High Colloidal Stability Research Articles

Interrogating the photoluminescent properties of carbon dots using quantitative 13C NMR combined with systematic photobleaching

In this work, molecular-level events accompanying the photobleaching of carbon dots (CDs) synthesized from ethylenediamine and citric acid (CACDs) were identified using solution-phase NMR. By combining quantitative 13C NMR data with fluorescence measurements we show that this new approach is capable of identifying not only molecular fluorophores in CACDs, but also their contribution to the overall CACD fluorescence and their relative photostability. Specifically, imidazo[1,2-a]pyridine-7-carboxylic acid (IPCA) is found to be the dominant (84 %) species responsible for fluorescence in CACDs along with a second undetermined source, most likely associated with the aromatic core which is significantly (approximately 20 times) more photostable than IPCA. The presence of these two fluorescent species with different photostabilities rationalizes not only the photobleaching kinetics but also the evolution of the fluorescence spectrum during photobleaching Diffusion-ordered spectroscopy (DOSY) also reveals that all of the IPCA molecules are trapped within or covalently bound to the CACD, but are not present as isolated molecules freely rotating in solution. Singlet oxygen is confirmed as a key ROS responsible for photobleaching, with prototypical photoproducts identified from mass spectrometry studies of citrazinic acid. Quantitative 13C NMR of CACDs is possible because their extremely high colloidal stability enables high concentrations (667 mg/mL) to remain stable in solution. The approach described in this study could be extended to identify the structure of chromophores in other CDs and interrogate molecular level processes that accompany CD sensing.

Polymers marry with carbon nanospheres: A promising strategy to develop high-performance filtrate reducer

Polymeric filtrate reducers have limited uses under high temperature and salinity conditions. The incorporation of nanoparticles to polymeric networks is a popular and effective method for creating high-performance filtrate reducers. However, present nanofillers are costly, have negative environmental consequences, and are difficult or impossible to disseminate. Herein, a simple hydrothermal process using low-cost and renewable glucose as raw ingredients resulted in hydroxy-rich carbon nanospheres (CNs). After modification by acryloyl chloride, the CNs were copolymerized with acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and sodium p-styrene sulfonate. The obtained CNs-doped polymers (CAAS) were able to maintain high viscosity and colloidal stability even after salt contamination and high temperature aging. CAAS-based drilling fluids can tolerate temperatures of up to 240 °C under 30% NaCl conditions. The API filtration loss (FLAPI) and the high-temperature high-pressure filtration loss (FLHTHP) were 10 and 63.5mL, respectively. Considering the low-cost and renewable raw materials, high dispersibility and high compatibility of CNs as well as significant improvement in thermal-resistance and salt-tolerance, this work provides a simple yet effective approach to developing high-performance filtrate reducers for complex geological conditions.

Aptamer-Encapsulated Cellular Nanoparticles for Neurotoxin Neutralization.

Aptamers are single-stranded oligonucleotides that fold into defined architectures for specific target binding. In this study, aptamers are selected that specifically bind to small-molecule neurotoxins and encapsulate them into cell membrane-coated nanoparticles (referred to as 'cellular nanoparticles' or 'CNPs') for effective neutralization of neurotoxins. Specifically, six different aptamers are selected that bind to saxitoxin (STX) or tetrodotoxin (TTX) and encapsulate them into metal-organic framework cores, which are then coated with neuronal cell membrane. The resulting CNPs exhibit high colloidal stability, minimal aptamer leakage, and effective protection of aptamer payloads against enzyme degradation. This detoxification platform combines membrane-enabled broad-spectrum neutralization with aptamer-based specific toxin binding, offering dual-modal neutralization mechanisms for efficient neurotoxin neutralization. The in vitro neutralization efficacy is demonstrated using a neuron osmotic swelling assay, a Na+ flux fluorescence assay, and a cytotoxicity assay. The in vivo neutralization efficacy is further validated using mouse models of STX and TTX intoxication in both therapeutic and preventative regimens. Overall, integrating aptamers with CNPs combines the strengths of both technologies, resulting in a robust solution for broad-spectrum toxin-neutralization applications.

