A novel composite scaffold of Cu-doped nano calcium-deficient hydroxyapatite/multi-(amino acid) copolymer for bone tissue regeneration

Abstract

Background and methods:

A Cu-doped composite scaffold of nano calcium-deficient hydroxyapatite (n-CDHA)/multi(amino acid) copolymer (MAC) was prepared. The structure, porosity, morphology and compressive strength of the scaffolds were characterized, the in vitro degradability in phosphate-buffered solution (PBS) and cell responses to the scaffolds were investigated, and in vivo stimulation of bone formation were analyzed.

Results:

The scaffolds showed the compressive strength of approximately 12 MPa and total porosity of about 81%. Weight loss of the composite scaffolds was 63% after 16-week immersion in PBS. Cu release in scaffolds showed a marked dependence on the initial amount in the scaffolds over time. Cu-doped n-CDHA/MAC scaffolds with the content of Cu 0.5% and 1% in mass ratio showed better cell responses to proliferation and differentiation of rat bone marrow stromal cells (rBMSCs) than that with no Cu. After 12-week implantation in rabbits, 1% Cu-doped n-CDHA/MAC showed better ability of angiogenesis and osteogenesis compared to 0% Cu-doped n-CDHA/MAC.

Conclusion:

The 1% Cu-doped n-CDHA/MAC composite scaffold showed good capacity of angiogenesis and osteogenesis, and the Cu showed positive effects on cell growth and osteogenesis. And it has potential to be used as bone regeneration scaffolds.

Keywords:

• calcium-deficient hydroxyapatite
• multi-(amino acid) copolymer
• copper
• osteogenesis
• degradability
• cytocompatibility

Acknowledgments

This research was funded by the National Natural Science Foundation of China Program (81501873), Science and Technology Project of Sichuan Province (2015SZ0085). Study approval was obtained from the Biomedical Ethics Committee of West China Hospital, Sichuan University (2017046A). We followed laboratory animal guideline for ethical review of animal welfare for the animal according to National Standard of China during the whole animal experiments. P.M. and H.P. contributed equally to this work and should be considered as equal first authors. The data supporting the results reported in the manuscript will not be shared due to our further research on the composite scaffolds.

Disclosure

The authors report no conflicts of interests in this work.