Rad Lab is an interdisciplinary research group who studies diverse problems in the areas of soft matter, interfacial processes, and transport phenomena using development of multiscale modeling and novel simulation methods.
We are particularly interested in fundamental understanding of the structure and dynamics of functional nanomaterials including macromolecules, surfactant, and nanoparticles in suspension or adsorbed at soft surfaces such as fluid-fluid interfaces and cell surfaces.
Rational Design and Cellular Targeting of Bioparticles
For most drugs to be therapeutically active, they must go inside the tumor cell. NP carrying drug payloads can be used to facilitate the drug delivery so that they attach the tumor cell and get carried inside. To this end, we need to get an enhanced understanding of the design and optimization of functionalized bioparticles for enhanced delivery and hopefully for the management or treatment of diseases. Targeted drug delivery is inherently a complex and multiscale problem; an extensive range of length and time scales are essential to the hydrodynamic and microscopic molecular interactions mediating NP motion in blood flow and their binding to and endocytosis by the cell surface. Therefore it is difficult to investigate those processes through scale-specific techniques.
The primary goal of this research is to integrate the rapidly increasing but still fragmented experimental observations on various targeted cell interactions with nanoparticles, possessing a range of stiffnesses and surface charges into a broad, rigorous, and unified knowledge framework. State of the art in the targeted drug delivery field is such that the paired roles of NP and cellular electromechanical properties in cell accessibility and endocytosis of nanoparticles remain poorly defined. We use a physiologically sound, computationally tractable predictive multiscale modeling combined with experimental and theoretical studies to explore the fundamental mechanics and electromechanics issues that underlie the endocytosis pathway of nanoparticles during the various stages of interactions with targeted cells. The problems under study play critical roles in cell interactions with nanomaterials with applications to nanotoxicity and targeted drug delivery and are also of fundamental interest to biomechanics and mechanobiology of cells.
Interfacial Transport Phenomena
Emulsions are ubiquitous in a wide range of technological applications, ranging from targeted drug delivery to enhanced oil recovery. Over the last several decades, significant research has been directed toward a fundamental understanding of emulsion behavior and stability. Analogous to molecular surfactants and amphiphiles, the adsorption of particles at the fluid-fluid interfaces can enhance the stability of emulsion droplets. While the majority of studies have predicted the behavior of surface heterogeneities of hard particles, few works have been conducted to quantify the influence of rheological and mechanical structures of particles on the rheology and stability of fluid interfaces and in a concentration-dependent manner.
A major goal of this research is to advance the understanding of the effect of mechanical stiffness and architecture of soft-swollen micron/nano-sized particles on emulsion stability and efficiency and how tuning the physicochemical structures of these surface-active particles can control the fluid interfacial behavior. We use a multiscale computational framework by combining classical molecular simulation techniques with computational fluid dynamics methods. The results of this project are likely to impact a wide range of technological applications, ranging from targeted drugs delivery, enhanced oil recovery to next-generation personal care products.