Aqueous phase transfer of near-infrared ZnCuInS2/ZnS quantum dots: Synthesis and characterization

Cadmium-free and NIR fluorescent QDs are promising candidates for bio-application. Thus, we present the synthesis of ternary ZnCuInS2/ZnS (ZCIS/ZnS) quantum dots (QDs) where the molar variation of Cu/Zn of the precursors was used to tune the optical and structural properties. QDs with Cu/Zn molar ratio of 2/1 passivated with ZnS exhibited the best optical properties. They showed dominant near-infrared photoluminescence (approx. 850 nm) and highest quantum yield (approx. 52 %, λexc = 500 nm). Therefore, they were further subject to modification to ensure their transfer to the aqueous phase and improve biocompatibility. For this, different functionalization approaches were used. The first method relied on encapsulation with polymers like PSMA (poly(styrene co-maleic anhydride)) and PMAO (poly(maleic anhydride-alt-1-octadecene) coupled with polyetheramine (JEFF; Jeffamine M-1000), and the second relied on hydrophilization with PMAO. Furthermore, we also applied a surface ligand exchange process using DHLA (dihydrolipoic acid) and polyethylene glycol (PEG)-appended DHLA. The comprehensive study indicated that ZnCuInS2/ZnS QDs functionalized with PMAO (ZnCuInS2/ZnS@PMO) exhibited the highest photoluminescence (PL QY) along with ensured high colloidal stability in aqueous media. Moreover, no noticeable deterioration of the photoluminescence profile was observed for all used functionalization approaches. However, a significant decrease in QY was observed for almost all functionalized QDs except those that were PMO-capped. The synthesized QDs were systematically characterized by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), UV–Vis absorption spectroscopy, and fluorescence spectroscopy. Biological studies indicate that the obtained hydrophilic ZCIS QDs are biocompatible and localized intracellularly inside endosomes.

Hydrophobic iron oxide nanoparticles: Controlled synthesis and phase transfer via flash nanoprecipitation

Iron oxide nanoparticles (IONPs) synthesized via thermal decomposition find diverse applications in biomedicine owing to precise control of their physico-chemical properties. However, use in such applications requires phase transfer from organic solvent to water, which remains a bottleneck.Through the thermal decomposition of iron oleate (FeOl), we systematically investigate the impact of synthesis conditions such as oleic acid (OA) amount, temperature increase rate, dwell time, and solvent on the size, magnetic saturation, and crystallinity of IONPs. Solvent choice significantly influences these properties, manipulating which, synthesis of monodisperse IONPs within a tunable size range (10-30 nm) and magnetic properties (75 to 42 Am2Kg-1) is obtained.To enable phase transfer of IONPs, we employ flash nanoprecipitation (FNP) for the first time as a method for scalable and precise size control, demonstrating its potential over conventional methods. Poly(lactic-co-glycolic acid) (PLGA)-coated IONPs with hydrodynamic diameter (Hd) in the range of 250 nm, high colloidal stability and high IONPs loadings up to 43% were obtained, such physicochemical properties being tuned exclusively by the size and hydrophobicity of starting IONPs. They showed no discernible cytotoxicity in human dermal fibroblasts, highlighting the applicability of FNP as a novel method for the functionalization of hydrophobic IONPs for biomedicine.

Zika Virus NS1 Protein Detection Using Gold Nanoparticle-Assisted Dynamic Light Scattering.

The Zika virus (ZIKV) is a global health threat due to its rapid spread and severe health implications, including congenital abnormalities and neurological complications. Differentiating ZIKV from other arboviruses such as dengue virus (DENV) is crucial for effective diagnosis and treatment. This study presents the development of a biosensor for detecting the ZIKV non-structural protein 1 (NS1) using gold nanoparticles (AuNPs) functionalized with monoclonal antibodies employing dynamic light scattering (DLS). The biosensor named ZINS1-mAb-AuNP exhibited specific binding to the ZIKV NS1 protein, demonstrating high colloidal stability indicated by a hydrodynamic diameter (DH) of 140 nm, detectable via DLS. In the absence of the protein, the high ionic strength medium caused particle aggregation. This detection method showed good sensitivity and specificity, with a limit of detection (LOD) of 0.96 µg mL-1, and avoided cross-reactivity with DENV2 NS1 and SARS-CoV-2 spike proteins. The ZINS1-mAb-AuNP biosensor represents a promising tool for the early and accurate detection of ZIKV, facilitating diagnostic and treatment capabilities for arboviral infections.

