Editorial: One- and Two-Dimensional Nanostructures for Drug Delivery Applications

Abstract

Site specific and targeted delivery of therapeutic agents to specific body parts for the treatment of diseases is essential to increase drug efficacy and reduce toxic side effects. Employing specially designed nanoparticles as carriers of these therapeutic agents has proven effective for transporting drugs to the target and releasing when needed. Targeting is achieved by binding ligands to the nanoparticle surface to increase their uptake by the cells, enabling the targeting of different cells by changing the ligands used. Triggered release, which allows for drug release only at the target site, is achieved by using functional materials as the carrier particles that respond to changes in the target environment. Spherical nanoparticles are the most widely used nanostructures due to their relatively simple synthesis. However, spherical nanoparticles suffer from low drug loading capacities. Compared to zero dimensional nanoparticles (i.e., spherical nanoparticles), one-dimensional nanostructures (i.e., nanorods, nanofibers or nanotubes) have the advantages of high loading capacities and enhanced targeting due to their high surface to volume ratios. However, compared to spherical nanoparticles, one-dimensional nanostructures have been explored less as drug carriers, which can be attributed to their relatively challenging fabrication methods. Longer circulation times, in addition to the alignment or tumbling of one-dimensional nanostructures during transport in the body, strongly impact the performance of these nanostructures as drug carriers. Although there are studies modeling the diffusion of these nanostructures in blood vessels, papers addressing the effect of their shape on the migration and transport mechanisms are limited. Furthermore, the effect of their shape on the uptake efficiency by the cells needs to be further explored. Similarly, two dimensional nanostructures have gained less attention compared to zero dimensional nanoparticles due to challenges in fabrication and severe immune response. However, recent studies have shown their significant benefits for particular treatments, such as multi-responsive control mechanisms and higher drug loading capacities. Therefore, this Research Topic invited researchers to contribute studies on recent advances in oneand two-dimensional nanostructures for drug delivery. We have collected three original research articles and one review, as reported below. Yeniyurt et al. in their publication present the functionalization of single-wall carbon nanotubes (SWNTs) with various Fmoc-amino acid-bearing polyethylene glycol (PEG) chains of different length by a non-covalent method. First, molecular dynamics studies allowed suitable Fmoc-amino acids to be selected for an effective surface coating of SWNTs; afterwards, in experimental studies Edited and reviewed by: Gianni Ciofani, Italian Institute of Technology, Italy