PEGylation on mixed monolayer gold nanoparticles: Effect of grafting density, chain length, and surface curvature

Lin, Jiaqi; Zhang, Heng; Morovati, Vahid; Dargazany, Roozbeh

doi:10.1016/j.jcis.2017.05.046

Cited by 51 publications

(40 citation statements)

References 62 publications

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“…42 Simulations indicate that a denser coating of shorter PEG chains can achieve similar effects to a sparser coating of longer PEG chains. 43 As both density and length of a molecular coating contribute to its biological effect, a short dense coating offers improved enhancement compared to a longer less dense coating with the same biological effect.…”

Section: B Effect Of Nanoparticle Sizementioning

confidence: 99%

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

et al. 2019

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Purpose Radiosensitizer enhanced radiotherapy provides the possibility of improved treatment outcomes by preferentially increasing the effectiveness of radiation within the tumor. Proton therapy offers improved sparing of tissue distal of the tumor along the beam path and reduced integral dose compared to conventional photon therapy. The combination of proton therapy with radiosensitizers offers the potential for an enhanced therapy with increased effect within the tumor and low integral dose. The simulations performed in this work determine the effect of nanoparticle characteristics and proton energy on the nanoscale dose and radiolysis yield enhancement for a single gold nanoparticle irradiated with a proton beam. This data can be used to determine optimal nanoparticle characteristics to enhance proton therapy. Methods A two‐stage Monte Carlo simulation was performed using Geant4. In the first stage of the simulation, the physical interactions of protons within a gold nanoparticle were modeled and the secondary electrons escaping the nanoparticle's surface were scored in a phase space file. In the second stage of the simulation, the phase space file was used as an input to model the physical interactions of the secondary electrons in water and the resulting production and chemical interactions of reactive species. By comparing a gold nanoparticle with an equivalent water nanoparticle, the nanoscale enhancement of dose and radiolysis yield was calculated. Results A large nanoscale enhancement of both the dose and radiolysis yield of up to a factor of 11 due to gold nanoparticles was found for most simulated conditions. For 50 nm gold nanoparticles, a large enhancement factor of 9–11 was observed for high proton energies; however, the enhancement was reduced for proton energies below 10 MeV. For 5 MeV incident protons, it was found that the enhancement factor was approximately 9 for gold nanoparticles of sizes 5–25 nm with a reduction in enhancement observed for nanoparticle sizes outside this range. Additionally, it was found that larger nanoparticle sizes resulted in greater total energy deposition and radiolysis yields per proton flux but with reduced efficiency per nanoparticle mass. It was observed that a large loss of enhancement occurred for thick nanoparticle coatings. However, for polyethylene glycol (PEG) coatings, coating density had a minimal effect on enhancement. Conclusions A large enhancement in dose and radiolysis yield was observed. However, the low‐energy secondary electrons produced within the gold for lower energy protons are susceptible to self‐absorption and result in the loss of enhancement observed for larger nanoparticles and thicker coatings. The radiolysis yield and dose increase with nanoparticle size; however, the yield and dose per gold mass decrease due to self‐absorption. Therefore, an intermediate nanoparticle size of approximately 10–25 nm maximizes both the radiolysis yield and dose as well as the enhancement. Coatings should be kept to the minimum effective thickness to limit ...

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Section: B Effect Of Nanoparticle Sizementioning

confidence: 99%

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

et al. 2019

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“…25,26 Behavior of PEGylated gold nanoparticles in an aqueous medium was simulated by coarse-grained or all-atom MD. 27,28 Classical MD was exploited both in the study of poly(methyl methacrylate) (PMMA)-grafted SiO 2 nanoparticles and SiO 2 nano-objects immersed in a polymeric (PEG) medium. 29,30 Binding of different polymers (including PEG) on an Fe 3 O 4 (111) flat surface and surfactant agents and drugs on Fe 3 O 4 nanoparticles were investigated by classical molecular dynamics.…”

Section: Introductionmentioning

confidence: 99%

Optimizing PEGylation of TiO₂ Nanocrystals through a Combined Experimental and Computational Study

et al. 2019

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PEGylation of metal oxide nanoparticles is the common approach to improve their biocompatibility and in vivo circulation time. In this work, we present a combined experimental and theoretical study to determine the operating condition that guarantee very high grafting densities, which are desirable in any biomedical application. Moreover, we present an insightful conformational analysis spanning different coverage regimes and increasing polymer chain lengths. Based on 13C NMR measurements and molecular dynamics simulations, we show that classical and popular models of polymer conformation on surfaces fail in determining the mushroom-to-brush transition point and prove that it actually takes place only at rather high grafting density values.

