Polymer nanocomposites based on functionalized carbon nanotubes

2.3. Ionic Liquids (ILs) 5374 2.4. Complexation Reactions on Oxidized CNTs 5375 2.5. Halogenation 5376 2.6. Cycloaddition Reactions 5377 2.7. Radical Additions 5379 2.8. Nucleophilic Additions 5381 2.9. Electrophilic Additions 5381 2.10. Electrochemical Modifications 5381 2.11. Plasma-Activation 5381 2.12. Mechanochemical Functionalizations 5382 3. Noncovalent Interactions 5382 3.1. Polynuclear Aromatic Compounds 5382 3.2. Interactions with Other Substances 5384 3.3. Interactions with Biomolecules 5385 4. Endohedral Filling 5386 4.1. Encapsulation of Fullerenes 5386 4.2. Encapsulation of Organic Substances 5387 4.3. Encapsulation of Inorganic Substances 5387 5. Decoration of CNTs with Metal Nanoparticles 5388 5.1. Covalent Linkage 5388 5.2. Direct Formation on Defect Sites 5388 5.3. Electroless Deposition 5388 5.4. Electrodeposition 5389 5.5. Chemical Decoration 5390 5.6. Deposition of Nanoparticles onto CNTs 5391 5.7. π-π Stacking and Electrostatic Interactions 5391 6. Concluding Remarks 5392 7. Acknowledgments 5392 8. References 5392

Current progress on the chemical modification of carbon nanotubes.

Carbon nanotubes (CNTs) have drawn special research attention because of their unique properties and potential applications. This review summarizes the research progress of organic chemical adsorption on CNTs, and will provide useful information for CNT application and risk assessment. Adsorption heterogeneity and hysteresis are two widely recognized features of organic chemical−CNT interactions. However, because different mechanisms may act simultaneously, mainly hydrophobic interactions, π−π bonds, electrostatic interactions, and hydrogen bonds, the prediction of organic chemical adsorption on CNTs is not straightforward. The dominant adsorption mechanism is different for different types of organic chemicals (such as polar and nonpolar), thus different models may be needed to predict organic chemical−CNT interaction. Adsorption mechanisms will be better understood by investigating the effects of properties of both CNTs and organic chemicals along with environmental conditions. Another major factor affec...

Adsorption Mechanisms of Organic Chemicals on Carbon Nanotubes

We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na2SO4 solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corro...

Graphene: Corrosion-Inhibiting Coating

Adsorptive removal of dyes from aqueous solution onto carbon nanotubes: a review.

Chemical oxidation of multiwalled carbon nanotubes

Chemical oxidation of multi-walled carbon nanotubes

Single-walled carbon nanotubes were functionalized along their sidewalls with hydroxyalkyl groups using a radical addition scheme. These moieties were found to be active in the polymerization of acrylic acid from the surface of the nanotubes by a redox radical mechanism. The resulting polymerized nanotubes were analyzed by UV-Vis, XPS, Raman and SEM techniques. The composite material was found to be soluble in aqueous media (pH > 5) and polar organic solvents. The reported grafting technique is expected to be suitable for industrial production of modified carbon nanotubes.

Covalently functionalized carbon nanotubes as macroinitiators for radical polymerization

The evidence for a role of somatic mutations, including copy-number variants (CNVs), in neurodegeneration has increased in the last decade. However, the understanding of the types and origins of these mutations, and their exact contributions to disease onset and progression, is still in its infancy. The use of single-cell (or nuclear) whole-genome sequencing (scWGS) has emerged as a powerful tool to answer these questions. In the present chapter, we provide laboratory and bioinformatic protocols used successfully in our lab to detect megabase-scale CNVs in single cells from multiple system atrophy (MSA) human postmortem brains, using immunolabeling prior to selection of nuclei for whole-genome amplification (WGA). We also present an unpublished comparison of scWGS generated from the same control substantia nigra (SN) sample, using the latest versions of popular WGA chemistries, MDA and PicoPLEX. We have used this protocol to focus on brain cell types most relevant to synucleinopathies (dopaminergic [DA] neurons in Parkinson’s disease [PD] and oligodendrocytes in MSA), but it can be applied to any tissue and/or cell type with appropriate markers. 

Somatic CNV Detection by Single-Cell Whole-Genome Sequencing in Postmortem Human Brain.


 Microsatellite instability (MSI) is caused by deficient DNA mismatch repair (MMR) and is a ubiquitous feature of cancer. Werner syndrome (WRN) helicase is involved in genome stability and DNA repair. We identified WRN as a synthetic-lethal target in dMMR/MSI cancers and highlighted WRN inhibition as a therapeutic option for dMMR/MSI cancers refractory to available therapies. A previously unappreciated genetic feature of dMMR/MSI cancer cells, DNA (TA)n-dinucleotide repeat expansions, were recently reported to cause vulnerability to WRN depletion. Our mechanistic understanding of TA-dinucleotide repeat expansion biology is limited, and their potential therapeutic implications are unclear. To investigate the landscape of these alterations in cancer, we inferred (TA)-dinucleotide repeat expansions by performing coverage analysis in a collection of hundreds of preclinical cancer models and human tumors (PCAWG) profiled by whole genome sequencing (WGS). We validated our findings in cancer cell lines and organoid cultures by performing long-read WGS. Furthermore, we investigated TA-expansions in single-cell-derived clones from human MSI tumors and cancer organoids. Finally, we inferred TA repeats in laser capture microdissection (LCMB)-derived samples obtained from patients affected by familial cancer predisposition syndromes. Our analysis unveils the landscape of TA-repeats alterations in a large collection of tumors and preclinical models, informing on the level of inter-tumor heterogeneity and their association with variable levels of WRN dependency. In addition, we investigated intra-patient tumor heterogeneity of TA-repeats length both within clonal organoids expanded from normal and neoplastic colorectal stem cells, and within different subclones derived from MSI cancer organoids. Furthermore, analysis of non-neoplastic and neoplastic tissues from patients affected by familial cancer predisposition syndromes revealed the pattern of TA-repeats expansions associated with various DNA-repair pathway alterations. Finally, we will discuss the clinical implications of our findings, as TA-repeats heterogeneity may affect sensitivity and resistance to the future generation of WRN inhibitors. Our data provide fresh insights into the inter and intra-tumoral heterogeneity of TA-dinucleotide repeat expansions in human cancers. These data contribute to understanding the role of MMR in cancer and exploiting Werner as a therapeutic target in cancer.
 Citation Format: Gabriele Picco, Shriram Bhosle, Maria Kalyva, Elena Grassi, Freddy Gibson, Angham Al Saedi, Sara Vieira, Mathijs Sanders, Livio Trusolino, Andrea Bertotti, Isidro Cortes-Ciriano, Mathew Garnett. MSI cancer associated DNA (TA)n-dinucleotide repeat expansions and implications for Werner synthetic lethality. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4327.

M. Kalyva

Papers

Chemical oxidation of multiwalled carbon nanotubes

Chemical oxidation of multi-walled carbon nanotubes

Covalently functionalized carbon nanotubes as macroinitiators for radical polymerization

Somatic CNV Detection by Single-Cell Whole-Genome Sequencing in Postmortem Human Brain.

Abstract 4327: MSI cancer associated DNA (TA)n-dinucleotide repeat expansions and implications for Werner synthetic lethality