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

Abstract

Poly (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.

Morphological 3D Analysis of PLGA/Chitosan Blend Polymer Scaffolds and Their Impregnation with Olive Pruning Residues via Supercritical CO2

“…Wang et al [ 23 ] reported the fabrication of a multi-modal cell structure of PLGA using scCO 2 , Lee et al [ 24 ] produced microcellular foaming of PLGA polymer that exhibits micrometer-sized pores (~50 μm) and shows great potential for new surgical implants for controlled release of paclitaxel, and Alvarez et al [ 25 ] produced PLGA foams using CO 2 at high pressure but below supercritical conditions. Other authors have mixed the formation of PLGA foams with other polymers or compounds such as polycaprolactone (PCL) [ 26 , 27 ], poly(3,4-etilendioxitiofeno) (PEDOT) [ 28 ], bioglass particles/poly(lactide-co-glycolide) (BG/PLGA) [ 29 ], Sr/Zn n-HAp and PLGA [ 30 ], or (PLGA)/superparamagnetic iron oxide nanoparticles (SPIONs) [ 23 , 31 , 32 ]. Chitosan (Ch), a biodegradable polysaccharide extracted from crustaceans, has been shown to be safe and non-toxic in both animals and humans.…”