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“…The dense brushes present on R1 and R2 repelled large proteins while loose R3 brush as well as loops conformations of A1 and A2 allowed the adsorption of these large proteins. These critical parameters have also been identified in recent studies, were both chain length and density were strongly involved in the steric repulsion of molecules [30,37]. It is worth noting that it is impossible to predict NPs behavior with proteins considering current usual parameters assessed in routine, namely NP size and potential zeta.…”

Section: Discussionmentioning

confidence: 79%

“…The notion of surface coverage includes the density, length, architecture and/or conformation of macromolecules grafted on NM's surface. This parameter regulates the way nanomaterials interact with proteins that is a major phenomenon occurring in vivo in biological fluids containing proteins, with a tremendous impact on the functionality and the biological activity of nanomaterials [28][29][30][31][32][33][34][35][36]. The importance of the understanding of the surface coverage of NMs has also recently been highlighted in a work studying different macromolecular grafting by Bertrand et al [37].…”

Section: Introductionmentioning

confidence: 99%

Characterization of nanomedicines’ surface coverage using molecular probes and capillary electrophoresis

Coty

Varenne

Benmalek

et al. 2018

European Journal of Pharmaceutics and Biopharmaceutics

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A faithful characterization of nanomedicine (NM) is needed for a better understanding of their in vivo outcomes. Size and surface charge are studied with well-established methods. However, other relevant parameters for the understanding of NM behavior in vivo remain largely inaccessible. For instance, the reactive surface of nanomedicines, which are often grafted with macromolecules to decrease their recognition by the immune system, is excluded from a systematic characterization. Yet, it is known that a subtle modification of NMs' surface characteristics (grafting density, molecular architecture and conformation of macromolecules) is at the root of major changes in the presence of biological components. In this work, a method that investigates the steric hindrance properties of the NMs' surface coverage based on its capacity to exclude or allow adsorption of well-defined proteins was developed based on capillary electrophoresis. A series of proteins with different molecular weights (MW) were used as molecular probes to screen their adsorption behavior on nanoparticles bearing different molecular architectures at their surface. This novel strategy evaluating to some degree a functionality of NMs can bring additional information about their shell property and might allow for a better perception of their behavior in the presence of biological components. The developed method could discriminate nanoparticles with a high surface coverage excluding high MW proteins from nanoparticles with a low surface coverage that allowed high MW proteins to adsorb on their surface. The method has the potential for further standardization and automation for a routine use. It can be applied in quality control of NMs and to investigate interactions between proteins and NM in different situations.

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PEGylation on mixed monolayer gold nanoparticles: Effect of grafting density, chain length, and surface curvature

Cited by 51 publications

References 62 publications

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

Optimizing PEGylation of TiO₂ Nanocrystals through a Combined Experimental and Computational Study

Characterization of nanomedicines’ surface coverage using molecular probes and capillary electrophoresis

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PEGylation on mixed monolayer gold nanoparticles: Effect of grafting density, chain length, and surface curvature

Cited by 51 publications

References 62 publications

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

Gold nanoparticle enhanced proton therapy: A Monte Carlo simulation of the effects of proton energy, nanoparticle size, coating material, and coating thickness on dose and radiolysis yield

Optimizing PEGylation of TiO2 Nanocrystals through a Combined Experimental and Computational Study

Characterization of nanomedicines’ surface coverage using molecular probes and capillary electrophoresis

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Optimizing PEGylation of TiO₂ Nanocrystals through a Combined Experimental and Computational Study