Geopolymer-Based Materials for the Removal of Ibuprofen: A Preliminary Study.

Every year, new compounds contained in consumer products, such as detergents, paints, products for personal hygiene, and drugs for human and veterinary use, are identified in wastewater and are added to the list of molecules that need monitoring. These compounds are indicated with the term emerging contaminants (or Contaminants of Emerging Concern, CECs) since they are potentially dangerous for the environment and human health. To date, among the most widely used methodologies for the removal of CECs from the aquatic environment, adsorption processes play a role of primary importance, as they have proven to be characterized by high removal efficiency, low operating and management costs, and an absence of undesirable by-products. In this paper, the adsorption of ibuprofen (IBU), a nonsteroidal anti-inflammatory drug widely used for treating inflammation or pain, was performed for the first time using two different types of geopolymer-based materials, i.e., a metakaolin-based (GMK) and an organic-inorganic hybrid (GMK-S) geopolymer. The proposed adsorbing matrices are characterized by a low environmental footprint and have been easily obtained as powders or as highly porous filters by direct foaming operated directly into the adsorption column. Preliminary results demonstrated that these materials can be effectively used for the removal of ibuprofen from contaminated water (showing a concentration decrease of IBU up to about 29% in batch, while an IBU removal percentage of about 90% has been reached in continuous), thus suggesting their potential practical application.

Gold nanoparticles decorated kaolinite mineral modified screen-printed electrode: Use for simple, sensitive determination of gallic acid in food samples.

The current study offers the nanomolar quantification of gallic acid (GAL) based on gold nanoparticles (AuNps) and kaolinite minerals (KNT) modified on a screen-printed electrode (SPE). The electrochemical behavior of GAL was performed using differential pulse voltammetry (DPV) in Britton Robinson (BR) buffer solution at pH 2.0 as a supporting electrolyte. Under the optimized DPV mode parameters, the oxidation peak current of GAL (at 0.72 V vs Ag/AgCl) increased linearly in the range between 0.002 µmolL-1 and 40.0 µmolL-1 with a detection limit of 0.50 nmolL-1. The effect of common interfering agents was also investigated. Finally, the applicability of the proposed method was verified by quantification analysis of GAL in black tea and pomegranate juice samples.

Influence of suspended particles and dissolved organic matters on virus enrichment in reclaimed water by two-step tangential flow ultrafiltration: Phenomena and mechanisms.

Enteric virus concentration in large-volume water samples is crucial for detection and essential for assessing water safety. Certain dissolution and suspension components can affect the enrichment process. In this study, tangential flow ultrafiltration (TFUF) was used as an enrichment method for recovering enteric virus in water samples. Interestingly, the bacteriophage MS2 recovery in reclaimed water and the reclaimed water without particles were higher than that in ultrapure water. The simulated reclaimed water experiments showed that humic acid (HA) (92.16% ± 4.32%) and tryptophan (Try) (81.50 ± 7.71%) enhanced MS2 recovery, while the presence of kaolin (Kaolin) inhibited MS2 recovery with an efficiency of 63.13% ± 11.17%. Furthermore, Atomic force microscopy (AFM) revealed that the MS2-HA cluster and the MS2-Try cluster had larger roughness values on the membrane surface, making it difficult to be eluted, whereas MS2-Kaolin cluster had compact surfaces making it difficult to be eluted. Additionally, the MS2-HA cluster is bound to the membrane by single hydrogen bond with SO, whereas both the MS2-Try cluster and the MS2-Kaolin cluster are bound to the membrane by two hydrogen bonds, making eluting MS2 challenging. These findings have potential implications for validating standardized methods for virus enrichment in water samples.

Effect of voltage gradients on EK-PRB remediation: Experimental and molecular dynamics simulations.

