+1 Recommend
    • Review: found
    Is Open Access

    Review of 'The Role of PEG Conformation in Mixed Layers: From Protein Corona Substrate to Steric Stabilization Avoiding Protein Adsorption.'

    The Role of PEG Conformation in Mixed Layers: From Protein Corona Substrate to Steric Stabilization Avoiding Protein Adsorption.Crossref
    Average rating:
        Rated 4 of 5.
    Level of importance:
        Rated 4 of 5.
    Level of validity:
        Rated 4 of 5.
    Level of completeness:
        Rated 4 of 5.
    Level of comprehensibility:
        Rated 4 of 5.
    Competing interests:

    Reviewed article

    • Record: found
    • Abstract: found
    • Article: found
    Is Open Access

    The Role of PEG Conformation in Mixed Layers: From Protein Corona Substrate to Steric Stabilization Avoiding Protein Adsorption.

    Although nanoparticles have been traditionally modified with a single ligand layer, mixture of ligands might help to combine different functionalities and to further engineer the NP surface. A detailed study of the competition between an alkanethiol (11-mercaptoundecanoic acid) and SH-PEG for the surface of AuNPs and the resultant behaviors of this model nanoconjugate is presented here. As a result, the physicochemical properties of these conjugates can be progressively tuned by controlling the composition and especially the conformation of the mixed monolayer. This has implications in the physiological stability. The controlled changes on the SH-PEG conformation rather than its concentration induces a change in the stabilization mechanism from electrostatic repulsion to steric hindrance, which changes the biological fate of NPs. Importantly, the adsorption of proteins on the conjugates can be tailored by tuning the composition and conformation of the mixed layer.

      Review information

      This work has been published open access under Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Conditions, terms of use and publishing policy can be found at www.scienceopen.com.

      gold nanoparticles,mixed layers,protein corona
      ScienceOpen disciplines:

      Review text

      The manuscript presents a thorough study of mixed pegylated self-assembled monolayers (SAMs) on gold nanoparticles (NPs). The authors have successfully attempted to address some deficiencies in NP surface modification studies, in particular by gaining insight into the affinities of different bioconjugates for the NP surface.

      In my view, the manuscript could benefit from a few clarifications. In particular,

      1. Some acronyms used in the manuscript appear field-specific and might need to be spelled out for a broader readership, e.g. SH-PEG and DMEM

      2. Showing the exact chemical structures for the two bioconjugates, MUA and SH-PEG, might be useful for further MD simulation and NP surface modification studies

      3. The most interesting observation of the present study is the effect of increasing MUA grafting density on PEG conformation. For comparison, it would be helpful to show how the increase in grafting density of PEG alone (in a single component SAM) affects the PEG conformation

      4. The authors conclude that PEG conformation changes with increasing MUA density. However, on page 5, when quantifying “PEG to MUA ratio” in the SAMs, the authors appear to ignore the change in the PEG “footprint” associated with the change in PEG conformation. A brief discussion concerning the effect of change in PEG conformation on “PEG to MUA ratio” in SAMs would be useful

      5. First line on page 7 refers to Figure 2b, where abscissa is “ Ratio SH-PEG/MUA”. The text on page 7 reads “… 0.7 [MUA]added/[SH-PEG]added…”, which is confusing

      6. To strengthen the argument on changes in PEG conformation from mushroom to brush, a comparison of NP hydrodynamic diameter values for SH-PEG/MUA ratios below and above 0.7 would be useful. Quite a few values for NP hydrodynamic diameters are mentioned in the manuscript, yet there appears to be no clear comparison of NP hydrodynamic diameter in relation to change in PEG conformation


      Comment on this review