Cellular uptake of nanoparticles as determined by particle properties, experimental conditions, and cell type

Chitosan nanovectors for siRNA delivery: New horizons for nonviral gene therapy

The growing interest in RNA-based therapeutics has positioned small interfering RNA (siRNA) as a promising tool for gene silencing with high specificity and efficacy. However, the successful clinical application of siRNA therapies requires efficient delivery systems to overcome extracellular and intracellular barriers. Chitosan, a naturally derived polysaccharide, has gained significant attention as a non-viral vector due to its biodegradability, biocompatibility, mucoadhesive properties, and capacity to enhance cellular uptake. These attributes make chitosan an attractive alternative to lipid-based nanoparticles, which currently dominate siRNA delivery platforms. Recent advancements in chitosan-based nanoformulations, including chemical modifications and functionalization strategies, have improved siRNA stability, targeting efficiency, and transfection potential, addressing key limitations such as low bioavailability and immunogenicity. Despite these advances, challenges remain in achieving optimal release kinetics, scalability, and consistent therapeutic efficacy. Future research efforts will focus on engineering chitosan derivatives with enhanced physicochemical properties, integrating multifunctional nanocarriers, and refining formulation strategies to bridge the gap between preclinical research and clinical translation. The continued development of chitosan-based siRNA therapeutics holds significant potential for advancing precision medicine and expanding treatment options for a variety of diseases, including cancer, metabolic disorders, and inflammatory conditions.

Short-term PS-NP exposure in early adulthood induces neuronal damage in middle-aged mice via microglia-mediated neuroinflammation

Nanoplastics (NPs) are ubiquitous environmental pollutants that have garnered considerable attention for their potential adverse health effects. In this study, male C57BL/6 J mice were orally treated with a mixture of 50-nm and 200-nm polystyrene (PS)-NPs for one week followed by measurements of their neurobehavioral performance and neuronal damage 10 months later. Notably, PS-NPs were detected in the brains of the mice by transmission electron microscopy (TEM) and a nanoscale hyperspectral microscope imaging system 10 months after the PS-NP exposure. The mice exposed to short-term PS-NPs exhibited cognitive dysfunction and anxiety-like symptoms, neuronal damage and synapse loss, and an increase in the number of M1-polarized microglia and A1-reactive astrocytes. Interestingly, the inhibition of microglial activation by minocycline significantly mitigated the PS-NP-induced synapse loss and neuron damage. In vitro studies showed that PS-NPs could be readily internalized by three types of neurovascular unit (NVU) cells, including microglia, astrocytes, and brain microvascular endothelial cells, via multiple pathways. RNA-seq analysis confirmed that microglia-mediated neuronal injury was associated with disturbances in synapse and cell death signaling pathways. Collectively, these findings suggest that short-term PS-NP exposure-induced neuroinflammation in early adulthood may not be resolved naturally but may deteriorate under the interaction of microglia and astrocytes, leading to synapse loss, neuron degeneration, and cognitive dysfunction in middle age. The results of the present study provide important insights into the potential neurological impacts of NPs and suggest that targeting microglia to suppress inflammation might be a potential intervention strategy for neurodegeneration induced by NPs.

The impact of cell density variations on nanoparticle uptake across bioprinted A549 gradients

Introduction

The safe-by-design of engineered nanoparticles (NPs) for any application requires a detailed understanding of how the particles interact with single cells. Most studies are based on two-dimensional, uniformly dense cell cultures, which do not represent the diverse and inhomogeneous cell environments found in situ. In-vitro models that accurately represent tissue complexity, including realistic cell densities, are essential to increase the predictive accuracy of studies on cell-NP interactions. This study uses a bioprinted cell gradient model to examine the relation between cell density and NP uptake in one dish.