Dual contrasting ability of NaGd0.7Eu0.3F4 nanocrystals tuned by their hydrophilic coating mode

This work introduces non-covalent hydrophilic coating of NaGd0.7Eu0.3F4 nanocrystals by polylysine (PL) and polyethyleneimine (PEI) for MRI and fluorescent imaging purposes. PL- and PEI-stabilized nanocrystals exhibit high colloidal stability, cell internalization, fluorescent contrasting of nuclei and cytoplasm, low cytotoxicity, and relaxivity (r1= 0.17 dm3 mmol–1 s–1 and r1 = 0.23 dm3 mmol–1 s–1).

Dual Luminescent Mn(II)-Doped Cu-In-Zn-S Quantum Dots as Temperature Sensors in Water.

CuInS2 quantum dots have emerged in the last years as non-toxic alternative to traditional Pb and Cd based quantum dots, especially for biological applications. In this work, the hydrothermal synthesis of alloyed Cu-In-Zn-S quantum dots (CIZS) doped with manganese(II) is explored, with different metal ratios (Mn-CIZSy). The doped quantum dots show the sensitized emission of Mn2+ (approximately ms lifetime), together with the emission of the CIZS structure (approximately µs lifetime). The relative contribution of Mn2+ emission is highly dependent on the composition of the CIZS hosting structure (In:Cu ratio). In addition to that, it is shown that Mn2+ sensitization requires a threshold energy, which suggests the involvement of an intermediate state in the sensitization mechanism. The long-lived emission intensity decay of Mn2+ shows a stable and reversible temperature response in physiological conditions (25-45°C, pH = 7.4). Mn-CIZSy quantum dots are thus interesting candidates as biological luminescent temperature probe thanks to their easy synthesis, high colloidal stability, insensitivity to dioxygen quenching and quantitative time-gated detection.

Emulsification capacity of pectin extracts from persimmon waste: Effect of structural characteristics and pectin-polyphenol interactions

Polyphenol-rich pectin extracts obtained from persimmon waste might have great potential due to their emulsification capacity. Their emulsion stabilizing properties may be influenced by pectin molecular structure and pectin-polyphenol interactions which in turn can be determined by the extraction conditions. Hence, this work aimed to study the influence of the molecular structure characteristics and their respective pectin-polyphenol interactions of three polyphenol-rich persimmon pectin extracts obtained by three different extraction conditions. Low, medium and high severity extraction conditions resulted in covalent phenolics-extract (CP-E), non-covalent phenolics-extract (NCP-E) and free phenolics-extract (FP-E), respectively. The electrical charge of pectin was strongly dependent on the pH, becoming more negative at increasing pH due to carboxyl group dissociation. CP-E and NCP-E in solution had more expanded conformations than FP-E, with greater intermolecular distances and hydrodynamic diameters ranging from 1089 to 1791 nm for CP-E and NCP-E, whereas from 529 to 782 nm for FP-E. Their interfacial layer thickness was thicker at pH 3 than at pH 7, probably due to multilayer organization as a result of less repulsion between pectin chains. All pectin extracts were able to decrease the interfacial tension of an oil droplet from 35 to at least 25 mN/m, with FP-E at pH 3 being the most efficient (13.89 ± 1.07 mN/m). Even so, submicron O/W emulsions with negative ζ-potential values could be formed with all pectin extracts. However, CP-E rendered O/W emulsions with higher colloidal stability than FP-E or NCP-E, which showed aggregation and creaming. These findings provide novel insights to re-valorize pectin from persimmon waste.

