Double Hydroxide Nanoparticles Research Articles

Preparation and Catalytic Properties of Gold Single-Atomand Cluster Catalysts Utilizing Nanoparticulate Mg-Al Layered Double Hydroxides.

Au single atoms and clusters were stabilized on Mg-Al layered double hydroxide nanoparticles (LDH NPs), and the obtained Au@LDH NPs were supported on SiO2 and CeO2. After hydrogen reduction, Au single atoms were found together with Au clusters on LDH/SiO2. In contrast to Au single-atomcatalysts which are deposited in metal vacancies of oxide supports, the LDH NPs stabilize small Au species despite the absence of metal vacancies. The obtained Au(0)@LDH/SiO2 catalyzed aerobic oxidation of alcohols, and Au single atoms maintained after the reaction. Given that only Au NPs were observed on bulk LDH, the abundant surface OH group of LDH NPs would contribute to stabilize Au, resulting in higher activity than Au/LDH-bulk. After calcination to transform LDH to mixed metal oxide (MMO), the obtained Au(0)@MMO/SiO2 also exhibited high catalytic activity. Moreover, Au(0)@LDH/CeO2 exhibited higher activity and excellent selectivity for hydrogenation of 4-nitrostyrene to 4-aminostyrene than conventional Au catalysts such as Au/CeO2 and Au/TiO2 even though onlyAu NPs were present. We demonstrated that Au size can be minimized using LDH NPs, exhibiting in high catalytic performance. The basic surface OH groups of LDH would be also beneficialfor deprotonation of alcohols and heterolytic H2dissociation in the catalytic reactions.

Thiolated layered double hydroxide-based nanoparticles: A study on mucoadhesiveness and cytotoxicity

The aim of this study was the synthesis and characterization of thiolated Mg/Al Layered double hydroxide nanoparticles (nLDH) that can adhere to mucosal surfaces. For this purpose, initially, nLDH were synthesized and then their surface was modified with L-cysteine (Cys). Then the Cys-modified nanoparticle structure (nLDHCys) was characterized by FTIR, XRD and FE-SEM/EDS, and the amount of thiol groups was determined using the iodometric method. The cytotoxicity properties of nLDH and LDHCys were examined on cervical (HeLa), fibroblast (L929) and colon (HT29) cell lines. In addition, the adhesion of nanoparticles to mucosal surfaces has been evaluated through mucin interaction experiments and ex vivo tests on ewe vaginal tissue. The results from characterization studies prove that Cys molecule has been successfully modified on the surface of nLDH. Cytotoxicity studies demonstrated that Cys modification did not negatively affect the cell viability, and these results were extremely close to those of nLDH. Ex vivo tests on ewe vaginal tissue and mucin interaction demonstrated that nLDHCys enhanced retention on the mucosal surface. Considering their retention ability to mucosal surface and their biocompatible nature, nLDHCys is expected to play an important role as a promising option for a safe mucoadhesive nanoparticle system for biological applications in the future.

Simultaneous adsorption of cadmium, zinc, and lead ions from aqueous solution by Montmorillonite clay coated with [formula omitted] nanoparticles

In this work, Montmorillonite (MMt) coated with MgCuAl-layered double hydroxide (LDH) nanoparticles as a new adsorbent (MCA-LDH@MMt) was synthesized via a low supersaturation characterized using BET, TEM, XRD, SEM/EDS, and FT-IR analysis. The adsorption studies were conducted in a ternary-batch system of three heavy metal ions (cadmium, zinc, and lead). The results showed that the MMt was successfully loaded with MgCuAl nanoparticles with a porosity of 44.63 % and a specific surface area of 76.63 m2/g. In addition, the surface morphology analysis showed that there were several changes in elemental dispersion, molar ratio, and molecular weights during the preparation of the used adsorbent. The influence of environmental parameters on the adsorption behavior was studied in detail, whereby the maximum adsorption capacity for the three metals ions was achieved at pH 5, 120 min contact time, 0.2 g/100 mL dose, and 50 mg/l initial metal ion concentration at 25 ± 1 °C. A pseudo-second-order model well correlates the kinetic data of the three metal ions (R2 > 0.991). The Cd2+ and Zn2+ isotherm data exhibited high compatibility with the Langmuir model, while the Freundlich model better fitted the Pb2+ isotherm data. The maximum adsorption capacity from the Langmuir model was 91.6, 164.9, and 129.2 mg/g for Cd2+, Zn2+, and Pb2+, respectively. Also, the adsorption process of the three metal ions onto MCA−LDH@MMt was primarily characterized by their spontaneous and exothermic nature. In conclusion, this study demonstrated that MCA-LDH@MMt is an effective adsorbent for the simultaneous adsorption of cadmium, zinc, and lead in aqueous solution, with the ability to recover the synthesized adsorbent after four consecutive cycles with a minimal reduction in adsorption ability.

