One Step Closer to Healthy Society Through Patient-Tailored Immunomodulating Therapy
The world’s first system for remotely modulating the immunity of macrophage was developed using tissue-penetrative light.
Professor Kang Heemin’s was published as a cover article in Advanced Materials.

▲ (From top left) Kim Yuri, a student in the integrated master-doctoral degree program of the Department of Materials Science and Engineering (first author); Professor Kim Jong Seung of the Department of Chemistry (coauthor); and Doctor Jang Ho Seong of KIST (coauthor); (from bottom left) Professor Kim Yongju of KU-KIST Graduate School of Converging Science and Technology (coauthor); Professor Kim Sehoon of KU-KIST Graduate School of Converging Science and Technology (corresponding author); and Professor Kang Heemin of the Department of Materials Science and Engineering (corresponding author).

The world’s first remote immunomodulation technology was developed with microgels and upconversion nanoparticles that are controlled by light to overcome existing limitations on the surface of biomaterials.

The results of the research, led by Professor Kang Heemin of the Department of Materials Science and Engineering at College of Engineering (corresponding author) and Professor Kim Sehoon of KIST (corresponding author), were published on October 21 as a cover article in Advanced Materials (IF: 32.086), one of the world’s most renowned journals in materials science and engineering.
- Title of article : Reversible Control of Photoswitchable Microgel for Dynamic Macrophage Regulation

Kim Yuri, a student in the integrated master-doctoral degree program (first author, Department of Materials Science and Engineering) took the lead in the study to synthesize optical isomers of which the structure is changed by UV and visible light and that form microgels using a polymer coupled with a cell-adhesive ligand and electrostatic attraction. In addition, the researchers synthesized upconversion nanoparticles that predominantly emit UV with an external infrared light source, and fabricated a material on which the upconversion nanoparticles are uniformly dispersed. On the material surface, the size change of the microgels with UV-induced expansion and the visible light-induced contraction was used to control the exposure of the cell-adhesive ligand. In addition, the in vivo and in vitro adhesion and the inflammatory and regenerative polarization of the macrophage, which is an immune cell, were controlled by the release of the internal small molecules according to water absorption.

▲ Cover of the journal

The cell-adhesive ligand-binding microgels were prepared by utilizing upconversion nanoparticles that predominantly emit UV and feature electrostatic attraction. The microgels, which utilize light from the outside rather than UV, are capable of reversibly controlling expansion and contraction through infrared light and visible light of a lower intensity than that of the conventional methods. This is a world first technology for remotely controlling the behavior of macrophages for immunomodulation.

The microgels developed in this study can be used to remotely stimulate the inflammatory and regenerative polarization of the macrophage by means of light, and so they are applicable to the development of a novel technology for remote regenerative treatment. The microgels can also be applied to the surfaces of various materials, in particular, to the immune system investigated in the present study. Therefore, the microgels can be applied to a global growing market, including implant systems, contributing to gaining market competitiveness with the source technologies.

▲ A schematic of the reversible remotely controlled microgel system based on a tissue-penetrative light source.

Professor Kang Heemin said, “The previous studies were directed to the static control of a single factor or a small number of factors, but our study is about a technology for dynamically and reversibly controlling cell behavior by using infrared light with a high tissue penetration based on photoreactions.” Regarding the significance and future directions of the research, he explained, “Patient-tailored immunomodulatory treatment is a technology that is essential to our society. Future studies will be conducted to overcome the limitations of the current system and understand immune responses further. The goal of this research is to make our community healthier through patient-tailored treatments.”

The present study was supported by the National Research Foundation of Korea (NRF) grant and the Mid-career Researcher Program funded by the Ministry of Science and ICT and the National Research Foundation of Korea.