A tuneable diatom biosilica interface for protein corona control and preferential plasma protein adsorption

A biomaterial contacting blood is coated by plasma proteins to form a protein corona, which dictates the biological response rather than the pristine surface. This corona balances clearance-promoting opsonins against stealth-promoting dysopsonins, and the surface properties that set this balance also determine which proteins accumulate at the interface. A single tuneable surface can therefore shape the corona the immune system reads while accumulating certain proteins through preferential adsorption. Here we profile the plasma corona of diatom biosilica, a renewable, hierarchically porous, and readily silanised platform, using centric Cyclotella striata TBI and pennate Navicula salinicola NLA, each functionalised with amine (APTES) or alkyl (OTS) groups. FTIR, elemental analysis, zeta potential, and contact angle measurements confirmed grafting and charge reversal, with the porous architecture largely preserved. The corona was resolved by label-free proteomics across twelve corona conditions, yielding 143 quantifiable proteins, and dissected by unsupervised clustering, statistical analyses, and biophysical property mapping that linked selectivity to surface properties. The corona separated into strongly and weakly bound fractions, with apolipoprotein dysopsonins held in the strongly bound corona, while albumin partitioned more towards the weakly bound fraction. Surface chemistry then tuned the selectivity, as the amine-bearing surface recruited complement and acidic proteins, whereas the alkylated surface instead suppressed total protein binding and shifted its sparse corona towards immune-recognition proteins. Morphology added a protein-specific layer of control on top of this chemistry-set background. Preferential adsorption of certain proteins could thus be directed by pairing surface chemistry with morphotype, making diatom biosilica a biogenic, reconfigurable route to control the plasma corona.