Supramolecular assembly of polycation/mRNA nanoparticles and in vivo monocyte programming

Size-dependent phagocytosis is a well-characterized phenomenon in monocytes and macrophages. However, this size effect for preferential gene delivery to these important cell targets has not been fully exploited because commonly adopted stabilization methods for electrostatically complexed nucleic acid nanoparticles, such as PEGylation and charge repulsion, typically arrest the vehicle size below 200 nm. Here, we bridge the technical gap in scalable synthesis of larger submicron gene delivery vehicles by electrostatic self-assembly of charged nanoparticles, facilitated by a polymer structurally designed to modulate internanoparticle Coulombic and van der Waals forces. Specifically, our strategy permits controlled assembly of small poly(β-amino ester)/messenger ribonucleic acid (mRNA) nanoparticles into particles with a size that is kinetically tunable between 200 and 1,000 nm with high colloidal stability in physiological media. We found that assembled particles with an average size of 400 nm safely and most efficiently transfect monocytes following intravenous administration and mediate their differentiation into macrophages in the periphery. When a CpG adjuvant is co-loaded into the particles with an antigen mRNA, the monocytes differentiate into inflammatory dendritic cells and prime adaptive anticancer immunity in the tumor-draining lymph node. This platform technology offers a unique ligand-independent, particle-size-mediated strategy for preferential mRNA delivery and enables therapeutic paradigms via monocyte programming.

Grape seed phenolic extracts encapsulation in polymeric nanoparticles: Characterization and in vitro evaluation against skin melanoma

Nanocarrier platforms encapsulating plant-based natural extracts have emerged as an attractive tool to increase the safety and stability of phytomedicines and nutraceuticals. In this study, phenolic fractions were extracted from grape seed waste, spray dried, and characterized. Grape seed extracts (GSE) of Marselan, a red international variety, and Obeidi, a Lebanese autochthonous white variety, had a total phenolic content (TPC) of 301 and 206 mg gallic acid equivalents (GAE)/g of dry matter, respectively, along with a high content of catechins, gallic acid, epicatechins, caffeic acid, syringic acid, and protocatechuic acid. A nanocarrier formulation was developed using poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PEG-PLGA), yielding GSE-loaded nanoparticles (NPs) with an average of 230 nm particle size and −35 mV zeta potential, 50% encapsulation efficiency, and sustained release over 96 h. GSE NPs exhibited high colloidal stability in terms of size and high chemical stability in terms of TPC and antioxidant activity for both Marselan and Obeidi when stored at 4 °C for 3 months. GSE NPs showed excellent biocompatibility in human dermal fibroblasts. Both NPs and crude extracts significantly suppressed the proliferation of B16–F10 melanoma cells, particularly Obeidi NPs. This study emphasizes the important role nanotechnology can play in the valorization of bioactive nutraceuticals by presenting GSE NPs as a promising nanoformulation against skin cancer.

Coordination-Driven Nanomedicine Mitigates One-Lung Ventilation-Induced Lung Injury via Radicals Scavenging and Cell Pyroptosis Inhibition.

One-lung ventilation (OLV) during thoracic surgery often leads to post-operative complications, yet effective pharmacological interventions are lacking. This study reports a baicalin-based metal-coordination nanomedicine with disulfiram (DSF) co-loading to address one-lung ventilation-induced lung injury and reperfusion injury (OLV-LIRI). Baicalin, known for its robust antioxidant properties, suffers from poor water solubility and stability. Leveraging nanotechnology, baicalin's coordination is systematically explored with seven common metal ions, designing iron/copper-mediated binary coordination nanoparticles to overcome these limitations. The self-assembled nanoparticles, primarily formed through metal coordination and π-π stacking forces, encapsulated DSF, ensuring high colloidal stability in diverse physiological matrices. Upon a single-dose administration via endotracheal intubation, the nanoparticles efficiently accumulate in lung tissues and swiftly penetrate the pulmonary mucosa. Intracellularly, baicalin exhibits free radical scavenging activity to suppress inflammation. Concurrently, the release of Cu2+ and DSF enables the in situ generation of CuET, a potent inhibitor of cell pyroptosis. Harnessing these multifaceted mechanisms, the nanoparticles alleviate lung injury symptoms without notable toxic side effects, suggesting a promising preventive strategy for OLV-LIRI.