Cadmium sequestration with MgCuAl-layered double hydroxide@montmorillonite nanocomposite in batch and circulated fluidized bed column experiments

In this study, montmorillonite cationic clay coated with MgCuAl-Layered double hydroxide nanoparticles was investigated for its capacity to adsorb cadmium ion (Cd2+) from aqueous solutions. Montmorillonite, MgCuAl−LDH, and a novel MgCuAl-Layered double hydroxide@montmorillonite nanocomposite (MCA−LDH@MMt) were characterized using various mechanisms including BET surface areas, XRD, TEM, FTIR, and SEM/EDS analysis. The adsorption behaviour of MCA−LDH@MMt towards Cd2+ ion was studied using batch and continuous flow systems. pH, contact time, initial Cd2+concentration, MCA−LDH@MMt dose and particle size, agitation speed, and temperature were examined in the batch system. The higher removal efficiency of Cd2+was reported at pH 5 at 70 mg/l initial concentration and 0.2 g/100 ml best adsorbent dose with 150 rpm. The adsorption of Cd2+ on MCA−LDH@MMt followed Langmuir model and yielded a maximum adsorption capacity of 129.82 mg/g. While the pseudo-second-order model better simulates the cadmium kinetics data, and adsorption rate parameters values showing that the adsorption process was chemisorption and the rate-determining step of controlling cadmium adsorption onto MCA−LDH@MMt not intra-particle diffusion. A three-phase, commonly known as gas-liquid-solid circulated fluidized bed column was used to continuously eliminate Cd2+. Four influencing parameters were studied: liquid and air flow rate, bed height, and initial Cd2+concentration. The adsorption efficiency of Cd2+in a continuous system increased when the liquid flow rate decreased and the bed height increased. The time required for MCA−LDH@MMt to reach saturation increases as the bed height and the air flow rate increase. Column data were described using Bohart-Adams, Thomas, and Yoon and Nelson models of adsorption for given experimental conditions. The Bohart-Adams could represent the initial regime of the breakthrough curves, while the Thomas model was better at describing the whole curve of metal ion adsorption for a given experimental condition.

Fast and efficient chromium(VI) extraction by colloidal Mg/Al layered double hydroxide nanoparticles

Due to the constraints associated with diffusion and mixing time, traditional kinetic and thermodynamic approaches were inadequate for probing the true mechanism of interaction between chromate and Layered Double Hydroxide (LDH). To circumvent these limitations, colloidal suspensions of Mg/Al-NO3 LDH, characterized by a positively charged surface (approximately +50 mV) in ultrapure water and a mean average diameter of 140 nm, allowing the formation of stable suspensions for days, were swiftly mixed with Cr(VI) suspensions at both pH = 4 and 9 using a stopped flow technique. This rapid mixing, accomplished in <5 milliseconds, enabled the examination of the initial stages of interaction between the toxic anion and the host compound. Two distinct steps in the adsorption process were identified: a very fast step (completed in <5 ms), representing up to 80% of the measured variation, and a slower step lasting up to 100 s. The fast step assumed to be driven by electrostatic interaction (ζ ∼ +50 mV) with the surface, and sites close to the surface are easily accessible to the chromate anions. The slower step corresponded to a diffusion process close or inside the particles. Chromate extraction efficiency was investigated through ultrafiltration tests, varying the LDH and chromate amounts, indicating that 2 nitrate ions are exchanged for 1 chromate, regardless of the pH considered, and a total exchange can be fulfilled with 0.1 g L−1 of LDH within the explored concentration range.

