Hydrodenticity to enhance relaxivity of gadolinium-DTPA within crosslinked hyaluronic acid nanoparticles

The efficacy of gadolinium (Gd) chelates as contrast agents for magnetic resonance imaging remains limited owing to poor relaxivity and toxic effects. Here, the effect of the hydration of the hydrogel structure on the relaxometric properties of Gd-DTPA is explained for the first time and called Hydrodenticity. Results: The ability to tune the hydrogel structure is proved through a microfluidic flow-focusing approach able to produce crosslinked hyaluronic acid nanoparticles, analyzed regarding the crosslink density and mesh size, and connected to the characteristic correlation times of the Gd-DTPA. Conclusion: Hydrodenticity explains the boosting (12-times) of the Gd-DTPA relaxivity by tuning hydrogel structural parameters, potentially enabling the reduction of the administration dosage as approved for clinical use.