Polymeric cryogels: an experimental and modeling integrated approach for biomedical and chromatographic applications

This thesis reports an integrated experimental and theoretical study on porous polymeric systems, concerning optimization for biomedical applications and modeling as possible stationary phases in chromatographic processes. The research covers two main areas: the first encompasses synthesis, characterization, and modeling of dextran-based cryogels for controlled drug delivery and tissue engineering, while the second is devoted to computational modeling of triply periodic geometries aimed at the design of e!ective chromatographic columns. The methacrylic derivatives of dextran were synthesized and systematically studied in the experimental section in order to define the window of formation of cryogel-like systems. The influence of polymer concentration, reagent ratio, and the presence of oxygen was investigated, highlighting the key role played by these parameters in determining crosslinking kinetics, porosity, and mechanical properties. By physical, structural and morphological analyses, the ranges of parameters allowing attainment of stable, highly interconnected macroporous networks were identified. Afterwards, the study was extended to the assessment of the effects exerted by polymer molecular weight and spacer length on swelling behavior, degradation rate, and mechanical response. Dextran-based cryogels were also tested as drug delivery systems employing vitamin B12 as model drug molecule: it has been proven that the loading method drastically a!ects the release mechanism. A mechanistic two-phase model was developed, able to successfully describe the transition between Fickian and non-Fickian release behaviors. To enhance biological performances, blended cryogels containing methacryol gelatin were prepared. The preparation method effectively combines structural robustness due to dextran derivatives with bioactivity from gelatin. Preliminary cellular adhesion and proliferation tests confirmed the potential of these systems as biocompatible scaffolds. On the theoretical side, a modified Mechano-Diffusion model was formulated to describe the swelling mechanics of cryogels, introducing porosity and polymer volume fraction to better represent the macroporous nature of the material. Finally, a computational study was carried out on chromatographic stationary phases modeled as triply periodic minimal surface (TPMS) structures. By employing the Two-Zone Moment Analysis, the hydrodynamic dispersion and kinetic performance of di!erent geometries were analyzed, identifying gyroid- and diamond-type structures as the most promising for high efficiency separations and feasible for advanced 3D printing fabrication. Overall, the approach presented here covers everything from material design to experimental characterization and theoretical modeling, thereby contributing to the further development of cryogel-based systems for bio-applications and providing significant insight into the principles of developing novel chromatographic media.