Characterisation of particles in solution - a perspective on light scattering and comparative technologies

Multi-laser nanoparticle tracking analysis (NTA): A unique method to visualize dynamic (shear) and dynamic (Brownian motion) light scattering and quantify nonliving natural organic matter (NNOM) in environmental water

Application of simultaneous multi-laser nanoparticle tracking analysis (NTA) to environmental water samples to investigate nonliving natural organic matter (NNOM) is introduced as an innovative method for observing particles directly in their native media. Multi-laser NTA results of particle visualization, particle number concentration, and particle size distribution elucidated particle dynamics in low and high total dissolved solids (TDS) aqueous environmental samples. A pond water sample and concentrate from a reverse osmosis (RO) treatment process (Stage 1) had 1.3 × 108 and 5.62 × 1019 particles/mL, respectively, (at time = 0) after filtration at 0.45 μm. Beyond the traditional applications for this instrument, this research presents novel evidence-based investigations that probe the existence of supramolecular structures in environmental waters during turbulence or quiescence. The pond water sample exhibited time-dependent aggregation as the volume distribution shifted to greater diameter during quiescence, compared to turbulence. Disaggregation (increased numbers of particles over time) was noted in the >250 nm to <600 nm region, and aggregation of >450 nm particles was also noted in the quiescent RO concentrate sample, indicative of depletion of small particles to form larger ones. Multi-laser NTA and dynamic light scattering (DLS) capabilities were compared and contrasted. DLS and NTA are different (complementary) particle sizing techniques. DLS yielded more information about the physical hydrogel in the NNOM hierarchy whereas multi-laser NTA better characterized meta-chemical and chemical hydrogel characteristics. Operationalization of innovation-moving from fundamental investigations to application-is supported by implementing novel analytical instrumentation as we address issues involving climate change, drought, and the scarcity of potable water. Multi-laser NTA can be used as a tool to study and optimize complex water and wastewater treatment processes. Questions about water treatment efficiencies, membrane fouling, assistance of pollutant transport, and carbon capture cycles affected by NNOM will benefit from insights from multi-laser NTA.

Condensed tannins from Pinus radiata bark: Extraction and their nanoparticles preparation in water by green method

This work reports for the first time the production of condensed tannin nanoparticles stable in water via modification with glycine betaine. Pine bark, as a byproduct from the paper industry, was used as a source of condensed tannins of high molecular weight. Different glycine betaine concentrations were tested to produce condensed tannin nanoparticles, and the obtained nanoparticles were subjected to several characterization techniques (Dynamic Light Scattering, Field emission scanning electron microscopy, Zeta potential, Fourier transform infrared spectroscopy-Attenuated total reflectance, thermogravimetric analysis). The results showed that the highest stability possessed nanoparticles with 40 wt% glycine betaine. The average particle size distribution evaluated by scanning microscopy was 124 nm. Besides, the glycine betaine-modified condensed tannin nanoparticles demonstrated higher thermal stability with the starting degradation temperature at 238 °C. Finally, obtained nanoparticles showed an antioxidant capacity of 34,209 ± 2194 μmol ET/100 g and low cytotoxicity towards healthy human cells, representing the high potential to be used as a carrier of active compounds in agriculture, food, drug and medical sector.

Current state of Nanomedicine Drug Products: An Industry Perspective

Nanomedicine drug products have reached an unprecedented high in terms of global commercial acceptance and media exposure with the approvals of the mRNA COVID-19 vaccines in 2021. In this paper, we examine the current state of the art for nanomedicine technologies as applied for pharmaceutical products and compare those trends with results from a recent IQ Consortium industry survey on nanomedicine drug products. We find that 1) industry companies continue to push the envelope in terms of new technologies for characterizing their specific drug products, 2) new analytical technologies continue to be utilized by industry to characterize the increasingly complex nanomedicine drug products and 3) alignment and communication are key between industry and regulatory authorities to better understand the regulatory filings that are being submitted. There are many CMC challenges that a company must overcome to successfully file a nanomedicine drug product. In 2022, the FDA Guidance on Drug Products containing Nanomaterials was published, and it provides a roadmap for submission of a nanomedicine drug product. We propose that our paper serves as a complimentary guide providing knowledge on specific CMC issues such as quality attributes, physicochemical characterization methods, excipients, and stability.

Impeding microbial biofilm formation and Pseudomonas aeruginosa virulence genes using biologically synthesized silver Carthamus nanoparticles

Long-term antibiotic treatment results in the increasing resistance of bacteria to antimicrobials drugs, so it is necessary to search for effective alternatives to prevent and treat pathogens that cause diseases. This study is aimed for biological synthesis of silver Carthamus nanoparticles (Ag-Carth-NPs) to combat microbial biofilm formation and Pseudomonas aeruginosa virulence genes. Ag-Carth-NPs are synthesized using Carthamus tenuis aqueous extract as environmentally friendly method has no harmful effect on environment. General factorial design is used to optimize Ag-Carth-NPs synthesis using three variables in three levels are Carthamus extract concentration, silver nitrate concentration and gamma radiation doses. Analysis of response data indicates gamma radiation has a significant effect on Ag-Carth-NPs production. Ag-Carth-NPs have sharp peak at λ max 425 nm, small and spherical particles with size 20.0 ± 1.22 nm, high stability up to 240 day with zeta potential around - 43 ± 0.12 mV, face centered cubic crystalline structure and FT-IR spectroscopy shows peak around 620 cm-1 that corresponding to AgNPs that stabilized by C. tenuis extract functional moiety. The antibacterial activity of Ag-Carth-NPs against pathogenic bacteria and fungi was determined using well diffusion method. The MIC values of Ag-Carth-NPs were (6.25, 6.25, 3.126, 25, 12.5, 12.5, 25 and 12.5 µg/ml), MBC values were (12.5, 12.5, 6.25, 50, 25, 25, 50 and 25 µg/ml) and biofilm inhibition% were (62.12, 68.25, 90.12, 69.51, 70.61, 71.12, 75.51 and 77.71%) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Candida tropicalis and Candida albicans respectively. Ag-Carth-NPs has bactericidal efficacy and significantly reduced the swarming, swimming motility, pyocyanin and protease production of P. aeruginosa. Furthermore, P. aeruginosa ToxA gene expression was significantly down regulated by 81.5%, while exoU reduced by 78.1%, where lasR gene expression reduction was 68%, while the reduction in exoU was 66% and 60.1% decrease in lasB gene expression after treatment with Ag-Carth-NPs. This activity is attributed to effect of Ag-Carth-NPs on cell membrane integrity, down regulation of virulence gene expression, and induction of general and oxidative stress in P. aeruginosa. Ag-Carth-NPs have no significant cytotoxic effects on normal human cell (Hfb4) but have IC50 at 5.6µg/mL against of HepG-2 cells. Limitations of the study include studies with low risks of silver nanoparticles for in vitro antimicrobial effects and its toxicity.

Functionalized Magnetic Fe3O4 Nanoparticles for Targeted Methotrexate Delivery in Ovarian Cancer Therapy

Magnetic Fe3O4 nanoparticles (MNPs) functionalized with (3-aminopropylo)trietoksysilan (APTES) or N-carboxymethylchitosan (CMC) were proposed as nanocarriers of methotrexate (MTX) to target ovarian cancer cell lines. The successful functionalization of the obtained nanostructures was confirmed by FT-IR spectroscopy. The nanoparticles were characterized by transmission electron spectroscopy (TEM) and dynamic light scattering (DLS) techniques. Their potential zeta, magnetization, and hyperthermic properties were also explored. MTX was conjugated with the nanocarriers by ionic bonds or by amide bonds. The drug release kinetics were examined at different pH and temperatures. The MTT assay showed no toxicity of the MNPs[APTES] and MNPs[CMC]. Finally, the cytotoxicity of the nanostructures with MTX attached towards the ovarian cancer cells was measured. The sensitivity and resistance to methotrexate was determined in simplistic 2D and spheroid 3D conditions. The cytotoxicity tests of the tested nanostructures showed similar values for inhibiting the proliferation of ovarian cancer cells as methotrexate in its free form. Conjugating MTX with nanoparticles allows the drug to be directed to the target site using an external magnetic field, reducing overall toxicity. Combining this approach with hyperthermia could enhance the therapeutic effect in vivo compared to free MTX, though further research on advanced 3D models is needed.

