Establishment of a biophysical model to optimize endoscopic targeting of magnetic nanoparticles for cancer treatment

Anjali A Roeth,1,* Ioana Slabu,2,* Martin Baumann,2 Patrick H Alizai,1 Maximilian Schmeding,1 Gernot Guentherodt,3 Thomas Schmitz-Rode,2 Ulf P Neumann1 1Department of General, Visceral and Transplant Surgery, University Hospital RWTH Aachen, 2Institute of Applied Medical Engineering, Helmholtz-Institute Aachen, RWTH Aachen, Aachen, 3Institute of Physics A, RWTH Aachen University, Aachen, Germany *These authors contributed equally to this work Abstract: Superparamagnetic iron oxide nanoparticles (SPION) may be used for local tumor treatment by coupling them to a drug and accumulating them locally with magnetic field traps, that is, a combination of permanent magnets and coils. Thereafter, an alternating magnetic field generates heat which may be used to release the thermosensitively bound drug and for hyperthermia. Until today, only superficial tumors can be treated with this method. Our aim was to transfer this method into an endoscopic setting to also reach the majority of tumors located inside the body. To find the ideal endoscopic magnetic field trap, which accumulates the most SPION, we first developed a biophysical model considering anatomical as well as physical conditions. Entities of choice were esophageal and prostate cancer. The magnetic susceptibilities of different porcine and rat tissues were measured with a superconducting quantum interference device. All tissues showed diamagnetic behavior. The evaluation of clinical data (computed tomography scan, endosonography, surgical reports, pathological evaluation) of patients gave insight into the topographical relationship between the tumor and its surroundings. Both were used to establish the biophysical model of the tumors and their surroundings, closely mirroring the clinical situation, in which we could virtually design, place and evaluate different electromagnetic coil configurations to find optimized magnetic field traps for each tumor entity. By simulation, we could show that the efficiency of the magnetic field traps can be enhanced by 38-fold for prostate and 8-fold for esophageal cancer. Therefore, our approach of endoscopic targeting is an improvement of the magnetic drug-targeting setups for SPION tumor therapy as it holds the possibility of reaching tumors inside the body in a minimal-invasive way. Future animal experiments must prove these findings in vivo. Keywords: drug targeting, simulation, SPION, prostate cancer, esophageal cance

Political dimensions of gender inclusive writing in Parisian universities

Écriture inclusive (EI) has long been the topic of public debates in France. These debates have become more intense in recent years, often focusing on the higher education system and culminating in the formulation of three separate laws banning it for public administration. In this paper, we investigate the foundations of these conflicts through a large quantitative corpus study of the (non)use of EI in Parisian undergraduate brochures. Our results suggest that Parisian university professors use EI not only to ensure gender neutral reference but also as a tool to construct their political identities. We show that both the use of EI and its particular forms are conditioned by how brochure writers position themselves on non gender‐related‐related issues within the French university's political landscape, which explains how conflicts surrounding a linguistic practice have become understood as conflicts about larger issues in French society. Our paper thus provides new information to be taken into account in the formulation and promotion of nonsexist language policies and sheds light on how feminist linguistic activism and its opposition are deeply intertwined with other kinds of social activism in present‐day France