Tapered Optical-Fiber Sensor for Label-Free Detection of Head and Neck Cancer Biomarkers in Saliva

Sunday, September 29, 2024

10:24 AM – 10:30 AM EDT

Location: MBCC, 208

Disclosure(s):

Jonathan D. West, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Casey A. Collet, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Tapered optical fiber sensors (TOFS) are an emerging technology for biosensing with high sensitivity. Cytokine IL-8 promotes tumorigenicity, metastasis, angiogenesis, and epithelial–mesenchymal transition (EMT) in head and neck squamous cell carcinoma (HNSCC). Salivary IL-8 has been used for early detection of HNSCC. Our goal is to use TOFS to detect IL-8 dissolved in artificial saliva as a proof of concept for point of care HNSCC diagnostic testing.

Methods: Feasibility study investigating the use of TOFS to detect IL-8 in saliva. The TOFS system contains four main parts: tapered optical fiber, reservoir (cell), laser light source, and detector. The fiber is tapered with a narrow waist region which harbors antibodies. To detect biomolecules, analytes (target biomolecules) are transported around the fiber in an aqueous solution and introduced to the waist region via the cell where antigen-antibody binding occurs. This binding alters the effective refractive index to quantify the wavelength’s phase change and measures the target biomolecule. The amplitude and phase of each signal is analyzed by Fourier analysis. The phase shift can be calculated to measure the change in the optical fiber waist and verify molecule detection. We exposed 100 pg/mL of IL-8 dissolved in PBS at 170 – 190 and 240 – 290 minutes.

Results: We conducted 65 trials using TOFS to detect IL8 antigens at three different concentrations dispersed in artificial saliva. The duration of laser warm-up phase was 1 hour. Noise in our system was 0.007 radians. Tethering of IgG (28 nm) and the binding of IL-8 (14 nm) to the tethered mouse anti-human IL8 IgG antibody both produced measurable phase shift. We detected as little as 10pg/ml or 7.1x105 IL8 molecule/l saliva. By comparison, salivary IL-8 concentration of a healthy person is 300 – 500 pg/mL and 1700 – 2500 pg/mL in HNSCC patients.

Conclusions: TOFS device is a highly sensitive biosensing system capable of detecting cytokine IL-8 in saliva at clinically relevant concentrations. This technology has the potential for application as a point-of-care device for detection, monitoring, and surveillance of HNSCC.

Presenting Author(s)

Jonathan D. West, MD

Resident
USC Caruso Department of Otolaryngology - Head and Neck Surgery
Los Angeles, CA, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Senior Author(s)

US

Uttam Sinha, MD

USC Caruso Department of Otolaryngology - Head and Neck Surgery, United States

Disclosure information not submitted.

Co-Author(s)

DL

Dechen Lin, PhD

Assistant Professor
Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry of USC
Los Angeles, California, United States

Disclosure information not submitted.
Casey A. Collet, MD

Resident
Keck School of Medicine of USC
Los Angeles, CA, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
CD

Cong Deng, PhD

Research Scientist
Department of Electro-Optics and Photonics, University of Dayton, United States

Disclosure information not submitted.
CR

Chaminda Ranathunga, PhD

Graduate Student
University of Dayton, United States

Disclosure information not submitted.
PB

Partha Banerjee, PhD

Professor
Department of Electro-Optics and Photonics, University of Dayton, United States

Disclosure information not submitted.