Hyaluronic Acid Nanoparticles with Parameters Required for In Vivo Applications: From Synthesis to Parametrization

Hyaluronic acid is an excellent biocompatible material for in vivo applications. Its ability to bind CD44, a cell receptor involved in numerous biological processes, predetermines HA-based nanomaterials as unique carrier for therapeutic and theranostic applications. Although numerous methods for the synthesis of hyaluronic acid nanoparticles (HANPs) are available today, their low reproducibility and wide size distribution hinder the precise assessment of the effect on the organism. A robust and reproducible approach for producing HANPs that meet strict criteria for in vivo applications (e.g., to lung parenchyma) remains challenging. We designed and evaluated four protocols for the preparation of HANPs with those required parameters. The HA molecule was cross-linked by novel combinations of carbodiimide, and four different amine-containing compounds resulted in monodisperse HANPs with a low polydispersity index. By a complex postsynthetic characterization, we confirmed that the prepared HANPs meet the criteria for inhaled therapeutic delivery and other in vivo applications.

Characterisation of titanium dioxide (nano)particles in foodstuffs and E171 additives by single particle inductively coupled plasma-tandem mass spectrometry using a highly efficient sample introduction system

This study addressed primarily the characterisation and quantification of titanium dioxide (TiO2) (nano)particles (NPs) in a large variety of commercial foodstuffs. The samples were purchased from local markets in Spain before the ban of TiO2 food additive (E171) in the EU. The analyses were carried out by single particle inductively coupled plasma-tandem mass spectrometry (spICP-MS/MS) in mass shift mode (oxidation of 48Ti to 48Ti16O (m/z = 64)) and using a highly efficient sample introduction system (APEX™ Ω). This novel analytical approach allowed accurate characterisation of a large panel of TiO2 NPs sizes ranging from ∼12 to ∼800 nm without isobaric interferences from 48Ca isotope, which is highly abundant in most of the analysed foodstuffs. TiO2 NPs were extracted from foodstuffs using sodium dodecyl sulphate (0.1%, w/v) and diluted with ultra-pure water to reach ∼ 1000 particles signals per acquisition. All the analysed samples contained TiO2 NPs with concentrations ranging from 1010 to 1014 particles kg-1, but with significant low recoveries compared to the total Ti determination. A selection of samples was also analysed using a similar spICP-MS/MS approach with a conventional sample introduction system. The comparison of results highlighted the improvement of the limit of detection in size (12 nm) by the APEX™ Ω system, providing nanoparticulate fractions ranging from ∼4% (cheddar sauce) up to ∼87% (chewing gum), which is among the highest nanoparticulate fractions reported in literature using a spICP-MS approach. In addition, two commercially available E171 additives were analysed using the previous approaches and other techniques in different European laboratories with the aim of methods inter-comparison. This study provides occurrence data related to TiO2 NPs in common commercial foodstuffs but it also demonstrates the potential of the novel analytical approach based on APEX™-ICP-MS/MS to characterise nano-size TiO2 particles in complex matrices such as foodstuffs.

Accumulation and toxicity of biologically produced gold nanoparticles in different types of specialized mammalian cells

The biologically produced gold nanoparticles (AuNPs) are novel carriers with promising use in targeted tumor therapy. Still, there are no studies regarding the efficacy of nanoparticle internalization by cancer and noncancer cells. In this study, AuNPs were produced by Fusarium oxysporum and analyzed by spectrophotometry, transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and Zetasizer. Obtained AuNPs were about 15 nm in size with a zeta potential of -35.8 mV. The AuNPs were added to cancer cells (4T1), noncancer cells (NIH/3T3), and macrophages (RAW264.7). The viability decreased in 4T1 (77 ± 3.74%) in contrast to NIH/3T3 and RAW264.7 cells (89 ± 4.9% and 90 ± 3.5%, respectively). The 4T1 cancer cells also showed the highest uptake and accumulation of Au (∼80% of AuNPs was internalized) as determined by graphite furnace atomic absorption spectroscopy. The lowest amount of AuNPs was internalized by the NIH/3T3 cells (∼30%). The NIH/3T3 cells exhibited prominent reorganization of F-actin filaments as examined by confocal microscopy. In RAW264.7, we analyzed the release of proinflammatory cytokines by flow cytometry and we found the AuNP interaction triggered transient secretion of tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In summary, we proved the biologically produced AuNPs entered all the tested cell types and triggered cell-specific responses. High AuNP uptake by tumor cells was related to decreased cell viability, while low nanoparticle uptake by fibroblasts triggered F-actin reorganization without remarkable toxicity. Thus, the biologically produced AuNPs hold promising potential as cancer drug carriers and likely require proper surface functionalization to shield phagocytizing cells.

Effect of precipitating agent, N2 gas, extract volume and pH on the magnetic properties of magnetite nanoparticles by green synthesis from aqueous pomegranate peel extract

Superparamagnetic nanoparticles (SPMNPs) have attracted considerable attention in biomedicine, particularly magnetic hyperthermia for cancer treatment. However, the development of efficient and eco-friendly methods for synthesizing SPMNPs remains a challenge. This study reports on a green synthesis approach for SPMNPs using pomegranate peel extract as a stabilizing agent. The effects of various synthesis parameters, including the type of precipitating agent (NH3 and NaOH), N2 gas, extract volume, and pH, were systematically investigated with regard to the size, morphology, and magnetic properties of the nanoparticles. The results showed that reducing the volume of the extract increased the saturation magnetization of the nanoparticles. N2 gas was found to be essential in preventing the oxidation of the nanoparticles. The type of precipitating agent also affected the size and magnetization of the nanoparticles, with NaOH leading to the synthesis of SPMNPs with higher magnetization (∼4 times) compared to NH3. Additionally, nanoparticles synthesized at pH 10 exhibited higher magnetization than those synthesized at pH 8 and 12. In conclusion, the optimized synthesis conditions significantly affected the magnetization and stability of SPMNPs. These nanoparticles are suitable for use in magnetic nanofluid hyperthermia applications.

Development and Evaluation of Docetaxel-Loaded Nanostructured Lipid Carriers for Skin Cancer Therapy

This study focuses on the design, characterization, and optimization of nanostructured lipid carriers (NLCs) loaded with docetaxel for the treatment of skin cancer. Employing a systematic formulation development process guided by Design of Experiments (DoE) principles, key parameters such as particle size, polydispersity index (PDI), zeta potential, and entrapment efficiency were optimized to ensure the stability and drug-loading efficacy of the NLCs. Combined XRD and cryo-TEM analysis were employed for NLC nanostructure evaluation, confirming the formation of well-defined nanostructures. In vitro kinetics studies demonstrated controlled and sustained docetaxel release over 48 h, emphasizing the potential for prolonged therapeutic effects. Cytotoxicity assays on human umbilical vein endothelial cells (HUVEC) and SK-MEL-24 melanoma cell line revealed enhanced efficacy against cancer cells, with significant selective cytotoxicity and minimal impact on normal cells. This multidimensional approach, encompassing formulation optimization and comprehensive characterization, positions the docetaxel-loaded NLCs as promising candidates for advanced skin cancer therapy. The findings underscore the potential translational impact of these nanocarriers, paving the way for future preclinical investigations and clinical applications in skin cancer treatment.

Optimizing mRNA-Loaded Lipid Nanoparticles as a Potential Tool for Protein-Replacement Therapy

Lipid nanoparticles (LNPs) tailored for mRNA delivery were optimized to serve as a platform for treating metabolic diseases. Four distinct lipid mixes (LMs) were formulated by modifying various components: LM1 (ALC-0315/DSPC/Cholesterol/ALC-0159), LM2 (ALC-0315/DOPE/Cholesterol/ALC-0159), LM3 (ALC-0315/DSPC/Cholesterol/DMG-PEG2k), and LM4 (DLin-MC3-DMA/DSPC/Cholesterol/ALC-0159). LNPs exhibited stability and homogeneity with a mean size of 75 to 90 nm, confirmed by cryo-TEM and SAXS studies. High mRNA encapsulation (95-100%) was achieved. LNPs effectively delivered EGFP-encoding mRNA to HepG2 and DC2.4 cell lines. LNPs induced cytokine secretion from human peripheral blood mononuclear cells (PBMCs), revealing that LM1, LM2, and LM4 induced 1.5- to 4-fold increases in IL-8, TNF-α, and MCP-1 levels, while LM3 showed minimal changes. Reporter mRNA expression was observed in LNP-treated PBMCs. Hemotoxicity studies confirmed formulation biocompatibility with values below 2%. In vivo biodistribution in mice post intramuscular injection showed significant mRNA expression, mainly in the liver. The modification of LNP components influenced reactogenicity, inflammatory response, and mRNA expression, offering a promising platform for selecting less reactogenic carriers suitable for repetitive dosing in metabolic disease treatment.

