Interactions between silver and gold nanoparticles of different sizes, shapes and surface structures with proteins of different glycosylation status

Za biomedicinsku primjenu nanočestica (NP) nužno je poznavati mehanizam njihove interakcije s biološkim sustavima. Ovaj rad istražuje interakcije NP s proteinima koje dovode do stvaranja proteinskog sloja na površini NP tzv. proteinske korone, što znatno utječe i na svojstva NP i na biološki sustav. U dosadašnjim istraživanjima nano-bio interakcija zanemarena je uloga glikana, koji su prisutni u strukturi većine proteina. Cilj istraživanja bio je utvrditi kako veličina, oblik te površinska struktura NP srebra i zlata utječu na prirodu i mehanizam njihove interakcije s proteinima različitoga glikozilacijskoga statusa korištenjem modela glikoziliranog transferina (glikoTRF) iz humanog seruma i neglikoziliranog rekombinantnog humanog transferina (ne-glikoTRF). Istražen je utjecaj fizikalno-kemijskih svojstava NP na jakost vezanja s proteinima, promjene sekundarnih struktura proteina te sastav proteinske korone. Istraživanje je provedeno i na goveđem serumskom albuminu (BSA) kako bi se dobiveni rezultati mogli usporediti s drugim istraživanjima koja uglavnom koriste BSA model. Ionska jakosti i pH biološkog medija značajno su utjecali na koloidnu stabilnost NP, dok je stvaranje proteinske korone stabiliziralo NP. Utvrđeno je da su jakost vezanja proteina na NP i promjene sekundarne proteinske strukture ovisni ne samo o veličini, obliku i površinskoj funkcionalizaciji NP, nego i o prisutnosti glikana na proteinima. Struktura -ploča značajnije se promijenila vezanjem ne-glikoTRF na NP manje specifične površine, što nije primijećeno za glikoTRF. Fizikalno-kemijska svojstva NP te glikozilacija proteina utjecali su i na sastav i koncentraciju proteinske korone na površini NP. Dobiveni rezultati ističu važnost glikozilacije proteina za nano-bio interakcije, što zajedno s potvrđenom ulogom fizikalno-kemijskih svojstava NP na te interakcije, pridonosi razumijevanju učinka NP na biološke sustave te se može koristiti u razvoju novih dijagnostičkih, prognostičkih i terapijskih nanoalata.For the biomedical application of nanoparticles (NPs) it is necessary to know the mechanism of their interaction with biological systems. This work was focused on the interactions of NPs with proteins, which lead to the formation of a protein layer on the surface of NPs so called protein corona which significantly affects both the properties of NPs and the biological system. In previous studies of nano-bio interactions, the role of glycans, which are present in the structure of most proteins, has been neglected. The aim of the study was to determine how the size, shape and surface structure of silver and gold NPs affect the nature and mechanism of their interaction with proteins of different glycosylation status using models of glycosylated transferrin (glycoTRF) from human serum and non-glycosylated recombinant human transferrin (non-glycoTRF). The influence of physicochemical properties of NPs on the strength of protein binding, changes in the secondary structures of proteins and the composition of the protein corona was investigated. The study was also performed on bovine serum albumin (BSA) so that the obtained results could be compared with other studies that mainly use the BSA model.The ionic strength and pH of the biological medium significantly affected the colloidal stability of NPs whereas the formation of the protein corona stabilized them. It was found that the strength of protein binding to NPs and changes in secondary protein structure depend not only on the size, shape and surface functionalization of NPs, but also on the presence of glycans on proteins. The structure of -plates changed significantly by binding non-glycoTRF to NPs of less specific surface area, which was not observed for glycoTRF. Physicochemical properties of NPs and glycosylation of proteins also affected the composition and concentration of protein corona on the surface of NPs . The obtained results emphasize the importance of protein glycosylation for nano-bio interactions, which together with the confirmed role of physicochemical properties of NPs on these interactions, contributes to understanding the effect of NPs on biological systems and can be used in the development of new diagnostic, prognostic and therapeutic nanotools