Excellent Colloidal Stability Research Articles

Metal-Solvent Complex Formation at the Surface of InP Colloidal Quantum Dots.

The surface chemistry of colloidal semiconductor nanocrystals (QDs) profoundly influences their physical and chemical attributes. The insulating organic shell ensuring colloidal stability impedes charge transfer, thus limiting optoelectronic applications. Exchanging these ligands with shorter inorganic ones enhances charge mobility and stability, which is pivotal for using these materials as active layers for LEDs, photodetectors, and transistors. Among those, InP QDs also serve as a model for surface chemistry investigations. This study focuses on group III metal salts as inorganic ligands for InP QDs. We explored the ligand exchange mechanism when metal halide, nitrate, and perchlorate salts of group III (Al, In Ga), common Lewis acids, are used as ligands for the conductive inks. Moreover, we compared the exchange mechanism for two starting model systems: InP QDs capped with myristate and oleylamine as X- and L-type native organic ligands, respectively. We found that all metal halide, nitrate, and perchlorate salts dissolved in polar solvents (such as n-methylformamide, dimethylformamide, dimethyl sulfoxide, H2O) with various polarity formed metal-solvent complex cations [M(Solvent)6]3+ (e.g., [Al(MFA)6]3+, [Ga(MFA)6]3+, [In(MFA)6]3+), which passivated the surface of InP QDs after the removal of the initial organic ligand. All metal halide capped InP/[M(Solvent)6]3+ QDs show excellent colloidal stability in polar solvents with high dielectric constant even after 6 months in concentrations up to 74 mg/mL. Our findings demonstrate the dominance of dissociation-complexation mechanisms in polar solvents, ensuring colloidal stability. This comprehensive understanding of InP QD surface chemistry paves the way for exploring more complex QD systems such as InAs and InSb QDs.

Nd3+-sensitized multilayered rare-earth nanocrystals with enhanced NIR-IIb luminescence for high resolution optical imaging

Luminescence imaging in the second near-infrared (NIR-II) window, particularly within the NIR-IIb (1500–1700 nm) sub-window, has been utilized for both fundamental research and clinical applications due to its exceptional spatiotemporal resolution. Nevertheless, efficient contrast agents designed for NIR-IIb imaging are still scarce. Herein, a multilayered rare-earth nanocrystal (NaYF4:Yb,Er,Ce@NaYF4:Yb,Nd@NaYF4) with strong NIR-IIb luminescence was designed and synthesized. The doping of Ce3+ ions in the core effectively suppresses the upconversion and boosts the downconversion luminescence by populating the Er 4I13/2 level. Additionally, by separating the sensitizer (Nd3+) and the activator (Er3+) in different layers, we are able to maximize the light absorption around 800 nm and reduce the cross relaxations between rare-earth elements, which leads to a strong downconversion emission around 1530 nm under 808 nm excitation. After passivation with NaYF4 shell and phase transfer with highly PEGylated mesoporous silica layer, the nanocomposites with excellent colloidal stability and bright NIR-IIb emission were obtained. With long blood circulation time in vivo, the fabricated nanocomposites enable high resolution and contrast luminescence imaging of the blood vessels and tumors in living mice. Moreover, the rare-earth nanocrystals with superior optical properties also hold great promise for various applications in optical sensing and biomedical imaging.

Sunlight-assisted green synthesis of gold nanocubes using horsetail leaf extract: A highly selective colorimetric sensor for Pb2+, photocatalytic and antimicrobial agent