Electrokinetic-Permeable Reaction Barrier (EK-PRB) coupled remediation technology can effectively treat heavy metal-contaminated soil near coal mines. This study was conducted on cadmium (Cd), a widely present element in the soil of the mining area. To investigate the impact of the voltage gradient on the remediation effect of EK-PRB, the changes in current, power consumption, pH, and Cd concentration content during the macroscopic experiment were analyzed. A three-dimensional visualized kaolinite-heavy metal-water simulation system was constructed and combined with the Molecular Dynamics (MD) simulations to elucidate the migration mechanism and binding active sites of Cd on the kaolinite (001) crystalline surface at the microscopic scale. The results showed that the voltage gradient positively correlates with the current, power consumption, and Cd concentration during EK-PRB remediation, and the average removal efficiency increases non-linearly with increasing voltage gradient. Considering power consumption, average removal efficiency, and cost-effectiveness, the voltage range is between 1.5 and 3.0 V/cm, with 2.5 V/cm being the optimal value. The results of MD simulations and experiments correspond to each other. Cd2+ formed a highly stable adsorption structure in contrast to the Al-O sheet on the kaolinite (001) crystalline surface. The mean square displacement (MSD) curve of Cd2+ under the electric field exhibits anisotropy, the total diffusion coefficient DTotal increases and the Cd2+ migration rate accelerates. The electric field influences the microstructure of Cd2+ complexes. With the enhancement of the voltage gradient, the complexation between Cd2+ and water molecules is enhanced, and the interaction between Cd2+ and Cl- in solution is weakened.

Synergistic adsorption and photocatalytic degradation of tetracycline using a Z-scheme kaolin/g-C3N4/MoO3 nanocomposite: A sustainable approach for water treatment.

This research focuses on the synthesis and application of a novel kaolin-supported g-C3N4/MoO3 nanocomposite for the degradation of tetracycline, an important antibiotic contaminant in water systems. The nanocomposite was prepared through a facile and environmentally friendly approach, leveraging the adsorption and photocatalytic properties of kaolin, g-C3N4 and MoO3 nanoparticles, respectively. Comprehensive characterization of the nanocomposite was conducted using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and optical spectra. The surface parameters were studied using N2 adsorption-desorption isotherm. The elemental composition was studied using X-ray photoelectron spectroscopy. The efficiency of the developed nanocomposite in tetracycline degradation was evaluated and the results revealed an efficient tetracycline degradation exhibiting the synergistic effects of adsorption and photocatalytic degradation in the removal process. The tetracycline degradation was achieved in 60 min. Kinetic studies and thermodynamic analyses provided insights into the degradation mechanism, suggesting potential applications for the nanocomposite in wastewater treatment. Additionally, the recyclability and stability of the nanocomposite were investigated, demonstrating its potential for sustainable and long-term application in water treatment.

Influence of kaolin and red clay on ceramic specimen properties when galvanic sludge is incorporated to encapsulate heavy metals.

This study presented the influence of two types of clay: kaolin (Kao) and red clay (RC) on the chemical and physical properties of ceramic specimens when galvanic sludge (GS) is incorporated to encapsulate heavy metals. Samples were obtained of GS from the industrial district of Manaus - Amazonas State, Brazil, and kaolin (Kao), and red clay (RC) from the Central Amazon. A fourth sample was prepared by mixing GS, Kao, and RC in the ratio 1:1:8 (GS + Kao + RC). This mixture was ground, and ceramic specimens were prepared, and heat treated at 950 °C and 1200 °C for three hours for phase detection, compressive strength, leaching of Fe, Ni and Cr metals and life cycle assessment. Galvanic sludge, Kao, and RC were also, and heat treated to at 950 °C and 1200 °C for three hours, obtaining GS950, GS1200, Kao950, Kao1200, RC950, and RC1200. The samples were submitted to XRF, XRD, Rietveld refinement, Mössbauer spectroscopy, TG/DTG/DSC, and SEM. The results show that the formation of nickel oxide and a spinel solid solution of the type Fe3+{Fe1-y3+,Fe1-x2+,Nix2+,Cry3+}O4 (in which [] = tetrahedral site, {} octahedral site) occurs in GS1200, which is caused by sulfate decomposition to SO2. At 1200 °C, heavy metals are encapsulated, forming other phases such as nickel silicate and hematite. Life cycle assessment was used to verify the sustainability and value of GS in clay for making bricks, and it indicated that the production of ceramics is feasible, reduces the use of clays, and is sustainable.

Thermo-catalytic pyrolysis of sewage sludge and techno-economic analysis: The effect of synthetic zeolites and natural sourced catalysts.

This work focuses to the value added utilization of animal sewage sludge into gases, bio-oil and char using synthetic zeolite (ZSM-5 and Y-zeolite) and natural sourced (diatomite, kaolin, perlite) materials as catalysts. Pyrolysis was performed in a one-stage bench-scale reactor at temperatures of 400 and 600 °C. The catalyst was mixed with the raw material before the pyrolysis. Catalysts had a significant effect on the yield of products, because the amount of volatile products was higher in their presence, than without them. In case of kaolin, due to the structural transformation occurring between 500-600 °C, a significant increase in activity was observed in terms of pyrolysis reactions resulting in volatiles. The hydrogen content of the gas products increased significantly at a temperature of 600 °C and in thermo-catalysts pyrolysis. In the presence of catalysts, bio-oil had more favourable properties.

