Composite hydrogels as tissue

Medical phantoms gain considerable attention in last decades when improving the educational process towards better outcomes or testing the possibilities and limits of existing and newly appearing medical diagnostic modalities. On the market there are a number of physical phantoms for equipment calibrations and some anthropomorphic phantoms used for educational purposes and dose measurements. The common feature for all phantoms is to mimic specific physical characteristics of the real biological tissues, chosen depending on the particular application. Commercial phantoms are important and they are well suited for standard tests but they fail when more specific investigations are required. Therefore, the development of materials for case-specific medical phantoms is necessary. This specificity requires easy and eco-friendly design with a simple route to modify and tune the final properties. Such are for instance gelatin-based composite hydrogels. In the present study we report the design of gelatin hydrogels with several additives (collagen and baking soda, psyllium husk and glass microbubbles). Their potential as tissue mimicking materials in diagnostic imaging is discussed by comparing their Hounsfield units with such for real biological tissues. The results show that such materials cover the range from soft tissues to some bones. The mechanical performance was also monitored, so that the hydrogels can be successfully mechanically manipulated during usage. The observed properties and their differences are discussed with respect to their morphology, as revealed by scanning electron microscopy. Acknowledgement: This work was supported by the Ministry of Education and Science of Bulgaria (MESB), through the National Research Fund of Bulgaria (research project ”Liquid crystal nanocomposites for applications in photonics, sensors and biomedicine“, No. KP 06 N58/6/2021). 1. V. Georgieva, N. Traikova, G. Exner (2024) Low-budget gelatine-based hydrogels for computed tomography tissue mimicking phantom materials, Rentgenologiya i radiologiya, LХIII(4), 221-227 2. V. Georgieva, G. Tankovski, N. Traikova, G. Exner (2025) Еffect of different fillers on hydrogels for application as tissue-substitute materials in Computed tomography, J. Phys. Conf. Ser., 2952, 012014, doi:10.1088/1742-6596/2952/1/012014 3. G. Tankovski, V. Georgieva, N. Traikova, G. Exner (2025) Engineering the mechanical and X- ray attenuation properties of gelatine composite hydrogels with a potential for tissue mimicking materials, J. Phys. Conf. Ser., 2952, 012015, doi:10.1088/1742- 6596/2952/1/012015