This work aims to establish a novel approach for the selective synthesis of gold nanoparticles (Au NPs) with defined shape and size as well as excellent colloidal stability via a facile and environmentally friendly manner. The polar extract from the leaves of the plant E. diffusum (EDLE), also known as horsetail, was used to synthesize gold NPs (EDLE@Au NPs). Fourier-transform infrared (FTIR) and UV–visible spectroscopy, scanning electron microscopy-energy dispersive X-rays (SEM-EDX), PXRD, dynamic light scattering (DLS), and zeta potential (ZP) were used to characterize as-synthesized EDLE@Au NPs. The SEM imaging revealed the cubic shape of EDLE@Au NPs. Interestingly, EDLE@Au NPs interacted with different metal ions, and a shift in the LSPR band to a higher wavelength was observed only in the case of Pb2+ ions. This provided a basis for using the EDLE@Au NPs as a selective colorimetric sensor for Pb2+ ions. A linear range of 20–350 µM and a limit of detection of 4.4 µM for Pb2+ detection was achieved. To elucidate the sensing mechanism, DLS and zeta potential analyses were carried out after addition of Pb2+. A significant decrease in the zeta potential along with an increase in the particle size of the Au NPs was observed after the addition of Pb2+, suggesting the aggregation of the nanoparticles. Further, the results of the antimicrobial study showed that EDLE@Au NPs were active against both gram-positive and gram-negative bacteria. An exceptional photocatalytic activity with 96.5% degradation efficiency of EDLE@Au NPs was examined against methylene blue dye.

Enhancing CAR‐NK Cells Against Solid Tumors Through Chemical and Genetic Fortification with DOTAP‐Functionalized Lipid Nanoparticles

AbstractNatural killer (NK) cells are crucial in the innate immune response and show promise in cancer immunotherapy, but face challenges in activation and targeted gene delivery. In this study, bifunctional lipid nanoparticles (DLNPs) containing 1,2‐dioleoyl‐3‐trimethylammonium‐propane (DOTAP), designed to bolster the antitumor efficacy of chimeric antigen receptor‐modified NK (CAR‐NK) cells by facilitating activation and efficient CAR mRNA delivery are introduced. The DLNPs, created by functionalizing FDA‐approved LNP compositions, exhibit excellent mRNA encapsulation and colloidal stability. NK cells primed with DLNPs show increased cytotoxicity against cancer cells via extracellular signal‐regulated kinase/Mitogen‐Activated Protein Kinase pathway modulation and mitochondrial dynamics changes. The DLNPs enter NK cells predominantly through clathrin‐mediated endocytosis, boosting mRNA delivery and overcoming NK cells' resistance to genetic manipulation. CAR‐NK cells targeting glypican‐3, prevalent in hepatocellular carcinoma, show significant therapeutic effects in an orthotopic mouse model. These findings underscore the potential of DLNPs in enhancing CAR‐NK cell therapy for solid tumors, marking a significant stride in NK cell‐based cancer immunotherapy and broadening prospects for NK cell‐related disease interventions.

Pivalic acid based N-doped carbon dots for drug delivery and antioxidant behaviour

Heteroatom doped surface engineered carbon dots has immense potential not only in their fluorescent sensing but also in nanocarrier for drug molecules and antioxidant behavior. Herein, we report a one-step thermal coupling synthesis of carbon dots from pivalic acid and naturally abundant gelatin (PGCDs). The as-synthesized PGCDs exhibited excellent colloidal stability, biocompatibility, and antioxidant activity. The surface of PGCDs was further modified with anticancer drug molecules to assess their drug delivery capabilities. The drug-loaded PGCDs demonstrated sustained release profiles, indicating their potential for controlled drug delivery applications. For understanding the drug delivery mechanism, the cumulative release data have been fitted into Weibull and Higuchi model. The PGCDs also showed pH sensitive release behavior where acidic environment has a better control in release profile compared to the alkaline pH. The concentration dependent radical activity shows more than 80% activity at below 1 mg/mL PGCDs concentration. Their low toxicity against live human cell lines could promote this PGCDs as a potential versatile nano-vector biomedical research area.

