Sierin LimView all speakers
Sierin Lim obtained both her B.S. and Ph.D. degrees from University of California, Los Angeles (UCLA) in Chemical Engineering and Biomedical Engineering, respectively. She joined Nanyang Technological University as Assistant Professor in the School of Chemical and Biomedical Engineering at the end of July 2007 after a 2.5-year postdoctoral research at University of California, Irvine (UCI).
Dr. Lim’s research focuses on the design, engineering, and development of hybrid nano/microscale devices from biological parts by utilizing protein engineering as a tool. Her main interests are in self-assembling protein-derived nanocapsules and photosynthetic biological materials. The project scopes range from understanding the self-assembly mechanism of the nanocapsules to their applications as theranostic carriers and nanoparticle synthesis template to improvement of electron transfer efficiency in a photosynthetic electrochemical cell.
Synthesis of monodispersed nanoparticles that are free from aggregation is particularly challenging using chemical methods. E. coli has been engineered to synthesize iron nanoparticle by increasing the metal intracellular sequestration and production of protein cage as the biological template. The protein cages are formed by self-assembly of multiple subunits forming highly uniform hollow spherical cage structures of nanometer size. Expression of both the FeoB iron transporter and ferritin under inducible promoter results in the production of approximately 10 mg of protein cage/liter of culture; loaded with up to 200 Fe/cage forming an iron core of ~8 nm. This loading can be optimized in vitro with the highest loading observed at 7000 Fe/cage. Besides serving as template, the protein cages have been shown to assist the solubilization and prevent the aggregation of the nanoparticle. Further modifications of the protein cages allow tailoring of its function as carriers for therapeutic and diagnostic agents. Due to their proteinaceous nature, the protein cages allow facile modifications on its internal and external surfaces, as well as the subunit interfaces. Modifications on the internal and the external surfaces allow conjugation of small molecule drugs or contrast agent and targeting ligands, respectively. The subunit interaction is of special interest in engineering triggered release property onto the protein cage. Applications of these protein cages as molecular carrier with triggered release capability will also be described.