Toxicokinetics Explain Differential Freshwater Ecotoxicity of Nanoencapsulated Imidacloprid Compared to Its Conventional Active Ingredient

Agricultural applications of nanotechnologies necessitate addressing safety concerns associated with nanopesticides, yet research has not adequately elucidated potential environmental risks between nanopesticides and their conventional counterparts. To address this gap, we investigated the risk of nanopesticides by comparing the ecotoxicity of nanoencapsulated imidacloprid (nano-IMI) with its active ingredient to nontarget freshwater organisms (embryonic Danio rerio, Daphnia magna, and Chironomus kiinensis). Nano-IMI elicited approximately 5 times higher toxicity than IMI to zebrafish embryos with and without chorion, while no significant difference was observed between the two invertebrates. Toxicokinetics further explained the differential toxicity patterns of the two IMI analogues. One-compartmental two-phase toxicokinetic modeling showed that nano-IMI exhibited significantly slower elimination and subsequently higher bioaccumulation potential than IMI in zebrafish embryos (dechorinated), while no disparity in toxicokinetics was observed between nano-IMI and IMI in D. magna and C. kiinensis. A two-compartmental toxicokinetic model successfully simulated the slow elimination of IMI from C. kiinensis and confirmed that both analogues of IMI reached toxicologically relevant targets at similar levels. Although nanopesticides exhibit comparable or elevated toxicity, future work is of utmost importance to properly understand the life cycle risks from production to end-of-life exposures, which helps establish optimal management measures before their widespread applications.

Quantitative analysis of mRNA-lipid nanoparticle stability in human plasma and serum by size-exclusion chromatography coupled with dual-angle light scattering

Understanding the stability of mRNA loaded lipid nanoparticles (mRNA-LNPs) is imperative for their clinical development. Herein, we propose the use of size-exclusion chromatography coupled with dual-angle light scattering (SEC-MALS) as a new approach to assessing mRNA-LNP stability in pure human serum and plasma. By applying a dual-column configuration to attenuate interference from plasma components, SEC-MALS was able to elucidate the degradation kinetics and physical property changes of mRNA-LNPs, which have not been observed accurately by conventional dynamic light scattering techniques. Interestingly, both serum and plasma had significantly different impacts on the molecular weight and radius of gyration of mRNA-LNPs, suggesting the involvement of clotting factors in desorption of lipids from mRNA-LNPs. We also discovered that a trace impurity (~1 %) in ALC-0315, identified as its O-tert-butyloxycarbonyl-protected form, greatly diminished mRNA-LNP stability in serum. These results demonstrated the potential utility of SEC-MALS for optimization and quality control of LNP formulations.

Chitosan/bovine serum albumin layer-by-layer assembled particles for non-invasive inhaled drug delivery to the lungs

Layer-by-Layer (LbL) assembly of polyelectrolytes on a solid core particle is a well-established technique used to deliver drugs, proteins, regenerative medicines, combinatorial therapy, etc. It is a multifunctional delivery system which can be engineered using various core template particles and coating polymers. This study reports the development and in-vitro evaluation of LbL assembled particles for non-invasive inhaled delivery to the lungs. The LbL assembled particles were prepared by successively coating polyelectrolyte macromolecules, glycol chitosan and bovine serum albumin on 0.5- and 4.5-μm polystyrene particles. The LbL assembly of polyelectrolytes was confirmed by reversible change in zeta potential and sequential increase in the particle size after accumulation of the layer. The prepared LbL particles were further assessed for aerodynamic properties using two distinct nebulizers, and toxicity assessment in normal lung cells. The in-vitro aerosolization study performed using next generation impactor coupled with Pari LC Plus and Aeroeclipse nebulizer showed that both the LbL assembled 0.5 and 4.5-μm particles had MMAD <5 μm confirming suitable aerodynamic properties for non-invasive lung delivery. The in-vitro cytotoxicity, and TEER integrity following treatment with the LbL assembled particles in normal lung epithelial and fibroblasts showed no significant cytotoxicity rendering the LbL assembled particles safe. This study extends the efficiency of LbL assembled particles for novel applications towards delivery of small and large molecules into the lungs.

Eradication of Klebsiella pneumoniae pulmonary infection by silver oxytetracycline nano-structure

Targeted bactericidal nanosystems hold significant promise to improve the efficacy of existing antimicrobials for treatment of severe bacterial infections by minimizing the side effects and lowering the risk of antibiotic resistance development. In this work, Silver Oxytetracycline Nano-structure (Ag-OTC-Ns) was developed for selective and effective eradication of Klebsiella pneumoniae pulmonary infection. Ag-OTC-Ns were prepared by simple homogenization-ultrasonication method and were characterized by DLS, Zeta potential, TEM and FT-IR. The antimicrobial activity of Ag-OTC-Ns was evaluated in vitro using broth micro-dilution technique and time-kill methods. Our study showed that MICs of AgNO3, OTC, AgNPs and Ag-OTC-Ns were 100, 100, 50 and 6.25 µg/ml, respectively. Ag-OTC-Ns demonstrated higher bactericidal efficacy against the targeted Klebsiella pneumoniae at 12.5 µg/ml compared to the free Oxytetracycline, AgNO3 and AgNPs. In vivo results confirmed that, Ag-OTC-Ns could significantly eradicate K. pneumoniae from mice lung in compare with free Oxytetracycline, AgNO3 and AgNPs. In addition, Ag-OTC-Ns could effectually diminish the inflammatory biomarkers levels of Interferon Gamma and IL-12, and as a result it could effectively lower lung damage in K. pneumoniae infected mice. Ag-OTC-Ns has no significant toxicity on tested mice along the experimental period, there was no sign of behavioral abnormality in the surviving mice indicating that the Ag-OTC-Ns is safe at the used concentration. Furthermore, capability of 5 kGy Gamma ray to sterilize Ag-OTC-Ns solution without affecting it stability was proven.

ULK1 Mediated Autophagy-Promoting Effects of Rutin-Loaded Chitosan Nanoparticles Contribute to the Activation of NF-κB Signaling Besides Inhibiting EMT in Hep3B Hepatoma Cells

Background

Liver cancer remains to be one of the leading causes of cancer worldwide. The treatment options face several challenges and nanomaterials have proven to improve the bioavailability of several drug candidates and their applications in nanomedicine. Specifically, chitosan nanoparticles (CNPs) are extremely biodegradable, pose enhanced biocompatibility and are considered safe for use in medicine.

Methods

CNPs were synthesized by ionic gelation, loaded with rutin (rCNPs) and characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The rCNPs were tested for their cytotoxic effects on human hepatoma Hep3B cells, and experiments were conducted to determine the mechanism of such effects. Further, the biocompatibility of the rCNPs was tested on L929 fibroblasts, and their hemocompatibility was determined.

Results

Initially, UV-vis and FTIR analyses indicated the possible loading of rutin on rCNPs. Further, the rutin load was quantitatively measured using Ultra-Performance Liquid Chromatography (UPLC) and the concentration was 88 µg/mL for 0.22 micron filtered rCNPs. The drug loading capacity (LC%) of the rCNPs was observed to be 13.29 ± 0.68%, and encapsulation efficiency (EE%) was 19.55 ± 1.01%. The drug release was pH-responsive as 88.58% of the drug was released after 24 hrs at the lysosomal pH 5.5, whereas 91.44% of the drug was released at physiological pH 7.4 after 102 hrs. The cytotoxic effects were prominent in 0.22 micron filtered samples of 5 mg/mL rutin precursor. The particle size for the rCNPs at this concentration was 144.1 nm and the polydispersity index (PDI) was 0.244, which is deemed to be ideal for tumor targeting. A zeta potential (ζ-potential) value of 16.4 mV indicated rCNPs with good stability. The IC50 value for the cytotoxic effects of rCNPs on human hepatoma Hep3B cells was 9.7 ± 0.19 μg/mL of rutin load. In addition, the increased production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential (MMP) were observed. Gene expression studies indicated that the mechanism for cytotoxic effects of rCNPs on Hep3B cells was due to the activation of Unc-51-like autophagy-activating kinase (ULK1) mediated autophagy and nuclear factor kappa B (NF-κB) signaling besides inhibiting the epithelial-mesenchymal Transition (EMT). In addition, the rCNPs were less toxic on NCTC clone 929 (L929) fibroblasts in comparison to the Hep3B cells and possessed excellent hemocompatibility (less than 2% of hemolysis).

