The Project

The BIOTRACK project aims to deeply investigate lithium fluoride (LiF) capabilities, both in the simple and functionalized crystal forms, as potential Fluorescent Nuclear Track Detector (FNTD) in radiobiological experiments with proton beam irradiation.

The peculiar features of LiF, an alkali halide well known for its applications as active laser medium and thermoluminescent dosimeter, make it sensitive to different ionizing radiations (electrons, X-rays, gamma rays, protons and heavy ions) inducing the formation of photoluminescent defects in the material, known as colour centres. When excited with blue light, these centres emit visible light with no need of post-irradiation development or treatment. Exploiting the really high spatial resolution of the detectors based on LiF crystals, FNTDs will be developed for application in radiobiology. Compared to currently used passive solid-state detectors, LiF crystals provide higher spatial resolution, allowing for more accurate dose measurements. Knowing the spatial distribution and the average dose locally delivered to tissues is crucial to evaluate the damage induced by the radiations employed in hadrontherapy.

The rising demand of innovative solutions to interface technological devices with biological systems requires to develop biocompatible detectors. Obtaining information on the energy deposited at the single cell level and about the physical parameters of the radiation beam is imperative for directly correlating the measured radiation with the cell response. To achieve this, the track detectors based on LiF will be functionalized with thin films of microgels (micro and nano-sized hydrogel particles) of poly(N-isopropylacrylamide) (PNIPAM). PNIPAM is indeed one of the mostly used polymers as substrate for cell cultures, thanks to the possibility to control its hydrophilic-to-hydrophobic transition by temperature changes in a range that is typical of physiological processes. Thanks to these features, thin films of microgel particles based on PNIPAM can be obtained with controlled thickness, roughness and hydrophobicity, allowing for LiF-based FNTDs functionalization. In this way, we aim to obtain innovative biocompatible detectors able to combine the high spatial resolution of LiF with the PNIPAM versatility, to fulfil the radiobiology requirements with low cost and totally sustainable solutions of potential interest for industries operating in the field.

Experimental activities qualifying the BIOTRACK project will be targeted to achieve two specific objectives:

1. Development of fluorescent nuclear track detectors based on lithium fluoride (LiF) for dosimetry and radiobiological experiments
2. Development of biocompatible hybrid (LiF-microgel) detectors of fluorescent tracks for radiobiological experiments on cell cultures.