Boron Nitride Nanotube-Mediated Stimulation of Cell Co-Culture on Micro-Engineered Hydrogels

Abstract

In this paper, we describe the effects of the combination of topographical, mechanical, chemical and intracellular electrical stimuli on a co-culture of fibroblasts and skeletal muscle cells. The co-culture was anisotropically grown onto an engineered micro-grooved (10 µm-wide grooves) polyacrylamide substrate, showing a precisely tuned Young’s modulus (∼ 14 kPa) and a small thickness (∼ 12 µm). We enhanced the co-culture properties through intracellular stimulation produced by piezoelectric nanostructures (i.e., boron nitride nanotubes) activated by ultrasounds, thus exploiting the ability of boron nitride nanotubes to convert outer mechanical waves (such as ultrasounds) in intracellular electrical stimuli, by exploiting the direct piezoelectric effect. We demonstrated that nanotubes were internalized by muscle cells and localized in both early and late endosomes, while they were not internalized by the underneath fibroblast layer. Muscle cell differentiation benefited from the synergic combination of topographical, mechanical, chemical and nanoparticle-based stimuli, showing good myotube development and alignment towards a preferential direction, as well as high expression of genes encoding key proteins for muscle contraction (i.e., actin and myosin). We also clarified the possible role of fibroblasts in this process, highlighting their response to the above mentioned physical stimuli in terms of gene expression and cytokine production. Finally, calcium imaging-based experiments demonstrated a higher functionality of the stimulated co-cultures.

Transformer Hydrogels: A Review

“…Unlike nonporous polymers, hydrogels can sustain cell viability within their interior due to their permeability and high water content. These characteristics offer the possibility to create optically, electrically, mechanically, and chemically responsive cell‐laden hydrogel biobots . For example, Chan et al developed a set of biointegrated machines using 3D printed hydrogel skeletons of surface modified poly(ethylene glycol)diacrylate (pEGDA) seeded with contractile muscle cells or cardiomyocytes .…”

Large‐Scale Fabrication of Porous Polymer Nanosheets for Engineering Hierarchical Cellular Organization

“…Thus, in the rolled myoblast construct, cellular contraction caused the nanosheet to slip on the hydrogel, along the longitudinal direction of the template alginate tube, and induced the formation of anisotropic microwrinkles on the nanosheet ( Figure a). We previously reported about directing myoblast alignment on microgrooved surface . However, in this study, we found that anisotropic alignment also occurred during the dynamic shape deformation from the edge of the nanosheet by contractile cells (Figure b,c) (i.e., Figure c was obtained by carefully detaching the rolled nanosheet with tweezers).…”

Nanotechnology in biorobotics: opportunities and challenges

“…Within this paradigm, nanoparticles can have an important role, e.g., as intracellular transducers to maximize muscle contractility (Ricotti et al 2013(Ricotti et al , 2014. Several nanotechnological tools will be needed to advance this field, especially if complex biorobots, constituted by multiple cell types (heterotypic cell clusters) will be addressed (Kamm and Bashir 2014).…”