Conclusion

The synthesized rCNPs were pH-responsive and possessed the physicochemical properties suitable for tumor targeting. The particles were effectively cytotoxic on Hep3B cells in comparison to normal cells and possessed excellent hemocompatibility. The very low hemolytic profile of rCNPs indicates that the drug could be administered intravenously for cancer therapy.

Improved Manufacturing Methods of Extracellular Vesicles Pseudotyped with the Vesicular Stomatitis Virus Glycoprotein

Extracellular vesicles (EV), which expose the vesicular stomatitis virus glycoprotein (VSVG) on their surface, are used for delivery of nucleic acids and proteins in human cell lines. These particles are biomanufactured using methods that are difficult to scale up. Here, we describe the development of the first EV-VSVG production process in serum-free media using polyethylenimine (PEI)-based transient transfection of HEK293 suspension cells, as well as the first EV-VSVG purification process to utilize both ultracentrifugation and chromatography. Three parameters were investigated for EV-VSVG production: cell density, DNA concentration, and DNA:PEI ratio. The best production titer was obtained with 3 × 106 cells/mL, a plasmid concentration of 2 µg/mL, and a DNA:PEI ratio of 1:4. The production kinetics of VSVG was performed and showed that the highest amount of VSVG was obtained 3 days after transfection. Addition of cell culture supplements during the transfection resulted in an increase in VSVG production, with a maximum yield obtained with 2 mM of sodium butyrate added 18 h after transfection. Moreover, the absence of EV-VSVG during cell transfection with a GFP-coding plasmid revealed to be ineffective, with no fluorescent cells. An efficient EV-VSVG purification procedure consisting of a two-step concentration by low-speed centrifugation and sucrose cushion ultracentrifugation followed by a heparin affinity chromatography purification was also developed. Purified bioactive EV-VSVG preparations were characterized and revealed that EV-VSVG are spherical particles of 176.4 ± 88.32 nm with 91.4% of protein similarity to exosomes.

Influence of SPION Surface Coating on Magnetic Properties and Theranostic Profile

This study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (MR/P) and co-precipitation at controlled pH (MpH), were explored, including the assessment of the coating's influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI). Parameters such as size, stability, morphology, and magnetic behavior were evaluated by a detailed characterization analysis. To assess their efficacy in imaging and therapy, relaxivity and hyperthermia experiments were performed, respectively. The results revealed that both synthetic methods lead to SPIONs with similar average size, 9 nm. Mössbauer spectroscopy indicated that samples obtained from MR/P consist of approximately 11-13% of Fe present in magnetite, while samples obtained from MpH have higher contents of 33-45%. Despite coating and functionalization, all samples exhibited superparamagnetic behavior at room temperature. Hyperthermia experiments showed increased SAR values with higher magnetic field intensity and frequency. Moreover, the relaxivity studies suggested potential dual T1/T2 contrast agent capabilities for the coated SPpH-Dx-Au-Gd sample, thus demonstrating its potential in cancer diagnosis.

Analytical Techniques for Characterizing Tumor-Targeted Antibody-Functionalized Nanoparticles

The specific interaction between cell surface receptors and corresponding antibodies has driven opportunities for developing targeted cancer therapies using nanoparticle systems. It is challenging to design and develop such targeted nanomedicines using antibody ligands, as the final nanoconjugate's specificity hinges on the cohesive functioning of its components. The multicomponent nature of antibody-conjugated nanoparticles also complicates the characterization process. Regardless of the type of nanoparticle, it is essential to perform physicochemical characterization to establish a solid foundation of knowledge and develop suitable preclinical studies. A meaningful physicochemical evaluation of antibody-conjugated nanoparticles should include determining the quantity and orientation of the antibodies, confirming the antibodies' integrity following attachment, and assessing the immunoreactivity of the obtained nanoconjugates. In this review, the authors describe the various techniques (electrophoresis, spectroscopy, colorimetric assays, immunoassays, etc.) used to analyze the physicochemical properties of nanoparticles functionalized with antibodies and discuss the main results.

Development of a fast and simple method for the isolation of superparamagnetic iron oxide nanoparticles protein corona from protein-rich matrices

The adsorption of proteins onto the surface of nanoparticle (NP) leads to the formation of the so-called "protein corona" as consisting both loosely and tightly bound proteins. It is well established that the biological identity of NPs that may be acquired after exposure to a biological matrix is mostly provided by the components of the hard corona as the pristine surface is generally less accessible for binding. For that reason, the isolation and the characterisation of the NP-corona complexes and identification of the associated biomolecules can help in understanding its biological behaviour. Established methods for the isolation of the NP-HC complexes are time-demanding and can lead to different results based on the isolation method applied. Herein, we have developed a fast and simple method using ferromagnetic beads isolated from commercial MACS column and used for the isolation of superparamagnetic NP following exposure to different types of biological milieu. We first demonstrated the ability to easily isolate superparamagnetic iron oxide NPs (IONPs) from different concentrations of human blood plasma, and also tested the method on the corona isolation using more complex biological matrices, such as culture medium containing pulmonary mucus where the ordinary corona methods cannot be applied. Our developed method showed less than 20% difference in plasma corona composition when compared with centrifugation. It also showed effective isolation of NP-HC complexes from mucus-containing culture media upon comparing with centrifugation and MACS columns, which failed to wash out the unbound proteins. Our study was supported with a full characterisation profile including dynamic light scattering, nanoparticle tracking analysis, analytical disk centrifuge, and zeta potentials. The biomolecules/ proteins composing the HC were separated by vertical gel electrophoresis and subsequently analysed by liquid chromatography-tandem mass spectrometry. In addition to our achievements in comparing different isolation methods to separate IONPs with corona from human plasma, this is the first study that provides a complete characterisation profile of particle protein corona after exposure in vitro to pulmonary mucus-containing culture media.

Mesoscale Clusters in the Crystallisation of Organic Molecules

The early stages of the molecular self-assembly pathway leading to crystal nucleation have a significant influence on the properties and purity of organic materials. This mini review collates the work on organic mesoscale clusters and discusses their importance in nucleation processes, with a particular focus on their critical properties and susceptibility to sample treatment parameters. This is accomplished by a review of detection methods, including dynamic light scattering, nanoparticle tracking analysis, small angle X-ray scattering, and transmission electron microscopy. Considering the challenges associated with crystallisation of flexible and large-molecule active pharmaceutical ingredients, the dynamic nature of mesoscale clusters has the potential to expand the discovery of novel crystal forms. By collating literature on mesoscale clusters for organic molecules, a more comprehensive understanding of their role in nucleation will evolve and can guide further research efforts.

Impedance nanobiosensor based on enzyme-conjugated biosynthesized gold nanoparticles for the detection of Gram-positive bacteria

In this report, gold nanoparticles (GNPS) were synthesized using cell-free extracts of seven different isolates, namely, Pseudomonas aerogenosa CEBP2, Pseudomonas sp. CEBP1, Pseudomonas pseudoalcaligenes CEB1G, Acinetobactor baumani CEBS1, Cuprividus sp. CEB3, Micrococcus luteus CUB12, and Pandoraea sp. CUB2S. The spectroscopic (UV-vis, FTIR, DLS, XRD, EDS) and microscopic (FESEM, TEM) results confirm the reduction of Au3+ to Au0 in the presence of biomolecules having reducing as well as self-stabilizing activity. In this green synthesis approach, the average particle size of biosynthesized GNPS might vary (4-60 nm) depending on the bacterial species, pH of the media, incubation time, and temperature. In this study, GSH-modified BSGNPs (Au-GSH) have shown antimicrobial activity with better stability against Gram-positive bacteria. After conjugation of lysozyme with Au-GSH (lyso@Au-GSH), the zone of inhibition was enhanced from 12 to 23 mm (Au-GSH). The TEM study shows the spherical GNP (16.65 ± 2.84) turns into a flower-shaped GNP (22.22 ± 3.12) after conjugation with lysozyme due to the formation of the protein corona. Furthermore, the nanobioconjugate (lyso@Au-GSH) was immobilized with Nafion on a glassy carbon electrode to fabricate a label-free impedance biosensor that is highly sensitive to monitor changes in the transducer surface due to biomolecular interactions. The uniquely designed biosensor could selectively detect Gram-positive bacteria in the linear range of 3.0 × 101-3 × 1010 cfu mL-1 with RE <5%. The proposed simplest biosensor exhibited good reproducibility (RSD = 3.1%) and excellent correlation (R2 = 0.999) with the standard plate count method, making it suitable for monitoring Gram-positive bacterial contamination in biofluids, food, and environmental samples.