Kaolin loaded gelatin sponges for rapid and effective hemostasis and accelerated wound healing.

Severe trauma with massive active blood loss, including liver and spleen rupture, arterial bleeding and pelvic fracture, will lead disability, malformation and even death. Therefore, it is very important to develop new, fast and efficient hemostatic materials. In this study, a novel Gelatin/Kaolin (GE/KA) composite sponge was developed. Meanwhile, to further investigate the effect of kaolin content on sponge properties, we prepared four types of sponges: GE/5% KA, GE/10% KA, GE/15% KA and GE/20% KA. The results of coagulation test in vitro showed that compared to the other groups, there were more activated adhered platelets and red blood cells on the surface of GE/15% KA. The results of hemostasis test in vivo showed that compared to other experimental groups, the GE/15% KA group had significantly less hemostasis time (liver hemostasis model: 69.50 ± 2.81 s; femoral artery hemostasis model: 75.17 ± 3.06 s) and bleeding volume (liver hemostasis model: 219.02 ± 10.39 mg; femoral artery hemostasis model: 948.00 ± 50.69 mg), and was similar to the commercial hemostasis material group. Additionally, the material properties of the sponge were characterized and its biocompatibility was verified as well through cell experiments and in vivo embedding experiments. All these results indicate that the optimal content of kaolin is 15%, which provides a theoretical basis for subsequent research. All in all, the novel GE/KA composite sponge prepared in this study can be used as a multifunctional hemostatic wound dressing for the treatment of complex wounds under various trauma scenes.

Analysing the role of Fe (II) on flocculation of sand-clay mixtures under estuarine mixing.

Estuaries are fragile environment that are most affected by climate change. One of the major consequences of climate change on estuarine processes is the enhancement in salt intrusion leading to higher salinity values. This has several implications on the estuarine sediment dynamics. Of the various factors that affect the flocculation of cohesive sediments, salinity and turbulence have been recognized as to have great significance. Many of the estuaries are contaminated with heavy metals, of which, the concentration of Iron (Fe (II)) are generally on the higher range. However, the influence of Fe (II) on the flocculation of cohesive sediments at various estuarine mixing conditions is not well known. The present study investigated the influence of Fe (II) on the flocculation of kaolin at various concentration of Fe (II), salinity and turbulence shear. The results indicated that Fe (II) and salinity have a positive influence on kaolin flocculation. The increase in turbulence shear caused an initial increase and then a decrease in floc size. In case of sand-clay mixtures, that are observed in mixed sediment estuarine environments, a reduction in the floc size was observed, which is attributed to the breakage of flocs induced by the shear of sand. Breakage coefficient, which is a measure of break-up of flocs, is generally adopted as 0.5 assuming binary breakage. The present study revealed that the breakage coefficient can take values from 0 to 1 and is a direct function of Fe (II) and salinity and an inverse function of turbulence and sand concentration. Thus, a new model for breakage coefficient with the influencing parameters has been proposed, which is an improvement of existing model that is expressed in terms of turbulence alone. Sensitivity analysis showed that the proposed model can very well predict the breakage coefficient of Fe (II) - kaolin flocs. Thus, the model can quantify the breakage coefficient of flocs in estuaries contaminated with Fe (II) that is a vital parameter for population balance models.

Copolymers functionalized with quaternary ammonium compounds under template chain exhibit simultaneously efficient bactericidal and flocculation properties: Characterization, performance and mechanism.

In this work, novel multifunctional cationic template copolymers with flocculation and sterilization capabilities were synthesized using a low-pressure ultraviolet (LP-UV) template polymerization method for the removal of kaolin and Escherichia coli (E. coli) from water. The influence of template agents on the structural performance of the copolymers was evaluated through characterization, which showed that template copolymer TPADM possesses a higher cationic charge density and a more complex rough surface, contributing to better flocculation performance than that of the non-template copolymer CPADM. Under optimal experimental conditions, TPADM-1 exhibited removal rates of 98.45% for kaolin and 99% for E. coli (OD600 =0.04), marginally outperforming the non-template copolymer. Simultaneously, TPADM-1 produced good adaptability to kaolin and E. coli wastewater in terms of wide pH, speculating that charge neutralization, adsorption bridging, patching, and sweeping simultaneously dominate the flocculation mechanism. Interestingly, SEM and 3D-EEM analysis confirm that the sterilization of E. coli occurs through two distinct functions: initially adsorption followed by subsequent cell membrane rupture and leakage of cellular contents, ultimately leading to cell death. This research further confirms the feasibility of the designed novel multifunctional copolymers for achieving simultaneous disinfection and turbidity removal, demonstrating practical applicability in real water treatment processes.

