Vertically aligned carbon nanotube micropillars induce unidirectional chondrocyte orientation

Abstract Articular cartilage is a highly organized tissue with very limited regenerative capacities. One limitation to mimic cartilage structure in tissue engineering is due to specific orientation of chondrocytes. Here, we use vertically aligned multi-wall carbon nanotubes (VA-MWCNT) micropillars to achieve unidirectional orientation of chondrocytes. We demonstrate that the attachment, proliferation and extracellular matrix (ECM) production by the chondrocytes is enhanced on VA-MWCNT micropillars compared to controls. The nanostructures offered by the VA-MWCNT allow the chondrocytes to anchor at cellular structure level, while mechanical flexibility of the VA-MWCNT micropillars mimics the cartilage’s natural ECM Young’s modulus. We exploit these features to extrapolate the contractile forces exerted by the chondrocytes on the micropillars. Our findings will guide the design of VA-MWCNT templates to model cell’s contractile forces. Furthermore, the capability of VA-MWCNTs to induce unidirectional chondrocytes orientation open new perspectives in cartilage tissue engineering

Aligned multi-walled carbon nanotube-embodied hydrogel via low magnetic field:a strategy for engineering aligned injectable scaffolds

Abstract Injectable scaffolds are a promising strategy to restore and regenerate damaged and diseased tissues. They require minimally invasive procedure and allow the formation of an in-situ structure of any shape. However, the formation of 3D in-situ structure with aligned morphologies using a method which could be easily transferred to clinical settings remains a challenge. Herein, the rational design of an aligned injectable hydrogel-based scaffold via remote-induced alignment is reported. Carboxylated multi-walled carbon nanotubes (cMWCNT) are aligned into hydrogel via low magnetic field. The uniform dispersion and alignment of cMWCNT into the hydrogel are clearly demonstrated by small angle neutron scattering. The obtained aligned cMWCNT-embodied hydrogel is stable over 7 days at room temperature and as well at body temperature (i.e. 37 °C). As unique approach, the formation of MWCNT-hydrogel composite is investigated combining rheology with molecular dynamic and quantum mechanical calculations. The increase of MWCNT concentration into the hydrogel decreases the total energy promoting structural stabilization and increase of stiffness. The remote aligning of injectable hydrogel-based scaffold opens up horizons in the engineering of functional tissues which requires specific cell orientation