Carbon nanotube (CNT) and nanofibrillated cellulose (NFC) reinforcement effect on thermoplastic polyurethane (TPU) scaffolds fabricated via phase separation using dimethyl sulfoxide (DMSO) as solvent.
Although phase separation is a simple method of preparing tissue engineering scaffolds, it suffers from organic solvent residual in the scaffold. Searching for nontoxic solvents and developing effective solvent removal methods are current challenges in scaffold fabrication. In this study, thermoplastic polyurethane (TPU) scaffolds containing carbon nanotubes (CNTs) or nanofibrillated cellulose fibers (NFCs) were prepared using low toxicity dimethyl sulfoxide (DMSO) as a solvent. The effects of two solvent removal approaches on the final scaffold morphology were studied. The freeze drying method caused large pores, with small pores on the pore walls, which created connections between the pores. Meanwhile, the leaching and freeze drying method led to interconnected fine pores with smaller pore diameters. The nucleation effect of CNTs and the phase separation behavior of NFCs in the TPU solution resulted in significant differences in the microstructures of the resulting scaffolds. The mechanical performance of the nanocomposite scaffolds with different morphologies was investigated. Generally, the scaffolds with a fine pore structure showed higher compressive properties, and both the CNTs and NFCs improved the compressive properties of the scaffolds, with greater enhancement found in TPU/NFC nanocomposite scaffolds. In addition, all scaffolds showed good sustainability under cyclical load bearing, and the biocompatibility of the scaffolds was verified via 3T3 fibroblast cell culture.
Department of Industrial Equipment and Control Engineering, South China University of Technology, Guangzhou 510640, China; Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Hao-Yang
HY
Mi
Department of Industrial Equipment and Control Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address: mexjing@scut.edu.cn.
Xin
X
Jing
Department of Engineering Physics, University of Wisconsin-Madison, WI 53706, USA.
Max R
MR
Salick
Department of Biomedical, University of Wisconsin-Madison, WI 53706, USA.
Travis M
TM
Cordie
Department of Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: turng@engr.wisc.edu.
Lih-Sheng
LS
Turng
D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D004121:Dimethyl Sulfoxide; D005612:Freeze Drying; D051379:Mice; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D016062:Porosity; D012997:Solvents; D023822:Tissue Engineering; D054457:Tissue Scaffolds
D001672:Biocompatible Materials; D037742:Nanotubes, Carbon; D011140:Polyurethanes; D012997:Solvents; D002482:Cellulose; D004121:Dimethyl Sulfoxide
Carbon nanotube; Nanofibrillated cellulose; Phase separation; Thermoplastic polyurethane; Tissue engineering scaffold