Tuning the Properties of Iron Oxide Nanoparticles in Thermal Decomposition Synthesis: A Comparative Study of the Influence of Temperature, Ligand Length and Ligand Concentration

AbstractWhilst the synthesis of magnetic nanoparticles via the non‐aqueous thermal decomposition method has proven to lead to the most defined products, the tailoring of their properties is still largely achieved empirically, in particular for metal oxide nanoparticles. In this paper, the influence of ligands with varying length and concentration on the properties of the resulting magnetic nanoparticles is studied, and it is shown that the reaction temperature rather than the ligand length or concentration crucially influences the properties in various ways. The obtained particles are characterized with regard to their size, morphology, crystallinity, and magnetic characteristics, using techniques like transmission electron microscopy (TEM), X‐ray diffraction (XRD), and superconducting quantum interference device (SQUID) magnetometry measurements. It is thereby shown that the optimum choice of ligand and synthesis conditions not only serves to ensure monodispersity of the resulting particles but also to realize high colloidal stability and redispersibility.

Zwitterionic nanoparticles from indocyanine green dimerization for imaging-guided cancer phototherapy

Indocyanine green (ICG), the only near-infrared (NIR) dye approved for clinical use, has received increasing attention as a theranostic agent wherein diagnosis (fluorescence) is combined with therapy (phototherapy), but suffers rapid hepatic clearance, poor photostability, and limited accumulation at tumor sites. Here we report that dimerized ICG can self-assemble to form zwitterionic nanoparticles (ZN-dICG), which generate fluorescence self-quenching but exhibit superior photothermal and photodynamic properties over ICG. The zwitterionic moieties confer ZN-dICG an ultralow critical micelle concentration and high colloidal stability with low non-specific binding in vivo. In addition, ZN-dICG can respond to the over-generated reactive oxygen species (ROSs) and dissociate to restore NIR fluorescence of ICG, amplifying the sensitivity via albumin binding for low-background imaging of tumors. Following systemic administration, ZN-dICG accumulated in tumors of xenograft-bearing mice for imaging primary and metastatic tumors, and induced tumor ablation under laser irradiation. The discovery of ZN-dICG would contribute to the design of translational phototheranostic platform with high biocompatibility. Statement of significanceIndocyanine green (ICG) has been extensively studied as a phototheranostic agent that combines imaging with phototherapies, but it suffers from rapid hepatic clearance, poor photostability, and limited accumulation at tumor sites. Here, we report a strategy to construct ICG dimers (ICG-tk-ICG) by conjugating two ICG molecules via a thioketal bond, which can self-assemble into zwitterionic nanoparticles (ZN-dICG) at ultralow critical micelle concentrations, exhibiting superior photothermal and photodynamic properties over ICG. ZN-dICG responds to the over-generated ROS in tumors and dissociates to restore the NIR fluorescence of ICG, enhancing the sensitivity via albumin binding for low-background imaging of tumors. This study offers a supramolecular strategy that may potentiate the clinical translation of ICG in imaging-guided cancer phototherapy.

Chiral‐induced highly efficient NIR–photothermal conversion of perylene diimide@silica nanocapsules for photothermal therapy