Synthesis, characterization, and application of honey stabilized inulin nanoparticles as colon targeting drug delivery carrier

Inulin (INU) is a versatile natural polysaccharide primarily derived from chicory roots. INU possesses the unique quality of evading digestion or fermentation in the early stages of the human digestive tract, instead reaching the lower colon directly. Exploiting on this distinctive attribute, INU finds application in the creation of targeted carrier systems for delivering drugs tailored to colon-related diseases. This study presents a novel method for synthesizing highly stable and non-aggregatory inulin nanoparticles (INU NPs) by ionotropic gelation method, using calcium chloride as crosslinker and natural honey as a stabilizing agent. Different formulation and process parameters were optimized for the synthesis of monodispersed INU NPs. These INU NPs efficiently encapsulated a hydrophilic drug irinotecan hydrochloride trihydrate (IHT) and drug loaded formulation (IINPs) demonstrated excellent colloidal and storage stabilities. Notably, these IINPs exhibited pH-dependent drug release, suggesting potential for colon-specific drug delivery. Anticancer activity of the NPs was found significantly higher in comparison to IHT through cytotoxicity and apoptosis studies against human colorectal carcinoma cells. Overall, this study revealed that the INU NPs synthesized by ionotropic gelation will be an efficient nanocarrier system for colon-targeted drug delivery due to their exceptional biocompatibility and stability in stomach and upper intestinal conditions.

Aptamer Clicked Poly(ferrocenylsilanes) at Au Nanoparticles as Platforms with Multiple Function[†

Aptamers are widely used in biosensing due to their specific sensitivity toward many targets. Thus, gold nanoparticle (AuNP) aptasensors are subject to intense research due to the complementary properties of aptamers as sensing elements and AuNPs as transducers. We present herein a novel method for the functional coupling of thrombin-specific aptamers to AuNPs via an anionic, redox-active poly(ferrocenylsilane) (PFS) polyelectroyte. The polymer acts as a co-reductant and stabilizer for the AuNPs, provides grafting sites for the aptamer, and can be used as a redox sensing element, making the aptamer-PFS-AuNP composite (aptamer-AuNP) a promising model system for future multifunctional sensors. The aptamer-AuNPs exhibit excellent colloidal stability in high ionic strength environments owing to the combined electrosteric stabilizing effects of the aptamer and the PFS. The synthesis of each assembly element is described, and the colloidal stability and redox responsiveness are studied. As an example to illustrate applications, we present results for thrombin sensitivity and specificity using the specific aptamer.

Ferroptosis boosted oral cancer photodynamic therapy by carrier-free Sorafenib-Ce6 self-assembly nanoparticles

Oral cancer is a disease with high morbidity and mortality worldwide and greatly impacts the quality of life, especially in patients with advanced stages. Photodynamic therapy (PDT) is one of the most effective clinical treatments for oral cancers. However, most clinically applied photosensitizers have several deficiencies, including oxygen dependence, poor aqueous solubility, and a lack of tumor-targeting ability. Herein, the carrier-free multifunctional Sorafenib (Sor), chlorin e6 (Ce6), and Fe3+ self-assembly co-delivery nanoparticles (Sor-Ce6 NPs) were constructed via combining a ferroptosis inducer Sor and a photosensitizer Ce6 for synergetic therapy. The as-synthesized Sor-Ce6 NPs presented excellent colloidal stability and water dispersity with good in vivo tumor-targeting ability. More significantly, the low dose of Sor-Ce6 NPs had little dark toxicity but produced significantly enhanced ROS and supplied O2 sustainably to increase phototoxicity through ferroptosis pathway. Notably, the Sor-Ce6 NPs showed significantly higher in vitro and in vivo anti-tumor efficacy than the Sor/Ce6 mixture due to the improvement of cellular uptake and the incorporation of foreign Fe ions in the system, which also confer the T1 magnetic resonance-guided imaging ability to the formed Sor-Ce6 NPs. Our study demonstrates a promising self-assembled strategy for overcoming hypoxia-related PDT resistance for oral cancer treatment.

Stable Inorganic Colloidal Tin and Tin-Lead Perovskite Nanocrystals with Ultralong Carrier Lifetime via Sn(IV) Control.

