20.500.12556/RUL-184692 Modeling thixotropic hydrogel carriers to limit healthy-tissue exposure via localized drug retention in chemotherapy In this work, we develop a coupled multiphysics model that integrates polymer carriers exhibiting time-dependent thixotropic structural recovery with Darcy flow, linear Biot poroelasticity and advection–diffusion transport in a spherically symmetric, isotropic and homogeneous tissue domain. The formulation explicitly links rheological evolution to pressure-driven flow, interstitial deformation and solute transport through a unified framework, enabling systematic prediction of post-injection behavior. Unlike conventional approaches that assume constant carrier properties, the present model incorporates a time-dependent viscosity evolution, capturing the transition from an initially shear-thinned state to a recovered, highly viscous structure. Numerical simulations using hydroxypropyl methylcellulose and methotrexate parameters as representative components demonstrate that rapid post-injection viscosity recovery suppresses pressure-driven transport and diffusion, thereby enhancing local drug retention near the injection site. A systematic sensitivity analysis identifies the equilibrium viscosity as the dominant parameter controlling spatial localization, whereas tissue mechanical properties exert a comparatively minor influence. An effectiveness metric based on the Kullback–Leibler divergence reveals a tumor-size-dependent trade-off between spatial coverage and retention. The proposed framework thus introduces a predictive tool for analyzing coupled rheological-transport interactions and for the rational design and optimization of thixotropy-enhanced local chemotherapy strategies. coupled multiphysics model thixotropy Biot poroelastic medium Darcy’s law advection - diffusion spherical symmetry hydroxypropyl methylcellulose HPMC methotrexate MTX povezani multifizikalni modeli tiksotropija Biotova poroelastičnost Darcyev zakon mehanika fluidov sferična simetrija hidroksipropil metilceluloza metotreksat true false true Angleški jezik Slovenski jezik Članek v reviji 2026-07-13 09:21:56 2026-07-13 09:22:08 2026-07-14 04:03:08 0000-00-00 00:00:00 2026 0 0 23 str. iss. 14, art. 1704 Vol. 18 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 532.135 2073-4360 10.3390/polym18141704 284508419 Brojan_..._Modeling_thixotropic....pdf Brojan_..._Modeling_thixotropic....pdf 1 34C90C6A96CC43EAAFC227CB602F82F9 e210cdff3306f1b580c7541220d9b3a655a6e0f5875119b299dd9211e741cba9 c97d5bb8-7e8b-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=237642 https://www.mdpi.com/2073-4360/18/14/1704 1 667cf4bb-7e8b-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=237641 Fakulteta za strojništvo 0 0 0