Surface Analysis of Nanocomplexes by X-ray Photoelectron Spectroscopy (XPS)

Korin, Eli; Froumin, N.; Cohen, Smadar

doi:10.1021/acsbiomaterials.7b00040

Cited by 141 publications

(72 citation statements)

References 35 publications

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“…The results are summarized in Table S1. In the spectrum of the Ca 2+ -pDNA complex (no AlgS), the C1 and N1 assigned to the DNA and O1, P2p, and Ca2p are in agreement with values reported for Ca(H 2 PO 4 ) 2 13, 15, 16, 17. In the AlgS-Ca 2+ -pDNA NPs, an additional peak for S2p binding energy appears, in agreement with that reported for CaSO 4 , and it is attributed to the binding of Ca 2+ to the sulfate group on AlgS.…”

Section: Resultssupporting

confidence: 87%

Co-assembled Ca2+ Alginate-Sulfate Nanoparticles for Intracellular Plasmid DNA Delivery

Goldshtein

Shamir

Vinogradov

et al. 2019

Molecular Therapy - Nucleic Acids

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Successful gene therapy requires the development of suitable carriers for the selective and efficient delivery of genes to specific target cells, with minimal toxicity. In this work, we present a non-viral vector for gene delivery composed of biocompatible materials, CaCl 2 , plasmid DNA and the semi-synthetic anionic biopolymer alginate sulfate (AlgS), which spontaneously co-assembled to form nanoparticles (NPs). The NPs were characterized with a slightly anionic surface charge (Zeta potential [ζ] = −14 mV), an average size of 270 nm, and their suspension was stable for several days with no aggregation. X-ray photoelectron spectroscopy (XPS) validated their ternary composition, and it elucidated the molecular interactions among Ca 2+ , the plasmid DNA, and the AlgS. Efficient cellular uptake (>80%), associated with potent GFP gene expression (22%–35%), was observed across multiple cell types: primary rat neonatal cardiac fibroblasts, human breast cancer cell line, and human hepatocellular carcinoma cells. The uptake mechanism of the NPs was studied using imaging flow cytometry and shown to be via active, clathrin-mediated endocytosis, as chemical inhibition of this pathway significantly reduced EGFP expression. The NPs were cytocompatible and did not activate the T lymphocytes in human peripheral blood mononuclear cells. Proof of concept for the efficacy of these NPs as a carrier in cancer gene therapy was demonstrated for Diphtheria Toxin Fragment A (DT-A), resulting in abrogation of protein synthesis and cell death in the human breast cancer cell line. Collectively, our results show that the developed AlgS-Ca 2+ -plasmid DNA (pDNA) NPs may be used as an effective non-viral carrier for pDNA.

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Section: Resultssupporting

confidence: 87%

Co-assembled Ca2+ Alginate-Sulfate Nanoparticles for Intracellular Plasmid DNA Delivery

Goldshtein

Shamir

Vinogradov

et al. 2019

Molecular Therapy - Nucleic Acids

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“…This leads to a decrease in electron density around phosphorus, resulting in the increment of binding energies. 46 Similar effects are described for complexes of DNA-like molecules with cations such as Ce 4+ . 47…”

Section: Resultsmentioning

confidence: 70%

Harnessing the Noncovalent Interactions of DNA Backbone with 2D Silicate Nanodisks To Fabricate Injectable Therapeutic Hydrogels

et al. 2018

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Injectable hydrogels present several advantages over prefabricated scaffolds including ease of delivery, shear-thinning property, and broad applicability in the fields of drug delivery and tissue engineering. Here, we report an approach to develop injectable hydrogels with sustained drug release properties, exploiting the chemical nature of the DNA backbone and silicate nanodisks. A two-step gelation method is implemented for generating a combination of noncovalent network points, leading to a physically cross-linked hydrogel. The first step initiates the development of an interconnected structure by utilizing DNA denaturation and rehybridization mechanism to form hydrogen bonds between complementary base pairs of neighboring DNA strands. The anisotropic charge distribution of two-dimensional silicate nanodisks (nSi) makes them an active center in the second step of the gelation process. Silicate nanodisks create additional network points via attractive electrostatic interactions with the DNA backbone, thereby enhancing the mechanical resilience of the formulated hydrogel. The thermally stable hydrogels displayed an increase in elasticity and yield stress as a function of nSi concentration. They were able to form self-supporting structures post injection due to their rapid recovery after removal of cyclic stress. Moreover, the presence of nanosilicate was shown to modulate the release of a model osteogenic drug dexamethasone (Dex). The bioactivity of released Dex was confirmed from in vitro osteogenic differentiation of human adipose stem cells and in vivo bone formation in a rat cranial bone defect model. Overall, our DNA-based nanocomposite hydrogel obtained from a combination of noncovalent network points can serve as an injectable material for bone regeneration and carrier for sustained release of therapeutics.

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“…X‐ray photoelectron spectroscopy (XPS) is a surface‐sensitive spectroscopic technique that is widely used to analyze the elemental composition and chemical state, as well as provide quantitative information of the elements within a material . In the vacancy‐rich nanocatalysts, the presence of vacancies would alter the electronic structure and chemical environment of the elements in the materials, which affects the bonding energies and results in the change of XPS spectrum, including peak shift, intensity variation, or the generation of new XPS peaks.…”

Section: Advanced Characterizations Of Functional Vacanciesmentioning

confidence: 99%

Noble Metal‐Free Nanocatalysts with Vacancies for Electrochemical Water Splitting

Yang

Wang

et al. 2018

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The fast development of nanoscience and nanotechnology has significantly advanced the fabrication of nanocatalysts and the in-depth study of the structural-activity characteristics of materials at the atomic level. Vacancies, as typical atomic defects or imperfections that widely exist in solid materials, are demonstrated to effectively modulate the physicochemical, electronic, and catalytic properties of nanomaterials, which is a key concept and hot research topic in nanochemistry and nanocatalysis. The recent experimental and theoretical progresses achieved in the preparation and application of vacancy-rich nanocatalysts for electrochemical water splitting are explored. Engineering of vacancies has shown to open up a new avenue beyond the traditional morphology, size, and composition modifications for the development of nonprecious electrocatalysts toward efficient energy conversion. First, an introduction followed by discussions of different types of vacancies, the approaches to create vacancies, and the advanced techniques widely used to characterize these vacancies are presented. Importantly, the correlations between the vacancies and activities of the vacancy-rich electrocatalysts via tuning the electronic states, active sites, and kinetic energy barriers are reviewed. Finally, perspectives on the existing challenges along with some opportunities for the further development of vacancy-rich noble metal-free electrocatalysts with high performance are discussed.

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Surface Analysis of Nanocomplexes by X-ray Photoelectron Spectroscopy (XPS)

Cited by 141 publications

References 35 publications

Co-assembled Ca2+ Alginate-Sulfate Nanoparticles for Intracellular Plasmid DNA Delivery

Co-assembled Ca2+ Alginate-Sulfate Nanoparticles for Intracellular Plasmid DNA Delivery

Harnessing the Noncovalent Interactions of DNA Backbone with 2D Silicate Nanodisks To Fabricate Injectable Therapeutic Hydrogels

Noble Metal‐Free Nanocatalysts with Vacancies for Electrochemical Water Splitting

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