Candidate I have been performing research in academic labs since high school, and have for a long time known that I want to pursue a carer in academia as a profesor. I have research experience in fields ranging from astronomy to environmental science to applied physics, and am now focusing on exploiting a fabrication technology I developed at the end of graduate school to solve a major problem in the field of tisue engineering. My interests lie in the development of smart materials and biomaterials, and I consider natural tissue in itself to be an ultimate form of smart material, able to interact with its environment in extraordinarily complex ways. I am not only interested in the research aspects of academia, but also care a great deal about teaching and mentoring young students;I have mentored several undergraduates and a masters student, helped direct student research in a class as an undergraduate, and have volunteered for a wide variety of outreach programs. During my postdoctoral experience in the Langer Lab, I will learn the skills necessary to become an independent investigator (such as proposal writing, mentoring, dealing with academic bureaucracies, etc.), and plan to apply for a faculty position within a few years. I also plan to learn more about the field of biomedical engineering, and the unique issues that are associated with it Environment The work discussed in the mentored phase of this proposal will be performed in the Langer Lab at MIT. The Langer lab is widely known as one of the leading research groups in a wide range of fields, including drug delivery, tissue engineering, smart materials, and biomedical device engineering. The Langer Lab is located at MIT, one of the leading research institutes in the country, with strong connections to several local hospitals. The independent phase of this proposal will be performed at a university with a strong biomedical engineering and materials science research program. Research (Please note highlighted sections contain proprietary information) The work discussed in this proposal focuses on developing 3D microfluidic networks inside hydrogels to act as artificial vascular systems in engineered tissue. Such vascular networks will be required for any engineered tissue of significant (and clinically useful) thickness, as diffusion limits the ability of nutrients and gasses to pass to and from cells embedded deep within a scaffold. The fabrication technique is based on the use of sacrificial melt-spun microfiber networks made from materials with pH-dependant solubility. The structures produced in many ways mimic natural capillary networks, and are produced with a rapid, simple, inexpensive, and scalable process.
The aims i n this proposal discuss techniques to produce the desired structures, as well as techniques for seeding cells on the channel walls (as an endothelial lining) as well as in the hydrogel material (as functional cells in a 3D matrix). In all cases, the cells will be maintained by media flow through the 3D channel system. In the mentored phase of this work, the scaffold fabrication technique will be developed, and seeding of cells on the channel walls will be demonstrated. This phase will also contain the initial work necessary to optimize the sacrificing technique to allow cells to be placed in the hydrogel, though it is possible this aim may continue through to the independent phase. The independent phase will demonstrate fabrication of 3D networks in a cell-laden hydrogel (first without, and then with, cells lining the channel walls as well). The independent phase will then develop co- culture systems in these vascularized hydrogels, and may also investigate the use of the 3D channel network to deliver factors to affect stem cells embedded within the hydrogel.
The progress of modern tissue engineering depends on the ability to form 3D vascular networks that are able to provide nutrients to cells inside of artificial tissue constructs. Using a new technique based on sacrificial melt-spun microfiber structures, we will be able to produce these networks rapidly and inexpensively, thereby rendering the resulting vascularized artificial tissue constructs accessible to the patient. The constructs will be made of hydrogels such as gelatin, which are very similar to natural tissue, and will contain cells that will allow the construct to function like native tissue.
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|Bellan, Leon M; Pearsall, Matthew; Cropek, Donald M et al. (2012) A 3D interconnected microchannel network formed in gelatin by sacrificial shellac microfibers. Adv Mater 24:5187-91|
|Bellan, Leon M; Kniazeva, Tatiana; Kim, Ernest S et al. (2012) Fabrication of a hybrid microfluidic system incorporating both lithographically patterned microchannels and a 3D fiber-formed microfluidic network. Adv Healthc Mater 1:164-7|