Thin-film composite (TFC) membranes incorporated with hydrophilic additives and layered double hydroxides (LDHs) for effective brackish water (BW) desalination

To overcome the limited water permeability of thin-film nanocomposite (TFN) membranes for brackish water reverse osmosis (BWRO) processes, we have incorporated a few amine or hydroxyl group terminated hydrophilic additives during interfacial polymerization when fabricating RO membranes and found that the membrane comprising 1 wt% 2-(2-hydroxyethyl)pyridine (2-(2-pyridyl)ethylahydroxide, PEH) has the best BWRO performance. The membrane was subsequently infiltrated with layered double hydroxide (LDH) nanoparticles by a post ethanol activation and could deliver a water permeability of 4.18 LMH bar−1 which is 100 % more than the control membrane without much compromising the salt rejection. The newly developed process not only incorporates nanofillers with the advantages of simplicity and decoupling from the interfacial polymerization process, but also endows the TFN membranes with enhanced separation performance. The study may provide useful insights to incorporate nanofillers by the solvent activation approach for the fabrication of TFN membranes.

Sulfate Radical Based In Situ Vaccine Boosts Systemic Antitumor Immunity via Concurrent Activation of Necroptosis and STING Pathway.

In situ vaccine (ISV) can provoke systemic anti-tumor immunity through the induction of immunogenic cell death (ICD). The development of ISV technology has been restricted by the limited and suboptimal ICD driven tumor antigen production which are currently relying on chemo-drugs, photo-/radio-sensitizers, oncolytic-virus and immunostimulatory agents. Herein, a sulfate radical (SO4 ·-) based ISV is reported that accomplishes superior tumor immunotherapy dispense from conventional approaches. The ISV denoted as P-Mn-LDH is constructed by intercalating peroxydisulfate (PDS, a precursor of SO4 ·-) into manganese layered double hydroxide nanoparticles (Mn-LDH). This design allows the stabilization of PDS under ambient condition, but triggers a Mn2+ mediated PDS decomposition in acidic tumor microenvironment (TME) to generate in situ SO4 ·-. Importantly, it is found that the SO4 ·- radicals not only effectively kill cancer cells, but also induce a necroptotic cell death pathway, leading to robust ICD signaling for eliciting adaptive immunity. Further, the P-Mn-LDH can activate the stimulator of interferon genes (STING) pathway to further boost anti-tumor immunity. Collectively, the P-Mn-LDH based ISV exhibited potent activity in inhibiting tumor growth and lung metastasis. When combined with immune checkpoint inhibitor, significant inhibition of distant tumors is achieved. This study underpins the promise of SO4 ·- based vaccine technology for cancer immunotherapy.

Polycarbonate ultrafiltration membrane modified with Mg–Al-layered double hydroxide nanoparticles for treatment of petroleum refinery wastewater

Polycarbonate ultrafiltration membrane modified with Mg–Al-layered double hydroxide nanoparticles for treatment of petroleum refinery wastewater

Interaction between Uranyl Cations and Layered Double Hydroxide Nanoparticles: Implications for Nuclear Wastewater Management

Interaction between Uranyl Cations and Layered Double Hydroxide Nanoparticles: Implications for Nuclear Wastewater Management

Polyether sulfone flat-sheet membrane impregnated with Mn-Al layered double hydroxide nanoparticles for green microfiltration of acrylamide in cocoa products.

A new polyether sulfone (PES) membrane modified with manganese-aluminum layered double hydroxide (Mn-Al LDH) was prepared and utilized in the membrane micro-solid phase extraction (M-µSPE) of acrylamide for the first time. The analyses were conducted using HPLC-UV. The extraction efficiency of the PES membrane was enhanced two-fold with the addition of LDH. The fabricated LDH@PES was characterized using ATR-FTIR, SEM, XRD, and nitrogen adsorption/desorption isotherms. The specific surface area, average pore diameter, thickness, cross-sectional channels, and LDH particle size of the LDH@PES membrane were determined. The extraction key factors including membrane composition, desorption conditions, sample pH, and salt concentration were studied. The method was validated by determining the limit of detection, the limit of quantification, linear range, r2, matrix effect, enrichment factor, and precision. Extraction recoveries ranged from 87.4 to 103.5% with RSD < 5.9%. Finally, the method's green features were assessed with the AGREE protocol. This is the first report on the application of LDH@PES for microfiltration/extraction of acrylamide in various chocolate and cocoa products.