Development and Characterization of New Miconazole-Based Microemulsions for Buccal Delivery by Implementing a Full Factorial Design Modeling

This research aimed to develop miconazole-based microemulsions using oleic acid as a natural lipophilic phase and a stabilizer mixture comprising Tween 20 and PEG 400 to solubilize miconazole as an antifungal agent known for its activity in oral candidiasis and to improve its bioavailability. The formulation and preparation process was combined with a mathematical approach using a 23-full factorial plan. Fluid and gel-like microemulsions were obtained and analyzed considering pH, conductivity, and refractive index, followed by extensive analyses focused on droplet size, zeta potential, rheological behavior, and goniometry. In vitro release tests were performed to assess their biopharmaceutical characteristics. Independent variables coded X1-Oleic acid (%, w/w), X2-Tween 20 (%, w/w), and X3-PEG 400 (%, w/w) were analyzed in relationship with three main outputs like mean droplet size, work of adhesion, and diffusion coefficient by combining statistical tools with response surface methodology. The microemulsion containing miconazole base-2%, oleic acid-5%, Tween 20-40%, PEG 400-20%, and water-33% exhibited a mean droplet size of 119.6 nm, a work of adhesion of 71.98 mN/m, a diffusion coefficient of 2.11·10-5 cm2/s, and together with remarked attributes of two gel-like systems formulated with higher oil concentrations, modeled the final optimization step of microemulsions as potential systems for buccal delivery.

Minimum Information for Conducting and Reporting In Vitro Intracellular Infection Assays

Bacterial pathogens are constantly evolving to outsmart the host immune system and antibiotics developed to eradicate them. One key strategy involves the ability of bacteria to survive and replicate within host cells, thereby causing intracellular infections. To address this unmet clinical need, researchers are adopting new approaches, such as the development of novel molecules that can penetrate host cells, thus exerting their antimicrobial activity intracellularly, or repurposing existing antibiotics using nanocarriers (i.e., nanoantibiotics) for site-specific delivery. However, inconsistency in information reported across published studies makes it challenging for scientific comparison and judgment of experiments for future direction by researchers. Together with the lack of reproducibility of experiments, these inconsistencies limit the translation of experimental results beyond pre-clinical evaluation. Minimum information guidelines have been instrumental in addressing such challenges in other fields of biomedical research. Guidelines and recommendations provided herein have been designed for researchers as essential parameters to be disclosed when publishing their methodology and results, divided into four main categories: (i) experimental design, (ii) establishing an in vitro model, (iii) assessment of efficacy of novel therapeutics, and (iv) statistical assessment. These guidelines have been designed with the intention to improve the reproducibility and rigor of future studies while enabling quantitative comparisons of published studies, ultimately facilitating translation of emerging antimicrobial technologies into clinically viable therapies that safely and effectively treat intracellular infections.

Instrument with an ultra-wide dynamic detection range for the optical counting and sizing of individual particles in suspensions

The characterization of dispersions, suspensions, and emulsions is important in a wide range of scientific applications and industries. Samples can consist of different materials and a wide range of particle sizes and concentrations. A single particle sizing and counting instrument with a dynamic detection range of ≥6 decades has been developed to detect single nano- and microparticles in aqueous suspensions based on light scattering measured in two directions. Hydrodynamic focusing is employed for particle separation and to provide stable conditions for light scattering detection. This gives the advantage of size resolution in the nm range, allowing, e.g., number based size distributions, classification of nanomaterials, determination of particle agglomerates, developments for dispersion stability analysis, or cutoff of filter media. In addition, concentration determination is based on sample volume measurement with <20 nl measurement uncertainty. We present results of particle detection in a size range from approximately above 40 nm for gold nanoparticles to 8 μm for polystyrene particles using a prototyped instrument of the LUMiSpoc® series produced by LUM GmbH. The data obtained demonstrate the advantages of single-particle detection, particularly for characterizing polydisperse systems, such as precise particle sizing in the nanometer range through light scattering intensity based on Mie scattering theory. In addition, we present particle concentration data based on the integrated measurement of sample volume, which allows particle concentration to be determined with an uncertainty of 2.5% (95% confidence interval). To achieve such small uncertainties, dilution series measurements must be used to correct for coincidence losses and particle adhesion.

Structural and Surface Properties of pH-Varied Fe2O3 Nanoparticles: Correlation with Antibacterial Properties

Hematite (Fe2O3) nanoparticles were synthesized using a hydrothermal synthesis route under different pH conditions (pH ∼8,10,11.5) (i.e., different ratios of H+/OH- ions). The sample synthesized at pH 10 had better motility toward the bacterial surface due to having an overall positive charge (ξ-potential = +11.10), leading to a minimal hydrodynamic size (Dτ = 186.6). The results are discussed in light of the relative ratio of H+/OH- that may affect bond formation by influencing the electronic clouds of the participating ions that can modify the structure. This, in turn, modifies crystallinity, strain, disorder, surface termination, and thereby, the surface charge, which has been correlated to the antibacterial properties of the nanoparticles due to the interaction between the respective opposite charges on the nanoparticle surface and bacterial cell wall. The structural modifications were correlated to all of these parameters in this work.

An in-depth physicochemical investigation of drug-loaded core-shell UiO66 nanoMOFs

Nanosized UiO66 are among the most studied MOF materials. They have been extensively applied in various areas, such as catalysis, gas absorption, electrochemistry, chemical sensing, and biomedical applications. However, the preparation of stable nano-sized UiO66 for drug delivery applications is challenging because of the high tendency of UiO66 to aggregate during storage. To address this issue, we coated UiO66 with oligomers made of crosslinked cyclodextrins. The coated UiO66 exhibited a good stability upon storage for more than three weeks, even for low quantities of coating materials. The resulting core-shell UiO66 were characterized using a set of complementary methods including microscopies, spectroscopies, X-ray diffraction, and thermogravimetric investigations. Size distribution was assessed by orthogonal methods. Cisplatin was loaded in the core-shell nanoparticles, followed by an in-depth analysis by asymmetric flow field-flow fractionation (AF4) hyphenated with inductively coupled plasma-mass spectrometry (ICP-MS). This method combines the extremely high elemental selectivity and ultratrace detection limits of mass spectrometry with the capacity of AF4 to differentiate the diverse populations present in the sample. Free cisplatin and UiO66-associated cisplatin could be well separated by AF4. AF4-ICP-MS/MS analysis provided the exact drug loading, without the need of separating the nanoparticles from their suspension media. These data suggest the potential of AF4-ICP-MS/MS in the optimization of drug delivery systems.

Multiple Natural Polymers in Drug and Gene Delivery Systems

Natural polymers are organic compounds produced by living organisms. In nature, they exist in three main forms, including proteins, polysaccharides, and nucleic acids. In recent years, with the continuous research on drug and gene delivery systems, scholars have found that natural polymers have promising applications in drug and gene delivery systems due to their excellent properties such as biocompatibility, biodegradability, low immunogenicity, and easy modification. However, since the structure, physicochemical properties, pharmacological properties and biological characteristics of biopolymer molecules have not yet been entirely understood, further studies are required before large-scale clinical application. This review focuses on recent advances in the representative natural polymers such as proteins (albumin, collagen, elastin), polysaccharides (chitosan, alginate, cellulose) and nucleic acids. We introduce the characteristics of various types of natural polymers, and further outline the characterization methods and delivery forms of these natural polymers. Finally, we discuss possible challenges for natural polymers in subsequent experimental studies and clinical applications. It provides an important strategy for the clinical application of natural polymers in drug and gene delivery systems.

