Nanomaterials: A Review about Halloysite Nanotubes, Properties, and Application in the Biological Field

Abstract

The use of synthetic materials and the attention towards environmental hazards and toxicity impose the development of green composites with natural origins. Clay is one of the candidates for this approach. Halloysite is a natural clay mineral, a member of the Kaolin group, with characteristic tubular morphology, usually named halloysite nanotubes (HNTs). The different surface chemistry of halloysite allows the selective modification of both the external surface and the inner lumen by supramolecular or covalent interactions. An interesting aspect of HNTs is related to the possibility of introducing different species that can be released more slowly compared to the pristine compound. Due to their unique hollow morphology and large cavity, HNTs can be employed as an optimal natural nanocarrier. This review discusses the structure, properties, and application of HNTs in the biological field, highlighting their high biocompatibility, and analyse the opportunity to use new HNT hybrids as drug carriers and delivery systems.

Total Bio-Based Material for Drug Delivery and Iron Chelation to Fight Cancer through Antimicrobial Activity

“…Antibacterial nanosystems have made impressive advances in cancer therapy overall, but there is still more work to be done before they can be used effectively and safely [ 51 , 52 ]. Because of their high biocompatibility and on-demand drug delivery, HNTs have received much interest recently in the biomedical area; by adding the appropriate chemotherapy or antibacterial medications, HNTs could be employed for antitumor or antibacterial treatments, as well as for the treatment of other diseases [ 29 ].…”

“…), it is less costly [ 27 , 28 ]. Large particle size, an abundance of hydrophilic hydroxyl groups for functionalization, high stability in biological fluids, and inexpensive cost are all benefits of HNTs for drug delivery carrier applications [ 29 , 30 ]. Halloysite nanotubes are harmless up to concentrations of 75 mg/mL, and parallel laser confocal observation of fluorescently labeled halloysite absorption of cells revealed the material’s position inside the cells, close to the nucleus, demonstrating cellular uptake [ 30 ].…”

Halloysite Nanotubes Decorated with Fe3O4 Nanoparticles and Tannic Acid for Effective Inhibition of E. coli Biofilm

“…nH 2 O). HNTs possess a high aspect ratio, large surface area, biocompatible properties, and excellent mechanical properties, making them highly attractive for various applications. , These nanotubes can be functionalized and modified to enhance their properties and enable tailored interactions with different substances. − HNTs typically have an internal diameter of 10–30 nm, an external diameter of 40–70 nm, and a length between 200 and 2000 nm . HNTs are one of the most important components of newly emerging nanocomposite agents utilized for drug delivery, coating materials, biomedical applications, tissue engineering scaffolds, decontamination purposes, catalysis, and packaging. − Fe 3 O 4 nanoparticles, another important material, have significant potential to be utilized in biomedical applications due to their magnetic properties.…”

Cellulose nanocrystal/halloysite nanotube composite aerogels for water purification

“…19 Halloysite nanotubes (HNTs) are naturally occurring aluminosilicate clay minerals with an intriguing tubular morphology. 20,21 These nanoclays have been used in many applications, for example, as nanocontainers to store and deliver antimicrobial agents, 22 as supports for low temperature methane oxidation catalysts, 23 and in oil/water separation. 24 HNTs are green and low-cost materials with remarkable sorbent properties, which make them excellent candidates for water treatment.…”