In-situ engineering catalytically active surfaces for tribocatalysis with layered double hydroxide nanoparticles

Ensuring long-lasting lubrication is vital for sustainable machinery operation, made possible by self-regenerating carbon-based tribofilms via tribocatalysis. Conventional methods use expensive catalytic coatings, posing challenges for replacement and maintenance in practice. Here, we are proposing catalytic layered double hydroxide (LDH) nanoparticles as cost-effective and easily replenished lubricant additives to engineer catalytically active surfaces in situ where binary and ternary LDHs with Ni2+, Co2+, and/or Cu2+ divalent cations alongside Al3+ trivalent cations are investigated for lubrication performance. Under 100 °C sliding condition equivalent to the lubricating temperature in an internal combustion engine, NiCoAl–CO3 LDH exhibits the lowest wear losses alongside the durable low-friction regime. This excellent performance is attributed to Co-containing spinel and oxide phases in the catalytic tribo-oxide layer which help stabilize and maintain the microstructures of the tribo-oxide layer. In contrast, deterioration in lubrication performance at this temperature was observed for copper-containing LDHs, especially NiCuAl–CO3 LDHs, which is due to the reduction of metallic oxides that drive phase separation in the catalytic oxide tribo-layers. The more stable tribo-oxide layers can result in thick, durable carbon-based tribofilm during sliding along with higher resistance to plastic deformation bulk interlayer. This study offers valuable insight into the synergy of catalytic oxide materials, opening avenues for a rational design of innovative catalytic nano-materials for tribocatalysis processes.

Boosting the sonodynamic performance of CoBiMn-layered double hydroxide nanoparticles via tumor microenvironment regulation for ultrasound imaging-guided sonodynamic therapy

Sonodynamic therapy (SDT), a promising strategy for cancer treatment with the ability for deep tissue penetration, has received widespread attention in recent years. Sonosensitizers with intrinsic characteristics for tumor-specific curative effects, tumor microenvironment (TME) regulation and tumor diagnosis are in high demand. Herein, amorphous CoBiMn-layered double hydroxide (a-CoBiMn-LDH) nanoparticles are presented as multifunctional sonosensitizers to trigger reactive oxygen species (ROS) generation for ultrasound (US) imaging-guided SDT. Hydrothermal-synthesized CoBiMn-LDH nanoparticles are etched via a simple acid treatment to obtain a-CoBiMn-LDH nanoparticles with abundant defects. The a-CoBiMn-LDH nanoparticles give greater ROS generation upon US irradiation, reaching levels ~ 3.3 times and ~ 8.2 times those of the crystalline CoBiMn-LDH nanoparticles and commercial TiO2 sonosensitizer, respectively. This excellent US-triggered ROS generation performance can be attributed to the defect-induced narrow band gap and promoted electrons and holes (e−/h+) separation. More importantly, the presence of Mn4+ enables the a-CoBiMn-LDH nanoparticles to regulate the TME by decomposing H2O2 into O2 for hypoxia relief and US imaging, and consuming glutathione (GSH) for protection against ROS clearance. Biological mechanism analysis shows that a-CoBiMn-LDH nanoparticles modified with polyethylene glycol can serve as a multifunctional sonosensitizer to effectively kill cancer cells in vitro and eliminate tumors in vivo under US irradiation by activating p53, apoptosis, and oxidative phosphorylation-related signaling pathways.

Enhancing iron content and growth of cucumber seedlings with MgFe-LDHs under low-temperature stress.