AbstractPhotothermal agents (PTAs) with ultra‐high photothermal conversion efficiency (PCE) activated upon near‐infrared (NIR) laser irradiation can heat up and destroy tumor cells under low‐intensity laser excitation to allow safe and efficient tumor therapy. Herein, an organic PTA with an outstanding PCE of 89.6% is developed from rationally designed perylene diimide (PDI) with electron‐donating cyclohexylamine moiety at the bay‐positions of its skeleton and chiral phenethylamine (PEA) moiety at its N terminals, termed here PEAPDI. The strong intermolecular interaction between the PDI skeletons induced by PEA together with the intramolecular charge transfer from cyclohexylamine to PDI skeleton severely quenches the fluorescence emission from PEAPDI and significantly enhances its NIR absorption, resulting in super NIR–photothermal conversion. PEAPDI molecules are subsequently encapsulated within silica nanocapsules (SNCs), creating PEAPDI@SNC. Characterized by its small hydrodynamic diameter, monodispersity, high PDI encapsulation efficiency, colloidal stability, and biocompatibility, PEAPDI@SNC exhibits prolonged blood circulation and enhanced permeability and retention effect, enabling targeted accumulation at the tumor site. An in vivo study using a 4T1 tumor–bearing mice model illustrates the agent's potent tumor ablation capability without side effects at low dosage under NIR laser irradiation (808 nm). The findings demonstrate PEAPDI@SNC's significant potential as a PTA for tumor treatment.

Effects of carbohydrate binding module of pullulanase type I on the raw starch rearrangement by enhancing the hydrolysis activity

Starch, a versatile ingredient used in various industries, often requires modification for improvements in its physicochemical and functional properties for utilization. Although carbohydrate-binding modules (CBMs) are non-catalytic domains that recognize and bind to the substrate without any enzymatic activity, CBMs are commonly found in the starch-modifying enzyme, pullulanase (PulA). Herein, we identified two PulAs from Deinococcus radiodurans and Deinococcus wulumuqiensis that differed in activity only by CBM composition. Structural comparison analysis showed unique substrate-binding coordination of CBMb1. The analysis with a deletion mutant (ΔCBMb1-DrPulA), and a chimeric mutant (CBMb1-DwPulA) revealed that CBMb1 can improve amylopectin but not pullulan hydrolysis. Moreover, CBMb1 introduction increased the hydrolysis activity of raw waxy corn starch by 60% which leads to the formation of distinct α-glucan microparticles (GMP). GMP produced using CBMb1-DwPulA exhibited B-type crystallinity, similar to that produced by DwPulA. However, a relatively high proportion of short-length maltooligosaccharides was observed in the GMP produced by CBMb1-DwPulA compared with that produced by DwPulA. This contributed to the formation of smaller particles, high colloidal dispersion stability, and increased the absolute value of the zeta potential. Altogether, our findings showed that Deinococcus sp.-derived CBMs can be used to customize GMPs by changing the debranching pattern.

Comparative Study of Physicochemical Properties and Antibacterial Potential of Cyanobacteria Spirulina platensis-Derived and Chemically Synthesized Silver Nanoparticles.

The "green synthesis" of nanoparticles (NPs) offers cost-effective and environmentally friendly advantages over chemical synthesis by utilizing biological sources such as bacteria, algae, fungi, or plants. In this context, cyanobacteria and their components are valuable sources to produce various NPs. The present study describes the comparative analysis of physicochemical and antibacterial properties of chemically synthesized (Chem-AgNPs) and cyanobacteria Spirulina platensis-derived silver NPs (Splat-AgNPs). The physicochemical characterization applying complementary dynamic light scattering and transmission electron microscopy revealed that Splat-AgNPs have an average hydrodynamic radius of ∼ 28.70 nm and spherical morphology, whereas Chem-AgNPs are irregular-shaped with an average radius size of ∼ 53.88 nm. The X-ray diffraction pattern of Splat-AgNPs confirms the formation of face-centered cubic crystalline AgNPs by "green synthesis". Energy-dispersive spectroscopy analysis demonstrated the purity of the Splat-AgNPs. Fourier transform infrared spectroscopy analysis of Splat-AgNPs demonstrated the involvement of some functional groups in the formation of NPs. Additionally, Splat-AgNPs demonstrated high colloidal stability with a zeta-potential value of (-50.0 ± 8.30) mV and a pronounced bactericidal activity against selected Gram-positive (Enterococcus hirae and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Salmonella typhimurium) bacteria compared with Chem-AgNPs. Furthermore, our studies toward understanding the action mechanism of NPs showed that Splat-AgNPs alter the permeability of bacterial membranes and the energy-dependent H+-fluxes via FoF1-ATPase, thus playing a crucial role in bacterial energetics. The insights gained from this study show that Spirulina-derived synthesis is a low-cost, simple approach to producing stable AgNPs for their energy-metabolism-targeted antibacterial applications in biotechnology and biomedicine.