Method

A549 lung epithelial cell density gradients within single inserts were produced with a bioprinter by modulating inter-droplet distances. After two days in culture, cells were exposed to Cy5-labeled silica NPs (SiO2 NPs, ∼112 nm, 20 μg/mL) for up to 48 h. Confocal fluorescence microscopy and 3D image analysis were used to quantify NP uptake, cell surface area, and cell volume. The relationship between NP uptake and the other parameters was then investigated statistically.

Results

Bioprinting enabled the creation of reproducible linear cell density gradients, allowing controlled modeling of density variations while preserving cell viability throughout the experiment. Increasing inter-droplet distances, from 0.1 mm to 0.6 mm, were used to achieve uniformly decreasing cell densities. SiO2 NP uptake per cell was around 50% higher in low-density regions compared to high-density areas across all time points, i.e., 6, 24, and 48 h post-exposure. This inverse relationship correlated with greater average cell surface area in lower-density regions, while differences in the proliferation rates of the A549 cells at varying densities did not significantly impact uptake, did not significantly impact uptake.

Conclusion

SiO2 NP uptake is significantly enhanced at lower cell densities, mainly due to the increased available surface area, revealing potential cell-NP interaction differences in tissues that present cell density variability. Our drop-on-demand bioprinting gradient model successfully supports the implementation of cell density gradients in in-vitro models to increase their relevance as new approach methodologies (NAMs) for next-generation risk assessment strategies.

Microplastic exposure reduces seed germination in a coastal plant

Plastic contamination presents major environmental threats through its degradation into micro-sized particles that are harmful to a variety of organisms, including plants. Among terrestrial habitats, coastal dunes are likely some of the most plastic-polluted, but very few studies thus far have examined microplastic effects on wild plants native to this habitat. Moreover, current research on microplastics has limited environmental relevancy due to the common use of homogenously shaped un-weathered microplastics in exceeding concentrations. Our research examined the effects of microplastics from biodegradable and non-biodegradable origin, in their pristine (raw) and weathered form, at a concentration of 106 particles per ml, on the native coastal plant Cutandia maritima. We first synthesized engineered microplastics of high environmental relevancy from bulk plastic products. Then, we exposed C. maritima plants to the microplastics in the soil. While no effect was found on the plants following chronic exposure to all microplastic types, weathered plastic reduced seed germination after exposure of the mother plants, suggesting epigenetic modifications might have an effect at the embryo stage. In contrast, direct exposure of microplastics, specifically polylactic acid, facilitated seeds germination. Our results highlight the importance of studying the effects of microplastic on seed germination and raise the ongoing ecological consequences of environmental microplastic coastal contamination, which should be taken into account in regulatory and environmental assessments.

Nanoparticles in liposomes: a platform for increased antibiotic selectivity in multidrug resistant bacteria in respiratory tract infections

Antibiotic resistance is a cause of serious illness and death, originating often from insufficient permeability into gram-negative bacteria. Nanoparticles (NP) can increase antibiotic delivery in bacterial cells, however, may as well increase internalization in mammalian cells and toxicity. In this work, NP in liposome (NP-Lip) formulations were used to enhance the selectivity of the antibiotics (3C and tobramycin) and quorum sensing inhibitor (HIPS-1635) towards Pseudomonas aeruginosa by fusing with bacterial outer membranes and reducing uptake in mammalian cells due to their larger size. Poly (lactic-co-glycolic) acid NPs were prepared using emulsion solvent evaporation and incorporated in larger liposomes. Cytotoxicity and uptake studies were conducted on two lung cell lines, Calu-3 and H460. NP-Lip showed lower toxicity and uptake in both cell lines. Then formulations were investigated for suitability for oral inhalation. The deposition of NP and NP-Lip in the lungs was assessed by next generation impactor and corresponded to 75% and 45% deposition in the terminal bronchi and the alveoli respectively. Colloidal stability and mucus-interaction studies were conducted. NP-Lip showed higher diffusion through mucus compared to NPs with the use of nanoparticle tracking analyzer. Moreover, the permeation of delivery systems across a liquid-liquid interface epithelial barrier model of Calu-3 cells indicated that NP-Lip could cause less systemic toxicity upon in-vivo like administration by aerosol deposition. Monoculture and Pseudomonas aeruginosa biofilm with Calu-3 cells co-culture experiments were conducted, NP-Lip achieved highest toxicity towards bacterial biofilms and least toxicity % of the Calu-3 cells. Therefore, the NP- liposomal platform offers a promising approach for enhancing antibiotic selectivity and treating pulmonary infections.