The development of cost-effective and eco-friendly fertilizers is crucial for enhancing iron (Fe) uptake in crops and can help alleviate dietary Fe deficiencies, especially in populations with limited access to meat. This study focused on the application of MgFe-layered double hydroxide nanoparticles (MgFe-LDHs) as a potential solution. We successfully synthesized and characterized MgFe-LDHs and observed that 1-10mg/L MgFe-LDHs improved cucumber seed germination and water uptake. Notably, the application of 10mg/L MgFe-LDHs to roots significantly increased the seedling emergence rate and growth under low-temperature stress. The application of 10mg/L MgFe-LDHs during sowing increased the root length, lateral root number, root fresh weight, aboveground fresh weight, and hypocotyl length under low-temperature stress. A comprehensive analysis integrating plant physiology, nutrition, and transcriptomics suggested that MgFe-LDHs improve cold tolerance by upregulating SA to stimulate CsFAD3 expression, elevating GA3 levels for enhanced nitrogen metabolism and protein synthesis, and reducing levels of ABA and JA to support seedling emergence rate and growth, along with increasing the expression and activity of peroxidase genes. SEM and FTIR further confirmed the adsorption of MgFe-LDHs onto the root hairs in the mature zone of the root apex. Remarkably, MgFe-LDHs application led to a 46% increase (p < 0.05) in the Fe content within cucumber seedlings, a phenomenon not observed with comparable iron salt solutions, suggesting that the nanocrystalline nature of MgFe-LDHs enhances their absorption efficiency in plants. Additionally, MgFe-LDHs significantly increased the nitrogen (N) content of the seedlings by 12% (p < 0.05), promoting nitrogen fixation in the cucumber seedlings. These results pave the way for the development and use of LDH-based Fe fertilizers.

Functionalized high entropy alloys with ZIF-8 and LDH nanolayers for next-generation drug eluting medical implants

In this study, high entropy alloys (HEA) were fabricated by mixing Ni, Co, Cr, Fe, and Mn powders and then subjected to spark plasma sintering (SPS). Samples were coated by Al-Zn-layered double hydroxide (LDH) nanoparticles (NPs), SiO2 coated Al-Zn-layered double hydroxide NPs (LDH@Sio2), and zeolite imidazole framework (ZIF-8 NPs) using the electrophoretic deposition (EPD) method. To enhance immune response, antiviral effects, and iron uptake, ascorbic acid was intercalated within LDHs and ZIF-8 NPs layers via the ion-exchange method. Microstructural properties were examined using the X-ray diffraction method (XRD), optical microscopy, and scanning electron microscopy (SEM). The corrosion behavior of the specimens was investigated by a potentiodynamic polarization scan (PDS). A UV–visible evaluation test was conducted to assess drug release from the coated samples. SEM images demonstrated a homogenous microstructural coating, and XRD results confirmed that successful incorporation of vitamin C into LDH NPs, as indicated by an increase in layer distance from 7.36 to 7.46 Å. UV–visible studies revealed that LDH@SiO2 NPs exhibited a vitamin C release rate exceeding 5% compared to other coatings. Cell adhesion and proliferation assays using the MTT assay further confirmed the biocompatibility of the samples and their appropriate biological response to MG63 cells.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

Chemical and physical modification of graphene oxide nano-sheets using casein, Zn-Al layered double hydroxide, alginate hydrogel, and magnetic nanoparticles for biomedical applications

In our study, we developed a novel nanobiocomposite using graphene oxide (GO), casein (Cas), ZnAl layered double hydroxide (LDH), sodium alginate (Alg), and Fe3O4 magnetic nanoparticles. To synthesize the GO, we used a modified Hummer's method and then covalently functionalized its surface with Cas protein. The functionalized GO was combined with as-synthesized ZnAl LDH, and the composite was conjugated with alginate hydrogel through the gelation process. Finally, we magnetized the nanobiocomposite using in-situ magnetization. The nanobiocomposite was comprehensively characterized using FT-IR, FE-SEM, EDX, and XRD. Its biological potential was assessed through cell viability, hemolysis, and anti-biofilm assays, as well as its application in hyperthermia. The MTT assay showed high cell viability percentages for Hu02 cells after 24, 48, and 72 h of incubation. The nanobiocomposite had a hemolytic effect lower than 3.84 %, and the measured bacterial growth inhibition percentages of E. coli and S. aureus bacteria in the presence of the nanobiocomposite were 52.18 % and 55.72 %, respectively. At a concentration of 1 mg.mL−1 and a frequency of 400 kHz, the nanocomposite exhibits a remarkable specific absorption rate (SAR) of 67.04 W.g−1, showcasing its promising prospects in hyperthermia applications.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

Two‐Way Regulation of MgFe‐LDH on ESC Cell Fate via Temporal Selective Activation of Different Cell Membrane Receptors

