Icon for: Ariel Ash-Shakoor

ARIEL ASH-SHAKOOR

Syracuse University
Years in Grad School: 1

Judges’ Queries and Presenter’s Replies

  • May 21, 2013 | 12:12 a.m.

    very nice job with the video. I am wondering if you can discuss more why wettability is such a critical factor for cell interactions with current biomaterials. I didnt understand the connection there. Also, how can one incorporate something into the PEM so that it releases in a controlled fashion as you suggested as the last topic of your video. Thanks and great job!

  • Icon for: Ariel Ash-Shakoor

    Ariel Ash-Shakoor

    Presenter
    May 21, 2013 | 07:24 p.m.

    Thank you for your intriguing questions, Dr. Shin. Wettability is a critical factor for cell interactions to determine if the cells will spread, proliferate, and reproduce on a substrate. The polarity of a surface dictates the wettability of the surface. Cells prefer moderately hydrophilic surfaces for normal cell functions. In regards to your second question, we should first realize that PEM multilayers are highly ionically crosslinked, in contrast with highly permeable hydrogels. One can embed enzymes within the polyelectrolyte multi-layers as proven in Mertz et. al., "Mechanotransductive surfaces for reversible biocatalysis activation” (Nature Materials 2009). This article illustrates the controlled release of enzymes upon an external mechanical stimulus. We would like to use similar methods to incorporate growth factors or other cell environment markers so that we can release these factors upon shape memory polymer activation.

  • Icon for: Peter Pfromm

    Peter Pfromm

    Judge
    May 21, 2013 | 11:01 a.m.

    Thanks, great job on the video and poster, especially so early in your graduate student career.

    While contact angle is certainly an important parameter, would you please comment on the changes the surface will go through once exposed to a “biological” environment of some sort where many large and small, organic and inorganic anions and cations are present? Will your carefully engineered surface not be immediately changed once it is contacted with a “bio” environment?

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    Ariel Ash-Shakoor

    Presenter
    May 21, 2013 | 07:20 p.m.

    Thank you for your question, Dr. Pfromm. You raise an interesting point about the application biocompatibility. Yes, the SMP PEM biomaterial will change as it interacts with the bio environment, but it is difficult to state the degree and extent of this change at this moment without in vivo, or at least in vitro tests. In order for free anions and cations to disrupt PEM coating structure, they must overcome (large) entropy for ion exchange within PEM macromolecular ion pairs. Though this is possible, we have not found this reported in literature to date. Nonetheless, your question has made me aware of this possibility! Furthermore, the surface charge can be tuned by the concentration of surface cation or surface anion for improved biomaterial interactions. The overall system is neutral except for the slight charge of the surface because the anions and cations are paired creating polyelectrolyte bilayers.

  • Icon for: Mary Albert

    Mary Albert

    Judge
    May 21, 2013 | 12:43 p.m.

    The poster jumps into PEM and SMP as substrates and the novelty of combining them in this work, but this is not my field and I am wondering about the context – are those the only two that have been previously used? Why focus on those two?

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    Ariel Ash-Shakoor

    Presenter
    May 21, 2013 | 07:12 p.m.

    Thank you for your question, Dr. Albert. Shape memory polymers and polyeletrolyte multi-layers have been used as biomaterial substrates separately with several noted benefits. Shape memory polymers can mimic biological surface topography and change shape upon stimulus activation triggered by physiological conditions. Polyeletrolyte multi-layers provide improved compatibility and wettability due to a change in substrate surface charge. This project is the first project to combine the two polymer systems with the potential of synergistic benefits. Other polymer systems have been used previously; however, we believe that this novel combination will create an optimally dynamic (SMP) and biocompatible (PEM) system. In addition to this, my advisors have experience working with both polymer systems in great detail.

  • May 21, 2013 | 03:42 p.m.

    Very nice job! You mention that your approach has the potential to enable advances across a broad range of biomaterials-based fields. Is there an application where you would not expect this approach to work well, and if so, why?

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    Ariel Ash-Shakoor

    Presenter
    May 21, 2013 | 07:10 p.m.

    Thank you for your question, Dr. Buneo. Your insight has helped me think of specific applications. While the combination of SMP and PEM as a biomaterial represents a system that can be used for several internal organs and soft tissues, it may need to be tailored specifically for different applications. For example, the stiffness or roughness may need to be changed significantly for different biological applications. Despite that this biomaterial has the potential to be used as vascular or bone tissue, the stiffness and chemistry will need to be altered for the best performance for each application. Currently, we do not foresee the present biomaterial system for use in very soft biological organ system applications such as brain implants or ocular devices due to mechanical incompatibility.

  • May 21, 2013 | 07:15 p.m.

    Great job. I had a couple of questions. First what types of cell-material interactions are you interested in? Are hydrophobicity and roughness the most important properties and why are they important. Second, how do you ensure sterility of these novel biomaterials which are intended for medical applications (can they be autoclaved or sterilized in some other way and if so, how does this process alter/affect the biomaterial)?

  • Icon for: Ariel Ash-Shakoor

    Ariel Ash-Shakoor

    Presenter
    May 21, 2013 | 08:08 p.m.

    Thank you Dr. McDonald for your astute questions. We are interested in tissue engineering and mechanobiology cell material interactions. Cells have the unique ability to sense their environment, elicit a response, and adapt to the environment change. We want to understand cell biological processes as this SMP-PEM biomaterial substrate changes for different stimuli thereby creating a new active cell culture technology.

    Hydrophobicity and roughness (or topography) are very important properties for cell material interactions because they are the first fundamental properties that dictate if the cells will attach, spread, and grow on the substrate. However, there are many very important properties for optimal cell material interactions because of the complexity of biological systems. Growth factors and mechanical properties are examples of other extremely important properties for biomimetic environments and improved cell interactions. We can potentially embed growth proteins within the PEM and release them upon activation of the SMP. We can also change the mechanical properties of the SMP to match different biological systems.

    In regards to your last question, the biomaterial substrate can be UV sterilized. Though I have not completed this part of the project yet, another student in my advisors’ lab was able to UV sterilize the same SMP biomaterial substrate for active cell culture in “Dynamic cell behavior on shape memory polymer substrates,” (Biomaterials 2011).

  • Further posting is closed as the competition has ended.

Presentation Discussion
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    Allen Miller

    Guest
    May 23, 2013 | 04:04 p.m.

    I like the presentation by Ariel Ash-Shakoor.

  • Icon for: Ariel Ash-Shakoor

    Ariel Ash-Shakoor

    Presenter
    May 23, 2013 | 04:07 p.m.

    Thank you Allen!

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    Janice Smith

    Guest
    May 26, 2013 | 05:27 p.m.

    Ms. Ariel Ash-Shakoor you are a very impressive young lady. Biomedical engineering is a noble and very difficult field of study; and you have mastered it. Your smart polymer will one day save many lives. Keep up the great work. Thank you!!

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    Ariel Ash-Shakoor

    Presenter
    May 27, 2013 | 09:10 a.m.

    Thank you Janice.

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    Martin McDermott

    Guest
    May 28, 2013 | 11:12 p.m.

    Having worked with Ariel Ash-Shakoor, I know her research skills and dedication will produce good work on this important subject.

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    Ariel Ash-Shakoor

    Presenter
    May 29, 2013 | 09:00 a.m.

    Thank you Dr. McDermott!

  • Further posting is closed as the competition has ended.