Recombinant collagen polypeptide as a versatile bone graft biomaterial

Izumi Ogura,Hideo Fushimi,Yoshitaka Ono,Ichiro Nishimura,Ai Okamura,Takahiro Hiratsuka

doi:10.1038/s43246-020-00089-9

Abstract

Autografts and allografts are currently considered the gold standard for grafting surgery; however, to meet the growing demand in fast-aging societies, synthetic biomaterials will play an increasingly important role. Here we report a biodegradable scaffold material composed of recombinant polypeptide based on the human type I collagen alpha 1 chain (RCPhC1) as a source of hydrogel-based graft materials. The flexibility to engineer ideal characteristics for bone grafts was demonstrated. The critical internal isotropic pore structure was generated through a designed thin-layer freeze casting process. The optimized biodegradation rate was controlled by dehydrothermal crosslinking by adjusting the amino acid composition of RCPhC1. As a result, RCPhC1 bone grafts manufactured by a highly scalable streamlined production protocol induced robust regeneration of mature bone tissue while being completely resorbed in pre-clinical animal models.

Highlights

Autografts and allografts are currently considered the gold standard for grafting surgery; to meet the growing demand in fast-aging societies, synthetic biomaterials will play an increasingly important role
Recombinant polypeptide based on human type I collagen alpha 1 chain (RCPhC1)
The core fragment of RCPhC1 was screened for sequence homology and it was found that pentapeptides including all amino acid substitutions matched the human collagen amino acid sequences (Fig. 1a)

Summary

Introduction

Autografts and allografts are currently considered the gold standard for grafting surgery; to meet the growing demand in fast-aging societies, synthetic biomaterials will play an increasingly important role. We report a biodegradable scaffold material composed of recombinant polypeptide based on the human type I collagen alpha 1 chain (RCPhC1) as a source of hydrogel-based graft materials. Bone graft materials are designed to mimic the structure or biochemical components of bone tissue. Demineralized bone allograft is a biodegradable natural polymer primarily composed of bone collagen ECM, which provides a scaffold for cellular migration and tissue regeneration[8]. We report a recombinant polypeptide based on the human type I collagen alpha 1 chain with sequence modifications (RCPhC1), which was developed to be a versatile source material highly suitable for flexible engineering controls to manufacture synthetic bone graft. Preclinical studies using rodent and canine bone defects demonstrated the high efficacy of RCPhC1 bone graft, which rapidly regenerated sizable bone tissue with structural maturity

Methods

Results

Conclusion