Current Nanoscience - Current Issue

Nanoparticles are important agents for targeted drug delivery to tissues or organs, or even solid tumour in certain instances. However, their surface charge distribution makes them amenable to recognition by the host immune mechanisms, especially the innate immune system, which interferes with their intended targeting, circulation life, and eventual fate in the body. We aimed to study the immunological response of iron oxide nanoparticles (Fe-NPs) and the role of the complement system in inducing an inflammatory cascade.

The complement system is an important component of the innate immune system that can recognise molecular patterns on the pathogens (non-self), altered self (apoptotic and necrotic cells, and aggregated proteins such as beta-amyloid peptides), and cancer cells. It is no surprise that clusters of charge on nanoparticles are recognised by complement subcomponents, thus activating the three complement pathways: classical, alternative, and lectin.

This study aimed to examine the ability of Fe-NPs to activate the complement system and interact with macrophages in vitro.

Complement activation following exposure of Fe-NPs to macrophage-like cell line (THP-1) was analyzed by standard protocol. Real-time PCR was used for mRNA-level gene expression analysis, whereas multiplex cytokine array was used for protein-level expression analysis of cytokines and chemokines.

Fe-NPs activated all three pathways to a certain extent; however, the activation of the lectin pathway was the most pronounced, suggesting that Fe-NPs bind mannan-binding lectin (MBL), a pattern recognition soluble receptor (humoral factor). MBL-mediated complement activation on the surface of Fe-NPs enhanced their uptake by THP-1 cells, in addition to dampening inflammatory cytokines, chemokines, growth factors, and soluble immune ligands.

Selective complement deposition (mostly via the MBL pathway in this study) can make pro-inflammatory nanoparticles biocompatible and render them anti-inflammatory properties.

In the paper, Boletus Brucella was used as carbon source material to prepare carbon dots (CDs) by one-step hydrothermal method. The CDs had high quantum yield and high photostability.

A range of characterization studies were conducted on CDs, and the results showed that the average particle size of CDs was 5 nm, emitting blue fluorescence. The optimal excitation wavelength was 337 nm, and the emission wavelength was 440 nm.

Based on the static quenching, the fluorescence of CDs could be effectively quenched by VB2. Therefore, a highly sensitive and selective fluorescent probe for detecting VB2 was constructed. The CDs were successfully used to detect tablets, human blood, and urine.

The recovery rate of VB2 was 97.55~99.45%, and the relative standard deviation was 1.29~3.76 (n=3).

In the present investigation, low molecular weight polyethylenimine (LMW PEI, 1.8 kDa PEI) was conjugated to dextrin via urethane units and tested to transfer plasmid encoding interleukin-12 (IL-12) plasmid. Although high molecular weight PEI (HMW PEI, 25 kDa PEI) has shown substantial transfection efficiency, its wide application has been hampered due to considerable cytotoxicity. Therefore, LMW PEI with low toxic effects was used as the core of our gene transfer construct.

LMW PEI was conjugated to dextrin via urethane units to improve its biophysical characteristics as well as cytotoxic effects. The conjugates were characterized in terms of buffering capacity, plasmid DNA condensation ability, particle size, and zeta potential as well as protection against enzymatic degradation. In Vitro experiments were carried out to evaluate the ability of these LMW PEI conjugates to transfer plasmid encoding human interleukin-12 (hIL-12) to the cells. The MTT assay was performed to measure the cell-induced toxicity of the conjugates.

The results of our study demonstrated that the PEI derivatives with higher amounts of amine content (i.e. higher conjugation degrees) have considerable buffering capacity and plasmid condensation ability. These conjugates could condense plasmid DNA at Carrier to Plasmid ratios (C/P) ≥2 and form polyplexes at the size range of 120-165 nm while their zeta potential was around 5.5-8.5 mV. The results of transfection efficiency demonstrated that the level of IL-12 production increased by 2-3 folds compared with unmodified LMW PEI while the level of cytotoxicity was not higher than 20%.

The strategy used in this study shows a promising way to prepare gene carriers with high transfection efficiency and low toxicity.

The rise in antimicrobial resistance, caused by the production of biofilms by bacteria, is a significant concern in the field of healthcare. Nanoemulsion technology presents itself as a viable alternative in the quest to circumvent antibiotic resistance in pathogenic bacteria.

