Physicochemical Properties and Efficacy of Poloxamer Bone Wax on Hemostasis at the Bone-Amputation Site.

Bone wax, an essential material for bone hemostasis in orthopedic, thoracic, and neurological surgeries, is defined as a substance that physically controls bleeding caused by bone fractures. Absorbable bone-wax products such as poloxamer multiblock copolymers can be topically applied, form a physical barrier, are biocompatible, and can be absorbed by/excreted from the body. However, absorbable bone waxes continue to have limited physical properties, poor bone adhesion, and low hemostatic quality. When applied to the affected area, they quickly dissolve in blood and body fluids, preventing maintenance of the physical barrier over a certain period and thereby reducing the hemostatic effect. This study introduces a new type of absorbable bone wax (OSSTOP) constructed from 2 poloxamer multiblock copolymers with different molecular weight ranges. To determine whether OSSTOP overcomes the limitations of the existing products, the physicochemical properties and efficacy of OSSTOP were compared with those of 2 existing absorbable bone-wax products, OSTENE and NOVOSEAL. The adhesive strengths, yield loads, and solubilities of the products were evaluated and compared in vitro. Hemostasis at the bone-amputation site and absorption/degradation of the products were then evaluated through animal experiments in vivo. The biological safety (cytotoxicity) of the newly developed OSSTOP was also assessed. A histological analysis confirmed superior hemostasis at the bone-amputation site and a favorable biological response after treatment with OSSTOP. We expect that OSSTOP will improve the convenience, hemostatic performance, and biocompatibility of bleeding cessation at bone-amputation sites in the clinical environment.