ß-Glucosidase on clay minerals: Structure and function in the synthesis of octyl glucoside.

ß-Glucosidase is a biological macromolecule that catalyzes the hydrolysis of various glycosides and oligosaccharides. It may also be used to catalyze the synthesis of glycosides under suitable conditions. Carrier-bound ß-glucosidase can enhance the enzymatic activity in the synthesis of glycosides in organic solvent solutions, although the molecular mechanism regulating activity is yet unknown. This study investigated the impact of utilizing montmorillonite (Mmt), attapulgite (Attp), and kaolinite (Kao) as carriers on the activity of ß-glucosidase from Prunus dulcis (PdBg). When Attp was used as carriers, the molecular dynamic (MD) simulations found the distance between pNPG and the active site residues E183 and E387 was minimally impacted by the adsorptions, hence PdBg maintained about 81.3 ± 0.89 % of its native activity. Out of the three clay minerals, the relative activity of PdBg loaded on Mmt was the lowest because of the highest electrostatic energy. The substrate channel of PdBg on Kao is directed towards the surface, limiting the accessibility of substrates. Secondary structure and conformation studies revealed that the conformational stability of PdBg in solvent solutions was enhanced by coupling to Attp. Unlike dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF) and 1,2-dimethoxyethane (DME), tert-butanol (t-BA) did not penetrate into the active site of PdBg interfering with its binding to the substrate. The maximum yield of n-octyl-ß-glucoside (OGP) synthesis catalyzed by Attp-immobilized PdBg reached 48.3 %.

Mechanism analysis of a novel natural cationic modified dextran flocculant and its application in the treatment of blue algal blooms.

Blue algae, a type of harmful microalgae, are responsible for causing harmful algal blooms that result in severe environmental issues. To address this problem, a biopolysaccharide-based flocculant was developed for treating blue algae blooms. This flocculant was created by modifying high molecular weight dextran using the natural cationic monomer betaine (Dex-Bet), making it environmentally friendly. Various techniques were used to characterize the prepared Dex-Bet flocculant, including infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The effectiveness of the Dex-Bet flocculant was evaluated using kaolin-simulated wastewater. The results showed that the treated supernatant had a transmittance of up to 98.25 %. Zeta potential analysis revealed that the main mechanisms of flocculation were charge neutralization, charge patching, and adsorption bridging. The application of Dex-Bet in treating blue-green algae resulted in a maximum removal rate of 98.2 %. This study provides a potential flocculant for blue algae bloom treatment.

Synthesis of chitosan-based grafting magnetic flocculants for flocculation of kaolin suspensions.

A series of novel chitosan-based magnetic flocculants FS@CTS-P(AM-DMC) was prepared by molecular structure control. The characterization results showed that FS@CTS-P(AM-DMC) had a uniform size of about 21.46 nm, featuring a typical core-shell structure, and the average coating layer thickness of CTS-P(AM-DMC) was about 5.03 nm. FS@CTS-P(AM-DMC) exhibited excellent flocculation performance for kaolin suspension, achieved 92.54% turbidity removal efficiency under dosage of 150 mg/L, pH 7.0, even at high turbidity (2000 NTU) with a removal efficiency of 96.96%. The flocculation mechanism was revealed to be dominated by charge neutralization under acidic and neutral conditions, while adsorption and bridging effects play an important role in alkaline environments. The properties of magnetic aggregates during flocculation, breakage, and regeneration were studied at different pH levels and dosages. In the process of magnetophoretic, magnetic particles collide and adsorb with kaolin particles continuously due to magnetic and electrostatic attraction, transform into magnetic chain clusters, and then further form three-dimensional network magnetic aggregates that can capture free kaolin particles and other chain clusters. Particle image velocimetry confirmed the formation of eddy current of magnetic flocs and experienced three stages: acceleration, stabilization, and deceleration.

Local Clays from China as Alternative Hemostatic Agents.