Recommendations for reproducibility of cerebrospinal fluid extracellular vesicle studies

Cerebrospinal fluid (CSF) is a clear, transparent fluid derived from blood plasma that protects the brain and spinal cord against mechanical shock, provides buoyancy, clears metabolic waste and transports extracellular components to remote sites in the brain. Given its contact with the brain and the spinal cord, CSF is the most informative biofluid for studies of the central nervous system (CNS). In addition to other components, CSF contains extracellular vesicles (EVs) that carry bioactive cargoes (e.g., lipids, nucleic acids, proteins), and that can have biological functions within and beyond the CNS. Thus, CSF EVs likely serve as both mediators of and contributors to communication in the CNS. Accordingly, their potential as biomarkers for CNS diseases has stimulated much excitement for and attention to CSF EV research. However, studies on CSF EVs present unique challenges relative to EV studies in other biofluids, including the invasive nature of CSF collection, limited CSF volumes and the low numbers of EVs in CSF as compared to plasma. Here, the objectives of the International Society for Extracellular Vesicles CSF Task Force are to promote the reproducibility of CSF EV studies by providing current reporting and best practices, and recommendations and reporting guidelines, for CSF EV studies. To accomplish this, we created and distributed a world-wide survey to ISEV members to assess methods considered 'best practices' for CSF EVs, then performed a detailed literature review for CSF EV publications that was used to curate methods and resources. Based on responses to the survey and curated information from publications, the CSF Task Force herein provides recommendations and reporting guidelines to promote the reproducibility of CSF EV studies in seven domains: (i) CSF Collection, Processing, and Storage; (ii) CSF EV Separation/Concentration; (iii) CSF EV Size and Number Measurements; (iv) CSF EV Protein Studies; (v) CSF EV RNA Studies; (vi) CSF EV Omics Studies and (vii) CSF EV Functional Studies.

Current advances in niosomes applications for drug delivery and cancer treatment

The advent of nanotechnology has led to an increased interest in nanocarriers as a drug delivery system that is efficient and safe. There have been many studies addressing nano-scale vesicular systems such as liposomes and niosome is a newer generation of vesicular nanocarriers. The niosomes provide a multilamellar carrier for lipophilic and hydrophilic bioactive substances in the self-assembled vesicle, which are composed of non-ionic surfactants in conjunction with cholesterol or other amphiphilic molecules. These non-ionic surfactant vesicles, simply known as niosomes, can be utilized in a wide variety of technological applications. As an alternative to liposomes, niosomes are considered more chemically and physically stable. The methods for preparing niosomes are more economic. Many reports have discussed niosomes in terms of their physicochemical properties and applications as drug delivery systems. As drug carriers, nano-sized niosomes expand the horizons of pharmacokinetics, decreasing toxicity, enhancing drug solvability and bioavailability. In this review, we review the components and fabrication methods of niosomes, as well as their functionalization, characterization, administration routes, and applications in cancer gene delivery, and natural product delivery. We also discuss the limitations and challenges in the development of niosomes, and provide the future perspective of niosomes.

Dually Modified Cellulose as a Non-Viral Vector for the Delivery and Uptake of HDAC3 siRNA

RNA interference can be applied to different target genes for treating a variety of diseases, but an appropriate delivery system is necessary to ensure the transport of intact siRNAs to the site of action. In this study, cellulose was dually modified to create a non-viral vector for HDAC3 short interfering RNA (siRNA) transfer into cells. A guanidinium group introduced positive charges into the cellulose to allow complexation of negatively charged genetic material. Furthermore, a biotin group fixed by a polyethylene glycol (PEG) spacer was attached to the polymer to allow, if required, the binding of targeting ligands. The resulting polyplexes with HDAC3 siRNA had a size below 200 nm and a positive zeta potential of up to 15 mV. For N/P ratio 2 and higher, the polymer could efficiently complex siRNA. Nanoparticles, based on this dually modified derivative, revealed a low cytotoxicity. Only minor effects on the endothelial barrier integrity and a transfection efficiency in HEK293 cells higher than Lipofectamine 2000TM were found. The uptake and release of the polyplexes were confirmed by immunofluorescence imaging. This study indicates that the modified biopolymer is an auspicious biocompatible non-viral vector with biotin as a promising moiety.

Magnetic Hydrogel Beads as a Reusable Adsorbent for Highly Efficient and Rapid Removal of Aluminum: Characterization, Response Surface Methodology Optimization, and Evaluation of Isotherms, Kinetics, and Thermodynamic Studies

Biopolymers such as alginate and gelatin have attracted much attention because of their exceptional adsorption properties and biocompatibility. The magnetic hydrogel beads produced and used in this study had a core structure composed of magnetite nanoparticles and gelatin and a shell structure composed of alginate. The combination of the metal-ion binding ability of alginate and the mechanical strength of gelatin in magnetic hydrogel beads presents a new approach for the removal of metal from water sources. The beads were designed for aluminum removal and fully characterized using various methods, including Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, microcomputed tomography, and dynamic mechanical analysis. Statistical experimental designs were employed to optimize the parameters of the adsorption and recovery processes. Plackett-Burman Design, Box-Behnken Design, and Central Composite Design were used for identifying the significant factors and optimizing the parameters of the adsorption and recovery processes, respectively. The optimum parameters determined for adsorption are as follows: pH: 4, contact time: 30 min, adsorbent amount: 600 mg; recovery time: reagent 1 M HNO3; and contact time: 40 min. The adsorption process was described by using the Langmuir isotherm model. It reveals a homogeneous bead surface and monolayer adsorption with an adsorption capacity of 5.25 mg g-1. Limit of detection and limit of quantification values were calculated as 4.3 and 14 μg L-1, respectively. The adsorption process was described by a pseudo-second-order kinetic model, which assumes that chemisorption is the rate-controlling mechanism. Thermodynamic studies indicate that adsorption is spontaneous and endothermic. The adsorbent was reusable for 10 successive adsorption-desorption cycles with a quantitative adsorption of 98.2% ± 0.3% and a recovery of 99.4% ± 2.6%. The minimum adsorbent dose was determined as 30 g L-1 to achieve quantitative adsorption of aluminum. The effects of the inorganic ions were also investigated. The proposed method was applied to tap water and carboy water samples, and the results indicate that magnetic hydrogel beads can be an effective and reusable bioadsorbent for the detection and removal of aluminum in water samples. The recovery values obtained by using the developed method were quantitative and consistent with the results obtained from the inductively coupled plasma optical emission spectrometer.

Synthesis of copaiba (Copaifera officinalis) oil nanoemulsion and the potential against Zika virus: An in vitro study

Zika virus (ZIKV) has spread all over the world since its major outbreak in 2015. This infection has been recognized as a major global health issue due to the neurological complications related to ZIKV infection, such as Guillain-Barré Syndrome and Zika virus Congenital Syndrome. Currently, there are no vaccines or specific treatments for ZIKV infection, which makes the development of specific therapies for its treatment very important. Several studies have been developed to analyze the potential of compounds against ZIKV, with the aim of finding new promising treatments. Herein, we evaluate the ability of a copaiba (Copaifera officinalis) oil nanoemulsion (CNE) to inhibit ZIKV. First, the highest non-cytotoxic concentration of 180 μg/mL was chosen since this concentration maintains 80% cell viability up to 96h after treatment with CNE in VERO cells resulted from MTT assay. The intracellular uptake assay was performed, and confirmed the internalization of the nanoemulsion in cells at all times analyzed. VERO cells were infected with ZIKV and simultaneously treated with CNE and the nanoformulation without oil (ENE) at the highest non-toxic concentration. The results evaluated by plaque assay revealed a viral inhibition of 80% for CNE and 70% for ENE. A dose-dependence assay revealed that the CNE treatment demonstrated a dose-dependent response in the viral RNA levels, whereas all ENE tested concentrations exhibited a similar degree of reduction. Taken together, our results suggest CNE as a promising nano-sized platform to be further studied for antiviral treatments.

Conjugation of microbial-derived gold nanoparticles to different types of nucleic acids: evaluation of transfection efficiency

In this study, gold nanoparticles produced by eukaryotic cell waste (AuNP), were analyzed as a transfection tool. AuNP were produced by Fusarium oxysporum and analyzed by spectrophotometry, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) were used before and after conjugation with different nucleic acid (NA) types. Graphite furnace atomic absorption spectroscopy (GF-AAS) was used to determine the AuNP concentration. Conjugation was detected by electrophoresis. Confocal microscopy and quantitative real-time PCR (qPCR) were used to assess transfection. TEM, SEM, and EDS showed 25 nm AuNP with round shape. The amount of AuNP was 3.75 ± 0.2 µg/µL and FTIR proved conjugation of all NA types to AuNP. All the samples had a negative charge of - 36 to - 46 mV. Confocal microscopy confirmed internalization of the ssRNA-AuNP into eukaryotic cells and qPCR confirmed release and activity of carried RNA.

