Pegylated silica nanoparticles: cytotoxicity and macrophage uptake

  • Giulia Glorani
  • Riccardo Marin
  • Patrizia Canton
  • Marcella Pinto
  • Giamaica Conti
  • Giulio Fracasso
  • Pietro Riello
Research Paper


Here, we present a thorough study of pegylated silica nanoparticle (SNP) interaction with different biological environments. The SNPs have a mean diameter of about 40 nm and are coated with polyethylene glycol (PEG) of different molecular weights. The physicochemical characterization of SNPs allowed the confirmation of the binding of PEG chains to the silica surface, the reproducibility of the synthesis and the narrow size-dispersion. In view of clarifying the SNP interaction with biological environments, we first assessed the SNP reactivity after the incubation with two cell lines (macrophages RAW 264.7 and primary human fibroblasts), observing a reduced toxicity of pegylated SNPs compared to the bare ones. Then, we investigated the effect of the protein adsorption on the SNP surface using the model serum protein, bovine serum albumin (BSA). We found that the protein adsorption takes place more heavily on poorly pegylated SNPs, promoting the uptake of the latter by macrophages and leading to an increased mortality of these cells. To better understand this mechanism by means of flow cytometry, the dye Ru(bpy)3Cl2 was incorporated in the SNPs. The overall results highlight the SNP potentialities as a drug delivery system, thanks to the low interactions with the macrophages.


Silica Silica nanoparticles Polyethylene glycol PEG Pegylation Macrophage Interaction BSA Cell uptake Biocompatibility 



The authors thank Mr. A. Skripka for the helpful discussions.

Compliance with ethical standards

This study was funded by Fondazione Cariverona, Verona Nanomedicine Initiative and Italian Minister of Health RF-2010-2305526.

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

11051_2017_3964_MOESM1_ESM.docx (4.7 mb)
ESM 1 Electronic Supplementary Information (ESI) available: [Details of the experimental procedure for the synthesis of mPEG5000-silane and mPEG550-silane, bare and pegylated SNPs and FSNPs; cell cultures; XRPD pattern and high magnification SEM image of bare SNPs (S), SEM micrographs of samples S25a, S8b, and S50a50b; FTIR spectra, DLS and z-potential analysis of the three series of samples; molybdate test calibration curve; PL-PLE spectra of FSNPs; SDS-PAGE of selected samples after soaking in BSA and human serum; semi-quantitative analysis of the serum protein adsorption on the SNP surface; cell viability tests on fibroblasts and RAW264.7 macrophages before and after BSA soaking at 24 h and 48 h; cell viability tests of bare and pegylated FSNPs on RAW 264.7 macrophages; raw flow cytometry data for the macrophages uptake of FSNPs]. (DOCX 4.70 mb)


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Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  • Giulia Glorani
    • 1
  • Riccardo Marin
    • 1
  • Patrizia Canton
    • 1
  • Marcella Pinto
    • 2
  • Giamaica Conti
    • 3
  • Giulio Fracasso
    • 2
  • Pietro Riello
    • 1
  1. 1.Dipartimento di Scienze Molecolari e NanosistemiUniversità Ca Foscari di VeneziaVenezia MestreItaly
  2. 2.Dipartimento di Medicina, Sezione di ImmunologiaUniversità degli Studi di VeronaVeronaItaly
  3. 3.Dipartimento di Scienze Neurologiche e del MovimentoUniversità degli Studi di VeronaVeronaItaly

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