Understanding the Adsorption of Peptides and Proteins onto PEGylated Gold Nanoparticles

Polyethylene glycol (PEG) surface conjugations are widely employed to render passivating properties to nanoparticles in biological applications. The benefits of surface passivation by PEG are reduced protein adsorption, diminished non-specific interactions, and improvement in pharmacokinetics. However, the limitations of PEG passivation remain an active area of research, and recent examples from the literature demonstrate how PEG passivation can fail. Here, we study the adsorption amount of biomolecules to PEGylated gold nanoparticles (AuNPs), focusing on how different protein properties influence binding. The AuNPs are PEGylated with three different sizes of conjugated PEG chains, and we examine interactions with proteins of different sizes, charges, and surface cysteine content. The experiments are carried out in vitro at physiologically relevant timescales to obtain the adsorption amounts and rates of each biomolecule on AuNP-PEGs of varying compositions. Our findings are relevant in understanding how protein size and the surface cysteine content affect binding, and our work reveals that cysteine residues can dramatically increase adsorption rates on PEGylated AuNPs. Moreover, shorter chain PEG molecules passivate the AuNP surface more effectively against all protein types.

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Dosimetry and Radioenhancement Comparison of Gold Nanoparticles in Kilovoltage and Megavoltage Radiotherapy using MAGAT Polymer Gel Dosimeter

Journal of Biomedical Physics and Engineering ◽

10.31661/jbpe.v9i2apr.827 ◽

2019 ◽

Vol 9 (2Apr) ◽

Cited By ~ 1

Author(s):

S Farahani ◽

N Riyahi Alam ◽

S Haghgoo ◽

M Khoobi ◽

Gh Geraily ◽

...

Keyword(s):

Gold Nanoparticles ◽

3D Visualization ◽

Energy Levels ◽

Polymer Gel ◽

External Radiotherapy ◽

Dose Enhancement ◽

Internal Radiotherapy ◽

Boost Radiotherapy

Background: Numerous unique characteristics of the nanosized gold, including high atomic number, low toxicity, and high biocompatibility make it one of the most appropriate nanostructures to boost radiotherapy efficacy. Many in-vivo and in-vitro investigations have indicated that gold nanoparticles (AuNPs) can significantly increase tumor injuries in low kilovoltage radiotherapy. While deep-lying tumors require much higher energy levels with greater penetration power, and investigations carried out in megavoltage energy range show contradictory results.Objective: In this study, we quantitatively assess and compare dose enhancement factors (DEFs) obtained through AuNPs under radiation of Cobalt-60 source (1.25MeV) versus Iridium-192 source (0.380 KeV) using MAGAT gel dosimeter.Material and Methods: MAGAT polymer gel in both pure and combined with 0.2 mM AuNPs was synthesized. In order to quantify the effect of energy on DEF, irradiation was carried out by Co-60 external radiotherapy and Ir-192 internal radiotherapy. Finally, readings of irradiated and non-irradiated gels were performed by MR imaging.Result: The radiation-induced R2 (1/T2) changes of the gel tubes doped with AuNPs compared to control samples, upon irradiation of beams released by Ir-192 source showed a significant dose enhancement (15.31% ±0.30) relative to the Co-60 external radiotherapy (5.85% ±0.14).Conclusion: This preliminary study suggests the feasibility of using AuNPs in radiation therapy (RT), especially in low-energy sources of brachytherapy. In addition, MAGAT polymer gel, as a powerful dosimeter, could be used for 3D visualization of radiation dose distribution of AuNPs in radiotherapy.

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Faculty Opinions recommendation of New biarsenical ligands and tetracysteine motifs for protein labeling in vitro and in vivo: synthesis and biological applications.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1008432.106257 ◽

2002 ◽

Author(s):

Wen-hong Li

Keyword(s):

Protein Labeling ◽

Biological Applications ◽

In Vivo Synthesis

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Cancerous Cell Destruction Using Low Level Ultrasound in the Presence of Gold Nanoparticles: An in vitro Study on 4T1 Cells

Current Nanoscience ◽

10.2174/1573413714666180220124403 ◽

2018 ◽

Vol 14 (4) ◽

pp. 329-334

Author(s):

Ahmad Shanei ◽

Neda Attaran ◽

Marziyeh Mirzaeiyan ◽

Mohammad Reza Salamat ◽

Hossein Hejazi

Keyword(s):

Gold Nanoparticles ◽

In Vitro Study ◽

Vitro Study ◽

Low Level ◽

Cell Destruction ◽

Cancerous Cell ◽

4T1 Cells

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Interference of Gold Nanoparticles with In vitro Endotoxin Detection Assays

Current Nanoscience ◽

10.2174/1573413715666181212120013 ◽

2020 ◽

Vol 16 (2) ◽

pp. 204-213 ◽

Cited By ~ 1

Author(s):

Melissa A. Vetten ◽

Mary Gulumian

Keyword(s):

Gold Nanoparticles ◽

Gold Nanoparticle ◽

Surface Reactivity ◽

In Vitro Assays ◽

Limulus Amebocyte Lysate ◽

Chromogenic Assay ◽

Nanoparticle Suspensions ◽

Endotoxin Contamination ◽

Factor C

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.

