Search results for "halloysite nanotubes"
showing 10 items of 56 documents
Selective Cytotoxic Activity of Prodigiosin@halloysite Nanoformulation
2020
Prodigiosin, a bioactive secondary metabolite produced by Serratia marcescens, is an effective proapoptotic agent against various cancer cell lines, with little or no toxicity toward normal cells. The hydrophobicity of prodigiosin limits its use for medical and biotechnological applications, these limitations, however, can be overcome by using nanoscale drug carriers, resulting in promising formulations for target delivery systems with great potential for anticancer therapy. Here we report on prodigiosin-loaded halloysite-based nanoformulation and its effects on viability of malignant and non-malignant cells. We have found that prodigiosin-loaded halloysite nanotubes inhibit human epithelia…
Past, Present and Future Perspectives on Halloysite Clay Minerals
2020
Halloysite nanotubes (HNTs), clay minerals belonging to the kaolin groups, are emerging nanomaterials which have attracted the attention of the scientific community due to their interesting features, such as low-cost, availability and biocompatibility. In addition, their large surface area and tubular structure have led to HNTs’ application in different industrial purposes. This review reports a comprehensive overview of the historical background of HNT utilization in the last 20 years. In particular it will focus on the functionalization of the surfaces, both supramolecular and covalent, following applications in several fields, including biomedicine, environmental science and catalysis.
Halloysite/Keratin Nanocomposite for Human Hair Photoprotection Coating
2020
We propose a novel keratin treatment of human hair by its aqueous mixtures with natural halloysite clay nanotubes. The loaded clay nanotubes together with free keratin produce micrometer-thick protective coating on hair. First, colloidal and structural properties of halloysite/keratin dispersions and the nanotube loaded with this protein were investigated. Above the keratin isoelectric point (pH = 4), the protein adsorption into the positive halloysite lumen is favored because of the electrostatic attractions. The ζ-potential magnitude of these core-shell particles increased from -35 (in pristine form) to -43 mV allowing for an enhanced colloidal stability (15 h at pH = 6). This keratin-cla…
Separation of halloysite/kaolinite mixtures in water controlled by sucrose addition: The influence of the attractive forces on the sedimentation beha…
2022
In this work, we propose an easy strategy for the separation of halloysite/kaolinite mixtures in sucrose aqueous solution. Preliminarily, we investigated the influence of the sucrose addition on the colloidal stability of kaolinite nanoplates and halloysite nanotubes (HNTs) dispersed in water. Dynamic Light Scattering (DLS) measurements revealed that the HNTs aqueous mobility is dependent on the sucrose concentration, while the ζ-potential is negligibly affected by the addition of the carbohydrate in the aqueous solvent. On the other hand, any variations on the surface charge and dynamic behavior of kaolinite were detected in the presence of sucrose. The obtained ζ-potential and DLS results…
Halloysite nanotubes filled with MgO for paper reinforcement and deacidification
2021
Abstract A novel material for the deacidification and protection of paper has been designed by using MgO filled halloysite nanotubes (Hal). The ability of MgO loaded nanotubes to control the acidic conditions was evaluated by pH measurements in aqueous solvent. Afterwards, paper was impregnated into hydroxypropyl cellulose dispersions containing the consolidating material. A simulation of strong acidic conditions allowed us to evaluate the deacidification effect of the composite material on the samples. In particular, the paper reaches a pH of 7.7 after 1 h exposition to HNO3 vapours when MgO-Hal nanoparticles are added to the impregnation mixture at a concentration of 10 wt% and it remains…
Modification of halloysite lumen with dopamine derivatives as filler for antibiofilm coating
2023
Hypothesis: Development of nanocomposite coating with antibiofilm properties is of fundamental importance to efficient fight biofilm formation preventing infections in biomedical area. In this context, halloysite nanotubes (HNTs), biocompatible and low-cost clay mineral, have been efficiently used as filler for different polymeric matrices affording several nanocomposites with appealing antimicrobial properties. The modification of HNTs surfaces represents a valuable strategy to improve the utilization of the clay for biological purposes. Experiments: Herein, the covalent modification of the HNTs lumen with properly designed dopamine derivatives with different perfluoroalkyl chain length is…
Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices
2019
[EN] Based on the unique ability of defibrillated sepiolite (SEP) to form stable and homogeneous colloidal dispersions of diverse types of nanoparticles in aqueous media under ultrasonication, multicomponent conductive nanoarchitectured materials integrating halloysite nanotubes (HNTs), graphene nanoplatelets (GNPs) and chitosan (CHI) have been developed. The resulting nanohybrid suspensions could be easily formed into films or foams, where each individual component plays a critical role in the biocomposite: HNTs act as nanocontainers for bioactive species, GNPs provide electrical conductivity (enhanced by doping with MWCNTs) and, the CHI polymer matrix introduces mechanical and membrane pr…
Halloysite-Based Bionanocomposites
2017
Scientific research has been invigorated by a new class of biodegradable materials as alternatives to polymers derived from fossils. Such biomaterials can also offer economic advantages because they are derived from renewable resources. Several biopolymers (gelatin, chitin, chitosan, starch, pectin, cellulose and its modified versions, etc.) have been exploited to produce films and formulations. Their use is limited because of fast degradation, predominant hydrophilic character, and, in some cases, unsatisfactory mechanical properties. However, the properties of these polymers can be improved by using inorganic fillers such as additives. Halloysite nanotube is a promising green filler for t…
Halloysite nanotubes loaded with peppermint essential oil as filler for functional biopolymer film
2016
Abstract The purpose of this paper is to show how a functional bionanocomposite film with both antioxidant and antimicrobial activities was successfully prepared by the filling of a pectin matrix with modified Halloysite nanotubes (HNT) containing the essential peppermint oil (PO). Firstly, HNT surfaces were functionalized with cucurbit[6]uril (CB[6]) molecules with the aim to enhance the affinity of the nanofiller towards PO, which was estimated by means of HPLC experiments. The HNT/CB[6] hybrid was characterized by several methods (thermogravimetry, FT-IR spectroscopy and scanning electron microscopy) highlighting the influence of the supramolecular interactions on the composition, therma…
Halloysite nanotubes-carbon dots hybrids multifunctional nanocarrier with positive cell target ability as a potential non-viral vector for oral gene …
2019
Abstract Hypothesis The use of non-viral vectors for gene therapy is hindered by their lower transfection efficiency and their lacking of self-track ability. Experiments This study aims to investigate the biological properties of halloysite nanotubes-carbon dots hybrid and its potential use as non-viral vector for oral gene therapy. The morphology and the chemical composition of the halloysite hybrid were investigated by means of high angle annular dark field scanning TEM and electron energy loss spectroscopy techniques, respectively. The cytotoxicity and the antioxidant activity were investigated by standard methods (MTS, DPPH and H2O2, respectively) using human cervical cancer HeLa cells …