The aim of this research was to form a sustainable nanoemulsion from Z. multiflora, and evaluate its antibacterial and anti-biofilm activities against the clinical isolates of Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus.

Bioactive compounds of the oil were identified using GC-MS. Zataria multiflora essential oil (ZMEO) nanoemulsion was formulated as a water-dispersible nanoemulsion with a diameter of 184.88 ± 1.18 nm. The antibacterial and antibiofilm activities of the essential oil in both pure and nanoemulsion forms were assessed against pathogenic bacteria causing hospital-acquired infections using minimal inhibitory concentrations (MICs) and the microtiter method, respectively.

The main constituents were found to be linalool (78.66%), carvacrol (14.25%), and α-pinene (4.53%). Neither ZMEO nor the emulsified ZMEO showed any antimicrobial activity. However, ZMEO exhibited a low inhibition of biofilm formation by P. mirabilis, S. aureus, and P. aeruginosa. The most promising finding was that when the emulsified ZMEO was present at a concentration of 750 µg/mL, it significantly reduced biofilm formation by the aforementioned bacteria to 39.68% ± 2.62, 56.54% ± 3.35, and 59.60% ± 2.88, respectively. This result suggests that ZMEO nanoemulsion has the potential to effectively disrupt persistent biofilms and enhance the penetration of antimicrobial agents into the biofilm matrix.

In conclusion, the study provides evidence supporting the use of ZMEO nanoemulsion as a potential treatment option for combating biofilm-related infections caused by Pseudomonas aeruginosa, Proteus mirabilis, and Staphylococcus aureus. Further research is warranted to explore the practical application of the proposed essential oil in clinical settings.

In our previous studies, we have identified Gsk-3β as a crucial target molecule in response to Danhong injection for cerebral ischemia intervention. Furthermore, it can serve as a molecular imaging probe for medical diagnosis. Bacterial magnetic particles (BMPs), synthesized by magnetotactic bacteria, are regarded as excellent natural nanocarriers.

In this study, we utilized biological modification and chemical crosslinking techniques to produce a multifunctional BMP known as “RVG29-BMP-FA-Gsk-3β-Ab”, which exhibits both magnetic properties and brain-targeting capabilities. Then, a combination of analytical techniques was used to characterize the properties of the multifunctional BMPs. Finally, we evaluated the cell targeting ability of the RVG29-BMP-FA-Gsk-3β-Ab.

The multifunctional BMPs were observed to possess uniform size and shape using TEM analysis, with a particle size of 70.1±7.33 nm. Zeta potential analysis revealed that the nanoparticles exhibited a regular and non-aggregative distribution of particle sizes. Relative fluorescence intensity results demonstrated that the complex of 1 mg of RVG29-BMP-FA-Gsk-3β-Ab could bind to FITC-RVG29 polypeptide at a concentration of 2189.5 nM. Cell viability analysis indicated its high biocompatibility and minimal cytotoxicity. The RVG29-BMP-FA-Gsk-3β-Ab was observed to possess active targeting towards neuronal cells and fluorescence imaging capabilities in vitro, as evidenced by fluorescence imaging assays. The complex of RVG29-BMP-FA-Gsk-3β-Ab exhibited favourable properties for early diagnosis and efficacy evaluation of traditional Chinese medicine in treating cerebral ischemia.

This study establishes a fundamental basis for the prospective implementation of multimodal imaging in traditional Chinese medicine for cerebral ischemia.

Dihydroquercetin (DHQ), also known as taxifolin, is a flavonoid commonly found in many plants. Dihydroquercetin has been documented to have powerful antioxidant activity and many beneficial properties for human health, especially its ability to inhibit certain types of cancer cells. However, its low solubility and bioavailability are major obstacles to biomedical applications. Moreover, DHQ is chemically unstable and quickly degrades when exposed to alkaline conditions.

In the present study, a DHQ nanoemulsion formulation was prepared by Self Nano-Emulsifying Drug Delivery System (SNEDDS) technique to overcome the above disadvantages.

The obtained nanoemulsion system was evaluated for its micro-properties, stability, and in vitro cytotoxic activity against some cancer cells using tetrazolium dyes (MTS assay).

