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TRACK 6 TRACK 6 Technical Program

gradients. This microfluidic platform is novel in combining biochemical and bond the two layers to the intervening porous membrane. The dual channel
biophysical cues and can be used towards development of a new class design facilitates simulation of physiological flow conditions while also en-
of biological assays for investigating developmental biology and disease abling precise spatiotemporal control of the cell microenvironment in each
pathogenesis at the single cell resolution. compartment. Preliminary work has successfully demonstrated co-culture
of transformed choriocarcinoma cells (BeWo) and primary human placental
villous endothelial cells in this microengineered model. We have demon-
Plasmonic Biosensors Based on Gratings strated cell-cell fusion in the BeWo cell population on-chip through activation
of the protein kinase A pathway to mimic trophoblast syncytialization, a key
process in placental development. Cell fusion was assessed through ob-
Poster Presentation. NEMB2016-6144 servation of changes in cell morphology and E-cadherin expression, as well
as quantification of human chorionic gonadotropin (hCG) production, which
Soheila Mashhadi, Norfolk State University, Norfolk, VA, United is increased in syncytialized trophoblasts. Additionally, we have worked to
States, Frances Williams, Norfolk State University, Chesapeake, characterize the molecular permeability of the trophoblast-endothelial cell
VA, United States, Rabia Hussain, Natalia Noginova, Norfolk State interface within the placenta-on-a-chip device. Glucose is the chief energy
University, Norfolk, VA, United States substrate for the placenta and fetus and is an essential nutrient for fetal de-
velopment. Thus, we have investigated rates of glucose transfer between
Surface Plasmon Resonance (SPR) biosensors are in demand for the de- the maternal and fetal compartments on-chip. This work represents the first
tection of chemical and biological species for many applications including steps towards development of a placenta-on-a-chip microsystem that will
environmental monitoring, food safety monitoring, and for the pharmaceuti- provide new capabilities as a research tool for placental biology research.
cal and medical industries. Such applications require devices that are highly
sensitive and provide real-time sensing. SPR biosensors incorporate surface
electromagnetic waves (surface plasmon polaritons) which propagate on Point-of-Care Diagnosis of Hemoglobin Disorders with a Mobile
the boundary of a metal-dielectric interface. Changes to the boundary, Electrophoresis Chip
such as binding of biomolecules on the metal surface, produce changes
in the optical signals to be measured. Thus, SPR devices can detect small Poster Presentation. NEMB2016-6035
concentrations of an analyte, in real-time, making them favorable for these
applications. SPR sensors use several methods of optical excitation and this
work investigated grating-coupled surface plasmon resonance (GSPR) for Ryan Ung, Yunus Alapan, Muhammad Hasan, Megan Romel-
bio-sensing applications. fanger, Tolulope Rosanwo, Asya Akkus, Case Western Reserve
University, Cleveland, OH, United States, Kutay Icoz, Mehmet Ca-
This paper presents the design of a GSPR device in order to realize a highly kar, Abdullah Gul University, Kayseri,Turkey, Connie Piccone, Jane
sensitive sensor. The fabrication process flow for this device is discussed Little, Umut Gurkan, Case Western Reserve University, Cleveland,
and includes using interference lithography (IL) to create the periodic grating OH, United States
features. IL was used instead of electron beam lithography because it can
expose bigger areas and does not need expensive photoresists. A metallic In developing countries, diagnostic tests for homozygous (HbSS) or com-
bi-layer of chrome and gold was deposited on the device using thermal pound heterozygous (HbSC or HbS-Beta thalassemia) sickle cell disease
deposition techniques. The final step of fabrication included functionalization (SCD) are not readily available at the point-of-care (POC). Very few infants
of the device for biosensing capabilities. During processing, the materials are screened in Africa for SCD because of the high cost, time for sample
were characterized using various techniques including atomic force micros- transfer to a central laboratory (2-6 weeks), and level of skill needed to
copy (AFM) and a scanning electronic microscope (SEM). These results will run traditional tests. The World Health Organization recognizes a crucial
be presented as well.
need for early detection of SCD in newborns, since it is estimated that 70%
SCD-related deaths in Africa are preventable with early cost-effective inter-
ventions. The diagnostic barrier can be broken with affordable, POC tools
A Microengineered Model of the Human Placental Barrier that facilitate early detection immediately after birth or at the time of immu-
nization. To address this unmet clinical need, we have developed a mobile
Poster Presentation. NEMB2016-6065 electrophoresis platform (HemeChip) for reliable, affordable, and rapid diag-
nosis of SCD.
Cassidy Blundell, Ariana Schanzer, University of Pennsylvania, The HemeChip uses a microfabricated platform, with a material cost less
Philadelphia, PA, United States, Emily J Su, University of Colorado than $0.87 per device, housing cellulose acetate electrophoresis to rapidly
Denver, Aurora, CO, United States, Samuel Parry, University of separate hemoglobin (Hb) types. Less than 5 microliters of blood, which can
Pennsylvania Perelman School of Medicine, Philadelphia, PA, Unit- be obtained through a finger stick or heel stick, is processed on a piece of
ed States, Dan Dongeun Huh, Department of Bioengineering, Uni- cellulose acetate paper via an applied electric field in alkaline buffer within
versity of Pennsylvania, Philadelphia, PA, United States 10 minutes. We clinically tested and benchmarked HemeChip against stan-
dard clinical methods using 51 blood samples from 14 patients.
During pregnancy, the maternal-fetal interface of the human placenta regu-
lates the exchange of nutrients, oxygen, metabolic waste, and xenobiotics The HemeChip reliably identifies and discriminates amongst Hb C/A2, S, F
between the mother and fetus. During late gestation, this critical barrier in and A0. The HemeChip hemoglobin concentration results were correlated
the placental chorionic villi consists of maternal villous trophoblasts and fetal (Pearson Correlation Coefficient (PCC) of ~0.96 for all Hb types tested) with
capillary endothelial cells, which are located in close apposition to facilitate standard clinical hemoglobin screening methods, including high perfor-
efficient exchange between the maternal intervillous space and fetal circula- mance liquid chromatography (HPLC). The agreement between the Heme-
tion. Our biomimetic model of the human placental barrier leverages micro- Chip and HPLC results were assessed using the Bland-Altman plot, which
engineering technology to develop a miniaturized cell culture platform that showed a strong agreement between estimated (HemeChip) and actual
reconstitutes the three-dimensional microarchitecture and dynamic micro- (HPLC) hemoglobin percentages. The majority (95.5%) of the differences
environment of the human placental maternal-fetal interface. This “placenta- between actual and estimated hemoglobin percentages were within the lim-
on-a-chip” device enables compartmentalized co-culture of human villous its of agreement. Furthermore, the receiver Operating-Characteristic (ROC)
trophoblasts and fetal endothelial cells on a thin, semipermeable polymeric curves showed more than 0.89 sensitivity and 0.86 specificity for identifica-
membrane. The microdevice is composed of two poly(dimethylsiloxane) tion of hemoglobin types using the HemeChip, based on the band travelling 85
(PDMS) layers, each containing a hollow microchannel, fabricated using distance from the sample application point.
standard soft lithography techniques. A thin PDMS mortar layer is used to