KAIST

< (From left) KAIST Dr. Changjin Seo, Professor Sangyong Jon >

A breakthrough technology has been developed to overcome the limitation where stem cells fail to survive for long periods in the body, even when administered in large quantities. Stem cells are vital for regenerating damaged tissues or recovering injured areas. A KAIST research team has successfully enhanced both the survival rate and therapeutic efficacy of these cells by developing a 3D culture technology that precisely designs the cellular microenvironment. This achievement is expected to transcend the current limits of stem cell therapy and reshape the landscape of regenerative medicine.

On April 29th, the research team—led by Professor Sangyong Jon from the Department of Biological Sciences and featuring researchers Changjin Seo, Dohyeon Kim, Junhyuk Song, Sun-Young Kim, Youngju Son, and Afia Tasnim Rahman—announced the development of a novel culture technology to grow healthier stem cells. The team implemented a 3D platform by applying a polymer matrix (an artificial structure coating the culture substrate) to an "artificial floor" that mimics the natural in vivo environment. On this platform, they cultured human adipose-derived stem cells (hADSCs) in three dimensions, confirming a dramatic improvement in cellular function and therapeutic impact.

Human adipose-derived stem cells have been favored for clinical use due to their ease of harvest, high proliferation, and low immune rejection. However, traditional 2D (planar) culture methods cause cells to age and lose function over time. Previous 3D methods, such as forming cell aggregates (spheroids), also faced hurdles in maintaining long-term survival and functionality within the body.

To solve this, the research team developed a densely cross-linked synthetic polymer material composed of siloxane (a biocompatible polymer of silicon and oxygen), named "poly-Z."

This material modifies the physicochemical properties of the culture substrate to promote the adsorption of albumin proteins found in the culture medium. As a result, cells do not adhere to the floor but instead self-assemble into 3D spheroid structures. These spheroids showed increased production of the extracellular matrix (ECM), creating an environment highly similar to the human body and demonstrating performance far superior to conventional methods.

Experimental results showed that stem cells cultured on the poly-Z platform exhibited enhanced differentiation potential and immunomodulatory functions, with a significantly increased survival time inside the body.

< Schematic of hADSC Spheroid Formation on the Synthetic Polymer Matrix, Poly-Z >

Notably, in animal models of acute colitis and acute liver injury, this method showed significantly higher therapeutic efficacy than conventional methods. This suggests that even with the same dosage, the cells live longer and act more vigorously. The team confirmed that the activation of integrin and FAK signaling pathways—the mechanisms through which cells sense and respond to their environment—strengthened the stem cells' functions, allowing them to better perceive their surroundings and perform more effectively after transplantation.

Professor Sangyong Jon stated, "This research proves that a precisely engineered synthetic polymer-based 3D environment can simultaneously enhance the function and therapeutic efficacy of stem cells. We expect this to be widely utilized in developing next-generation cell therapies for various incurable diseases, including inflammatory conditions."

The study, with Dr. Changjin Seo from the KAIST InnoCORE AI-Drug Discovery Center as the lead author, was published online on March 31 in the international journal Advanced Science (Impact Factor: 14.1).

• Paper Title: Polymer Matrix-Based 3D Culture Significantly Enhances the Differentiation and Immunomodulatory Functions of Human Adipose-Derived Stem Cells
• DOI: https://doi.org/10.1002/advs.202518704

This research was supported by the Korea Multi-Ministry Regenerative Medicine Project, the KAIST InnoCORE Program, and the Leader Research Grant of the National Research Foundation of Korea.