In recent years, the coagulation properties of inorganic minerals such as kaolin and zeolite have been demonstrated. This study aimed to assess the hemostatic properties of three local clays from China: natural kaolin from Hainan, natural halloysite from Yunnan, and zeolite synthesized by our group. The physical and chemical properties, blood coagulation performance, and cell biocompatibility of the three materials were tested. The studied materials were characterized by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). All three clays showed different morphologies and particle size, and exhibited negative potentials between pH 6 and 8. The TGA and DSC curves for kaolin and halloysite were highly similar. Kaolin showed the highest water absorption capacity (approximately 93.8% ± 0.8%). All three clays were noncytotoxic toward L929 mouse fibroblasts. Kaolin and halloysite showed blood coagulation effects similar to that exhibited by zeolite, indicating that kaolin and halloysite are promising alternative hemostatic materials.

Sorption of oxytetracycline to microsized colloids under concentrated salt solution: A perspective on terrestrial-to-ocean transfer of antibiotics.

The sorption of antibiotics on soil minerals and their cotransport have been widely studied for the past few years; however, these processes in concentrated salt solutions (estuary-like conditions) are not fully understood. This study aims to determine the possible sorption of oxytetracycline (OTC) on various natural and synthesized microsized minerals (including haematite, goethite, kaolinite, bentonite, lateritic, kaolinitic and illitic soil clays) under conditions mimicking pure, fresh, brackish and sea waters. The sorption of OTC was found to decrease in surface charge (herein zeta potential), hence altering the colloidal properties of the materials used. The sorption capacities of soil clays for OTC follow the inequality illitic soil clay > kaolinitic soil clay > lateritic soil clay, and the sorption capacities were found to decrease at higher salt concentrations. Seawater can intensify the release of the sorbed OTC from soil clay surfaces while favouring the coaggregation of the remaining OTC with soil clays. This implies that the long-range transport of OTC or other similar antibiotics can be governed by the mineralogical composition/properties of the suspended particles. More importantly, increasing salt concentrations in estuaries may form a chemical barrier at which limited amounts of OTC/antibiotics can pass through, while the remaining OTC/antibiotics can be favoured to aggregate simultaneously with suspended mineral particles.

Magnetic coagulation and flocculation of kaolin suspension using Fe3O4 with plant polyphenol self-assembled flocculants.

In this work, magnetic flocculant (Fe3O4@PP) was synthesized using plant polyphenol (PP) as a shaping ligand via in situ self-assembly. Characterization results revealed that Fe3O4@PP exhibited uniform particle size and excellent dispersibility with PP coating amount of 16.4 %. Experimental results suggested that Fe3O4@PP showed excellent turbidity removal efficiency in a wide pH range (3.0-10) and initial turbidity range (50-2000 NTU). Under the optimal conditions, Fe3O4@PP achieved 95.2 % of turbidity removal for simulated kaolin suspension and 96.9 % for actual wastewater. Fe3O4@PP exhibited excellent recycling and reusability properties, with high recycling efficiency of 93.3 % even after the fifth cycle. Microscopic observation revealed the formation process of magnetic flocs, involving particle aggregation, chain and cluster formation, and dense network aggregate formation. The structural characteristics and size of magnetic flocs were found to be significantly influenced by the combined effects of magnetic force, electric charge, van der Waals force, and functional groups on the surface of PP. The extended Deryaguin-Landau-Verwey-Overbeek models indicated that magnetic interactions were the primary mechanism for magnetic flocculation, accompanied by charge neutralization, adsorption bridging, sweeping, and net trapping.

Insight into the Morphological Properties of Nano-Kaolinite (Nanoscrolls and Nanosheets) on Its Qualification as Delivery Structure of Oxaliplatin: Loading, Release, and Kinetic Studies.

Natural kaolinite underwent advanced morphological-modification processes that involved exfoliation of its layers into separated single nanosheets (KNs) and scrolled nanoparticles as nanotubes (KNTs). Synthetic nanostructures have been characterized as advanced and effective oxaliplatin-medication (OXAP) delivery systems. The morphological-transformation processes resulted in a remarkable enhancement in the loading capacity to 304.9 mg/g (KNs) and 473 mg/g (KNTs) instead of 29.6 mg/g for raw kaolinite. The loading reactions that occurred by KNs and KNTs displayed classic pseudo-first-order kinetics (R2 > 0.90) and conventional Langmuir isotherms (R2 = 0.99). KNTs exhibit a higher active site density (80.8 mg/g) in comparison to KNs (66.3 mg/g) and raw kaolinite (6.5 mg/g). Furthermore, compared to KNs and raw kaolinite, each site on the surface of KNTs may hold up to six molecules of OXAP (n = 5.8), in comparison with five molecules for KNs. This was accomplished by multi-molecular processes, including physical mechanisms considering both the Gaussian energy (<8 KJ/mol) and the loading energy (<40 KJ/mol). The release activity of OXAP from KNs and KNTs exhibits continuous and regulated profiles up to 100 h, either by KNs or KNTs, with substantially faster characteristics for KNTs. Based on the release kinetic investigations, the release processes have non-Fickian transport-release features, indicating cooperative-diffusion and erosion-release mechanisms. The synthesized structures have a significant cytotoxicity impact on HCT-116 cancer cell lines (KNs (71.4% cell viability and 143.6 g/mL IC-50); KNTs (11.3% cell viability and 114.3 g/mL IC-50). Additionally, these carriers dramatically increase OXAP's cytotoxicity (2.04% cell viability, 15.4 g/mL IC-50 (OXAP/KNs); 0.6% cell viability, 4.5 g/mL IC-50 (OXAP/KNTs)).

