BME Summer Seminar - Wed., Aug. 5
Event Date: | August 5, 2015 |
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Hosted By: | Weldon School of Biomedical Engineering |
Time: | 12:30 p.m. |
Location: | MJIS 2001, WL campus |
Priority: | No |
College Calendar: | Show |
"Clinical imaging guidance for preventative care of photocarcinogenesis"
Michelle Visbal-Onufrak (Dr. Young Kim, advisor)
Abstract: Examining a small area using conventional microscopic techniques is often not appropriate for an assessment of clinically relevant areas for diagnosis and treatment. Consequently, no simple and cost-effective imaging methods exist that are available to provide clinicians or laypersons with an adequate visual guide for treating affected areas at a clinically relevant scale. Limitation of conventional imaging technologies hampers effective diagnosis and preventive care in large organs, such as the skin. With skin cancer being the most common and fastest growing type of cancer in the US, there is a need for an imaging method that is suitable for properly identifying and treating high risk areas over a large field or patch of tissue. In this respect, this research focuses on the technological development of mesoscopic (i.e. between microscopic and macroscopic) biomedical imaging device that can provide label-free and non-invasive visualizations of field cancerization over a clinically-relevant, heterogeneous area. Implementing this mesoscopic imaging method into a clinical system would allow for probing endogenous and intrinsic tissue properties, subtle changes in tissue microenvironments from alterations in extracellular microstructures and inflammatory hyperemia over a large area in a label-free manner, thus making it suitable for applications ranging from cancer risk assessment to cancer prevention and treatment planning. To establish the achievability of this mesoscopic imaging method, a series of tissue phantom studies were performed to characterize image contrast, resolution and penetration depth of our imaging system, as well as for determining hemoglobin concentration based on spectral analysis. Experimental carcinogenesis studies were also conducted using a murine model for imaging of precancerous lesions using the aforementioned imaging technique.
"Degradation and Cell Survival in a Fast-Degrading Thiol-Acrylate based Hydrogel"
Alarbi Elhashmi (Dr. Tien-Min Gabriel Chu/Dr. Alyssa Panitch, co-advisors)
Abstract: Successfully regenerate cranium tissue is an integral step to restore craniofacial functions. Due to complex geometry, obtaining grafts that matches the geometry of the missing bone tissue becomes a challenge. Researchers are therefore exploring craniofacial tissue engineering by combining mesenchymal stem cells (MSCs) with scaffold biomaterials to regenerate the missing cranial tissue. Though several cellular delivery methods have been explored, achieving high rate of cell survival after implantation still remains a challenge, due to many factors, including slow degradation of the cell carrier, low rate of diffusivity in the carrier, and the adverse effects from degradation byproducts. Potentially, a fast-degrading, (MSC)-encapsulating hydrogel can be used in conjunction with a 3D scaffold to provide efficient regeneration in the craniofacial area. Recently, Hao and Lin developed a photo-polymerizeable biodegradable hydrogel system based on thiol-acrylate for hepatic cell encapsulation. This current hydrogel, however, has a longer degradation time and higher polymer content than we need for mesenchymal stem cell delivery in cranial regeneration. A biodegradable poly(ethylene glycol)-diacrylate (PEGDA) hydrogel was prepared by visible light initiated thiol-acrylate photopolymerization method. PEGDA hydrogel groups were prepared with 5 to 12 wt% macromere formulations, and bi-functional thiol concentrations at 1 to 9 mM. The degradation rates of PEGDA groups were examined via swelling ratio kinetic of hydrogels. Furthermore, to measure the viscosity of the fluid, oscillation viscometry analyses were performed on all groups. The degradation rate of PEGDA gel primarily depended on the ratio of PEGDA weight percentage (wt%) and Dithiothreitol (DTT) molarity. To evaluate cell viabilities and differentiation, AlamarBlue, ALP and Von Kossa staining assays were preformed. To evaluate inducing bone regeneration to bridge a critical-sized segmental defect, the most efficient ratio found will be examined on rabbit animal model. This study provided important fundamental concepts for future research on a biodegradable poly(ethylene glycol)-diacrylate hydrogels for clinical transition research.
***Bring your lunch to seminar – BMEGSA will provide snacks and drinks***
available via WebEx meeting in SL220A at IUPUI*
2015-08-05 12:30:00 2015-08-05 13:30:00 America/Indiana/Indianapolis BME Summer Seminar - Wed., Aug. 5 Michelle Visbal-Onufrak (Dr. Young Kim, advisor) and Alarbi Elhashmi (Dr. Tien-Min Gabriel Chu/Dr. Alyssa Panitch, co-advisors) will present their current research at this week's BME summer seminar. MJIS 2001, WL campus