Sandcastle Worm‐Inspired Blood‐Resistant Bone Graft Binder Using a Sticky Mussel Protein for Augmented In Vivo Bone Regeneration

Abstract

Xenogenic bone substitutes are commonly used during orthopedic reconstructive procedures to assist bone regeneration. However, huge amounts of blood accompanied with massive bone loss usually increase the difficulty of placing the xenograft into the bony defect. Additionally, the lack of an organic matrix leads to a decrease in the mechanical strength of the bone-grafted site. For effective bone grafting, this study aims at developing a mussel adhesion-employed bone graft binder with great blood-resistance and enhanced mechanical properties. The distinguishing water (or blood) resistance of the binder originates from sandcastle worm-inspired complex coacervation using negatively charged hyaluronic acid (HA) and a positively charged recombinant mussel adhesive protein (rMAP) containing tyrosine residues. The rMAP/HA coacervate stabilizes the agglomerated bone graft in the presence of blood. Moreover, the rMAP/HA composite binder enhances the mechanical and hemostatic properties of the bone graft agglomerate. These outstanding features improve the osteoconductivity of the agglomerate and subsequently promote in vivo bone regeneration. Thus, the blood-resistant coacervated mussel protein glue is a promising binding material for effective bone grafting and can be successfully expanded to general bone tissue engineering.

Improving the thermostability of horseradish peroxidase by incorporating into water-immiscible coacervates

“…Looking for novel matrix materials, there were attracted by recent publications of (Kim et al, 2016;Choi et al, 2011) on water-immiscible coacervates prepared by reaction of negatively charged hyaluronic acid (НА) and a positively charged recombinant mussel adhesive protein (rMAP) containing tyrosine residues (rMAP/HA). T h e re s u l ts o n e x p e r im e n ta l s tu d y o f thermostability improvement of horseradish peroxidase (HRP) by its encapsulation in these In our opinion, more promising way to increase the enzymes' thermostability is related to different types of encapsulation despite the various post-translational machineries.…”

“…The incubation mixture contained 0.9 ml of 100 mM phosphate citrate (pH=5. Thus, taking into account all the above the following two-step procedure was performed according to the method of Kim et al, (2016) and enzymatic activity assay performed following published procedure of Yan et al, (2006). The final procedure: measurement of enzymatic activity.…”

“…In addition, the obtained saturated solution of HRP in PBS was filtered through filter paper. For complex coacervation between rMAP and HA solutions, the optimal ratio of 7:3 (w/w), was used, which was proposed in the study (Kim et al, 2016). The condensed coacervate phase was prepared by stirring the mixture of prepared HRP, rMAP and o HA solutions at ratio 10:7:3 for 20 min at 4 C. The brown precipitate was collected by centrifuging at 14,000 g, the supernatant was separated and the precipitate, frozen to the temperature of liquid nitrogen and freeze-dried.…”

“…The potential of rMAP/HA coacervate as an effective binding material for grafts is described in study (Kim et al, 2016). The authors of article mentioned that their investigation of interaction between HA and rMAP was stimulated by the sandcastle worminspired complex coacervation using these two components.…”

Fabrication and Mechanical Properties of Engineered Protein‐Based Adhesives and Fibers

“…The adhesion to biological surfaces was attributed to the noncovalent and covalent interactions between DOPA and tissue surface. In addition, the rmfp/HA coacervate enhanced the mechanical and hemostatic properties of the bone graft agglomerate . Tirrell and co‐workers prepared coacervates by mixing recombinant fusion protein fp‐151‐RGD and HA .…”