Dr. Lee has a long-standing interest in the field of Nanomedicine for the clinical use in a wide range of topics in drug delivery systems, biomaterials, tissue engineering and molecular imaging. This includes polymeric nanoparticles, organic probes and macroscopic devices for the application to the human health and disease. His research background is multidisciplinary with training in organic chemistry, biophysics and nanotechnology.
Current Research Projects:
Project 1. Stimuli Responsive Drug Delivery Systems. One of the key challenges in clinical cancer therapy is targeted and localized delivery of the drugs. In other words, the goal is to deliver the anticancer drugs to desired targets and selectively attack the cancer cells with minimal toxicity of the healthy tissue and other undesirable side effects. However, it is difficult to maintain drug levels within the narrow concentration window required to avoid toxicity due to overdose or ineffective treatment from underdosing. Here, we develop near-infrared (NIR) light sensitive drug delivery systems (DDS) that can release active molecules at the appropriate site and at a rate that adjusts in response to the progression of the disease including cancer and age-related macular degeneration.
Project 2. Chemiluminescence and Fluorescence Molecular Imaging. The widespread introduction of relatively cheap, technically-straightforward and planar optical imaging stations has made it possible to incorporate small animal optical imaging into mainstream biomedical research and drug discovery programs where there is a need to rapidly assess the pharmacological relevance of experimental drugs and therapies. Recently, In vivo molecular imaging is beginning to have a major positive impact on human health and employs a molecular probe that emits a signal only from the site of probe localization or activation. However, fluorescent probes for in vivo optical imaging have shown an obvious limitation that is restricted tissue penetration. Here, we design a self-illuminating nanoparticle that can emit both chemiluminescence and fluorescence for whole animal imaging and image-guided surgery. The designed nanoparticles emitting near-infrared (NIR) radiation with wavelengths in the region of 650-900 nm would have a distinct advantage due to diminished Raman scattering and low background of autofluorescence. In addition, planar chemiluminescence mode would be used to locate a relatively deep probe-targeted tumor, and then after the tumor is exposed by surgery, bright fluorescence visualization would be employed to accurately define the resection margin and facilitate the subsequent pathology evaluation.
Project 3. Targeted Magnetic Nano-/Micro-particles for Microfluidic Capture/Separation of CTCs from Blood. To understand cancer metastasis, the study of circulating tumor cells (CTCs) in blood from tumor-bearing animals and cancer patients is crucial. Thus, efforts in biomedical engineering for isolating and analyzing CTCs have focused on fabricating micro-/nano-materials, characterizing their functional properties and designing devices that particularly use lab-on-a-chip techniques for ex vivo medical processes. Despite recent remarkable advances, it has shown the lack of tools to detect, isolate and expand CTCs in culture due to the extremely low frequency of CTCs (<1 in 109 blood cells). To transcend these limitations, recent multidisciplinary initiatives are aimed at generating smart polymeric devices and micro-/nano-materials with use of sophisticated methodologies. Here, we design a rationally functionalized magnetic nano-/micro-particle with synthetic target molecules and develop a microfluidic device for efficiently detecting/isolating CTCs from blood.
Project 4. Controlled Release of Multiple Growth Factors (Regenerative Medicine). Implants are relatively quick solutions for mitigating the urgent medical episodes. However, it requires permanent stationing of the foreign materials in the patients’ bodies, which may cause various complications such as chronic inflammation at the site of implantation. Biomedical systems that mimic the natural wound healing processes and promote the regeneration of tissues have high feasibility. Growth factors are potent therapeutics for wound healing and tissue regeneration. For growth factor based therapies to be more efficient and effective, it is desired that the delivery system is capable of releasing multiple growth factors with controlled release rates that depend on the patients’ therapeutic needs. Incorporating heparin into the delivery vehicle has been one popular choice for the controlled release of growth factors since many growth factors have innate binding affinities toward heparin mostly through ionic interactions. However, one major drawback of such a method is the release rate of each growth factor is already predetermined by its affinity to heparin and cannot be altered. Here, we design novel growth factor releasing from hydrogel and biodegradable nanoparticle systems, which are capable of releasing multiple growth factors at programmed rates. These novel delivery systems will serve as an important step toward the controlled spatio-temporal presentation of growth factor release for tissue engineering.