Performance of a contact textile-based light diffuser for photodynamic therapy

Khan, Tania; Unternährer, Merthan; Buchholz, Julia; Kaser-Hotz, Barbara; Selm, Bärbel; Rothmaier, Markus; Walt, Heinrich

doi:10.1016/S1572-1000(05)00182-1

« Previous Next »Photodiagnosis and Photodynamic Therapy
Volume 3, Issue 1 , Pages 51-60, March 2006

Performance of a contact textile-based light diffuser for photodynamic therapy

Tania Khan
- Research Division of Gynecology, Department of OB/GYN, University Hospital, Zürich CH-8091, Switzerland
Merthan Unternährer
- Research Division of Gynecology, Department of OB/GYN, University Hospital, Zürich CH-8091, Switzerland
- Institute for Biomedical Engineering, ETH Zürich CH-8092, Switzerland
Julia Buchholz
- Research Division of Gynecology, Department of OB/GYN, University Hospital, Zürich CH-8091, Switzerland
- Section of Diagnostic Imaging and Radiation Oncology, VETSUISSE faculty, University of Zürich, Zürich CH-8057, Switzerland
Barbara Kaser-Hotz
- Section of Diagnostic Imaging and Radiation Oncology, VETSUISSE faculty, University of Zürich, Zürich CH-8057, Switzerland
Bärbel Selm
- Empa - Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Protection and Physiology, St. Gallen CH-9014, Switzerland
Markus Rothmaier
- Empa - Swiss Federal Laboratories for Materials Testing and Research, Laboratory for Protection and Physiology, St. Gallen CH-9014, Switzerland
Heinrich Walt, PhD
- Research Division of Gynecology, Department of OB/GYN, University Hospital, Zürich CH-8091, Switzerland
- Corresponding author. Tel.: +41 1 255 5372; fax: +41 1 255 4553.

published online 08 February 2006.

Summary

Background

Medical textiles offer a unique contact opportunity that could provide value-added comfort, reliability, and safety for light or laser-based applications. We investigated a luminous textile diffuser for use in photodynamic therapy.

Methods

Textile diffusers are produced by an embroidery process. Plastic optical fibers are bent and sewn into textile to release light by macrobending. A reflective backing is incorporated to improve surface homogeneity, intensity, and safety. Clonogenic assay (MCF-7 cells) and trypan blue exclusion (NuTu19 cells) tests were performed in vitro using 0.1μg/ml m-THPC with three textile diffusers and a standard front lens diffuser. Heating effects were studied in solution and on human skin. PDT application in vivo was performed with the textile diffuser on equine sarcoids (three animals, 50mW/cm², 10–20J) and eight research animals. Lastly, computer simulations were performed to see how the textile diffuser might work on a curved object.

Results

At low fluency rate, there is a trend for the textile diffuser to have lower survival rates than the front lens diffuser for both cell lines. The textile diffuser was observed to retain more heat over a long period (>1min). All animals tolerated the treatments well and showed similar initial reactions. The simulations showed a likely focusing effect in a curved geometry.

Conclusions

The initial feasibility and application using a textile-based optical diffuser has been demonstrated. Possibilities that provide additional practical advantages of the textile diffuser are discussed.

Keywords: Photodynamic therapy, Tissue optics, Uniform irradiation, Luminous textile, Flexible light application, Photomedicine, Plastic optical fiber