Current Research
OHC fluorescence image

OHC membrane tether
OHC tether formation

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Electromotility and Membrane Electromechanics

Using a novel instrument that combines optical trapping with voltage clamping and fluorescence imaging, we are studying the electromechanical properties of the cochlear outer hair cells (OHCs) plasma membrane in collaboration with Dr. William Brownell in the Department of Otorhynolaryngology at Baylor College of Medicine, Doctors Aleksander Popel and Alexander Spector in the Department of Biomedical Engineering at Johns Hopkins University, and Dr. Robert Raphael in the Department of Bioengineering. The OHCs are the only known biological materials capable of producing electrically-evoked forces, known as electromotility, over a wide range of frequencies (up to at approximately 50 kHz and possibly higher). Characterizing the electromechanical properties of the OHCs plasma membrane, and understanding the contribution of prestin to electromotility not only has implications for understanding the normal hearing process and strategies for treatment of specific types of hearing loss, but also direct relevance to design and development of membrane (lipid) -based micro/nano-electromechanical devices that could potentially be used for diagnostic and therapeutic purposes.

Portwine stain image

Microcapsules containing ICG
Courtesy of Jie Yu.

Chromophore-encapsulated Nano-Assembled Complexes for Optical Therapy

We are also developing new techniques to improve the efficacy of optical treatment for various types of tissue anomalies. The current therapeutic approach used in clinics relies on the selective absorption of laser irradiation to elicit spatially-confined thermal damage. Through collaborations with Dr. Michael Wong in the Department of Chemical and Biomolecular Engineering, we are investigating the utility of novel microcapsules containing chromophores to serve as exogenously administered optical targets. These capsules allow for the localized delivery of chromophores sensitive to near infrared wavelengths, which penetrate deeper within tissue and are absorbed less by interfering intrinsic chromophores such as melanin.