Biosynthesis of Platinum Nanoparticles PlNPs by Bacterial Strain Rhodococcus erythropolis

The biosynthesis of platinum nanoparticles (PlNPs) using the bacterial strain Rhodococcus erythropolis offers a greener alternative to conventional chemical and physical synthesis methods. This study explores the potential of R. erythropolis to produce PlNPs by leveraging its biological machinery to reduce platinum ions and stabilize the resulting nanoparticles. The biosynthesis was conducted under varying conditions of pH, temperature, and sodium platinite concentrations to optimize yield and particle characteristics. The nanoparticles were characterized. The outcome reflects that PlNPs exhibit distinct size-dependent optical properties and crystallinity, with extracellular proteins from R. erythropolis playing a crucial role in nanoparticle stabilization. The optimized biosynthesis process produced PlNPs with high colloidal stability and significant potential for applications in catalysis and environmental remediation. This study advances the understanding of microbial nanoparticle production, highlighting a sustainable pathway for the synthesis of biocompatible and catalytically active platinum nanoparticles.

A facile bio–inspired route of synthesizing Solanum sisymbriifolium fruit extract mediated silver nanoparticles: Pharmaceutical and environmental aspects

The present research work focused on biological synthesis of silver nanoparticles using Solanum sisymbriifolium aqueous fruit extract (AgNPs@SsFE) and determining their pharmaceutical and environmental aspects for the first time. The phytochemicals extracted from S. sisymbriifolium fruit extract (SsFE) contributed in reducing the average particle size of green synthesized AgNPs@SsFE to 23.17 nm and served as capping agents. Further, when AgNPs@SsFE were characterized using PSA, ZP, FE–SEM, Elemental mapping, EDX, HR–TEM, SAED, FTIR and XRD, exhibited the high colloidal stability, spherical shape and crystalline nature of the nanoparticles. Moreover, the synthesized AgNPs@SsFE exhibited enhanced antioxidant activity in comparison to SsFE when assayed via DPPH, FRAP, •NO and H2O2 scavenging methods. The Agar well–diffusion analysis unveiled AgNPs@SsFE to possess greater antibacterial activity against highly pathogenic gram–negative strains than gram–positive strains. Besides, the synthesized AgNPs@SsFE established itself to be a strong photocatalyst by degrading the methylene blue cationic dye under Solar and UV irradiations. These features of synthesized AgNPs@SsFE are found promising to convince the efficacy of SsFE in synthesizing the nanoparticles which can be useful in modern medicine and clinical applications.

Innovative multifunctional nanocapsules with antibacterial, perfume, and UV-initiated coating properties

Polymer nanocapsules containing fragrance were fabricated for antibacterial, pleasing scent and UV-coating applications. Poly (2-methacryloyloxy dodecyl dimethyl ammonium chloride-4-allyloxy-2-hydroxybenzophenone)-block-polymethyl methacrylate-iodide (P(QAC12-BP)-b-PMMA-I) was first synthesized by solution iodine transfer polymerization (solution ITP) for use as a polymerizable surfactant in miniemulsion polymerization where benzalkonium chloride (BKC) was used as a cosurfactant. The nanocapsules were prepared using poly(methyl methacrylate–divinylbenzene) (P(MMA–DVB)) as a shell, whereas mangosteen oil (MO) was used as a fragrance core model for aroma. High colloidal stability nanocapsules with a size of about 213 nm were obtained. The nanocapsule surface contained QAC12 segments of 15.10 µmol/g-capsule (UV measurement), giving the high positive charge (+70 mV). An essential oil encapsulated inside the nanocapsule had a high encapsulation efficiency (>90%). The nanocapsules effectively inhibited bacterial growth because of QAC12 and BKC on their surface. The nanocapsules are able to coat the substrate via UV-activated covalent bonds of the BP segment.