The research of fluoresville is highly interdisplinary and broadly falls at the interface of synthetic dye chemistry and medicinal chemistry. We are also in close collaborations with pharmacologists. The students receive extensive training in many different aspects of chemistry and pharmacy, such as molecular engineering, organic synthesis, spectroscopy, medicinal chemistry, cell culture, microscopy and pharmacology.
We’re synthetic dye chemists. The primary goal of our research is to create structurally novel and high-performanc dye scaffolds for biological, material, medicinal, and agricultural applications.
1. Development of deep NIR absorbing and emitting dyes for theranostic and material applications
Infrared dyes are a value subset of organic small molecule dyes with diverse important applications across a range of fields. Polymethine cyanine is the earlist dyes of the class and presumably remains the most widely acknowledged class. Others include (na/)phthalocyanines, quinones, metal complexes, radical dyes, etc. There are also a few other organic dyes, i.e. squaraines and analogs, BODIPY derivatives, xanthene derivatives etc. absorbing in the NIR region.
One important field of application is biomedical theranostics. NIR dyes can help to see deeper into tissue are superior over these dyes spectrally active in the shorter wavelength. These dyes are expected to be bright, easily functionalized, and stable. Cy7 dyes, e.g. indocyanine green (ICG), are most commonly employed. However, there are no biocompatible dyes to make available the the spectral region of 800-1000 nm for microscopic studies. ICG absorbs at ca. 780 nm. Cyanine dyes that can absorb beyond 800 nm are not stable enough for practical use. We've been very successful in this regard, though this research is still in its infancy. We have developed a series of fluorophores (ECX dyes), which absorb and emit at 880 nm and 920 nm respectively. They are the current bench-mark and will surely be welcomed across the diciplines. Through collaboration with companies, we'll make these dyes in large enough volume to share.
One may say that light in the 800-1000 nm are not easily detected. Once, it was true. These wavelengths are too long for PMT, and yet too short for InGaAs detectors. However, this technical barrier has been alleviated. Ador Ltd. has deep-cooled EMCCD camera exhibiting a quantum efficency over 80% for light of 900 nm.
Besides, these NIR dyes can also have tremendous potentials in material based applications, in security printing, bandpass filters, laser protective eyewares, night vision and NIR stealth wear,et.
2. Development of Molecular tools for degenerative diseases
The Alzeimer's disease is a neurodegenerative disease that has recently drawn tremendous public attention. Our cardiovascular system also gets old as we age and so is our immune system. Coronary artery disease and arthritis are often the pathological outcomes. These conditions are often irreversible, i.e. not cured by medical interventions, though progresses have been made to temperarorily relieve the symptoms and controll the diseases from getting worse. For this reason, it is of vital importance for scientist to unveil the fundamental pathology of these degenerative diseases and these information will be critical for eventual development of any feasible preventive measures.
We have noticed, probably along with many others, that It is in the cardiovascular system, nervous system and immune system that nitric oxide (NO) is constantly produced in high flux and these three systems suffer from degenerative diseases. And nitric oxide can result in oxdative damages to cell components. So, it is very tempting to propose that the accumulation of oxidative damages resulted by nitric oxide and its downstream metabolites accounts for the development of any denegerative diseases. Therefore, we have intense interests developing small molecule chemical tools, including probes, donors and scavengers, for the field of nitric oxide biology. This line of our research has been a great success and yielded a number of high impact publications.
3. Discovery of bioactive lead compounds from a chemical library of small molecule dyes
For many years, dyes were not routinely screened for bioactivity regardless of the discovery of first synthetic anticbiotic, Prontosil, by Gerhard Domagk.
Recently, the Y.-T. Chang group has re-pioneered the screening of fluorescent dye library exhibiting high structural diversity for bioactive compounds, a stategy Chang later named Diversity Oriented Fluorescence Library Approach (DOFLA). Various small molecule fluorescent probes were discovery, which could detect small molecule targets, nucleic acids, proteins, cells and live animals. His success has inspired S.-B. Park to creation of his Seoul-Flour dye library and subsequent discovery of a probe for lipid droplines.
We are synthetic dye chemists, have developed novel dye synthesis and have prepared many dyes of various classes. Why shouldn't we do biological screening through collaborations and try our luck? Actually, we must admit that we are luckier than we have expected.