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JHU Seal

Research

Our research interests span broadly in the areas of molecular assembly, nanoparticles, hydrogels, supramolecular polymers, drug delivery, cancer diagnosis and treatments. The work listed below provides a brief overview of a few projects that exemplify our research interests and future direction.

Molecular Engineering of Anticancer Drugs

spheresdrugsEffective delivery of small molecule anticancer drugs into tumor sites remains a great challenge in cancer chemotherapy.  Intravenous administration of anticancer drugs typically requires either chemical modification or the use of delivery vehicles due to their poor water solubility and cytotoxicity to normal cells.  At the same time, in order to minimize the side effects of introducing alien chemicals or materials other than the drug itself, a high drug loading capacity is preferred.  The objective of this project is to develop novel routes for the production of nanoarchitectures that could incorporate the drug molecules in a quantitative way. We explore not only the potential intermolecular interactions that drug molecules offer for self-assembly into a variety of nanoarchitectures for improved pharmacokinetics and controlled release, but also concepts for the fabrication of cell-specific nanostructures independent of the molecular structures of the drugs.

Fundamental Design of Supramolecular Polymers

Supramolecular polymers are polymeric arrays of small molecular building units linked by non-covalent interactions. The non-covalent and living nature of such supramolecular polymers provides unique properties that expand the functional space of classical covalent polymers, but at the same time leads to relatively less defined features such as persistence lengths and contour lengths. The objective of the project is to develop an in-depth understanding of thermodynamic and kinetic factors that affect the association of small molecular building units into supramolecular polymers, and to use this knowledge to achieve precise control over the persistence lengths and contour lengths of individual supramolecular polymers.

Nanobeacons for Cancer Theranostics

Real time visualization of the location and expression level of proteins in living cells offers essential information on many important cellular and subcellular events and thus provides vast opportunities for the development of new strategies for tumor diagnosis and cancer therapeutics. The over-expression and relative abundance of certain proteases in cancers, such as cathepsins and matrix metalloproteases (MMPs), provide attractive targets for tumor screening. The accurate temporal and spatial mapping of proteases requires the use of non-invasive, highly sensitive molecular probes to convert specific chemical reactions or binding/recognition events to detectable fluorescent or radioactive signals. In this project, we propose to develop supramolcular nanoprobes for early-stage cancer diagnosis and imaging.

Functional Nanostructures with Anisotropic Surface Chemistries

anisotropic nanospheresOne of the greatest challenges in the development of discrete nanostructures for biomedical imaging, tumor diagnosis and drug delivery is the ability to precisely control their interactions with targeted objects in biological systems, particularly with cells of interest. The interaction of nanomaterials with cells is known to be very complex and is governed by the chemical, physical and mechanical properties of the nanomaterials.  In principle, the surface properties of nanostructures are a primary factor in determining the outcome of their interactions with cells. This project is aimed at developing novel strategies to fabricate nanostructures with anisotropic, well-defined surface chemistries that could provide specific cell adhesion, unique pharmacokinetics and cellular uptake pathways.