Welcome to the BioSM Group@DGIST

Soft matter and biological physics are closely related branches of physics because many parts of biological cells and tissues consist of soft matter systems. Using theoretical modelings and computer simulations, our group focuses primarily on understanding the underlying physical mechanisms of biological systems from molecular to cellular scales and investigating free energy landscapes and conformational changes of polymer complexes. We are also interested in modeling and simulations of aqueous electrolytes and identifying the mechanism of ion transport. Current research topics include membrane proteins structure & function, functional & mechanical properties of biological soft matter, cell-penetrating peptides(CPPs) & drug delivery, ion transport in water-in-salt electrolytes(WISEs), etc.

Group Members

Principal Investigator

Seungho Choe

Associate Professor, Dept. of Energy Science & Engineering

Graduate Students

Afira Mariam

PhD Student (April 2022 ~ )

Muhammad Raza

MS Student (April 2022 ~ )

Shanjida Akter

MS Student (September 2022 ~ )

Alumni

Daam Heo

Intern (June 2022 ~ July 2022)

Current Projects

Cell-Penetrating Peptides(CPPs) and Drug Delivery

Cell-Penetrating Peptides(CPPs) can deliver pharmacologically active molecules (e.g., proteins, plasmid-DNA, liposomes, and nanoparticles) into cells, and thus they have great potential as future therapeutics. However, the uptake mechanisms are still debated.

Functional and Mechanical Properties of Biological Soft Matter

It is crucial to identify basic structures’ functional and mechanical properties, such as peptides, DNAs, and membranes(bilayer or monolayer), to understand mechanisms of various biological functions at molecular scales. We have been developing theoretical models of these structures to investigate their mechanical properties and interactions between those structures.

Ion Transport in Water-In-Salt Electrolytes (WISEs)

Recently, water-in-salt electrolytes (WISEs) have attracted much attention due to their wider electrochemical stability window than conventional dilute aqueous electrolytes. WISEs have been used in batteries and supercapacitors, however, the ion transport mechanism has not been fully understood.

Light-harvesting: Mechanisms of Energy Transfer

Light-harvesting is one of the research areas that study materials and molecules that capture solar light photons. This includes studies to understand better the light-harvesting properties of photosynthetic organisms or artificial systems designed to promote photochemical reactions.

Membrane Proteins Structure and Function

Membrane proteins(e.g, enzymes, receptors, ion channels, transporters, etc.) play crucial roles in all organisms, and they are the primary drug targets for pharmaceuticals. Our general goal is to understand various membrane proteins’ functional properties and identify suitable drugs to control their biological functions.

Modeling and Simulations of Self-Assembly of Polymers

The self-assembly of polymers is one of the emerging fields within material sciences, offering many potential applications in nanotechnology and nanobiotechnology. It is necessary to investigate the energy landscape between the self-assembled polymers and explore the fate of these polymers and how the final morphology can be obtained.

Molecular Dynamics Studies of Polyelectrolyte-Polyampholyte Complexes

Polyelectrolytes(PEs) are polymers carrying either positively or negatively charged ionizable groups, while polyampholytes(PAs) are charged polymers with both positively and negatively charged groups. The adsorption of PEs and PAs onto charged chains and surfaces has been extensively studied for a long time because of its importance in biology, materials science, soft matter research, etc.

Path Sampling of Rare Events

Path sampling approaches can enhance the efficiency of simulating rare events, e.g., protein folding, protein (un)binding, cellular signaling, etc. The Weighted Ensemble (WE) method is one of the most powerful and flexible path sampling techniques.

Theoretical Modeling of a Cell Division and the Min System

In E. coli, the Min protein system, which consists of Min C, Min D, and Min E proteins, plays a vital role in positioning the cell division. We have been working on partial differential equations which describe the Min system.