Alginate-Based Material System for Medical Applications: From Multipurpose Phantom to Chronic Disease Treatment

Phantoms are specialized models designed to mimic the properties of human tissue or body structures for use in various medical and healthcare applications. These phantoms are usually made for single application. For example, calibration phantoms usually contain materials with known density, size, or other physical properties e.g., polyethylene, acrylic, and polycarbonate, which can be used in computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US) to calibrate the imaging equipment, ensure accurate measurements, and detect potential issues or deviations. They are not applicable for utilization in surgery training. Phantoms for surgery training are usually made from soft materials like silicones, utilized for educational and skill development purposes. They replicate anatomical structures and allow medical students and professionals to learn basic surgical techniques, honing advanced skills, and improving the dexterity and coordination. However, these phantoms exhibit limited suitability for hands-on surgical training. Surgical practice inherently involves destructive procedures, thereby precluding the subsequent reutilization of the phantoms. Materials like silicones owing to their resistance to natural degradation processes, exhibit persistence in the environment over an extended period, thereby constraining its applicability in the context of surgical training. These commercial phantoms have relatively high cost, which limits their use, especially in developing countries.<br/><br/>Another type of phantom is the so-called multipurpose phantom, which integrates multiple imaging modalities and allows for surgery practice within a single construct. For example, these phantoms can be measured under CT and US, after which the students or surgeons can be trained to identify the tumor from the CT and US images and then practice removing the tumor. However, the cost of making such phantoms is usually extremely high due to the materials and complicated fabricating process. In this work, we have developed a facile material system based on alginate and vegetable fat for fabricating the multipurpose phantom. The mechanical, US and CT properties of the materials can be tuned independently to achieve the desired properties of the individual organ and tissue within one material system. The used materials are cheap and easy to obtain even in resource-constrained or developing countries. Moreover, they are 100% vegan, food safe and biodegradable, which is highly suitable for surgery practice that is destructive. These advantages also make it the perfect material system for fabricating patient-specific phantoms for difficult surgery planning and practicing.<br/><br/>In addition to the medical phantoms, the alginate-based hydrogel can be further functionalized with nanoparticles for cardiovascular and musculoskeletal disease treatment. By incorporation of nanoparticles, the injectability or printability of the hydrogels can be modified and the release of the bioactive substances can be achieved under controlled conditions.