Microfluidic Cell Sorting and Analysis

Separation and analysis of cells is important for biomedical research, diagnostics, and cell therapeutics. We are developing new technologies to analyze and sort cells that minimize sample processing and improve performance over existing methods. We have pioneered microlfuidic devices for sorting of cells in continuous flow based on transient cell-surface adhesion, called cell rolling. In this process, we use molecular-level cell-surface interactions to steer cells flowing in microlfuidic devices, resulting in separation with high purity and recovery. For example, we have demonstrated the ability to directly separate cells from blood without prior sample processing, which opens the possibility of monitoring the white blood cells at the point of care. We have also developed devices to analyze cells based on adhesion- The cell-surface interactions directly result in a visual readout by affecting the motion of cells flowing through the devices. These devices are being used to elucidate the adhesion behavior of mesenchymal stem cells, which are gaining increasing attention for cell therapies. Finally, we have also developed a microfluidic circuit with a feed-forward loop to sort particles based on size and deformability, and are studying the flow of cells through constrained microchannels. People: Suman Bose, Chia-Hua Lee
Collaboration: Jeffrey Karp (BWH), Krystyn Van Vliet (MIT), Angela Belcher (MIT)

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Nanoparticles for Drug Delivery

Biodegradable lipid and polymeric nanopoarticles with the ability to target diseased tissue and release drugs in a controlled manner are highly promising as carriers for drug therapy. We are using microfluidic devices for synthesis of polymeric nanoparticles with tunable properties and homogeneous distributions. Our aim is to control their properties such as size, charge, homogeneity, and drug loading by rapid mixing of precursors during nanoprecipitation. These devices are being used for understanding the role of nanoparticle properties on their in vitro and in vivo behavior to develop nanoparticles and to optimize them for different applications. People: Jong-min Lim, Sunandini Chopra
Collaboration: Omid Farokhzad (BWH), Robert Langer (MIT)

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Nanostructured Membranes for Water Purification and Gas Separations

Controlling the nanoscale structure of materials offers new avenues for advancing membrane technology. We are developing new membranes for water purification and gas separations. We have developed membranes that employ short hydrophobic nanopores to trap vapor, and enable practically isothermal vapor-phase transport across two liquid menisci separated by a sub-micron vapor gap. This membrane decouples the transport from membrane material, presenting opportunities to make them chlorine-resistant. It can potentially reject all non-volatile material such as boron that is otherwise difficult to remove using polymeric membranes. We are also developing graphene-based membranes that exploits flow through nanometer-scale pores in graphene. Theoretical studies have shown the potential of these membranes for high-flux water purification and gas separations. We are developing methods to fabricate such membranes and techniques to study mass transport through graphene. People: Jongho Lee, Sean O'Hern, Tarun Jain, Michael Boutilier
Collaboration: Nicolas Hadjiconstantinou (MIT), Jing Kong (MIT), Evelyn Wang (MIT), Juan Carlos Idrobo (ORNL), Tahar Laoui and Faizur Rehman (KFUPM)

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Nanofluidic Devices for DNA Analysis

Nanofluidic devices have unique capabilities for manipulation and sensing of DNA molecules at the single-molecule level. We have developed nanofluidic devices that employ multiple measurements on single molecules to enhance the ability to size DNA molecules. We have also developed a fabrication technique to integrate membranes containing nanopores into microfluidic devices, which decreases noise and enables the design of networks containing nanopores. Combined with active control of molecules, these devices can provide improved DNA analysis and sorting capabilities. People: Tarun Jain
Collaboration: Carlos Aguilar (MIT Lincoln Labs), Pete Carr (MIT Lincoln Labs)

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