Prof. Anuradha Subramanian's talk

Jun 28, 2018 - 16:00

Jun 28, 2018 - 17:00

Room No. 118 ground floor Chemical Engg. Dept.

Seminars

Prof. Anuradha Subramanian Department of Chemical & Biomolecular Engineering University of Nebraska Lincoln

Abstract: (Abstract with images is attached as a pdf file) As articular cartilage is avascular with limited ability for self-repair and as a result osteoarthritis and other cartilage injuries are biomedical burdens. Ultrasound has become an indispensable tool in diagnostic imaging is an FDA approved noninvasive therapy mechanism and is used as an operative tool. While high intensity US (1-3 W/cm2) finds utility in ablative applications there is a paucity of published work that investigates the ability of pulsed low intensity US (pLIUS 1-50 mW/cm2) to improve cartilage repair outcomes. Thus we investigated continuous LIUS (cLIUS) in cartilage restoration (Guha Thakurta:2016). To attain clinically relevant transformative outcomes; in a departure from previous studies that employ empirical approaches we opted for a systematic approach that combines modeling and experiments. To elucidate underlying mechanisms in ultrasound induced bioeffects we first showed in Fig 1A that low-intensity ultrasound (cLIUS) applied at resonance induces deformation equivalent to that applied at 1MHz and significantly higher intensities (170kPa) (Miller 2017). A mechanochemical model that linked the mechanical stimulation of ultrasound and the increased mechanical energy density in the nucleus to the downstream targets of the ERK pathway showed that ultrasound stimulation induces frequency dependent gene expression as a result of altered rates of transcription factors binding to chromatin. The bifurcation behaviour of the cell when it is excited near resonance showed multiplicity (Fig. 1C). Thus there exists an optimal range of frequencies for ultrasound treatment where mechanical energy coupling is maximized (Miller 2017) and we identified the resonant frequency of an in vivo chondrocyte to be in the range of 3.5−4.1 (Fig. 1B). Our investigations on the extent of cLIUS propagation through the joint space suggests high attenuation; thus the effectiveness of ultrasound on patient specific cartilage restoration depends on optimal transducer positioning and transducer parameters (Fig. 1D). Finally as shown in Fig. 2(A to D) cLIUS was shown to positively impact tissue engineering approaches based on MSCs and adult chondrocytes.Bio-sketch: Anu Subramanian graduated with a degree in Chemical Engineering from LIT-Nagpur. She has a doctorate in ChemE from Virginia Tech-Blacksburg VA. Prof. Anuradha Subramanian is currently Professor in the Department of Chemical & Biomolecular Engineering at the University of Nebraska–Lincoln. Her current research interests are in the area of biomaterial development and further use of these biomaterials in (a) bioseparations and (b) biomedical applications. Her research in biomaterials and tissue engineering focuses on the synthesis and development of novel biofunctional materials for potential biomedical applications synthesized from natural polymers and ceramics. She also has a research focus on the engineering of mammalian cell lines to produce therapeutic proteins.