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Jianjun GuanAssistant ProfessorPhD, Zhejiang University, 2000 Tel. (614) 292-9743 Office: 494 Watts Hall |
About Dr. Guan's research
Dr. Guan's research interests are biomaterials and tissue engineering. His goal is to employ materials and biological tools to engineer tissues that function like native tissues to replace damaged or diseased tissues in the body. He is interested in development nano-structured biomimetic biomaterials that mimic many functions of the native extracellular matrices (ECM) found in tissues, and engineer mechano-active soft tissues such as cardiac muscle and blood vessel, hard tissues such as bone with developed biomimetic biomaterials. His research covers materials science, polymer chemistry, drug delivery, cell biology and tissue engineering fields. Tissue engineering is an emerging field that applies principles of sciences and engineering to develop biological substitutes to restore, maintain, or improve tissue function. The basic strategy of tissue engineering is to combine appropriate cells with three-dimensional scaffold and organize into tissues under appropriate conditions. Scaffold serves as a mechanical support, providing microenvironment for cell. The ideal scaffold should not only act as a structural support but also possess some biomimetic properties of ECM. Scaffolds for soft tissues regeneration should also have mechanical properties similar to the target tissue. Current biomaterials for soft tissue engineering possess some but not all of these characteristics. Dr. Guan's research utilizes biomimetic strategy to develop biomaterials that are chemically, mechanically and structurally mimicking ECM and having properties appropriate for engineering of soft and hard tissues.
Biomimetic biomaterials
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| Gradient and elastic scaffold to mimic the structure of cardiac muscle. |
In real tissues, cells are surrounded by ECM. Besides providing structural support, ECM plays a significant role in the regulation of tissue growth and development.From this standpoint, soft tissue scaffolds should properly respond to microenvironment like ECM does during tissue development. It is reasonable to expect that an ECM mimicking tissue scaffold will play a significant role in tissue regeneration in vitro as native ECM does in vivo. Three-dimensional scaffold matching the mechanical properties of the tissues that they are replacing are preferred for soft tissue engineering, since such materials might transmit mechanical forces to the developing tissue during in vitro or in vivo development. Scaffold with high elasticity, having molecular and structural similarity as ECM seems to be desirable. Besides, scaffold should also provide biochemical signals that influence cell migration, proliferation, differentiation and functions. Dr. Guan's work aims at development 1) biomimetic elastomeric polymers partially mimic ECM in molecular level and has elasticity and strength suitable for soft tissue reconstruction; 2) biomimetic nano-structured scaffolds to structurally mimic ECM's nanoscale and mechanically mimic mechanical properties of target tissue; 3) bioinspired modification to incorporate appropriate biochemical cues into scaffold; and 4) Biomimetic, injectable and highly flexible hydrogels for repairing tissue defects by minimally invasive surgery.
Cardiovascular tissue engineering
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Highly aligned nanofibrous and elastic scaffold (top) and mesenchymal stem cells microintegrated nanofibrous tissue construct (bottom). |
Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Approximately 57 million North American people suffer from one or more forms of cardiovascular disease and the cost of treatment exceeds $260 billion. There has been an urgent demand for effective treatment options. Tissue engineering provides such a prospect. Dr. Guan's research focuses on the construction of cardiovascular tissues such as cardiac muscle, blood vessel and heart valve with biomimetic biomaterials. Dr. Guan's group is developing a technique that be able to spontaneously assembly cells (primary or stem cells), biomolecules loaded microspheres and biomimetic scaffold under high voltage electrical field to form highly cellularized constructs capable of releasing biomolecules that may guide stem cell differentiation and induce extracellular matrix secretion. Differentcell types could be electrosprayed in sequence into nano-structured biomimetic scaffold fabricated by electrospinning with previously optimized processing parameters. Multi-layered tissue construct could be fabricated by repeating deposition cells into biomimetic scaffold. This approach enables rapidly building highly cellularized tissue constructs. It could largely shorten tissue constructs building time as compare to traditional method, where a porous scaffold is firstly created into which cells are seeded and cultured. The assembled highly cellularized construct could be implanted directly.
Besides cardiovascular tissues, Dr. Guan is also interested in engineering other tissues such as small intestine and bone.
