Thermal evaluation of laser exposures in an in vitro retinal model by microthermal sensing

• Published in: Journal of biomedical optics 2014-09, Vol.19 (9), p.097003-097003
• Main Authors: Choi, Tae Y, Denton, Michael L, Noojin, Gary D, Estlack, Larry E, Shrestha, Ramesh, Rockwell, Benjamin A, Thomas, Robert, Kim, Dongsik
• Format: Article
• Language: English
• Subjects: Beams (radiation); Cell Line; Cell Survival - radiation effects; Damage; Equipment Design; Exposure; Hot Temperature; Humans; Laser beams; Lasers; Models, Biological; Recording; Retinal Pigment Epithelium - cytology; Retinal Pigment Epithelium - radiation effects; Sensors; Signatures; Thermocouples; Thermography - methods
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.JBO.19.9.097003

A temperature detection system using a micropipette thermocouple sensor was developed for use within mammalian cells during laser exposure with an 8.6-μm beam at 532 nm. We have demonstrated the capability of measuring temperatures at a single-cell level in the microscale range by inserting micropipette-based thermal sensors of size ranging from 2 to 4  μm into the membrane of a live retinal pigment epithelium (RPE) cell subjected to a laser beam. We setup the treatment groups of 532-nm laser-irradiated single RPE cell and in situ temperature recordings were made over time. Thermal profiles are given for representative cells experiencing damage resulting from exposures of 0.2 to 2 s. The measured maximum temperature rise for each cell ranges from 39 to 73°C; the RPE cells showed a signature of death for all the cases reported herein. In order to check the cell viability, real-time fluorescence microscopy was used to identify the transition of pigmented RPE cells between viable and damaged states due to laser exposure.