TEGylated Double-Walled Carbon Nanotubes as Platforms to Engineer Neuronal Networks

Double-Walled Carbon Nanotubes Enable Breakdown of the Trade-off between Ion Selectivity and Water Permeability

Although evidence has been presented for desalination potentials in single-walled carbon nanotubes (SWCNTs), it is still very challenging to overcome the trade-off between ion selectivity and water permeability by simply tuning the carbon nanotube (CNT) size. In this work, we prove that double-walled carbon nanotubes (DWCNTs) can make it. Employing a series of molecular dynamics simulations, we find a striking phenomenon that tuning the combination architecture of DWCNTs can significantly improve the desalination performance, with the salt rejection rate even reaching 100% in some cases while maintaining high levels of water flux. Specifically, under a certain outer CNT (20,20), with the increase in inner CNT radius, the salt rejection rate reaches a maximum for the CNT (9,9), attributed to the small size of the inner CNT and the space between the two CNT walls that significantly impedes the ion passage; however, it still allows the passage of massive water. Furthermore, as the pressure difference increases, the water flux greatly increases, while the salt rejection rate only slightly decreases for the CNTs (8,8) and (9,9), effectively addressing the trade-off between ion selectivity and water permeability. As a result, optimizing the architecture of DWCNTs should be an effective strategy for designing an efficient desalination membrane, which is still a challenge for SWCNTs.

Electroconductive Collagen-Carbon Nanodots Nanocomposite Elicits Neurite Outgrowth, Supports Neurogenic Differentiation and Accelerates Electrophysiological Maturation of Neural Progenitor Spheroids

Neuronal disorders are characterized by the loss of functional neurons and disrupted neuroanatomical connectivity, severely impacting the quality of life of patients. This study investigates a novel electroconductive nanocomposite consisting of glycine-derived carbon nanodots (GlyCNDs) incorporated into a collagen matrix and validates its beneficial physicochemical and electro-active cueing to relevant cells. To this end, this work employs mouse induced pluripotent stem cell (iPSC)-derived neural progenitor (NP) spheroids. The findings reveal that the nanocomposite markedly augmented neuronal differentiation in NP spheroids and stimulate neuritogenesis. In addition, this work demonstrates that the biomaterial-driven enhancements of the cellular response ultimately contribute to the development of highly integrated and functional neural networks. Lastly, acute dizocilpine (MK-801) treatment provides new evidence for a direct interaction between collagen-bound GlyCNDs and postsynaptic N-methyl-D-aspartate (NMDA) receptors, thereby suggesting a potential mechanism underlying the observed cellular events. In summary, the findings establish a foundation for the development of a new nanocomposite resulting from the integration of carbon nanomaterials within a clinically approved hydrogel, toward an effective biomaterial-based strategy for addressing neuronal disorders by restoring damaged/lost neurons and supporting the reestablishment of neuroanatomical connectivity.

Fabrication of a Co-Mo-Based Metal-Organic Framework for Growth of Double-Walled Carbon Nanotubes

Double-walled carbon nanotubes (DWCNTs) make up a unique class of carbon nanotubes (CNTs) that are particularly intriguing for scientific research and are promising candidates for technological applications. A more precise level of control and greater yields can be achieved via catalytic chemical vapor deposition (CCVD), which involves the breakdown of a carbonaceous gas over nanoparticles. The addition of molybdenum to the system can increase the selectivity with regard to the number of walls that exist in the obtained CNTs. As reported herein, we have designed and synthesized a novel Co-Mo-MOF, [Co(3-bpta)1.5(MoO4)]·H2O (where 3-bpta = N,N'-bis(3-pyridyl)terephthalamide), and employed the Co-Mo-MOF as a bimetallic catalyst precursor for the CCVD approach to prepare high-quality DWCNTs. The Co-Mo-MOF was employed after being calcined in N2 and H2 at 1100 °C and decomposing into CoO, CoMoO4, and MoO3. Existing CoMoO4 is unaltered after reduction in H2 at 1100 °C, while CoO and MoO3 are converted into Co0 and MoO2, and more CoMoO4 is created at the expense of Co0 and MoO2 without clearly defining agglomeration. Finally, the interaction between metallic Co particles and C2H4 is what initiates the formation of DWCNTs. In-depth discussion is provided in this paper regarding the mechanism underlying the high selectivity and activity of Co-Mo catalysts in regulating the development and structure of DWCNTs. The DWCNTs also offer excellence performance when they are used as water purification agents and as selective sorbents. This work opens a feasible way to use MOFs as a way to produce MWCNTs, thus blazing a new trail in the field of MOF-derived carbon-based materials.

Hydrogels from a Self-Assembling Tripeptide and Carbon Nanotubes (CNTs): Comparison between Single-Walled and Double-Walled CNTs

Supramolecular hydrogels obtained from the self-organization of simple peptides, such as tripeptides, are attractive soft materials. Their viscoelastic properties can be enhanced through the inclusion of carbon nanomaterials (CNMs), although their presence can also hinder self-assembly, thus requiring investigation of the compatibility of CNMs with peptide supramolecular organization. In this work, we compared single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) as nanostructured additives for a tripeptide hydrogel, revealing superior performance by the latter. Several spectroscopic techniques, as well as thermogravimetric analyses, microscopy, and rheology data, provide details to elucidate the structure and behavior of nanocomposite hydrogels of this kind.