Scientists develop lab-scale laser device for treatments based on optical hyperthermia applications

Researchers from Universidad Politécnica de Madrid, in collaboration with Universitat Politécnica de Valencia and CIBER's Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), have designed a laser device specifically designed for optical hyperthermia applications.

A joint research project of Universidad Politécnica de Madrid (UPM), Universitat Politécnica de Valencia (UPV) and CIBER's Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) has developed a low cost lab-scale device for treatments based on optical hyperthermia applications through laser. This technique is used, for instance, in therapies against skin cancer and it aims to kill the tumor cells by overheating them. This research work has been published in Sensors and Actuators A Physical journal.

According to the researchers, overheating is achieved by irradiating synthesized metallic nanoparticles. "When receiving radiation, the particles heat the tumor tissue reaching a temperature between 42 °C and 48 °C, by maintaining such temperature we can cause a hypoxia that leads to a cellular death" explains Roberto Montes, a researcher from UPV.

The prototype developed by both UPM and UPV researchers consists of an infrared laser with a power up to 500mW able to provide a power density up to 4W/cm2, a sensor that records the temperature in real time during the irradiation and a laser power regulator, among other components.

However, if the laser is applied on tissues that were previously impregnated with gold nanoparticles (Au-NPs), which is the case of this study by Andy Hernández y Cristina Latorre, we achieve a located overheating. This presents a great advantage facing other techniques that are not able to distinguish between healthy tissues and damage tissues", says Roberto Montes.

This work shows the keys to elaborate a device for a low cost optical hyperthermia technique. The main innovation compared to other marketed equipments lies on it has all the needed elements for the experimental phase, controlling as many variables as possible. "When designing the prototype, we payed attention to the smallest details, such the control of temperature at the cabin, since it is essential to carry out a good work" adds Javier Ibáñez from UPV.

According to the researchers, there are diverse laser applicators in the market used in dermatology and even surgery. At certain power and wavelengths, the laser energy is converted into heat and produces ablation (burn). The new system does not aim to "burn" the cells with the adjacent inflammation that this causes, but to introduce nanoheaters into such cells that when excited by the laser, they increase their temperature between 42 °C and 48 °C, resulting in hypoxia leading the cells to a "natural" death".

This equipment is already being successfully used in vitro cellular crops and in therapies that combine hyperthermia with the controlled release of drugs. "Although the equipment has been designed to exclusively work in a lab environment, once the technique is developed, it could be easily applied to a hospital environment with small changes." Of course, we are in an initial phase, there is much to do for its clinical usage: animal tissue testing, later testing on living animals, and finally to verify its application in patients", add Javier Ibáñez.​