National Yang Ming Chiao Tung University

08/27/2024 | Press release | Distributed by Public on 08/27/2024 08:50

NYCU Develops Self-Healing Hydrogel: Combining New Biomaterials with 3D Printing to Reduce Animal Testing

Translated by Hsuchuan
Edited by Chance Lai

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Inspired by the process of spider silk production, Associate Professor Ming-Chia Li from the Department of Biological Science & Technology at the College of Engineering Bioscience, National Yang Ming Chiao Tung University (NYCU), has developed a groundbreaking nanocomposite hydrogel with self-healing capabilities. Using biomimetic 3D printing, Professor Li successfully fabricated Gyroid cell scaffolds and human outer ears.

Featured as the cover story for the 25th-anniversary issue of Biomacromolecules, this innovative material overcomes the limitations of traditional cell culture methods. By leveraging new biomaterials and 3D printing technology, scientists can replicate the three-dimensional structures and environments of real-world tissues and organs, reducing the need for animal testing and thereby enhancing animal welfare.

Operating biomimetic 3D printing

Innovative Biomimicry: The Process of Spider Silk Inspires Advanced Hydrogel Development

Professor Li explains that spider silk is known for its remarkable strength and elasticity, making it an ideal model for biomimicry. Hydrogels, which contain a high water content similar to human tissues, can mimic the natural extracellular matrix of target tissues. The research team set out to replicate the properties of spider silk in hydrogels, leading to the design of a nanocomposite hydrogel that enhances stretchability and self-healing capabilities.

To develop this hydrogel, the team utilized the non-crystallizing properties of G-polymer, which, through random physical entanglement within the hydrogel system, increased the material's elasticity. Additionally, the researchers incorporated boronate ester bonds, formed between boric acid and the -OH groups of the G-polymer side chains, to endow the material with self-healing characteristics.


The hydrogel also contains Laponite, a charged nanoscale disc, which forms a "house-of-cards" structure in solution due to electrostatic interactions. When a specific shear force is applied to the hydrogel, these electrostatic forces are temporarily disrupted, causing the material to transition from a gel state to a solution state-a phenomenon known as shear thinning. This property is crucial for evaluating the printability of hydrogel materials.

Drawing on the salting-out phenomenon observed in spider silk production, the hydrogel's protein molecules are enhanced in mechanical strength by the presence of high concentrations of inorganic salt ions. This has enabled the successful printing of Gyroid cell scaffolds and human outer ears without the need for support materials.

This technique can be applied to digital twin biological 3D printing, where biomedical imaging scans bring real-world data into a computer platform to construct digital models. These models can be used for biomechanical studies through fluid dynamics simulations, and then returned to the real world through 3D printing technology. The excellent biocompatibility of this material paves the way for clinical treatment and related research applications.

Associate Professor Ming-Chia Li's lab team