Using colloidal nanodiscs for 3D tissue bioprinting and tissue models

June 29, 2022

Nanowork News) Extrusion-based 3D printing/bioprinting is a promising approach for the generation of patient-specific, tissue-engineered grafts. However, a major challenge with extrusion-based 3D printing and bioprinting is that most materials currently used do not have the versatility to be used in a wide variety of applications.

New nanotechnology has been developed by a team of researchers at Texas A&M University that uses colloidal interactions of nanoparticles to print complex geometries that can mimic tissue and organ structure. The team, led by Dr. Akhilesh Gaharwar, associate professor and Presidential Impact Fellow in the Department of Biomedical Engineering, has introduced colloidal solutions of 2D nanosilicates as a platform technology to print complex structures.

2D nanosilicates are disc-shaped inorganic nanoparticles with a diameter of 20 to 50 nanometers and a thickness of 1 to 2 nanometers. These nanosilicates form a ‘house of cards’ structure above a certain concentration in water, a so-called colloidal solution.

These colloidal solutions have attractive properties when studying the deformation of a material, such as increased viscosity and yield stress, as well as shear thinning, where the viscosity decreases under stress, and thixotropic behavior, where a material deforms in response to applied forces. The Gaharwar Laboratory uses the rheological properties of these nanosilicates for extrusion-based 3D printing. dr. Akhilesh K. Gaharwar, assistant professor in the Department of Biomedical Engineering, introduced colloidal solutions of 2D nanosilicates as a platform technology to print complex structures via 3D bioprinting. (Image: Texas A&M Engineering) (click image to enlarge)

The results of the team’s research have been published in the journal Bioprinting“2D Nanosilicate for Additive Manufacturing: Rheological Modifier, Sacrificial Ink, and Support Bath”

Some major challenges in extrusion-based 3D printing are the inability to print tall and complex structures, as soft materials flow under gravity and cannot form self-supporting structures. To overcome these challenges, researchers used and demonstrated colloidal nanosilicates as a platform technology for bioprinting using three different approaches.

In the first approach, Satyam Rajput, a graduate biomedical engineering student in the Gaharwar Laboratory and the lead author of the paper, designed a shear-thinning ink composed of nanosilicates and water-soluble polymers such as agarose, alginate, kappa-carrageenan, gelatin, gelatin methacryloyl, polyethylene glycol, and N -isopropylacrylamide. The printable ink formulation showed good conformability.

In the second approach, the team demonstrated the use of nanosilicates as sacrificial ink, a tool designed to fail and be removed, to design microfluidic devices for in vitro disease modeling. These perfusable devices can be used in a variety of applications to mimic and study vascular physiology and fluid mechanics, disease models, tissue organization and function, therapeutic tissue engineering and 3D cell culture models, and drug screening.

In the third approach, the researchers used a colloidal nanosilicate gel as a support bath for 3D printing by canceling out surface tension and gravity. A series of complex structures such as a bifurcated vessel, femur, meniscus, DNA double helix, heart and trifoliate valve were printed in the support bath.

“The versatility of nanosilicates could be widely applied in additive manufacturing, tissue engineering, drug delivery and medical devices,” said Gaharwar.

#colloidal #nanodiscs #tissue #bioprinting #tissue #models

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