Inorganic tin (Sn) perovskite nanocrystals offer a promising solution to the potential toxicity concerns associated with their established lead (Pb)-based counterparts. Yet, achieving their superior stability and optoelectronic properties remains an ongoing challenge. Here, we report a synthesis of high-symmetry α-phase CsSnI3 nanocrystals with an ultralong 278 ns carrier lifetime, exceeding previous benchmarks by 2 orders of magnitude through meticulous Sn(IV) control. The nanocrystals demonstrate excellent colloidal stability, uniform monodispersity, and a distinct exciton peak. Central to these outcomes is our designed solid-liquid antioxidation suspension of tri-n-octylphosphine (TOP) and zerovalent tin (Sn(0)) that fully addresses the unique coexisting oxygen-driven and solvent-driven Sn oxidation mechanisms in Sn perovskite nanocrystal synthesis. We uncover the largely undervalued function of TOP in mitigating oxygen-driven Sn oxidation and introduce Sn(0) powder to generate a synergistic antioxidation function with TOP, significantly reducing Sn(IV)-induced defects and distortions and contributing to enhanced optoelectronic properties. Strikingly, this approach also profoundly impacts inorganic Sn-Pb perovskite nanocrystals, boosting lifetimes by 2 orders of magnitude and increasing photoluminescence quantum yield over 100-fold to 35%. Our findings illuminate the potential of Sn-based nanocrystals for optoelectronic applications.

Plasmon-powered chemistry with visible-light active copper nanoparticles.

In the quest for affordable materials for performing visible-light driven chemistry, we report here intriguing optical and photothermal properties of plasmonic copper nanoparticles (CuNPs). Precise tuning of reaction conditions and surface functionalization yield stable and monodisperse CuNPs, with a strong localized surface plasmon absorption at ∼580 nm. The molar extinction coefficient is estimated to be ∼7.7 × 107 M-1 cm-1 at 580 nm, which signifies their suitability for various light-harnessing studies. The characteristic wine-red colour and crystallography studies confirm the presence of mainly Cu(0) atoms in CuNPs, which showed excellent long-term colloidal and compositional stability under ambient conditions (at least 50 days). The as-synthesized oleylamine-capped CuNPs are ligand-exchanged with charged thiolate ligands of both polarities to form stable dispersions in water, with complete retention of their plasmonic properties and structural integrity (for ∼2 days and ∼6 h under inert and ambient conditions, respectively). Photothermal-conversion efficiency of CuNPs is estimated to be ∼80%, raising the surrounding temperature to ∼170 °C within ∼30 s of irradiation with a 1 W 532 nm diode laser, which is 'hot' enough to perform useful solar-vapor generation and high-temperature crystal-to-crystal phase transformation. Our work projects plasmonic CuNPs as an affordable and effective alternative to conventional metal NPs to harness light-matter interactions for future plasmon-powered chemistry.

Tumor-activated targetable photothermal chemotherapy using IR780/zoledronic acid-containing hybrid polymeric nanoassemblies with folate modification to treat aggressive breast cancer.

To effectively treat aggressive breast cancer by tumor-activated targetable photothermal chemotherapy, in this work, folate (FA)-modified hybrid polymeric nanoassemblies (HPNs) with a poly(ethylene glycol) (PEG)-detachable capability are developed as vehicles for tumor-targeted co-delivery of IR780, a lipophilic photothermal reagent, and zoledronic acid (ZA), a hydrophilic chemotherapy drug. Through hydrophobic interaction-induced co-assembly, IR780 molecules and ZA/poly(ethylenimine) (PEI) complexes were co-encapsulated into a poly(lactic-co-glycolic acid) (PLGA)-rich core stabilized by the amphiphilic FA-modified D-α-tocopheryl poly(ethylene glycol) succinate (FA-TPGS) and acidity-sensitive PEG-benzoic imine-octadecane (C18) (PEG-b-C18) conjugates. The developed FA-ZA/IR780@HPNs with high ZA and IR780 payloads not only showed excellent colloidal stability in a serum-containing milieu, but also promoted IR780-based photostability and photothermal conversion efficiency. Furthermore, for FA-ZA/IR780@HPNs under simulated physiological conditions, the premature leakage of IR780 and ZA molecules was remarkably declined. In a mimetic acidic tumor microenvironment, the uptake of FA-ZA/IR780@HPNs by FA receptor-overexpressed 4T1 breast cancer cells was remarkably promoted by PEG detachment combined with FA receptor-mediated endocytosis, thus effectively hindering migration of cancer cells and augmenting the anticancer efficacy of photothermal chemotherapy. Notably, the in vivo studies demonstrated that the FA-ZA/IR780@HPNs largely deposited at 4T1 tumor sites and profoundly suppressed tumor growth and metastasis without severe systemic toxicity upon near infrared (NIR)-triggered IR780-mediated hyperthermia integrated with ZA chemotherapy. This work presents a practical strategy to treat aggressive breast tumors with tumor-triggered targetable photothermal chemotherapy using FA-ZA/IR780@HPNs.

