Carbon nanotube-incorporated collagen hydrogels improve cell alignment and the performance of cardiac constructs

Abstract

Carbon nanotubes (CNTs) provide an essential 2-D microenvironment for cardiomyocyte growth and function. However, it remains to be elucidated whether CNT nanostructures can promote cell–cell integrity and facilitate the formation of functional tissues in 3-D hydrogels. Here, single-walled CNTs were incorporated into collagen hydrogels to fabricate (CNT/Col) hydrogels, which improved mechanical and electrical properties. The incorporation of CNTs (up to 1 wt%) exhibited no toxicity to cardiomyocytes and enhanced cell adhesion and elongation. Through the use of immunohistochemical staining, transmission electron microscopy, and intracellular calcium-transient measurement, the incorporation of CNTs was found to improve cell alignment and assembly remarkably, which led to the formation of engineered cardiac tissues with stronger contraction potential. Importantly, cardiac tissues based on CNT/Col hydrogels were noted to have better functionality. Collectively, the incorporation of CNTs into the Col hydrogels improved cell alignment and the performance of cardiac constructs. Our study suggests that CNT/Col hydrogels offer a promising tissue scaffold for cardiac constructs, and might serve as injectable biomaterials to deliver cell or drug molecules for cardiac regeneration following myocardial infarction in the near future.

Conductive Scaffolds for Cardiac and Neuronal Tissue Engineering: Governing Factors and Mechanisms

“…CNTs have been proposed to act as electrical shortcuts and confirmed beneficial to cellular growth . They were employed by Sun et al to improve mechanical elasticity, as well as impart electrical conductivity to a collagen hydrogel . 1 wt% CNT–collagen hydrogel proved best for neonatal rat ventricular myocytes growth, while 2 wt% leads to toxicity.…”

Specific Features of Structure, Electrical Conductivity and Interlayer Adhesion of the Natural Polymer Matrix from the Layers of Branched Carbon Nanotube Networks Filled with Albumin, Collagen and Chitosan

“…The framework of such materials is a branched CNT network, and the filler is one of the proteins or a protein complex. The effectiveness of the use of CNT for cardiac regeneration is confirmed by the results of many papers [13][14][15][16]. It has been established that the introduction of CNTs into the structure of polymer 124 increases electrical conductivity and improves the excitation threshold of a biomass material [13].…”

“…A hydrogel based on methacrylate anhydride and CNT was developed in [14] to support the functioning and growth of cardiomyocytes. It has been shown that the collagen hydrogel reinforced with CNTs significantly improves the functioning of cardiomyocytes [15]. It was found that the addition of CNT improves the structural integrity and biomechanical properties of film bioconstructions from chitosan, and as a result promotes proliferation and differentiation of myofibroblasts without induction of toxicity and apoptosis [16].…”

Injectable Hydrogel-Based Nanocomposites for Cardiovascular Diseases

“…Nanotube-injectable hydrogel can increase cell adhesion sites and ameliorate the arrangement structure of hydrogels to ensure cell-to-cell integrity to increase the survival rate of cardiomyocytes. For instance, carbon nanotube-incorporated collagen hydrogels can improve arrangement to promote cellcell integrity and accelerate the regeneration of functional tissues in 3-D hydrogels (Sun et al, 2017). Recently, in addition to superior biocompatibility and electrical conductivity as well as appropriate adhesion sites, the nanotube composite injectable hydrogels were designed to provide sites for bioactive substance adhesion.…”