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  • Undergraduate Poster Abstracts
  • Bioengineering/Biomedical Engineering

    Room Chesapeake 9

    ap047 ELUCIDATING LIPID DROPLET FORMATION: LIPID COMPONENT OF LIPID DROPLETS DEPEND ON THE FORMATION SITE

    • Zuania Pacheco del Rio ;
    • Paul Dalhaimer ;

    n/a

    ELUCIDATING LIPID DROPLET FORMATION: LIPID COMPONENT OF LIPID DROPLETS DEPEND ON THE FORMATION SITE

    Zuania Pacheco del Rio, Paul Dalhaimer.

    The University of Tennessee, Knoxville, Knoxville, TN.

    Obesity is one of the most widespread diseases in the world, and it has been related to several health complications. Obesity is due to an excess of the quantity of neutral lipids stored in organelles called lipid droplets (LDs). Our goal is to determine how LDs form from the endoplasmic reticulum (ER) in order to improve the understanding of the cellular origins of obesity. The yeast Schizosaccharomyces pombe (S. pombe) and its mutant CDC25, which can be arrested at mitotic stage g2, were used. Unusual LD formation behavior was observed when CDC25 cells were arrested; LDs were forming close to the peripheral ER. We believe this difference is due to the lipid content on the cells. Chromatography analysis was performed to discern the content of the lipids between wild-type and CDC25 cells. We found an increase in the amount of sterol esters (SE) vs. triacylglycerol (TAG) in CDC25-arrested cells, and an increase in the amount of TAG vs. SE in wild type when LDs were forming at the nuclear ER. We tagged dgk1p and cpt1, enzymes in the catabolic pathway of TAG, with mYFP and found both enzymes were highly localized to the nuclear ER. Our findings indicate that LDs that are being formed in the peripheral ER are composed of SE, while the LDs formed at the nuclear ER are composed of TAG. This will be the first time this distinction on formation events and content of LDs is described in the field.

    ap048 ACOUSTIC COMPUTATIONAL SIMULATION OF AN UPPER RESPIRATORY AIRWAY TO EVALUATE EUSTACHIAN TUBE FUNCTION

    • Justo Torres-Rodriguez ;
    • Samir Ghadiali ;

    n/a

    ACOUSTIC COMPUTATIONAL SIMULATION OF AN UPPER RESPIRATORY AIRWAY TO EVALUATE EUSTACHIAN TUBE FUNCTION

    Justo Torres-Rodriguez, Samir Ghadiali.

    The Ohio State University, Columbus, OH.

    Otitis media (OM), characterized by middle ear (ME) inflammation, is the most commonly treated disease among children, and chronic OM is mainly due to an inability to open an upper-respiratory airway, the eustachian tube (ET). Standard therapies do not address the biomechanical abnormalities of ET dysfunction, although they can have a significant functional impact. Therefore, there is a significant need for technologies that can diagnose its patient-specific mechanisms and identify the most efficacious treatment. Sonotubometry is a non-invasive diagnostic test of ET function that measures sound transmission through the ET during swallowing. Currently, sonotubometry readings can only be indirectly associated with ET dysfunction biomechanics. Thus, we hypothesize that computational models of sonotubometry can provide information about how changes in tissue properties, such as fluctuating tensor and levator veli palatini muscle forces (FTVP and FLVP), directly influence sonotubometry output. We imported an anatomically accurate model of an adult patient's ET into COMSOL finite-element software in order to simulate the tissue and acoustic behavior that occurs during sonotubometry under varying muscle forces and tissue stiffness. Preliminary sound profiles exhibit a peak value and a width at 50% amplitude. These show that increasing FTVP produces larger openings (larger peaks) while increasing FLVP reduced opening times (decreased widths), whereas tissue stiffening appeared relatively ineffectual, suggesting that clinical measurements of width and peak may be good indicators of muscle function. We are confident that these models will provide new ways to interpret diagnostic information and improve OM treatment.

    ap049 HYDROGEL NANOCOMPOSITE SENSORS WITH COLORIMETRIC RESPONSE UPON PROTEIN EXPOSURE

    • Leopoldo Torres Jr. ;
    • Omar Ayyub ;
    • Peter Kofinas ;

    n/a

    HYDROGEL NANOCOMPOSITE SENSORS WITH COLORIMETRIC RESPONSE UPON PROTEIN EXPOSURE

    Leopoldo Torres Jr., Omar Ayyub, Peter Kofinas.

    University of Maryland, College Park, College Park, MD.

    The detection of pathogens is of utmost importance for the prevention of infection in health care facilities. Current technologies designed to achieve this purpose require expensive machinery, technical training, and sample preparation which can be costly. Developing materials that can produce a visible colorimetric response would prove to be cost effective by eliminating the need for machinery and technical personnel. Photonic crystals (PCs) have the potential for biosensing due to their color-producing nanostructures. PCs have been investigated for such applications, with sensors responding to low concentrations of chemicals, proteins, and other stimuli such as pH change and strain. In 3D photonic crystal hydrogel nanocomposites, the stimulus induces a swelling or deswelling event that alters the distance between nanoparticles, thus changing the wavelength of reflectance. However, very few photonic crystal sensors can produce a visible color shift. Our group recently developed a photonic crystal with highly charged silica nanoparticles that produced a color shift (~240 nm) from red to blue upon exposure to chymotrypsin. The hydrogel nanocomposite was designed so that the enzyme would encounter a dicystine peptide in the polymer network and disrupt the crosslinks. This frees charged particles and allows them to become closer in proximity. Additionally, the storage modulus increased by 1500% through the remodification of the network crosslinks. Here, we exploit the limits of this mechanism by comparing photonic crystal sensors with varying particle sizes to observe the effects on reflectance wavelength, storage modulus, and time for transition.