‘Stretching and Shrinking’, the commercialization of patient-specific customized treatments is approaching
A control system has been developed to remotely control in vivo nanocoils
Expectations for the development of customized implant materials with nanometer-level dynamic control

▲ Professor Kang Hee-min (corresponding author), Professor Kim Young-keun (corresponding author), 

Min Sun-hong (first author, integrated master's and doctoral student), 

Ko Min-jun (first author, integrated master's and doctoral student)

A research team from the College of Engineering's Department of Materials Science and Engineering has developed an in vivo nanocoil system that can remotely control cell adhesion and differentiation on the surface of implant materials in real time.

This study, with contributions by Min Sun-hong (first author, integrated master's and doctoral student), Ko Min-jun (first author, integrated master's and doctoral student), Professor Kim Young-keun (corresponding author), and Professor Kang Hee-min (corresponding author), was published on February 3 (Korean time) in the International Journal of Advanced Materials (impact factor: 27.398).
* Paper Title: Remote Control of Time-Regulated Stretching of Ligand-Presenting Nanocoils In Situ Regulates the Cyclic Adhesion and Differentiation of Stem Cells

Stem cells sense their surroundings and can differentiate into tissue cells that fit the environment. By using these characteristics, it is possible to induce stem cell differentiation into various organ tissue cells, such as bone, fat, muscle, myocardium, blood vessels, and cartilage, which is drawing attention in the regenerative medicine and engineering fields. However, one problem is that the regulation of stem cell adhesion, as well as differentiation, in the body is not smooth.
* Stem Cell: Since relatively undifferentiated stem cells can differentiate into specific cells according to their surrounding environment, they are being focused on as core cells for patient-specific treatments, such as living body regeneration, artificial organ formation, and cell therapy.

The research team used a cobalt-iron magnetic nanocoil made by electroplating to create an external magnetic field for reversibly and remotely controlling the spacing of cell-adherent RGD ligands on the surface of implant material to develop a system capable of controlling stem cell adhesion and differentiation.
* Cobalt-iron magnetic nanocoil: A nanostructure with a reversible characteristic in which a nanowire with a thickness of about 70 nm is twisted with an outer diameter of 180 nm and a total length of 1 μm. It expands when a magnetic field is applied and shrinks to its original length without a magnetic field.
* RGD ligand: The amino acid sequence of fibronectin among proteins in the extracellular matrix that mediates cell adhesion. The receptor integrin, present on the cell membrane, recognizes RGD ligands and allows cells to adhere.

The nanocoil was induced to precisely control the spacing of the RGD ligand at the nanometer level remotely in real time using a magnetic field in vitro and in vivo. When the nanocoil is stretched by the magnetic field and RGD ligands are presented at wide intervals, it was confirmed that the adhesion rate of stem cells and their differentiation rate into bone cells were successfully improved.

The development of a nanocoil system that can remotely control the treatment point according to a patient's needs is significant in verifying the possibility of precisely controlling stem cells in vivo for implant materials and suggests the possibility of the commercialization of customized stem cell therapy.

This research was carried out with support from the Ministry of Science and ICT and the National Research Foundation of Korea’s Young Researcher Support Project and Mid-career Researcher Support Project.

< Figure Description >

▲Figure 1. Schematic illustration of an in vivo nanocoil control system
Schematic illustration of a system capable of controlling the attachment and differentiation of stem cells through nano-sized stretching/shrinking that can precisely control the gap between the ligands on the surface of the implant material using a nanocoil.

▲Figure 2. Schematic illustration of a stem cell control system according to in vivo ligand spacing
Schematic illustration of successfully improving the adhesion rate of stem cells and their differentiation rate into bone cells when the nanocoil is stretched by the magnetic field and the ligands are presented at wide intervals. The nanocoil was induced to control the gap of the ligand remotely in real time using an external magnetic field.