On the role of organic matter composition in fresh-water kaolinite flocculation.

Organic matter has long been understood to affect fine sediment flocculation, yet the specific effects of different types of organic matter remain only partially understood. To address this knowledge gap, laboratory tank experiments were conducted in fresh water to investigate the sensitivity of kaolinite flocculation to varying organic matter species and contents. Three species of organic matter (xanthan gum, guar gum and humic acid) were investigated at varying concentrations. Results revealed a significant enhancement in kaolinite flocculation when organic polymers (xanthan gum and guar gum) were introduced. In contrast, the addition of humic acid had minimal influence on aggregation and floc structure. Notably, the nonionic polymer guar gum demonstrated greater efficacy in promoting the development of floc size compared to the anionic polymer, xanthan gum. We observed non-linear trends in the evolution of mean floc size (Dm) and boundary fractal dimension (Np) with increasing ratios of organic polymer concentration to kaolinite concentration. Initially, increasing polymer content facilitated the formation of larger and more fractal flocs. However, beyond a certain threshold, further increases in polymer content hindered flocculation and even led to the break-up of macro-flocs, resulting in the formation of more spherical and compact flocs. We further quantified the co-relationships between floc Np and Dm and found that larger Np values corresponded to larger Dm. These findings highlight the significant impact of organic matter species and concentrations on floc size, shape and structure, and shed light on the complex dynamics of fine sediment and associated nutrients and contaminants in fluvial systems.

Recent Advances in Kaolinite Nanoclay as Drug Carrier for Bioapplications: A Review.

Advanced functional two-dimensional (2D) nanomaterials offer unique advantages in drug delivery systems for disease treatment. Kaolinite (Kaol), a nanoclay mineral, is a natural 2D nanomaterial because of its layered silicate structure with nanoscale layer spacing. Recently, Kaol nanoclay is used as a carrier for controlled drug release and improved drug dissolution owing to its advantageous properties such as surface charge, strong biocompatibility, and naturally layered structure, making it an essential development direction for nanoclay-based drug carriers. This review outlines the main physicochemical characteristics of Kaol and the modification methods used for its application in biomedicine. The safety and biocompatibility of Kaol are addressed, and details of the application of Kaol as a drug delivery nanomaterial in antibacterial, anti-inflammatory, and anticancer treatment are discussed. Furthermore, the challenges and prospects of Kaol-based drug delivery nanomaterials in biomedicine are discussed. This review recommends directions for the further development of Kaol nanocarriers by improving their physicochemical properties and expanding the bioapplication range of Kaol.

Layered Clay Minerals in Cancer Therapy: Recent Progress and Prospects.

Cancer is one of the deadliest diseases, and current treatment regimens suffer from limited efficacy, nonspecific toxicity, and chemoresistance. With the advantages of good biocompatibility, large specific surface area, excellent cation exchange capacity, and easy availability, clay minerals have been receiving ever-increasing interests in cancer treatment. They can act as carriers to reduce the toxic side effects of chemotherapeutic drugs, and some of their own properties can kill cancer cells, etc. Compared with other morphologies clays, layered clay minerals (LCM) have attracted more and more attention due to adjustable interlayer spacing, easier ion exchange, and stronger adsorption capacity. In this review, the structure, classification, physicochemical properties, and functionalization methods of LCM are summarized. The state-of-the-art progress of LCM in antitumor therapy is systematically described, with emphasis on the application of montmorillonite, kaolinite, and vermiculite. Furthermore, the property-function relationships of LCM are comprehensively illustrated to reveal the design principles of clay-based antitumor systems. Finally, foreseeable challenges and outlook in this field are discussed.