AbstractStem cell fate regulation by biomaterials has considerable therapeutic potential; however, the mechanisms whereby biomaterials instruct stem cells for accurate fate regulation still need to be elucidated. Layered double hydroxide (LDH) nanoparticles are widely used for tissue regeneration because of their excellent physicochemical properties and biocompatibility. This study reveals that MgFe‐LDH has bidirectional regulatory effects on the differentiation of mouse embryonic stem cells into neural progenitor cells, essentially suppressing cell differentiation on the 1st day and promoting cell differentiation on the 3rd day. Single‐cell transcriptome sequencing and simulated computation of structural analysis demonstrate that MgFe‐LDH interacts with the membrane receptors leukemia inhibitory factor receptor (LIFR, 15 nm above the cell membrane) and pached1 (PTCH1, 6 nm above the cell membrane) on the 1st and 3rd day of differentiation, respectively. LIFR has more contact with MgFe‐LDH than PTCH1 and relatively weaker electrostatic interaction energies (−11010.0 and −9829.3 kJ mol−1 for PTCH1 and LIFR, respectively). These factors determine receptor binding and activation priority, followed by cell fate regulation. The results indicate that MgFe‐LDH regulate the activity and fate of stem cells dually, thus creating possibilities for personalized therapy in neurodevelopment and regenerative medicine through an in‐depth study of cell membrane receptors.

Intranasal delivery of phenytoin loaded layered double hydroxide nanoparticles improves therapeutic effect on epileptic seizures

Improving the efficiency of antiseizure medication entering the brain is the key to reducing its peripheral toxicity. A combination of intranasal administration and nanomedicine presents a practical approach for treating epileptic seizures via bypassing the blood-brain barrier. In this study, phenytoin (PHT) loaded layered double hydroxide nanoparticles (BSA-LDHs-PHT) were fabricated via a coprecipitation − hydrothermal method for epileptic seizure control. In this study, we expound on the preparation method and characterization of BSA-LDHs-PHT. In-vitro drug release experiment shows both rapid and continuous drug release from BSA-LDHs-PHT, which is crucial for acute seizure control and chronic epilepsy therapy. In-vivo biodistribution assays after intranasal administration indicate excellent brain targeting ability of BSA-LDHs. Compared to BSA-Cyanine5.5, BSA-LDHs-Cyanine5.5 were associated with a higher brain/peripheral ratio across all tested time points. Following intranasal delivery with small doses of BSA-LDHs-PHT, the latency of seizures in the pentylenetetrazole-induced mouse models was effectively improved. Collectively, the present study successfully designed and applied BSA-LDHs-PHT as a promising strategy for treating epileptic seizures with an enhanced therapeutic effect.

Fluorescence study of the interaction between albumin and layered double hydroxides

Layered double hydroxides nanoparticles (LDH-NP) are increasingly studied for biomedical applications. Nevertheless, their interaction with biomolecules such as proteins needs further exploration for an effective application. In this work, the adsorption of bovine serum albumin (BSA) on LDH-NP and the conformation changes of the protein upon adsorption were characterized using fluorescence spectroscopy. First, the quenching of tryptophan residues of BSA by chloride-intercalated LDH-NP was explored and the BSA adsorption capacity of LDH-NP were determined. Then, the structural conformation of the protein was analyzed by fluorescence spectroscopy (including synchronous, polarization and quenching studies) at different surface coverages. Finally, the proclivity of adsorbed BSA molecules to assemble as amyloid fibril was evaluated. Due to the positive charging and low curvature of LDH-NP, BSA molecules were strongly adsorbed, which produced a quenching of the protein fluorescence and a large adsorption capacity. The effect on BSA conformation was dependent on surface coverage (SC): at low values ,t he tryptophan residues were in more hydrophobic environments and more accessible to quenchers than al high ones. At low SC, there is space between the BSA molecules to spread on the surface, which led to a conformation change. Contrarily, the native conformation around tryptophan residues of BSA was preserved at high SC due to the tight packing of the adsorbed protein molecules. As a result, BSA molecules are stabilized against the formation of amyloid fibrils at high SC, while at low SC they present a similar fibrillation than free BSA.