School of Clinical Medicine, HKUMed, believes this groundbreaking material innovation will have multiple benefits for orthopedic treatment. He said, “The new technology significantly simplifies surgical procedures and reduces overall operation time. The material demonstrates exceptional strength, toughness and superior biocompatible properties.

“Apart from filling defects in complex orthopedic surgeries, it can provide stability and promote bone healing. It offers a more flexible, safe and efficient solution for orthopedic and reconstructive surgery. Last but not least, we can expand its application in neurosurgery and dentistry in the near future.”