About Us

Meet the PI

Baran Sumer, M.D.
Baran Sumer, M.D.

I am a full-time clinician scientist faculty member in the Department of Otolaryngology. I have extensive experience with transoral resection using transoral laser microsurgery and transoral robotic surgery, having performed hundreds of these minimally invasive procedures for head and neck cancer. In addition to head and neck cancer, we treat a variety of advanced skin cancers in the head and neck region, including squamous and basal cell cancers and melanoma.  I have performed hundreds of resections and reconstructions for these cutaneous malignancies. Some of the primary challenges, during these operations, are delineation of cancer from normal tissues, especially in previously treated areas, and detection and destruction of residual microscopic disease.

My research began with an interest in solving surgical problems using nanoprobes. Initially in my collaboration with Jinming Gao, we explored various nanoprobe designs, including probes with unusual shapes to help increase circulation half-life. Very quickly our work evolved to traditional polymeric micelles and we applied them to improve an existing technology underutilized in cancer therapy; photodynamic therapy (PDT). PDT while elegant has several shortcomings such as low log kill rates, lack of efficacy in hypoxic environments, lack of tissue penetration with activating light and systemic phototoxicity. Combining surgery with micelles for delivery of novel PDT dyes, we were able to sequester and quench the dye in the core of the nanoprobes. This theoretically will eliminate systemic phototoxicity since this is due to circulating active dye. Furthermore, the micelles would concentrate the dye in the tumor bed, due to the EPR effect. Finally, we overcame the light penetration problem by combining PDT with surgical excision. We would use PDT as adjuvant therapy after the macroscopic tumor had been removed to treat the tumor bed for residual disease.  This leveraged the strength of surgery (high log kill) with the strength of PDT (diffuse killing of residual microscopic disease) to augment the efficacy of both. With the invention of pH sensitive polymers, we were further able to show that the pH sensitive polymers acting as electron donors could overcome the limitation of hypoxia for PDT and allow good generation of reactive oxygen species, even in relatively low oxygen environments.