In situ analysis of the bio-nano interface formed by silica nanoparticles and protein media using XRay Photon Correlation Spectroscopy

CAROLINE EZEQUIEL DE PAULO DA SILVA; AGUSTIN SILVIO PICCO; MARIANGELA B. M. AZEVEDO; MARILINA CATHCARTH; ALINE RIBEIRO PASSOS; MATEUS BORBA CARDOSO

Campinas-SP

Encuentro; 34th LNLS Annual Users' Meeting (RAU); 2023

Brazilian Synchrotron Light Laboratory (LNLS) of the Brazilian Center for Research in Energy and Materials (CNPEM)

Silica nanoparticles (SiO2NPs) have shown great promise in the field of nanomedicine, being attractive for variousbiomedical applications such as diagnostic and therapeutics [1,2]. To harness their full potential for real-worldapplications, it is imperative to thoroughly characterize these systems in the biological environments, where theywill be used. Traditionally, this task is performed by dynamic light scattering (DLS) in very dilute standardizedenvironments, such as in aqueous and buffered media. However, for NPs embedded in complex biologicalenvironments (e.g. blood), the application of DLS becomes unfeasible due to the lack of transparency of thesemedia to visible light. In such scenarios, X-Ray Photon Correlation Spectroscopy (XPCS) is a technique fullycapable to provide information about the dynamics of the SiO2NPs in biological media and derive informationon hydrodynamic diameter, among other parameters. The assessment of data derived from X-ray PhotonCorrelation Spectroscopy (XPCS) enables the monitoring of both protein adsorption and nanoparticle aggregationprocesses [3]. Aiming to study SiO2NPs in environments closely resembling biological ones, we conducted XPCSexperiments at the Cateretê beamline with a set of bare-SiO2NPs and SiO2NPs-PEG (diameters ranging 200-600 nm, 10 mg/mL) in different media: water, phosphate buffer saline (PBS 100 mM), bovine serum albumin(BSA 5 mg/mL in PBS 100 mM) and fetal serum bovine (FBS 10% in PBS 100 mM). It was observed for all thebare-SiO2NPs an increasing in the relaxation time with the presence of protein media (BSA and FBS), due to theadsorption of protein and/or nanoparticle aggregation. On the other hand, for SiO2NPs-PEG, the relaxation timedid not change regardless the media which they are dispersed. These results confirmed that XPCS can provideinformation of protein corona formation onto and aggregation of SiO2NPs in biological media and the impact ofdifferent functionalization.Acknowledgements: We acknowledge the financial support of the Fundação de Amparo àPesquisa do Estado deSão Paulo (FAPESP processes 2023/02144-1 and 2021/12071-6). We acknowledge the LNLS for the use ofthe Cateretê beamline (Proposal 20222240)References: [1] L.B. Capeletti, L.M.D. Loiola, A.S. Picco, M. da Silva Liberato, M.B. Cardoso, 8 - SilicaNanoparticle Applications in the Biomedical Field, in: G. Ciofani (Ed.), Smart Nanoparticles for Biomedicine,Elsevier, 2018: pp. 115–129.[2] L. Tang, J. Cheng, Nano Today. 8 (2013) 290–312.[3] F. Otto, X. Sun, F. Schulz, C. Sanchez-Cano, N. Feliu, F. Westermeier, W.J. Parak, Small. 18 (2022)2201324.