Fabrication of Biodegradable Polyurethane Foam Scaffolds with Customized Shapes and Controlled Mechanical Properties by Gas Foaming Technique

Abstract

Poly( -caprolactone) (PCL)-based polyurethane (PU) foam scaffolds with different mechanical properties are fabricated using a gas foaming technique to use as porous substitutes for ear or bone with cartilage. PCL diol or triol is used as a polyol in PU foam for biocompatibility and biodegradation, with an aqueous gelatin solution as a blowing agent. The highly porous inner and outer structures of the scaffolds are developed by employing a silicone surfactant and sulfuric acid, respectively. The PU scaffolds prepared by PCL diol show ductile and flexible properties, whereas the PU scaffolds prepared by PCL triol exhibit high compression strength. In vitro test reveals the low toxicity of the PU scaffolds and the high ALP activity of MC3T3-E1 cells in the PU scaffold prepared by PCL triol. By taking advantage of the difference in mechanical properties, customized PU scaffolds with ear or bone shapes are fabricated using a silicone mold. The PU scaffolds with two compartments of PCL diol and triol (corresponding to cartilage and bone, respectively) are fabricated as a substitute for bone with cartilage. It is believed that the PU scaffolds with highly porous structure and controlled mechanical properties have wide potential application for tissue engineering.

Medical Applications of Porous Biomaterials: Features of Porosity and Tissue‐Specific Implications for Biocompatibility

“…Adapted with permission. [ 67 ] 2021, Wiley‐VCH GmbH; E) 3D‐printed via melt electrospinning writing. Adapted with permission.…”

“…[ 62,63 ] The resulting high porosity from both gas foaming and freeze casting make both of these methods widely used for tissue engineered scaffolds in general, and can generate materials with pores sufficiently large for bone ingrowth. [ 36,66,67 ]…”

“…[62,63] The resulting high porosity from both gas foaming and freeze casting make both of these methods widely used for tissue engineered scaffolds in general, and can generate materials with pores sufficiently large for bone ingrowth. [36,66,67] Decellularizing tissues is another strategy commonly investigated to create biocompatible and porous materials, used for notable tissue scaffold applications like bioartificial hearts. [68] However, the resulting scaffolds often lack mechanical integrity, or contain pores only a few nanometers in diameter which are too small for host cells to repopulate.…”

“…Copyright 2019, John Wiley and Sons; D) gas-foaming. Adapted with permission [67]. 2021, Wiley-VCH GmbH; E) 3D-printed via melt electrospinning writing.…”

Supercritical CO2blown poly(ε-caprolactone) covalent adaptable networks towards unprecedented low density shape memory foams

“…[1][2][3][4][5][6][7] In the latter, biodegradable foams are particularly interesting to design implants for therapeutic purposes [8][9][10] as well as scaffolds for tissue engineering. [11][12][13] Among the biodegradable materials used for biomedical purposes, semi-crystalline poly (e-caprolactone) (PCL) has been widely studied because of its biocompatibility and remarkable mechanical properties afforded by a low glass transition temperature (T g B À60 1C) and a melting temperature easily achieved above the body temperature (T m B 60 1C). Furthermore, when PCL is chemically crosslinked, the resulting covalent networks exhibit excellent shape memory properties, making them particularly appealing for the development of the mini-invasive surgery making available self-deploying devices.…”