Incorporating Span 80 surfactant into lipid nanocapsules improves their biocompatibility and cellular uptake in B16F10 melanoma cells

Surfactant-shell lipid nanocapsules (LNCs) are promising skin delivery systems. They are composed of an oily core with a stabilising shell of surfactant and phosphatidylcholine. LNCs' hydrodynamic diameter can be easily tuned by varying the surfactant content in the formulation. Hydrophilic surfactants incorporated into LNCs have shown toxicity in mammalian cells. To date, the toxicity of all published surfactant-shelled LNCs produced by the the phase inverson temperature (PIT) method has been investigated using hydrophilic surfactants, with no studies examining the impact of incorporating hydrophobic surfactants on LNCs' in vitro behaviour. Span 80 is a hydrophobic surfactant and has been extensively used in manufacturing various ranges of nanoparticles. The present study formulated Span 80-containing LNCs to evaluate their in vitro behaviour in the B16F10 melanoma cell line. LNC-100-S8 of Kolliphor HS15/Span 80 (65/35 w/w%) and original LNC100-0 LNCs of Kolliphor HS15 with a hydrodynamic diameter of 100 nm were prepared using the PIT method. A salt aggregation test confirmed increased surface hydrophobicity of LNC100-S8 compared to LNC100-0. Cytotoxicity assays demonstrated that LNC100-S8 had a three-fold lower cytotoxicity than LNC100-0 (IC80 = 11757 μg/mL vs 3184 μg/mL). Flow cytometry analysis indicated significantly higher cellular uptake of LNC100-S8 compared to LNC100-0, with 1.52-fold, 1.46-fold, and 1.67-fold increase at 1 h, 3 h, and 24 h, respectively . Mechanistic investigations revealed that LNC100-S8 uptake predominantly occured via phosphoinositide 3-kinase (PI3K)-regulated macropinocytosis and actin-dependent endocytosis, whereas LNC100-0 also utilised Na+/H+ exchanger-mediated macropinocytosis. Furthermore, protein corona analysis demonstrated increased interactions between LNC100-S8 and B16F10-conditioned media proteins, leading to bimodal size distribution and elevated polydispersity index (>0.3), which influenced their endocytic pathways. Overall, Our findings revealed the high promise of our Span 80-containing LNCs as a drug delivery system with enhanced cellular uptake and biocompatibility in B16F10 melanoma cells compared to conventional LNCs composed of Kolliphor HS15 surfactant, highlighting their potential uses in topical delivery to melanoma and other skin diseases.

Elucidating the uptake and trafficking of nanostructured lipid carriers as delivery systems for miRNA