Doxorubicin loaded thermostable nanoarchaeosomes: a next-generation drug carrier for breast cancer therapeutics.

Breast cancer has a poor prognosis due to the toxic side effects associated with high doses of chemotherapy. Liposomal drug encapsulation has resulted in clinical success in enhancing chemotherapy tolerability. However, the formulation faces severe limitations with a lack of colloidal stability, reduced drug efficiency, and difficulties in storage conditions. Nanoarchaeosomes (NA) are a new generation of highly stable nanovesicles composed of the natural ether lipids extracted from archaea. In our study, we synthesized and characterized the NA, evaluated their colloidal stability, drug release potential, and anticancer efficacy. Transmission electron microscopy images have shown that the NA prepared from the hyperthermophilic archaeon Aeropyrum pernix K1 was in the size range of 61 ± 3 nm. The dynamic light scattering result has confirmed that the NA were stable at acidic pH (pH 4) and high temperature (70 °C). The NA exhibited excellent colloidal stability for 50 days with storage conditions at room temperature. The cell viability results have shown that the pure NA did not induce cytotoxicity in NIH 3T3 fibroblast cells and are biocompatible. Then NA were loaded with doxorubicin (NAD), and FTIR and UV-vis spectroscopy results have confirmed high drug loading efficiency of 97 ± 1% with sustained drug release for 48 h. The in vitro cytotoxicity studies in MCF-7 breast cancer cell lines showed that NAD induced cytotoxicity at less than 10 nM concentration. Fluorescence-activated cell sorting (FACS) results confirmed that NAD induced late apoptosis in nearly 92% of MCF-7 cells and necrosis in the remaining cells with cell cycle arrest at the G0/G1 phase. Our results confirmed that the NA could be a potential next-generation carrier with excellent stability, high drug loading efficiency, sustained drug release ability, and increased therapeutic efficacy, thus reducing the side effects of conventional drugs.

A gold nanocluster/MIL-100(Fe) bimodal nanovector for the therapy of inflammatory disease through attenuation of Toll-like receptor signaling.

A better understanding of the molecular and cellular events involved in the inflammation process has opened novel perspectives in the treatment of inflammatory diseases, particularly through the development of well-designed nanomedicines. Here we describe the design of a novel class of anti-inflammatory nanomedicine (denoted as Au@MIL) synthesized through a one-pot, cost-effective and green approach by coupling a benchmark mesoporous iron(III) carboxylate metal organic framework (MOF) (i.e. MIL-100(Fe)) and glutathionate protected gold nanoclusters (i.e. Au25SG18 NCs). This nano-carrier exhibits low toxicity and excellent colloidal stability combined with the high loading capacity of the glucocorticoid dexamethasone phosphate (DexP) whose pH-dependent delivery was observed. The drug loaded Au@MIL nanocarrier shows high anti-inflammatory activity due to its capacity to specifically hinder inflammatory cell growth, scavenge intracellular reactive oxygen species (ROS) and downregulate pro-inflammatory cytokine secretion. In addition, this formulation has the capacity to inhibit the Toll-like receptor (TLR) signaling cascade namely the nuclear factor kappa B (NF-κB) and the interferon regulatory factor (IRF) pathways. This not only provides a new avenue for the nanotherapy of inflammatory diseases but also enhances our fundamental knowledge of the role of nanoMOF based nanomedicine in the regulation of innate immune signaling.

