This 2022 rodent study compared capabilities of intranasal nanoparticle sulforaphane and free sulforaphane to mitigate brain damage caused by a common cancer treatment:

“Non-invasive intranasal (IN) trafficking of therapeutic agents with nanocarriers can enhance efficacy of drug delivery, biodistribution, bioavailability, and absorption against enzymatic degradation and extracellular transportation. Direct IN trafficking of nanocarriers is expected to reduce drug wastage, administration frequency, and undesirable adverse effects.

The nasal route for brain-targeted delivery of sulforaphane (SF) loaded within iron oxide nanoparticles (Fe₃O₄-NPs) was based on improving physicochemical stability of SF, and to enhance its bioavailability by avoiding oral route drawbacks like extensive first-pass metabolism and intestinal drug degradation.

Cisplatin (CIS) significantly induced a significant increase in acetylcholinesterase activities and lipid peroxides, and a significant decrement in glutathione and nitric oxide contents. We aimed to explore the nanotherapeutic potential of intranasally delivered SF loaded within Fe₃O₄-NPs (N.SF) against CIS-induced neurotoxicity through different biochemical, behavioral, and histological investigations.

Treatment with N.SF was more capable of mitigating both CIS-induced striatal and cortical injuries. IN treatment with either SF or N.SF showed equal alleviative potential regarding CIS-induced hippocampal or cerebellar injury.

These encouraging results demonstrated the potential use of iron-oxide NPs as neurotherapeutic agents, and confirmed the possibility of developing a novel promising and non-invasive intranasal delivery system for treatment of CIS-induced neurotoxicity.”

https://link.springer.com/article/10.1007/s12640-022-00555-x “Neuroprotective Potential of Intranasally Delivered Sulforaphane-Loaded Iron Oxide Nanoparticles Against Cisplatin-Induced Neurotoxicity”

I found this study from it citing a paper in Do broccoli sprouts treat migraines?