Role of Particle Size in Translational Research of Nanomedicines for Successful Drug Delivery: Discrepancies and Inadequacies

Despite significant research progress in substantiating the therapeutic merits of nanomedicines and the emergence of sophisticated nanotechnologies, the translation of this knowledge into new therapeutic modalities has been sluggish, indicating the need for a more comprehensive understanding of how the unique physicochemical properties of nanoparticles affect their clinical applications. Particle size is a critical quality attribute that impacts the bio-fate of nanoparticles, yet precise knowledge of its effect remains elusive with discrepancies among literature reports. This review aims to address this scientific knowledge gap from a drug development perspective by highlighting potential inadequacies during the evaluation of particle size effects. We begin with a discussion on the major issues in particle size characterization along with the corresponding remedies. The influence of confounding factors on biological effects of particle size, including colloidal stability, polydispersity, and in vitro drug release, are addressed for establishing stronger in vitro-in vivo correlation. Particle size design and tailoring approaches for successful nanoparticulate drug delivery beyond parenteral administration are also illustrated. We believe a holistic understanding of the effect of particle size on bio-fate, combined with consistent nanoparticle manufacturing platforms and tailored characterization techniques, would expedite the translation of nanomedicines into clinical practice.

Critical nanomaterial attributes of iron-carbohydrate nanoparticles: Leveraging orthogonal methods to resolve the 3-dimensional structure

Intravenous iron-carbohydrate nanomedicines are widely used to treat iron deficiency and iron deficiency anemia across a wide breadth of patient populations. These colloidal solutions of nanoparticles are complex drugs which inherently makes physicochemical characterization more challenging than small molecule drugs. There have been advancements in physicochemical characterization techniques such as dynamic light scattering and zeta potential measurement, that have provided a better understanding of the physical structure of these drug products in vitro. However, establishment and validation of complementary and orthogonal approaches are necessary to better understand the 3-dimensional physical structure of the iron-carbohydrate complexes, particularly with regard to their physical state in the context of the nanoparticle interaction with biological components such as whole blood (i.e. the nano-bio interface).

Self-stabilizing performance of γ-oryzanol in oil-in-water emulsions and solid dispersions

The surface activity of γ-oryzanol was evaluated by the pendant drop method (PDM), and its self-stabilizing properties were investigated by high-pressure homogenization (HPH) and solvent displacement method (SDM). Emulsions prepared by HPH were highly unstable due to the poor surface-active character of γ-oryzanol as identified by the PDM. In contrast, solid dispersions fabricated by SDM had comparable particle size to those prepared using Tween 80 (T80) as surfactant, and were stable up to 30 days of storage at 4 °C. The self-stabilizing properties of γ-oryzanol were attributed to the mechanism of spontaneous particle formation in SDM and to the ability of γ-oryzanol molecules to prevent particles aggregation by electrostatic repulsion. The outcome of this study indicates the potential of encapsulating selected bioactive compounds, such as γ-oryzanol, in stable colloidal systems by SDM without adding emulsifier(s), regardless of their surface-active character.

Method development for the intraoral release of nanoparticles from dental restorative materials

OBJECTIVE

The aim of this study was the development of a novel in-vitro method to evaluate the intraoral release of wear particles with a diameter< 1 µm from dental restorative materials.

METHODS

Test fixtures for a dual-axis chewing simulator (CS-4.8, SD Mechatronik, Feldkirchen-Westerham, Germany), consisting of three components to mount the specimens and a solvent (distilled water) as well as a zirconia antagonist to transfer the masticatory forces onto the specimen was developed. Ceram.x Spectra™ ST HV (CS) and Filtek™ Supreme XTE (FS) specimens (n = 3) were fixed into the mounts and immersed in 25 ml solvent. All specimens were subjected to 500.000 wear cycles with a load of 49 N. The particle size distribution of the suspensions were examined by dynamic light scattering (DLS). The collected particles were characterised by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). For wear quantification, the surfaces of the specimens were photo-optically scanned and the wear was measured. For the statistical analysis, one-way ANOVA and post-hoc Scheffé tests were applied.

RESULTS

DLS showed particle diameters< 1 µm (CS: 18.06 nm-1.64 µm, FS: 72.30 nm-2.31 µm). SEM/EDS indicated an association between the detected elements and the materials' composition. FS showed significantly higher volume loss (p = 0.007) and maximum depth of the wear profile (p = 0.005) than CS, but no significant differences in the surface loss (p = 0.668).

SIGNIFICANCE

The novel method is able to detect material dependent particles to the size of nanoscale after in-vitro abrasion.

Nanoparticle Tracking Analysis of Urinary Extracellular Vesicle Proteins as a New Challenge in Laboratory Medicine

Urinary extracellular vesicle (uEV) proteins may be used as specific markers of kidney damage in various pathophysiological conditions. The nanoparticle-tracking analysis (NTA) appears to be the most useful method for the analysis of uEVs due to its ability to analyze particles below 300 nm. The NTA method has been used to measure the size and concentration of uEVs and also allows for a deeper analysis of uEVs based on their protein composition using fluorescence measurements. However, despite much interest in the clinical application of uEVs, their analysis using the NTA method is poorly described and requires meticulous sample preparation, experimental adjustment of instrument settings, and above all, an understanding of the limitations of the method. In the present work, we demonstrate the usefulness of an NTA. We also present problems encountered during analysis with possible solutions: the choice of sample dilution, the method of the presentation and comparison of results, photobleaching, and the adjustment of instrument settings for a specific analysis. We show that the NTA method appears to be a promising method for the determination of uEVs. However, it is important to be aware of potential problems that may affect the results.

Protein-Templated Metal Nanoclusters: Molecular-like Hybrids for Biosensing, Diagnostics and Pharmaceutics

The use of proteins as biomolecular templates to synthesize atomically precise metal nanoclusters has been gaining traction due to their appealing properties such as photoluminescence, good colloidal- and photostability and biocompatibility. The synergistic effect of using a protein scaffold and metal nanoclusters makes it especially attractive for biomedical applications. Unlike other reviews, we focus on proteins in general as the protective ligand for various metal nanoclusters and highlight their applications in the biomedical field. We first introduce the approaches and underlined principles in synthesizing protein-templated metal nanoclusters and summarize some of the typical proteins that have been used thus far. Afterwards, we highlight the key physicochemical properties and the characterization techniques commonly used for the size, structure and optical properties of protein-templated metal nanoclusters. We feature two case studies to illustrate the importance of combining these characterization techniques to elucidate the formation process of protein-templated metal nanoclusters. Lastly, we highlight the promising applications of protein-templated metal nanoclusters in three areas-biosensing, diagnostics and therapeutics.

N-Acetylcysteine-Loaded Magnetic Nanoparticles for Magnetic Resonance Imaging

Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by the rapid onset of lung inflammation Therefore, monitoring the spatial distribution of the drug directly administered to heterogeneously damaged lungs is desirable. In this work, we focus on optimizing the drug N-acetylcysteine (NAC) adsorption on poly-l-lysine-modified magnetic nanoparticles (PLLMNPs) to monitor the drug spatial distribution in the lungs using magnetic resonance imaging (MRI) techniques. The physicochemical characterizations of the samples were conducted in terms of morphology, particle size distributions, surface charge, and magnetic properties followed by the thermogravimetric quantification of NAC coating and cytotoxicity experiments. The sample with the theoretical NAC loading concentration of 0.25 mg/mL was selected as an optimum due to the hydrodynamic nanoparticle size of 154 nm, the surface charge of +32 mV, good stability, and no cytotoxicity. Finally, MRI relaxometry confirmed the suitability of the sample to study the spatial distribution of the drug in vivo using MRI protocols. We showed the prevailing transverse relaxation with high transverse relaxivity values and a high r₂⁽*⁾/r₁ ratio, causing visible hypointensity in the final MRI signal. Furthermore, NAC adsorption significantly affects the relaxation properties of PLLMNPs, which can help monitor drug release in vitro/in vivo.

Quantification of monodisperse and biocompatible gold nanoparticles by single-particle ICP-MS

Bioanalytical and biomedical applications often require nanoparticles that exhibit narrow size distributions and biocompatibility. Here, we demonstrate how different synthesis methods affect gold nanoparticle (AuNPs) monodispersity and cytotoxicity. Using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS), we found that the size distribution of AuNPs synthesized with a cetyltrimethylammonium chloride (CTAC) cap was significantly improved compared to AuNPs synthesized with citrate capping agents. We determined an up to 4× decrease in the full width at half maximum (FWHM) value of the normal distributions of AuNP diameter and up to a 12% decrease in relative standard deviation (RSD). While the CTAC-capped AuNPs exhibit narrow nanoparticle size distributions, they are cytotoxic, which limits safe and effective bioanalytical and biomedical applications. We sought to impart biocompatibility to CTAC-capped AuNPs through a PEGylation-based surface ligand exchange. We developed a unique ligand exchange method driven by physical force. We demonstrated the successful PEGylation using various PEG derivatives and used these PEGylated nanoparticles to further bioconjugate nucleic acids and peptides. Using cell viability quantification, we confirmed that the monodisperse PEGylated AuNPs were biocompatible. Our monodisperse and biocompatible nanoparticles may advance safe and effective bioanalytical and biomedical applications of nanomaterials.