Smart hybrid copolymer-coated silica nanosystems with dual responsiveness as a carrier for positive charged molecules

Smart nanosystems consisting of inorganic particles and responsive polymers display significant and remarkable aspects. Such combined work exploits a facile path for multifunctional nanomaterials and facilitates various novel technological applications due to “live” polymer components. Here, we report the design and synthesis of a new platform of smart hybrid nanosystems (SHN) for positively charged probe loading and specific release under pH and temperature-controlled conditions. The SHN was prepared by a simple sequential method that produced an integrated core–shell nanomaterial with a dual stimulus response and excellent colloidal stability. Further, we demonstrate by crossing DLS and NMR results that these core–shell nanosystems present transduction from both stimuli to a mechanical shrinkage of the polymeric shell, leading to a remote-controlled dual response that can be synthetically tuned by controlling the molar ratio between monomers. Finally, we studied the potential of these SHN as molecular carriers and demonstrated that they are useful for selective ionic encapsulation of positively charged molecules, which release is controlled by the dual responsiveness. We successfully extended this concept to doxorubicin release triggered by T and pH changes, which opens possibilities of using these SHN improving results and patient compliance in chemotherapy treatments.

Designing a Stable and Electrically Conductive Colloidal Suspension for Improved Flow Electrode Capacitive Deionization

With increasing effects from major droughts and water shortages, water desalination has garnered significant technological interest. Like many technologies, desalination suffers from high energy consumption, capital cost, process inefficiencies, and material degradation. Flow electrode capacitive deionization (FCDI) is a relatively new water desalination technology that combines aspects of electrodialysis and capacitive deionization to deliver a device which can achieve >90% water recovery at high productivity and thermodynamic efficiency. A fundamental challenge in FCDI, though, is engineering an electrically conductive slurry with excellent colloidal stability. Here, we explore the tradeoff between electrical conductivity and sedimentation rate using commercially available surfactants. We find that the optimal surfactant is non-intuitive and strongly depends on the type of carbon used in the slurry (e.g., activated carbon, carbon black, etc.).This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant #22-DR-011. IM release number: LLNL-ABS-846651.

Dual strategy to improve the oral bioavailability of efavirenz employing nanomicelles and curcumin as a bio-enhancer

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor.Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized “nano-sized” therapy for AIDS patients.

Polyampholyte-grafted silica nanoparticles for shale plugging under high-temperature and extreme-salinity conditions

Nano-/submicron-scale plugging is critical for wellbore stability during shale gas exploitation but typically fails under high-temperature and extreme-salinity conditions due to colloidal instability. Herein, polyampholyte polymers (ZP) were grafted from the surface of silicon dioxide (SiO2) nanoparticles through surface-triggered free radical polymerization to generate nanoplugging additives (SiO2-g-ZP). SiO2-g-ZP exhibited excellent colloidal dispersion stability with a nano/submicron size distribution in 35 w/v% sodium chloride (NaCl) and 11 w/v% calcium chloride (CaCl2) brines at 160 °C for a long time and over a wide pH range, and efficiently plugged 220 nm and ∼20 μm pores and 5 μm fractures at 160 °C and 3.5–5.5 MPa. Three critical aspects of observation and analysis obtained through microstructure analysis and molecular dynamics (MD) simulations helped elucidate the mechanisms that control the SiO2-g-ZP's performances: an increase in SiO2-g-ZP's hydration capability with salinity due to the antipolyelectrolyte behaviours of ZP coatings with zwitterionic nature, an efficient mitigation of Na-bent agglomeration even at harsh conditons due to the preferential adsorption of SiO2-g-ZP rather than Na+, Ca2+ and Cl− on Na-bent, and the presence of a nanosilica core and rigid groups and massive hydratable groups. The first two aspects caused a perfect matching of particles in muds to pores and fractures in formation and the third aspect helped enhance the SiO2-g-ZP's thermal resistance and residence in the pores and fractures. This work provides a novel approach that can be broadly generalized to address the thermal- and salt-tolerance challenges of colloidal systems used in the exploration and development of deep and complex shale formations.

