Engineering Wet-resistant and Osteogenic Nanocomposite Adhesive to Control Bleeding and Infection after Median Sternotomy.

Median sternotomy surgery stands as one of the prevailing strategies in cardiac surgery. In this study, the cutting-edge bone adhesive is designed, inspired by the impressive adhesive properties found in mussels and sandcastle worms. We have created an osteogenic nanocomposite coacervate adhesive by integrating a cellulose-polyphosphodopamide interpenetrating network, quaternized chitosan, and zinc, gallium-doped hydroxyapatite nanoparticles. This adhesive is characterized by robust catechol-metal coordination which effectively adheres to both hard and soft tissues with a maximum adhesive strength of 900 ±38 kPa on the sheep sternum bone, surpassing that of commercial bone adhesives. The release of zinc and gallium cations from nanocomposite adhesives and quaternized chitosan matrix imparts remarkable antibacterial properties and promotes rapid blood coagulation, in vitro and ex vivo. It is also proved that this nanocomposite adhesive exhibits significant in vitro bioactivity, stable degradability, biocompatibility, and osteogenic ability. Furthermore, the capacity of nanocomposite coacervate to adhere to bone tissue and support osteogenesis contributes to the successful healing of a sternum bone defect in a rabbit model in vivo. In summary, these nanocomposite coacervate adhesives with promising characteristics are expected to provide solutions to clinical issues faced during median sternotomy surgery. This article is protected by copyright. All rights reserved.

Strong and bioactive bioinspired biomaterials, next generation of bone adhesives.

The bone adhesive is a clinical requirement for complicated bone fractures always articulated by surgeons. Applying glue is a quick and easy way to fix broken bones. Adhesives, unlike conventional fixation methods such as wires and sutures, improve healing conditions and reduce postoperative pain by creating a complete connection at the fractured joint. Despite many efforts in the field of bone adhesives, the creation of a successful adhesive with robust adhesion and appropriate bioactivity for the treatment of bone fractures is still in its infancy. Because of the resemblance of the body's humid environment to the underwater environment, in the latest decades, researchers have pursued inspiration from nature to develop strong bioactive adhesives for bone tissue. The aim of this review article is to discuss the recent state of the art in bone adhesives with a specific focus on biomimetic adhesives, their action mechanisms, and upcoming perspective. Firstly, the adhesive biomaterials with specific affinity to bone tissue are introduced and their rational design is studied. Consequently, various types of synthetic and natural bioadhesives for bone tissue are comprehensively overviewed. Then, bioinspired-adhesives are described, highlighting relevant structures and examples of biomimetic adhesives mainly made of DOPA and the complex coacervates inspired by proteins secreted in mussel and sandcastle worms, respectively. Finally, this article overviews the challenges of the current bioadhesives and the future research for the improvement of the properties of biomimetic adhesives for use as bone adhesives.

Corrosion, mechanical and bioactivity properties of HA-CNT nanocomposite coating on anodized Ti6Al4V alloy.

Hydroxyapatite-carbon nanotubes (HA-CNTs) nanocomposite coating was applied by electrophoretic method on anodized Ti alloy to investigate its stability in simulated body fluid (SBF). The biocoating was characterized by using scanning electron microscope (SEM) for microstructure, X-ray diffraction (XRD) for crystallography. The effect of CNTs concentration on the coating properties was also investigated and found out that CNTs up to 5% has various improving effect on the system. It increased corrosion resistance and adhesion of the coating to the substrate and decreased the number of cracks on the coating. The results of the in vitro test showed that the cell viability increased with increasing the concentration of CNTs to 3 wt.% CNTs. Graphical abstract.