Characterization of diffusing sub-10 nm nano-objects using single anti-resonant element optical fibers

Accurate characterization of diffusing nanoscale species is increasingly important for revealing processes at the nanoscale, with fiber-assisted nanoparticle-tracking-analysis representing a new and promising approach in this field. In this work, we uncover the potential of this approach for the characterization of very small nanoparticles (<20 nm) through experimental studies, statistical analysis and the employment of a sophisticated fiber and chip design. The central results is the characterization of diffusing nanoparticles as small as 9 nm with record-high precision, corresponding to the smallest diameter yet determined for an individual nanoparticle with nanoparticle-tracking-analysis using elastic light scattering alone. Here, the detectable scattering cross-section is limited only by the background scattering of the ultrapure water, thus reaching the fundamental limit of Nanoparticle-Tracking-Analysis in general. The obtained results outperform other realizations and allow access to previously difficult to address application fields such as understanding nanoparticle growth or control of pharmaceuticals.

Bio-functionalized magnetic nanoparticles for cost-effective adsorption of U(vi): experimental and theoretical investigation

U(vi) removal using cost-effective (production cost: $14.03 per kg), biocompatible, and superparamagnetic Cinnamomum tamala (CT) leaf extract-coated magnetite nanoparticles (CT@MNPs or CT@Fe₃O₄ nanoparticles) from water resources was studied. From pH-dependent experiments, the maximum adsorption efficiency was found to be at pH 8. Isotherm and kinetic studies were performed and found to follow Langmuir isotherm and pseudo-second order kinetics, respectively. The maximum adsorption capacity of CT@MNPs was calculated to be 45.5 mg of U(vi) per g of nanoparticles (NPs). Recyclability studies suggest that over 94% sorption was retained even after four consecutive cycles. The sorption mechanism was explained by the point of the zero-charge experiment and the XPS measurement. Additionally, calculations using density functional theory (DFT) were carried out to support the experimental findings.

Nano Differential Scanning Fluorimetry as a Rapid Stability Assessment Tool in the Nanoformulation of Proteins

The development and production of innovative protein-based therapeutics is a complex and challenging avenue. External conditions such as buffers, solvents, pH, salts, polymers, surfactants, and nanoparticles may affect the stability and integrity of proteins during formulation. In this study, poly (ethylene imine) (PEI) functionalized mesoporous silica nanoparticles (MSNs) were used as a carrier for the model protein bovine serum albumin (BSA). To protect the protein inside MSNs after loading, polymeric encapsulation with poly (sodium 4-styrenesulfonate) (NaPSS) was used to seal the pores. Nano differential scanning fluorimetry (NanoDSF) was used to assess protein thermal stability during the formulation process. The MSN-PEI carrier matrix or conditions used did not destabilize the protein during loading, but the coating polymer NaPSS was incompatible with the NanoDSF technique due to autofluorescence. Thus, another pH-responsive polymer, spermine-modified acetylated dextran (SpAcDEX), was applied as a second coating after NaPSS. It possessed low autofluorescence and was successfully evaluated with the NanoDSF method. Circular dichroism (CD) spectroscopy was used to determine protein integrity in the case of interfering polymers such as NaPSS. Despite this limitation, NanoDSF was found to be a feasible and rapid tool to monitor protein stability during all steps needed to create a viable nanocarrier system for protein delivery.

An Overview of Nanoemulgels for Bioavailability Enhancement in Inflammatory Conditions via Topical Delivery

The anti-inflammatory drugs that are generally available possess the disadvantage of hydrophobicity, which leads to poor permeability and erratic bioavailability. Nanoemulgels (NEGs) are novel drug delivery systems that aim to improve the solubility and permeability of drugs across the biological membrane. The nano-sized droplets in the nanoemulsion enhance the permeation of the formulation, along with surfactants and co-surfactants that act as permeation enhancers and can further improve permeability. The hydrogel component of NEG helps to increase the viscosity and spreadability of the formulation, making it ideal for topical application. Moreover, oils that have anti-inflammatory properties, such as eucalyptus oil, emu oil and clove oil, are used as oil phases in the preparation of the nanoemulsion, which shows a synergistic effect with active moiety and enhances its overall therapeutic profile. This leads to the creation of hydrophobic drugs that possess enhanced pharmacokinetic and pharmacodynamic properties, and simultaneously avoid systemic side effects in individuals with external inflammatory disorders. The nanoemulsion's effective spreadability, ease of application, non-invasive administration, and subsequent ability to achieve patient compliance make it more suitable for topical application in the combat of many inflammatory disorders, such as dermatitis, psoriasis, rheumatoid arthritis, osteoarthritis and so on. Although the large-scale practical application of NEG is limited due to problems regarding its scalability and thermodynamic instability, which arise from the use of high-energy approaches during the production of the nanoemulsion, these can be resolved by the advancement of an alternative nanoemulsification technique. Considering the potential advantages and long-term benefits of NEGs, the authors of this paper have compiled a review that elaborates the potential significance of utilizing nanoemulgels in a topical delivery system for anti-inflammatory drugs.

Dynamic Light Scattering: A Powerful Tool for In Situ Nanoparticle Sizing

Due to surface effects and quantum size effects, nanomaterials have properties that are vastly different from those of bulk materials due to surface effects. The particle size distribution plays an important role in chemical and physical properties. The measurement and control of this parameter are crucial for nanomaterial synthesis. Dynamic light scattering (DLS) is a fast and non-invasive tool used to measure particle size, size distribution and stability in solutions or suspensions during nanomaterial preparation. In this review, we focus on the in situ sizing of nanomaterial preparation in the form of colloids, especially for metal oxide nanoparticles (MONs). The measuring principle, including an overview of sizing techniques, advantages and limitations and theories of DLS were first discussed. The instrument design was then investigated. Ex-situ and in situ configuration of DLS, sample preparations, measurement conditions and reaction cell design for in situ configuration were studied. The MONs preparation monitored by DLS was presented, taking into consideration both ex situ and in situ configuration.

Nanoparticle surface stabilizing agents influence antibacterial action

The antibacterial properties of nanoparticles are of particular interest because of their potential to serve as an alternative therapy to combat antimicrobial resistance. Metal nanoparticles such as silver and copper nanoparticles have been investigated for their antibacterial properties. Silver and copper nanoparticles were synthesized with the surface stabilizing agents cetyltrimethylammonium bromide (CTAB, to confer a positive surface charge) and polyvinyl pyrrolidone (PVP, to confer a neutral surface charge). Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and viable plate count assays were used to determine effective doses of silver and copper nanoparticles treatment against Escherichia coli, Staphylococcus aureus and Sphingobacterium multivorum. Results show that CTAB stabilized silver and copper nanoparticles were more effective antibacterial agents than PVP stabilized metal nanoparticles, with MIC values in a range of 0.003 μM to 0.25 μM for CTAB stabilized metal nanoparticles and 0.25 μM to 2 μM for PVP stabilized metal nanoparticles. The recorded MIC and MBC values of the surface stabilized metal nanoparticles show that they can serve as effective antibacterial agents at low doses.

Parenteral Lipid-Based Nanoparticles for CNS Disorders: Integrating Various Facets of Preclinical Evaluation towards More Effective Clinical Translation

Contemporary trends in combinatorial chemistry and the design of pharmaceuticals targeting brain disorders have favored the development of drug candidates with increased lipophilicity and poorer water solubility, with the expected improvement in delivery across the blood-brain barrier (BBB). The growing availability of innovative excipients/ligands allowing improved brain targeting and controlled drug release makes the lipid nanocarriers a reasonable choice to overcome the factors impeding drug delivery through the BBB. However, a wide variety of methods, study designs and experimental conditions utilized in the literature hinder their systematic comparison, and thus slows the advances in brain-targeting by lipid-based nanoparticles. This review provides an overview of the methods most commonly utilized during the preclinical testing of liposomes, nanoemulsions, solid lipid nanoparticles and nanostructured lipid carriers intended for the treatment of various CNS disorders via the parenteral route. In order to fully elucidate the structure, stability, safety profiles, biodistribution, metabolism, pharmacokinetics and immunological effects of such lipid-based nanoparticles, a transdisciplinary approach to preclinical characterization is mandatory, covering a comprehensive set of physical, chemical, in vitro and in vivo biological testing.