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Radiosensitization of Prostate Cancers In Vitro and In Vivo to Erbium-filtered Orthovoltage X-rays Using Actively Targeted Gold Nanoparticles

Scientific Reports ◽

10.1038/s41598-017-18304-y ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 12

Author(s):

Allison M. Khoo ◽

Sang Hyun Cho ◽

Francisco J. Reynoso ◽

Maureen Aliru ◽

Kathryn Aziz ◽

...

Keyword(s):

Gold Nanoparticles ◽

X Rays ◽

Prostate Cancers

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Gold nanoparticles affect the cryopreservation efficiency of in vitro-derived shoot tips of bleeding heart

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-021-02069-4 ◽

2021 ◽

Author(s):

Dariusz Kulus ◽

Alicja Tymoszuk

Keyword(s):

Gold Nanoparticles ◽

Alginate Bead ◽

Stability Index ◽

Shoot Tips ◽

Start Codon ◽

Lamprocapnos Spectabilis ◽

Colloid Dispersion ◽

Recovery Medium ◽

Alginate Matrix

AbstractThe popularity of nanoparticles (NPs) is continuously increasing. To date, however, there has been little research on the application of NPs in plant cryopreservation, i.e. storage of tissues in liquid nitrogen (LN). The aim of this study is to analyze the effect and evaluate the usefulness of gold nanoparticles (AuNPs) in regard to cryobiology studies. In vitro-derived shoot tips of Lamprocapnos spectabilis ‘Valentine’ were cryopreserved with the encapsulation-vitrification protocol. Gold nanoparticles (at 10–30 ppm concentration; 13 nm in size) were added either into the preculture medium; to the protective bead matrix during encapsulation; or to the recovery medium after rewarming of samples. The control plants were produced from cryopreserved explants non-treated with nanoparticles or treated with colloid dispersion medium without NPs. A non-LN-treated standard was also considered. The influence of AuNPs on the cryopreservation efficiency was determined by evaluating the recovery rate of explants and their morphogenic response; the membrane stability index (MSI); the concentration of pigments in shoots; and the antioxidant enzymes activity. The genetic stability of the plant material was evaluated using Start Codon Targeted Polymorphism (SCoT) markers. It was found that 10 ppm of AuNPs added into the alginate bead matrix improved the recovery level of LN-derived shoot tips (70.0%) compared to the non-NPs-treated cryopreserved control (50.5%). On the other hand, the presence of nanoparticles in the recovery medium had a deleterious effect on the survival of explants. AuNPs usually had no impact on the MSI (73.9–85.9%), except for those added into the recovery medium at the concentration of 30 ppm (decline to 55.8%). All LN-derived shoots were shorter and contained less chlorophyll and carotenoids than the untreated standard. Moreover, the application of AuNPs affected the enzymatic activity in L. spectabilis. Minor genetic variation was found in 8.6% of plants if AuNPs were added either into the preculture medium (at 10 and 20 ppm) or to the alginate matrix (at 30 ppm). In conclusion, AuNPs added at a lower concentration (10 ppm) into the protective bead matrix can significantly improve the cryopreservation efficiency in L. spectabilis with no alternation in the DNA sequence.

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Phosphatidylserine-Gold Nanoparticles (PS-AuNP) Induce Prostate and Breast Cancer Cell Apoptosis

Pharmaceutics ◽

10.3390/pharmaceutics13071094 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1094

Author(s):

Allan Radaic ◽

Nam E. Joo ◽

Soo-Hwan Jeong ◽

Seong-II Yoo ◽

Nicholas Kotov ◽

...

Keyword(s):

Breast Cancer ◽

Gold Nanoparticles ◽

Biomedical Applications ◽

Therapeutic Potential ◽

Control Treatment ◽

Track Record ◽

Males And Females ◽

Breast And Prostate Cancer ◽

First Time

Prostate and breast cancer are the current leading causes of new cancer cases in males and females, respectively. Phosphatidylserine (PS) is an essential lipid that mediates macrophage efferocytosis and is dysregulated in tumors. Therefore, developing therapies that selectively restore PS may be a potential therapeutic approach for carcinogenesis. Among the nanomedicine strategies for delivering PS, biocompatible gold nanoparticles (AuNPs) have an extensive track record in biomedical applications. In this study, we synthesized biomimetic phosphatidylserine-caped gold nanoparticles (PS-AuNPs) and tested their anticancer potential in breast and prostate cancer cells in vitro. We found that both cell lines exhibited changes in cell morphology indicative of apoptosis. After evaluating for histone-associated DNA fragments, a hallmark of apoptosis, we found significant increases in DNA fragmentation upon PS-AuNP treatment compared to the control treatment. These findings demonstrate the use of phosphatidylserine coupled with gold nanoparticles as a potential treatment for prostate and breast cancer. To the best of our knowledge, this is the first time that a phosphatidylserine-capped AuNP has been examined for its therapeutic potential in cancer therapy.

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