Porous 3D polyurethane composite scaffolds with incorporation of highly mineralized calcium citrate for bone tissue engineering

Abstract

High mineralization activity is a crucial requirement in bone tissue engineering. In this study, a novel calcium citrate compounded amorphous calcium phosphate (CAP)/polyurethanes (PUs) composite porous 3D scaffold was developed by in situ polymerization via gas foaming method. The physical and chemical properties were characterized and discussed. The results showed that the HDI can react mildly with hydroxyl (–OH) groups of PEG, while gas foaming action was caused by the release of CO₂ occurred in the reactive process, resulting in a uniform porous structure of PUs scaffold. The porosities of the synthetic PEGCAP porous scaffolds are all above 70% with high interconnectivity, while the porosity decreased 27% with increasing CAP to 40%. Furthermore, the mechanical properties of porous scaffolds enhanced about 16 times after addition of CAP. After immersing in simulated body fluid (SBF), the surface structure of the porous scaffold kept stable, and surface deposits formed, indicating that the porous scaffold has good mineralization activity. In addition, the in vitro cells proliferation assay confirms the excellent bioactivity of PEGCAP porous scaffolds.

Graphical Abstract

Keywords:

• Calcium citrate
• 3D scaffold
• high mineralization
• polyethylene glycol
• porous structure

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

KL contributed to experimental design and discussion, wrote manuscript. XHC and XYZ interpreted the data, contributed to discussion, wrote manuscript. SYZ, PCZ, JFL and LW contributed to experimental design and discussion, wrote manuscript, reviewed/edited manuscript. All authors read and approved the final manuscript.

Additional information

Funding

This work was jointly supported by the National Natural Science Foundation of China [No. 41673109], Sichuan Science and Technology Program [2021YFH0098], Sichuan Science and Technology Program [CN 2019077], the Science and Technology Department Project of Sichuan Province [2017SZ0185, 2018SZDZX0022], and Key Project of Sichuan Vanadium and Titanium Industry Development Research Center [2018VTCY-Z-01].