Labs

Clinical and basic science researchers within the Department of Otolaryngology – Head and Neck Surgery actively contribute to the overall body of knowledge within the field. Patient-oriented investigations and biomedical research are conducted in all subspecialties: otology, rhinology, head and neck, pediatrics, laryngology, and facial plastics. The ultimate goal of this research is to improve patient care through better understanding of a variety of conditions in Otolaryngology – Head and Neck Surgery.

The spiral ganglion (nerves) of the inner ear.
The spiral ganglion (nerves) of the inner ear.

Voice Science and Laryngology Laboratory

Ted Mau M.D., Ph.D. (UTSW Otolaryngology-Head and Neck Surgery)

The Department offers rich opportunities in basic, applied, and clinical research in laryngology and voice science for residents. The Laryngeal Physiology and Biomechanics Laboratory is equipped for investigations of laryngeal tissue mechanics, physiology as well cell biological and acoustic aspects of voice production. The Laryngeal Tissue Engineering Laboratory focuses on biomaterial development for vocal fold tissue.

Ted Mau, M.D., Ph.D., runs a virtual laboratory to develop computational tools in laryngology. Some of the tools have been used to investigate the effect of vocal fold injections on cricoarytenoid joint motion, the 3D conformations of the injected boluses in the larynx, and the electroglottographic signal changes reflecting the voice fluctuations in adductor spasmodic dysphonia. A more recent project aims to create a laryngeal surgery planning tool based on a voice simulator developed at the National Center for Voice and Speech.

In addition to these laboratory-based projects, the UT Southwestern Voice Center has several ongoing clinical studies. These include a randomized prospective trial of the efficacy of stretch-and-flow voice therapy in the treatment of muscle tension dysphonia.

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Cochlear Implant Electrode Array Lab

Kenneth H. Lee, M.D., Ph.D.  (UTSW Otolaryngology-Head and Neck Surgery)
Walter Voit, Ph.D. (Materials Science and Engineering, UT Dallas)

We are developing a novel self-coiling cochlear implant electrode array with the use of Shape Memory Polymers (SMP). These arrays allow for fewer traumas during insertion. The arrays are designed to be straight at room temperature but are activated to coil to match the shape of the turn in scala tympani as it warms to body temperature during insertion. We are coupling insertion with a linear actuator to allow for a controlled robotic insertion at constant velocity that matches the shape re-conformation kinetics of the SMP.

The figure right compares the insertion of a self-coiling SMP implant array which makes minimal to no contact with the cochlear walls during insertion in comparison to standard straight arrays which make substantial contact along the lateral wall of scala tympani during insertion which results in fibrosis and limits implant function.

This work compliments Dr. Lee’s earlier studies concerning growth of inner ear neural fibers associated with BDNF in furthering the utility of cochlear implants. In addition to these laboratory-based projects, Dr. Lee is involved in several ongoing clinical studies.

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Otology Lab

Karen Pawlowski, Ph.D. (UTSW Otolaryngology-Head and Neck Surgery)
Edward Lobarinas, Ph.D, (School of Behavioral and Brain Sciences, UT Dallas)

Otology Lab

Our lab investigates diseases and agents that cause hearing loss. Hearing loss affects about 15 percent of children and young adults in the U.S. and costs the U.S. close to $300,000 per individual adult, primarily in loss of work productivity. Progression of hearing loss in the elderly increases social isolation and may contribute to the progression of dementia. Treatments, such as hearing aids and classroom assistance, can help to minimize effects. However, the development of successful individualized treatments to minimize hearing loss would greatly improve quality of life for the hearing impaired.

Our research focuses on defining the causes of peripheral hearing loss at the cellular level, within the temporal bone; the external, middle, and inner ear. At present, our limited understanding of the specific physiology of loss of function limits hearing treatment outcomes. It is our hope that the information gained through collaboration with colleagues within UT Southwestern (Repa Laboratory), UT Dallas, and beyond will help determine novel clinical measures to improve hearing health.

Our lab is also involved in testing newly formulated antibiotics for ototopical use. These novel antibiotics are designed to target resistant strains of microorganisms commonly associated with otitis media and otitis externa. Without treatment, these infections have the potential to lead to permanent hearing loss as well as systemic infections. Before new formulations can be tested for their effectiveness, they need to be tested to ensure they are safe for use in the ear. We test the formulations in animal models to determine their potential for ototoxic effects.

Hearing loss has been associated with increased plasma lipid levels and corresponding changes in major vessels, leading to the long held assumption that this type of hearing loss is secondary to vascular disease. However, our recent findings have revealed a role for cellular lipid dysregulation within the inner ear tissues themselves, that directly affect inner ear physiology. Given the prevalence of lipid dysregulation within the aging population, it is possible that lipid dysregulation is a factor in age related hearing loss. Our lab in collaboration with the Repa Laboratory is examining mouse models of conditions that cause lipid dysregulation to determine if there is concurrent hearing loss.

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Head and Neck Oncology Nanoparticle Lab

Baran Sumer, M.D. (UTSW Otolaryngology-Head and Neck Surgery)
Jinming Gao, Ph.D. (UTSW Simmons Comprehensive Cancer Center)

Chart
PTN function by (a) Sequestration of fluorescent dye in the hydrophobic core of the micelle formed from pH responsive amphiphilic polymer which dissociates in aqueous solution at the transition pH. In contrast to a molecular pH sensor the fluorescence is binary; all or nothing due to (b) cooperativity based on side chain protonation and noncovalent interaction between the polymer chains and can be tuned to a variety of pH trigger points. (c) The on/off binary behavior is analogous to electronic transistors and allows sharp delineation and a large order of magnitude difference between tumor and background fluorescence (d).

Our primary research interest is in the development of nanoparticles and nanodevices for surgical applications. Some of the primary challenges during cancer ablation surgery are differentiation of cancer from normal tissues, especially in previously treated areas, and detection and destruction of residual microscopic disease.

Recently our lab established pH transistor nanoparticles (PTN) that, in response to pH, show binary off/on behavior, remaining completely dark until exposed to a specific tuned pH where they reach 100 percent fluorescence.

The ultra-pH-sensitive property is a nanoscale phenomenon arising from the self-assembly of amphiphilic copolymers. The PTN display a dramatically sharpened pH response (∆pHoff/on< 0.15 pH, compared to 2 pH units for small molecular pH sensors). Based on inherent ability for these particles to indicate a sharp pH transition, we established a nanoprobe to fluorescently image dysregulated pH, a universal hallmark of cancer.

Critically, the binary all or nothing fluorescence, with no intermediate state, digitizes the analog biological signal or event, pH, allowing amplification without noise or distortion. These PTN have transformed tumor detection but also represent a new paradigm of digitizing an analog biological signal, opening doors to the exciting possibility of other applications in tumor imaging, delivery of therapeutics, and cellular targeting.

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Affiliated Researchers

Roger W. Chan, Ph.D.
Adjunct Associate Professor
Laryngology

Dr. Chan is involved in both basic and applied studies of the human larynx. In particular, his focus is on vocal fold tissue mechanics and biorheology and their relationships with voice acoustics and laryngeal physiology. Another area of emphasis is tissue engineering and regenerative medicine, where various types of extracellular matrix scaffolds are being developed as tissue replacements for surgical applications

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