Green Chemistry for Biomimetic Materials: Synthesis and Electrospinning of High-Molecular-Weight Polycarbonate-Based Nonisocyanate Polyurethanes

Abstract

Conventional synthesis routes for thermoplastic polyurethanes (TPUs) still require the use of isocyanates and tinbased catalysts, which pose considerable safety and environmental hazards. To reduce both the ecological footprint and human health dangers for nonwoven TPU scaffolds, it is key to establish a green synthesis route, which eliminates the use of these toxic compounds and results in biocompatible TPUs with facile processability. In this study, we developed high-molecular-weight nonisocyanate polyurethanes (NIPUs) through transurethanization of 1,6hexanedicarbamate with polycarbonate diols (PCDLs). Various molecular weights of PCDL were employed to maximize the molecular weight of NIPUs and consequently facilitate their electrospinnability. The synthesized NIPUs were characterized by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry. The highest achieved molecular weight (M w ) was 58,600 g/mol. The NIPUs were consecutively electrospun into fibrous scaffolds with fiber diameters in the submicron range, as shown by scanning electron microscopy (SEM). To assess the suitability of electrospun NIPU mats as a possible biomimetic load-bearing pericardial substitute in cardiac tissue engineering, their cytotoxicity was investigated in vitro using primary human fibroblasts and a human epithelial cell line. The bare NIPU mats did not need further biofunctionalization to enhance cell adhesion, as it was not outperformed by collagen-functionalized NIPU mats and hence showed that the NIPU mats possess a great potential for use in biomimetic scaffolds.

Enabling New Approaches: Recent Advances in Processing Aliphatic Polycarbonate‐Based Materials

“…ES of biocompatible aPCs for use as scaffolds in tissue engineering is highly appealing, because the resulting fibrous mats exhibit high porosity, large surface area, and a structure resembling the extracellular matrix. [94][95][96][97] In 2005, Jia et al successfully electrospun nanofibers from aPCs for the first time. [17] In this research, a series of ABA-type triblock copolymers comprising TMC and ɛ-caprolactone with varying molar ratios were synthesized via ROP.…”

Electrospinning of collagen: enzymatic and spectroscopic analyses reveal solvent-independent disruption of the triple-helical structure

“…Briefly, a thin layer of collagen was spun atop fibrous non-isocyanate polyurethane mats (ES-PU), which provided structural support and had been produced and tested for biocompatibility as described previously. 31 The rat tail collagen was spun out of a 33 g L À1 collagen solution in 5 M acetic acid/ethanol (1 : 2) at a flow rate of 0.3 mL h À1 and voltage of 21 kV. To separate the effects of morphology and material, some ES-PU mats were coated with rat tail collagen to obtain coated biofunctionalized electrospun polyurethane mats (ES-PU + Col).…”

“…Primary human dermal (foreskin) fibroblasts (hDFs) and human epithelial cells (MeT-5A, ATCC) were cultured and seeded onto the scaffolds as described previously. 31 Briefly, hDFs were isolated from foreskin biopsies under approval by the local ethics committee at the Tu ¨bingen University Hospital (495/2018BO2 approved on 19th October, 2018). hDFs were seeded at 2.67Á10 5 cells per cm 2 and hMCs were seeded at 4.00Á10 5 cells per cm 2 .…”

In Vitro Effects of Waterborne Polyurethane 3D Scaffolds Containing Poly(lactic-co-glycolic acid)s of Different Lactic Acid/Glycolic Acid Ratios on the Inflammatory Response

“…Many materials have been applied to the synthesis of tissue engineering scaffolds including natural and synthetic materials [ 20 ]. The most-used natural materials for this purpose include gelatin [ 21 ], collagen [ 22 ], sodium alginate [ 23 ], etc., and the most-used synthetic biomaterials include polycaprolactone (PCL) [ 24 ], polycarbonate diol (PCDL) [ 25 ], polyurethane (PU) [ 26 ], etc. Among these materials, polyurethane, which has gained significant attention due to its good biocompatibility and adjustability, is a versatile biomaterial [ 27 ].…”