Whether Carbon Nanotubes Are Capable, Promising, and Safe for Their Application in Nervous System Regeneration. Some Critical Remarks and Research Strategies

Abstract

Carbon nanotubes are applied in or considered for different fields of medicine. Among them is the regeneration or rebuilding of nervous system components, which still lack substantial progress; this field is supported by carbon nanotubes to a great extent as the principal material. The limited research on this issue has involved PU/silk/MWCNTs, PCL/silk/MWCNTs, PCL/PGS/CNTs, chitin/CNTs, PGF/CNTs, CNTs/PGFs/PLDLA, MWCNTs/chitosan, MWCNTs/PPy, PLA/MWCNTs, PU/PAA/MWCNts, GelMA/SACNTs, and CNTs alone, which have been subjected to different surface modifications and applied in the form of solid materials or scaffolds that are degradable or nondegradable. So far, these attempts have shown that the use of surface-modified MWCNTs is a promising way to improve the functions of nervous systems as a whole, even though some drawbacks, such as the potential cytotoxicity or the weak adhesion of CNTs to other components, may appear and be eliminated by their proper functionalization. The present review presents an idea of a nonbiodegradable scaffold structure composed of a chosen conductive polymer that is able to create a scaffold structure, a selected nanocarbon form (with MWCNTs as the first candidate), and a corrosion-resistant metal as a conductor. Other substances are also considered for their ability to increase the mechanical strength and adhesion of CNTs and their biological and electrical properties. The novelty of this approach is in the simultaneous use of nanocarbon and conductive metallic fibers in a polymer scaffold structure.

Adverse Effects of Non-Metallic Nanoparticles in the Central Nervous System

“…Pure carbon NPs constitute the largest and most important group of nmNPs, whic include nanotubes, nanohorns, nano-onions, nanodiamonds, fullerenes and graphene and exhibit large diversity in structure, morphology, physical properties and chemica reactivity [1,[12][13][14][15]. Another carbon-containing, large group of nmNPs are dendrimers These NPs have a highly branched three-dimensional structure, consisting of an initia core, several internal layers, repetitive units and several terminal active surface groups The presence of a hydrophobic core and multiple surface groups makes them a good candidate for high-load drug carriers [1,16,17].…”

“…Pure carbon NPs constitute the largest and most important group of nmNPs, which include nanotubes, nanohorns, nano-onions, nanodiamonds, fullerenes and graphene, and exhibit large diversity in structure, morphology, physical properties and chemical reactivity [1,[12][13][14][15]. Another carbon-containing, large group of nmNPs are dendrimers.…”

A Combined Computational and Experimental Analysis of PLA and PCL Hybrid Nanocomposites 3D Printed Scaffolds for Bone Regeneration

“…Kakarla et al [8] used the representative volume elements (RVE) method and FEA to study the maximum stress distributions and mechanical properties of boron nitride nanotubes (BNNTs)reinforced gelatin (G) and alginate (A) hydrogel. Also, efforts have been made using matrices PLA and PCL with fillers like multiwall carbon nanotubes (MWCNTs), chitosan (CS) and silk [14][15][16][17]. It has been found recently that PCL/CS/CNT composite matches well with the heart's electrical conductivity [16].…”

A computational and experimental mechanical study of nanocomposites for 3D printed scaffolds with a new geometry

“…Olivares et al used also FEA method to study the mechanical and fluid properties in gyroid and hexagonal scaffolds of 55% and 70% porosity [5]. Also effort has been done using as a bulk or either a matrix polycaprolactone (PCL) [8], [9] as PCL is a proper candidate for tissue regeneration, due to its' high mechanical properties [10]. Recently, it has been found that it has a good match with the heart's electrical conductivity [9].…”