(4n) Utilizing Geometrically and Chemically Anisotropic Particles for Biomedical Applications

Flow
lithography (FL) pioneered by the Doyle group in MIT has been a powerful
synthesis technique that enables the mass-production of hydrogel microparticles with geometrical and chemical patterns. The
technique combines photolithography with microfluidic methods, providing
precise control over shape and chemical patchiness in particles. Much
of my PhD works has been focused on the development of advanced flow
lithography that can achieve much higher degree of geometrical and chemical
complexity in particles than before. Briefly, my techniques can be used to
create hydrogel particles with 3D morphologies and chemical patterns. Also, I
have extended the process of FL to non-PDMS based channels (ex. glass or
plastic channels), and prepared novel class of functional particles using water
insoluble monomers, organic solvents, and hydrophobic functional entities such
as quantum dots, ruthenium dyes, and single-walled carbon nanotubes.

One
of the powerful advantages of the anisotropic multifunctional hydrogel
particles prepared by FL is that the particles are very well-suited for the
biomedical applications. Typically, the gel particles are synthesized
from monomers based on polyethylene glycol which is bio-friendly, highly
tunable, and can be functionalized with a variety of biomolecules. Also, the
controlled shapes and chemical patterns in particles can provide unique
function for applications in diagnosis, treatment, and tissue engineering. For
example, multifunctional barcoded particles have been
designed for the rapid screening of target biomolecules in a complex biological
mixture. Another example can be the
artificial
red blood cells (RBCs). Recently, soft disk particles with a few micron
dimensions were synthesized to mimic RBCs, exhibiting the reversible
deformability which is the vital property to allow RBCs to function.

In this
presentation, I summarize the previous works, introduce current works that use the
particle technology to do research on cell motility with applications to
clinical cancer research as well as the separation of circulating tumor cells,
and emphasize the importance of future works to bridge the particle technology
to the biomedical area.

Selected
Publications (* denotes co-first author status)

Bong KW, Xu JJ, Kim JH, Chapin SC, Strano
MS, Gleason KK, Doyle PS. Non-polydimethylsiloxane Devices
for Oxygen-Free Flow Lithography. Nature Communications, 2012,
3, 805.

Bong KW*, Chapin SC*, Pregibon DC, Baah D, Floyd-Smith
TM, Doyle PS. Compressed-air Flow Control System. Lab Chip, 2011, 11(4): 743-747.

Suh SK*, Bong KW*, Hatton TA, Doyle PS. Using Stop-Flow Lithography
to Produce Opaque Microparticles: Synthesis and
Modeling. Langmuir, 2011, 27(22):13813-13819.

Bong KW, Bong KT, Pregibon DC, Doyle PS. Hydrodynamic Focusing Lithography. Angew. Chem. Int. Ed., 2010, 49(1): 87-90.

Bong KW, Chapin SC,
Doyle PS. Magnetic Barcoded Hydrogel Microparticles
for Multiplexed Detection. Langmuir, 2010, 26(11): 8008-8014.

Bong KW, Pregibon DC, Doyle PS. Lock release lithography for 3D and
composite microparticles. Lab Chip, 2009, 9(7): 863-866.