Measurement results showed that the DHQ nanoemulsion was successfully synthesized with typical mean droplet sizes from 9 to 11 nm, and revealed excellent stability over time. Dihydroquercetin in nanoemulsion form is more stable than the non-encapsulated form, as evidenced by the maintenance of droplet size in the nanometer range when dispersed in aqueous solution for up to 48 hours. This stability is particularly pronounced in both acidic and neutral environments. In vitro experiments on cytotoxic activities against A549, Hela, and HepG2 cancer cell lines indicated that the prepared DHQ nanoemulsion effectively inhibited the growth of all these cell lines with IC50 values (µg/mL) of 8.0, 20.4, and 29.5 respectively.

From the detailed results above, it is evident that the solubility and bioavailability of DHQ can be improved by creating its nanostructure in the form of nanoemulsions. Furthermore, the nano form of DHQ carried within stable nanoemulsions exhibited better performance in inhibiting cancer cells compared to free DHQ. Therefore, further research is required to explore the development of cancer therapeutics utilizing nano DHQ emulsions.

The use of targeted therapy has been increasing for cancer treatment. The aim of this study is to investigate chitosan-based ricin-Herceptin (rh) immunotoxin on breast cancer cell lines.

The gene construct encoding immunotoxin was designed, cloned, and expressed in E. coli BL21 (DE3). The expressed proteins were isolated by the nickel-nitrilotriacetic acid column and were analyzed by the Western-blotting. The cytotoxicity of immunotoxin was assayed on breast cell line MCF-7 and using MTT assay at 24 and 48 h treatment.

The immunotoxins extrication rate, size, loading percentage, and electric charge of nanoparticles were reported appropriately as 78%, 151.5 nm, 83.53%, and +11.1 mV, respectively. The encapsulated immunotoxins led to the death of 70% and 78% of MCF-7 cells at 24 and 48 h treatment, respectively. The noncapsulated counterparts at equal doses killed 53% and 62% of cancer cells at the same time points.

The chitosan-immunotoxins impose potential cytotoxic effects on cancer cells.

A modern genre of solar technology is Perovskite solar cells (PSCs), which are growing rapidly because they work well. The composition of links within the hole transport materials, electron transport materials and the footprint on PSCs is perovskite.

The traditional genre of lead halide perovskite can be swapped with a new perovskite compound called Cs2TiBr6. Cs2TiBr6 has better properties when it comes to light, electricity, and solar energy. When comparing the performance of various electron transport films (ETFs) for the effective operation of perovskite, TiO2 is recognized as an ETF as it has higher thermal stability, low-cost, and appropriate energy level.

The most productive hole transport film (HTF) for these perovskite solar cells, compared to other HTFs, has been demonstrated as V2O5.

The various solar cell characteristics of the proposed device, the “Au/V2O5/ Cs2TiBr6/TiO2/ TCO” perovskite solar cell, are investigated in this examination by tuning the parameters such as temperature, series resistance, defect density, etc.

This research delves into utilizing the Direct Laser Lithography System to produce micro/nanopattern arrays with grating-based periodic structures. Initially, refining the variation in periodic structures within these arrays becomes a pivotal pursuit. This demands a deep comprehension of how structural variation aligns with specific applications, particularly in photonics and material science.

Advancements in hardware, software, or process optimization techniques hold potential for reaching this objective. Using an optical beam, this system enables the engraving of moderate periodic and quasi-periodic structures, enhancing pattern formation in a three-dimensional environment. Through cost-effective direct-beam interferometry systems utilizing 405 nm GaN and 290 to 780 nm AlInGaN semiconductor laser diodes, patterns ranging from in period were created, employing 300 nm gratings.

The system's cost-efficiency and ability to achieve high-resolution permit the creation of both regular and irregular grating designs. By employing an optical head assembly from a blu-ray disc recorder, housing a semiconductor laser diode and an objective lens with an NA of 0.85, this system displays promising potential in progressing the fabrication of micro/nanopattern arrays.

Assessing their optical, mechanical, and electrical properties and exploring potential applications across varied fields like optoelectronics, photovoltaics, sensors, and biomedical devices represent critical strides for further exploration and advancement.