I don't know much about the MDR, but I've been working with nanomaterials for a couple of decades...
They used to be call "sub-micron"...but "Nanoparticle" was sexier and got much more government funding.
I'm in ceramic processing, and ceramic strength increases (typically) with smaller grains.
Alumina (Al2O3) goes translucent...almost transparent...when the grains are small enough (or large enough)...read "great armored windows".
And thermal shock resistance improves (read torch nozzles and blast furnace ladles and crucibles).
Finer and finer ceramic particles also mean lower firing temperature...read "I can make an Al2O3 and gold integrated circuit, instead of having to use platinum which costs more.
Catalysis (read catalytic converter, gas sensing, vapor sensing, explosives residue detection at the airport, etc.) works by exposed surface...finer particle = more surface...
There are hundreds of ceramic nanoparticles (Al2O3, ZrO2, fume silica for dessicants, TiO2 for paint opacifiers, paper coatings to render higher quality images (less ink bleed), holograms printed onto
beer bottles and windows, transparent solar cells (nano-silver particles to harvest power, but so fine you can't see them), etc.
Again, I don't know much about MDR...but these are the tip of the iceberg when it comes to nanoparticles currently market available.
Sumitomo Specialty Chemicals alpha alumina is available with particle sizes down to 30nm. Makes a nice smooth fired surface for magnetic recording media...or as a catalyst support for hydrogen separation...
HTH...I do not work for Sumitomo...