Professor Joonil Seog

umd logo

Assistant Professor Joonil Seog
Molecular Mechanics and Self-Assembly Laboratory


Will open in a new window. See the News page for all archived news.

Congratulations to Nitinun Varongchayakul, who won MSE's and the Dean's Master's Thesis Awards for “Direct Observation of Amyloid Nucleation under Nanomechanical Stretching"! More information here and here.

Spinning Engineered Silk Into Tiny Designs—With A Microscope
Seog group member Sara Johnson is investigating how an atomic force microscope (AFM) can be used to grow and weave threads of silk-elastin-like peptide polymers (SELPs) into specific patterns or shapes. More »

Seog Research Wins NSF CAREER Award
Novel methods will explain peptide and nanofiber behavior at molecular level. More »

Plasma for Disinfection Study Wins DOE Grant
Oehrlein, Seog will be first to characterize effects on biological molecules at molecular level. More »

Karcz Takes 2nd In Dean's M.S. Thesis Competition
Graduate student recognized for work with optical tweezers. More »

Seog Lab Installs Optical Mini-Tweezers
Molecular Mechanics Laboratory to use high resolution force spectroscopy for nanomedicine and nanobiotechnology research.  More »

Russ Wins Goldwater Scholarship
Bioengineering sophomore receives premier award for undergraduates. More »

About Professor Seog »

Research Focus Area 1:
Amyloid self-assembly on a surface under nanomechanical force

SELP logo made with AFMUnderstanding how biomacromolecules assemble to form functional complexes is at the center of fundamental efforts in chemistry, structural biology, biochemistry, and biophysics. Proteins can fold into a non-native state, which often leads to aggregated states which can further assemble into nanofibers known as amyloids. Some of the aggregated structures are known to be very toxic to neuronal cells, causing neurodegenerative diseases such as Alzheimer’s disease. In our lab, we study a silk-elastin-like protein polymer (SELP) to gain a fundamental understanding of amyloid self-assembling behaviors and nanostructures.

For the first time, we have provided experimental evidence for accelerated amyloid growth with directional control under nanomechanical force. Based upon our seminal work, we were able to create a “UMD” logo composed of multiple amyloid nanofibers at the sub-micrometer scale. Recently, we revealed that stretching of SELP molecule is crucial for formation of the amyloid nucleus. Based upon our fundamental understandings, we succeeded in creating a single nanofiber pattern with directional control. Knowledge from our work will broaden the current understanding of protein aggregation and assembly on surfaces, which will lead to translational research on aggregated proteins that are implicated in neurodegenerative diseases.

Research Focus Area 2:
DNA condensation for gene delivery applications

Illustration of optical tweezersGene therapy is a promising way to cure hereditary diseases and cancers. However, although a plethora of DNA carriers have been developed, their efficiency remains low, which prevents the methods from being clinically used. To address this challenge, a fundamental understanding of intermolecular interactions between DNA and carrier at the molecular level is critically needed. We have built an optical tweezers that directly measures inter- and intramolecular interactions of biomacromolecules at the single molecule level. The custom-built optical tweezers is capable of measuring sub-piconewton forces with sub-nanometer spatial resolution. Force measurements are carried out under specific physiological environments, which enable us to measure dynamic regulations of intermolecular interactions between DNA and carriers in real time. Directly measured molecular level interactions will provide insight on rational design criteria for DNA carriers, which have not been clearly provided yet despite a few decades of intensive works.

Learn more about Professor Seog's research »