Research Areas
Novel Functional Foods, Nanoencapsulation of Nutraceuticals/Drugs,
Biosensors, Single Molecule Force Spectroscopy/Chemical Force Microscopy,
Biopolymer Nanocomposites, Bionanotechnology
The overall theme of my research at Rutgers is the rational design of food
nano- or micro-structure for improved quality and performance. Most of my
research projects are multi-disciplinary in nature, and immerse students in
research fields including bionanotechnology, biopolymers, biochemistry, food
chemistry, and materials science. Following is a summary of my specific research
areas:
1. Nanoencapsulation of Nutraceuticals/Drugs
The development of high quality, stable dietary supplements with good oral bioavailability will
have a major impact on the food industry. One of the major challenges of dietary
flavonoids and carotenoids is their poor oral bioavailabily. A wide variety of
encapsulation platforms, including nanostructured emulsions, W/O/W or O/W/W
double emulsions, solid lipid or biopolymer–based nanoparticles, and direct
conjugation of phytochemicals to biopolymer side chains have been developed in
my lab to encapsulate plant polyphenolic compounds. Our results show that the
body absorption and the blood circulation time of phytochemicals inside the body
increase, therefore, the desired pharmaco-kinetics of these phytochemicals may
be achieved.
Self-Assembly of Biopolymers at Nanoscale
Because of the complexity of modern multi-component food systems, the physical properties of
food materials, such as phase behaviors, mechanical properties, and
intermolecular interactions between food components at different length scales (nano-,
micro-, and macro-scales) must be understood. Polysaccharides and proteins are
two key components in both natural and processed foods. The knowledge of their
interactions is of importance not only in making cost-efficient use of
functional ingredients, but also in designing novel food, controlling and
improving food ingredient structures and textural properties of fabricated
foods. We have developed new experimental techniques and computer simulation
algorithms to provide new insights into the self-assembly of food polymers in a
series of complex fluids:
- Hydrocolloid Gels: Hydrocolloids have been widely used as gelling
or thickening agents in the food industry; however, many issues related to
physical gelation in polymer solutions induced by self-assembly of polymer
chains remain unclear. We have developed a novel method that can predict and
construct phase diagram, as well as provide molecular level understanding of
sol-gel transitions of polymers through a combination of small-angle neutron
scattering and Monte Carlo simulation on the basis of a recently-developed
eight-site bond fluctuation algorithm.
- Protein/Polysaccharide Hybrids: Hybrids formed by polysaccharides
and proteins have already served as important materials in a variety of
food/drug delivery applications because they create a barrier of protein
between food ingredients and food matrices, and this barrier improves the
ingredient performance and shelf-life stability in many food systems.
- Chemical Force Microscopy: The macroscopic properties of food
biopolymers are determined to a great extent by the mechanical
characteristics of individual components, including such aspects as entropic
and enthalpic elasticities as well as their molecular conformations. Very
recently, the conformation of BSA as well as its interactions with
negatively-charged surface in saline solutions of different pH have been
investigated by SANS and AFM-based chemical force microscopy (CFM) (J. Phys.
Chem. B, 2008). A new approach to extract the contribution of elementary
interactions from the statistically averaged force-extension curves through
self-consistent fitting has been developed.
- Multilayer Biopolymer Films: In recent years considerable effort
has been devoted to the development of methods for the preparation of
composite food particles consisting of polymer cores covered with shells of
different chemical composition. Our approach is to assemble edible films
with controlled surface hydrophobicity and morphology through the formation
of multi-layer biopolymer films using a layer-by-layer (LBL) approach. We
have developed UV-Ozone treatment to modify the film hydrophobicity, and
electrostatic LBL deposition of charged biopolymers to form nanostructured
films with specific properties.
3. Quantum Dots:
To strengthen the power of these delivery
systems with the addition of the traceable and targetable capabilities, we have
developed a method to prepare water-soluble CdTe QDs with excellent chemical
stability and quantum yields (J. Phys. Chem. B, 2006; J. Phys. Chem. C, 2008).
Now these water-soluble QDs are ready to be incorporated into our nanoemulsion-
or nanoparticle-based delivery systems.
4. Drug/Protein Interactions:
Many studies showed that the interactions between polyphenols in tea and proteins may lead to the loss of
bioavailability of polyphenols and their antioxidant capacity. It is crucial to
understand the mechanism of binding between tea polyphenols and proteins.
Recently, we have used QCM-D to systematically monitor the binding between a
series of tea polyphenols, including EGCG (J. Agr. Food Chem., 2007), theaflavin,
thearubigin (J. Agr. Food Chem., 2007) and BSA surface. This approach can be
easily expended to the screening of nutraceuticals, as well as the studies of
binding between drugs and receptor proteins.
5. Nanoscale Biosensors for Pathogen Detection and Disease
Diagnosis:
Two types of biosensors have been developed in my laboratory: (1)
chip-based sensors, where high-capacity surfaces with increased number of probes
(and subsequently the amount of bound target) have been fabricated to generate
greater signal output, and (2) QCM-D based biosensors, where toxins or
pathogenic cells can be detected through the incorporation of direct immunoassay