Cationic nanostructured lipid carriers (cNLCs) represent promising non-viral carriers for nucleic acids, such as miRNAs, forming stable self-assembled miRNA complexes due to electrostatic interactions. Prepared by high-pressure homogenization, cNLC formulations, both with and without Nile Red dye demonstrated stable particle sizes in the range of 100-120 nm and positive surface charges (>30 mV), which are necessary for effective cellular uptake. The miRNA complexes formed at mass ratios of 1:2.5 and 1:5 showed similar stability and size, with positive zeta potentials, as well as high cell viability (> 80 %) in 3T3-L1 and MCF-7 cell lines. The cellular uptake studies of miRNA:cNLC complexes in both cell lines revealed that uptake was time- and concentration-dependent, with rapid initial uptake in 30 min and a zig-zag pattern over 24 h. To elucidate the endocytosis mechanism of miRNA:cNLC complexes, 3T3-L1 and MCF-7 cells were incubated with different inhibitors (chlorpromazine, 5-[N-ethyl-N-isopropyl] amiloride, dynasore, nystatin, or sodium azide with 2-deoxy-d-glucose). Results showed significant inhibition of uptake at low temperatures and with ATP depletion, suggesting endocytosis, particularly macropinocytosis, as the main uptake mechanism in 3T3-L1 cells. In MCF-7 cells, the uptake was less inhibited by the substances, indicating the need for more specific methods to fully decipher the endocytic mechanisms involved. Confocal laser scanning microscopy images revealed that the complexes are internalized in vesicles, and are primarily localized in the juxtanuclear region, suggesting trafficking through the endolysosomal system. Colocalization study with LysoTracker™ Green DND-26 showed significant colocalization of miRNA:cNLC complexes with lysosomes in 3T3-L1 cells, indicating trafficking through the endolysosomal system. In MCF-7 cells, colocalization was lower, suggesting macropinocytosis as the primary uptake mechanism. Additional studies showed partial colocalization between labeled NLCs and miRNA, indicating that about 50 % of miRNA is released from NLCs within 30 min post-transfection.

Local delivery of carboplatin-loaded hydrogel and calcium carbonate enables two-stage drug release for limited-dose radiation to eliminate mouse malignant glioma

Postoperative radiotherapy remains the gold standard for malignant glioma treatment. Clinical limitations, including tumor growth between surgery and radiotherapy and the emergence of radioresistance, reduce treatment effectiveness and result in local disease progression. This study aimed to develop a local drug delivery system to inhibit tumor growth before radiotherapy and enhance the subsequent anticancer effects of limited-dose radiotherapy. We developed a compound of carboplatin-loaded hydrogel (CPH) incorporated with carboplatin-loaded calcium carbonate (CPCC) to enable two-stage (peritumoral and intracellular) release of carboplatin to initially inhibit tumor growth and to synergize with limited-dose radiation (10 Gy in a single fraction) to eliminate malignant glioma (ALTS1C1 cells) in a C57BL/6 mouse subcutaneous tumor model. The doses of carboplatin in CPH and CPCC treatments were 150 μL (carboplatin concentration of 5 mg/mL) and 15 mg (carboplatin concentration of 4.1 μg/mg), respectively. Mice receiving the combination of CPH-CPCC treatment and limited-dose radiation exhibited significantly reduced tumor growth volume compared to those receiving double-dose radiation alone. Furthermore, combining CPH-CPCC treatment with limited-dose radiation resulted in significantly longer progression-free survival than combining CPH treatment with limited-dose radiation. Local CPH-CPCC delivery synergized effectively with limited-dose radiation to eliminate mouse glioma, offering a promising solution for overcoming clinical limitations.

Recent Advances in Multifaceted Drug Delivery Using Natural Polysaccharides and Polyacrylamide-based Nanomaterials in Nanoformulation

Rapid growth in nanotechnology, also known as 21st-century technology, is occurring in response to the increasing diversity of diseases. The development of safe and effective drug delivery methods to enhance bioavailability is of paramount importance. Researchers have focused on creating safe, cost-effective, and environmentally friendly nanoparticle construction processes. Natural polysaccharides, a type of multifaceted polymer with a wide range of applications and advantages, are particularly well suited for nanoparticle formulations, as they can mitigate the adverse consequences of synthetic nanoparticle formulations and promote sustainability. This review summarizes various sources of natural-based polysaccharides and polyacrylamide-based nanomaterials in nanoparticle preparation. Additionally, it discusses the use of natural polysaccharides in formulations beyond nanotechnology, highlighting their importance in green synthesis and different preparation methods.

