TONG, Yen Wah
	Assistant Professor
	PhD (Chem. Eng.) Toronto, 2000 BSc (Eng. Chem.) Queen's 1995
	Contact information Blk E5, 4 Engineering Drive 4, #03-15, Singapore 117576 Tel: (65) 6516 8467   Fax: (65) 6779 1936 Email: chetyw@nus.edu.sg
	My research team

RESEARCH

Designing of Polymer Surfaces for Controlling Cell-Material Interaction Surfaces play an important role in the development of a suitable scaffold for tissue engineering. Surface chemical and physical properties have been known to affect cell attachment, differentiation and function. Grafting of low-molecular weight poly(ethylene glycol) onto a polymer can effectively prevent cell and protein adhesion, while attaching peptides and extracellular matrix molecules can enhance cell adhesion. The effects of these factors on in vitro cultured liver cells will be studied.

Tissue Engineering Scaffold via Microspheres The current concept of tissue engineering uses a three-dimensional construct or scaffold as support for cell attachment in growing an organ in vitro. Porous polymeric cubes, layered interwovenfibers, rolled-up films, and hollow tubes are among the scaffolds being studied. However, there are limitations to current designs such as cell seeding, necrosis and vascularization. The maximum thickness of tissue obtained has been no larger than 10 mm. The research work will use a novel system of drug encapsulated microspheres as a support scaffold to tissue engineer a complete functional liver.

Synthesis of Novel Biodegradable Polymers as Biomaterials The majority of polymers that are in use today for biomedical applications are based on polylactide and polyglyoclide. While these have the necessary degradation and physical properties for use as sutures and drug delivery, they invoke a slight inflammatory response by the immune system. The synthesis of a new polymers derived from the extracellular matrix of the body can eliminate the negative immune response and increase the host acceptance.

Molecularly Imprinted Polymeric Nanoparticles for Bioseparations The use of molecular imprinting, where specific recognition of molecules based on shape, has been successfully used for the separation of small molecules. However for biological molecules such as proteins, separation is still a major issue. Using nanoparticles together with molecular imprinting can solve diffusion and rebinding problems. Polymeric nanospheres with surface imprinting has been shown to have specific protein recognition.

SELECTED PUBLICATIONS

Y. Liang, T.W. Jensen, E.J. Roy, C. Cha, R.J. DeVolder, R.E. Kohman, B.Z. Zhang, K.B. Textor, L.A. Rund, L.B. Schook, Y.W. Tong, and H. Kong, “Tuning the non-equilibrium state of a drug-encapsulated super stiff poly(ethylene glycol) hydrogel for stem and progenitor cell mobilization”, Biomaterials, 32 (7), 2004-2012 (2011). S.T. Khew, P.P. Panengad, M. Raghunath, and Y.W. Tong, “Characterization Of Amine Donor And Acceptor Sites For Tissue Type Transglutaminase Using A Sequence From The C-Terminus Of Human Fibrillin-1 And The N-Terminus Of Osteonectin”, Biomaterials, 31 (16), 4600-4608 (2010). N. Wiradhama, Y.W. Tong, and Y.Y. Yang, “Self-assembled oligopeptide nanostructures for co-delivery of drug and gene with synergistic therapeutic effect”, Biomaterials, 30 (17), 3100-3109 (2009). X.H. Zhu, Y. Tabata, C.H. Wang, and Y.W. Tong, “Delivery of basic fibroblast growth factor from gelatin microsphere scaffold for the growth of human umbilical vein endothelial cells”, Tissue Eng. A, 14 (12), 1939-1947 (2008). N. Wiradharma, M. Khan, Y.W. Tong, S. Wang, and Y.Y. Yang, “Self-assembled cationic peptide nanoparticles capable of inducing efficient gene expression in vitro”, Adv. Func. Mater., 18 (6), 943-951 (2008). C.J. Tan, H.G. Chua, K.H. Ker and Y.W. Tong+, “Preparation of bovine serum albumin surface-imprinted submicron particles with magnetic susceptibility through core-shell miniemulsion polymerization”, Anal. Chem., 80 (3), 683-692 (2008). C.J. Tan, S. Wangrangsimakul, R. Bai and Y.W. Tong, “Defining the interactions between proteins and surfactants for nanoparticle surface imprinting through miniemulsion polymerization”, Chem. Mater., 20 (1), 118-127 (2008). S.T. Khew and Y.W. Tong, “The specific recognition of a cell binding sequence derived from Type I collagen by Hep3B and L929 cells”, Biomacromolecules, 8 (10), 3153-3161 (2007). S.Q. Liu, N. Wiradharma, S.J. Gao, Y.W. Tong, and Y.Y. Yang, “Bio-functional micelles self-assembled from a folate-conjugated block copolymer for targeted intracellular delivery of anticancer drugs”, Biomaterials, 28 (7), 1423-1433 (2007). H.K. Chng, I. Islam, A.U.J. Yap, Y.W. Tong, and E.T. Koh, “Properties of a new root-end filling material”, J. Endodont., 31 (9), 665-668 (2005).