Multi‐modal cell structure formation of poly (lactic‐co‐glycolic acid)/superparamagnetic iron oxide nanoparticles composite scaffolds by supercritical CO2 varying‐temperature foaming

Abstract

AbstractPoly (lactic‐co‐glycolic acid) (PLGA)/superparamagnetic iron oxide nanoparticles (SPIONs) composite scaffold material was prepared by supercritical carbon dioxide varying‐temperature mode method. The multi‐modal cell structure was formed, and the mechanism was explained. The nuclei formed in the heating stage grew into large pores, while the nuclei formed in the depressurization stage grew into small pores. SPIONs caused pores to rupture and coalesce into small pores or large pores. The effects of foaming parameters, including the amount of SPIONs, saturation temperature, foaming temperature, foaming pressure, and depressurization rate on the properties of the scaffolds, were systematically studied. The results showed that the addition of SPIONs could improve the porosity and mechanical properties of the scaffold, and the obvious multi‐modal cell structure could be formed. In conclusion, by changing the foaming parameters, the PLGA/SPIONs composite scaffolds with various average diameters (11.93–790.52 μm), a wide range of porosity (62.98%–93.23%) and mechanical properties (0.38–11.12 MPa) could be obtained.