A Microscope That “Hears” Cancer Cells: The Photoacoustic Microscope

A “Photoacoustic Microscope” developed at Boğaziçi University by completely native technology combines light and sound to facilitate the detection of cancer cells.  Associate Professor Burçin Ünlü of Boğaziçi University Physics Department stated that they were also working on a new cancer treatment procedure where protons replace X-rays in radiotherapy so as to reduce damage to healthy cells.  Burçin Ünlü and his team have achieved remarkable advances in the field of early detection of cancer using the new technology developed at BU, the first of its kind in Turkey.

A physicist from Boğaziçi University develops a microscope that converts light to sound

In developing countries like Turkey, most of the R&D investment and research regarding health problems focus on cancer and cardiovascular diseases.  According to World Health Organization (WHO) data, the world population is aging at a rapid pace.  Therefore, the rate of diseases that commonly afflict the elderly, namely diabetes, joint diseases, cancer and cardiovascular diseases, have significantly increased.

Associate Prof. Burçin Ünlü underlined the role of Physics in the diagnosis and treatment of those diseases.  Ünlü and his team are developing new imaging systems that will constitute a turning point particularly in the diagnosis and treatment of cancer.

Ünlü pointed out that early diagnosis of cancer saves lives.  “We observe a decrease in deaths caused by breast cancer in recent years,” Ünlü stated, “because there have been some advances in early diagnosis procedures in breast cancer.  Particularly at the detection/diagnosis stage of these diseases, contributions of physicists are gaining in importance.   For example, within an institution like CERN there are teams working on the physics of diseases, focusing on developing medical devices for detection and diagnosis.”

The Photoacoustic Microscope was developed by Burçin Ünlü, a leading researcher in the fields of medical biophysics and bio-imaging, and his team including Boğaziçi University PhD students Esra Aytaç, Aytaç Demirkıran, and Nazire Uluç. The project is supported by BAP (Scientific Research Projects) and TUBITAK (The Scientific and Technological Research Council of Turkey).  The device will lead to significant developments in the detection and early diagnosis of cancerous tissues and cells.

A microscope that “hears” cancer cells has been developed at Boğaziçi University

Burçin Ünlü explained how the photoacoustic microscopy mechanism worked:  “We wince when we are pinched.  In this study, we touch or pinch biological tissue, that is, both normal and cancerous cells; in a way, we make those cells scream.  As you know, the human ear hears normal sounds as a frequency but it is impossible for us to hear the sound of cells or tissues.  So we developed a special microscope to allow us to hear the sound of a tissue.  The microscope we developed is equipped with a short pulse laser that transmits energy.  The short laser pulse directed to a tissue generates heat and the tissue expands, creating a sound frequency.  We aim to hear the sounds of cancerous and noncancerous cells by means of this sound frequency and be able to differentiate them from each other.”

The leading technology developed at BU will be published in Science Reports

Ünlü stated that theirs was the first and only team to develop the technology they used to build a microscope that combines lights and sound: the Photoacoustic Microscope. Ünlü and his team are currently working with doctors from Cerrahpaşa School of Medicine; their work on this technology is to be published in Nature – Scientific Reports shortly. 

“The technology underlying the development of this microscope is not used in Turkey at present,” said Ünlü, “although it has been advancing very rapidly in the world in the last 10-15 years.   We are trying to create sound waves on the tissue by increasing the heat by means of a laser beam.  To put it another way, we are converting light to sound.  The light you send to the tissue cannot travel through it in a straight line; it disperses.  But sound waves can travel longer distances through the tissue. Therefore, by using sound waves, our microscope can achieve deeper penetration.  Besides, using sound waves also eliminates the need for coloring or marking.  We are the first and only team working on this procedure in Turkey; we are using special lasers that nobody else in the world uses.  Working together with a team from Bilkent University, we have developed a completely national photoacoustics technology using fiber laser.”

Protons instead of X-rays in radiotherapy

Ünlü and his team have started working on a technology similar to the one they employed in photoacoustic microscopy, which they will apply to a new radiotherapy procedure.  The current radiotherapy procedures use X-rays; the new treatment procedure will send protons to cancerous cells instead of X-rays, thereby protecting healthy cells from damage. This system is being used on patients in about 50 health medical centers around the world.  In this project, the team will benefit from acoustic imaging technology to find out how protons affect cancerous tissue.

Ünlü explained that they would collaborate with the medical school of one of the leading research universities in the world in their next project, which is aimed at developing an imaging device equipped with this technology.

Optimal timing of cancer medication

Within the context of their studies focusing on cancer, Burçin Ünlü and his team including doctoral students Şirin Yonucu and Defne Yılmaz are conducting a collaborative project with the University of Waterloo in Canada.  The project involves research on the timing of cancer medication.  Ünlü stated that by optimizing the timing of cancer medication, they aim to help doctors with respect to the best treatment.

Burçin Ünlü’s team is comprised of BU Masters and PhD degree students Esra Aytaç, Aytaç Demirkıran, Nasire Uluç, Şirin Yonucu, Defne Yılmaz, İrem Demirkan, Ayşegül Tümer, Mert Tüzer, Çağrı Şenel, Serhat Kaya, Canberk Şanlı, and Alican Kartal.