Nanogels with covalently bound and releasable trehalose for autophagy stimulation in atherosclerosis

Atherosclerosis, cholesterol-driven plaque formation in arteries, is a complex multicellular disease which is a leading cause of vascular diseases. During the progression of atherosclerosis, the autophagic function is impaired, resulting in lipid accumulation-mediated foam cell formation. The stimulation of autophagy is crucial for the recovery of cellular recycling process. One of the potential autophagy inducers is trehalose, a naturally occurring non-reducing disaccharide. However, trehalose has poor bioavailability due to its hydrophilic nature which results in poor penetration through cell membranes. To enhance its bioavailability, we developed trehalose-releasing nanogels (TNG) for the treatment of atherosclerosis. The nanogels were fabricated through copolymerization of 6-O-acryloyl-trehalose with the selected acrylamide-type monomers affording a high trehalose conjugation (~ 58%, w/w). TNG showed a relatively small hydrodynamic diameter (dH, 67 nm) and a uniform spherical shape and were characterized by negative ζ potential (-18 mV). Thanks to the trehalose-rich content, TNG demonstrated excellent colloidal stability in biological media containing serum and were non-hemolytic to red blood cells. In vitro study confirmed that TNG could stimulate autophagy in foam cells and enhance lipid efflux and in vivo study in ApoE−/− mice indicated a significant reduction in atherosclerotic plaques, while increasing autophagic markers. In conclusion, TNG hold great promise as a trehalose delivery system to restore impaired autophagy-mediated lipid efflux in atherosclerosis and subsequently reduce atherosclerotic plaques.Graphical abstract

Protein bodies from hemp seeds: Isolation, microstructure and physicochemical characterisation

Protein bodies are naturally occurring storage organelles in plant seeds. Although the microstructure of protein bodies has been studied, their physicochemical behaviour and stability under different environmental conditions remain poorly understood. In this study, hemp seed protein bodies (HPBs) were obtained using a sonication-assisted aqueous enzymatic extraction method. Then, their microstructures were characterised using various microscopic techniques. Next, the protein composition was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE). Lastly, the influence of pH (2–13) on the colloidal stability and structural integrity of aqueous HPB dispersions was investigated. Detailed microscopic examination showed that the HPBs exhibited spherical shape with an average diameter of about 4.6 μm. The structure consisted of a protein crystalloid and several phytin globoids, all surrounded by a proteinaceous matrix and a single membrane. Globulin edestin was the most abundant storage protein in the HPBs as revealed by SDS–PAGE. The HPB dispersions exhibited excellent colloidal stability only at neutral pH as opposed to their aggregation and/or solubilisation at other pH levels tested. The HPBs also showed irreversible structural changes in response to pH variation. Specifically, little to no swelling of the particles was observed at pH 5 (around the isoelectric point (pI) of the hemp protein). However, when the pH shifted away from the pI, swelling, rupture and eventual dissolution of the particles were pronounced under both extreme acidic and alkaline conditions. These physicochemical behaviours make the HPBs an interesting pH-sensitive material for food applications, which will be explored in subsequent studies.

Hyaluronic Acid Nanogels: A Promising Platform for Therapeutic and Theranostic Applications.

Hyaluronic acid (HA) nanogels are a versatile class of nanomaterials with specific properties, such as biocompatibility, hygroscopicity, and biodegradability. HA nanogels exhibit excellent colloidal stability and high encapsulation capacity, making them promising tools for a wide range of biomedical applications. HA nanogels can be fabricated using various methods, including polyelectrolyte complexation, self-assembly, and chemical crosslinking. The fabrication parameters can be tailored to control the physicochemical properties of HA nanogels, such as size, shape, surface charge, and porosity, enabling the rational design of HA nanogels for specific applications. Stimulus-responsive nanogels are a type of HA nanogels that can respond to external stimuli, such as pH, temperature, enzyme, and redox potential. This property allows the controlled release of encapsulated therapeutic agents in response to specific physiological conditions. HA nanogels can be engineered to encapsulate a variety of therapeutic agents, such as conventional drugs, genes, and proteins. They can then be delivered to target tissues with high efficiency. HA nanogels are still under development, but they have the potential to become powerful tools for a wide range of theranostic or solely therapeutic applications, including anticancer therapy, gene therapy, drug delivery, and bioimaging.