Synthesis and characterization of poly (β-amino ester) polyplex nanocarrier with high encapsulation and uptake efficiency: impact of extracellular conditions

BACKGROUND

Poly (β-amino Ester) nanocarriers show promise for gene therapy, but their effectiveness can be limited by the environment within the body. This study aims to understand how common cell culture media components affect optimized PBAE nanocarrier performance in gene delivery.

METHODS

Optimized PBAE was synthesized based on Michael addition reaction and characterized by different assays, this study employed techniques like DLS and TEM to characterize PBAE nanocarriers, followed by cellular uptake analysis (flow cytometry and confocal imaging) and evaluation of gene expression under different polymer/DNA ratio ratios and media conditions.

RESULTS

The nanocarriers exhibited size under 200 nm and surface positive charge, with high encapsulation efficiency (up to 95%). Cellular uptake, transfection efficiency, and cytotoxicity were evaluated. Flow cytometry analysis revealed high cellular uptake (over 77% at 1 hour and up to 95% after 3 hours) and good viability. Transfection efficiency reached up to 80% with 2 μg DNA, particularly at weight ratios of 60 and 90.

CONCLUSION

The study also identified factors affecting transfection efficiency, including serum concentration and antibiotics in the culture medium, highlighting the importance of optimizing these conditions for future applications.

Aripiprazole-loaded niosome/chitosan-gold nanoparticles for breast cancer chemo-photo therapy

INTRODUCTION

Breast cancer, a formidable global health challenge for women, necessitates innovative therapeutic strategies with enhanced efficacy and minimal side effects. Aripiprazole (ARI), a widely used schizophrenia medication, exhibits promising potential in the treatment of breast cancer. As cancer therapy evolves towards a combination approach, multimodal nano-based delivery systems, such as ARI-loaded niosomes (NIOs) combined with Chitosan-Au nanoparticles for chemo-photothermal therapy, show promise over traditional chemotherapy alone by enhancing targeted efficacy and minimizing side effects.

METHODS

In this study, a niosomal formulation was designed, incorporating ARI and chitosan-coated AuNPs (i.e. NIOs/AuNPs-CS/ARI), to study the synergistic effect of photothermal/chemotherapy in breast cancer cells.

RESULTS

The nanosystems were characterized using UV-Vis spectroscopy and Fourier-transform infrared spectroscopy (FT-IR), confirming the successful synthesis steps. The hydrodynamic diameter of NIOs/AuNPs-CS was determined to be 44.62 nm with a zeta potential of -0.836. Also, Transmission Electron Microscopy (TEM) and Field-Emission Scanning Electron Microscopical (FE-SEM) analysis were performed to assess the size and morphology of NPs. The loading efficiency of ARI in NIOs and NIOs/AuNPs-CS was 75% and 88%, respectively. Furthermore, the release rate of the drug from NIOs/AuNPs-CS is higher than blank NIOs at two pH values (5.8 and 7.4). The cellular uptake of AuNPs-CS-encapsulated NIOs was considerably higher than that of blank NIOs. The Annexin V/PI staining assay showed that the apoptosis/necrosis rate was high in NIOs/AuNPs-CS/ARI (46%) and NIOs/ARI (36%) in 48 h. The results of MTT assessments demonstrated higher cytotoxicity by ARI-loaded NPs. The viability of MCF-7 cells treated with NIOs/AuNPs-CS/ARI was reduced from 60% and 50% to 40% and 20%, respectively, after 24 and 48 h upon laser irradiation.

CONCLUSION

The results of this experiment demonstrated the remarkable effectiveness of NIOs/AuNPs-CS/ARI in cancer treatment, owing to their unique properties, including the PTT capability and pH sensitivity.

Chitosan-Based Nanocapsules as a Delivery System of Hydrophobic Carnosic Acid, A Model Neuroprotective Drug

Introduction

Since the population of Europe is rapidly aging, the number of cases of neurodegenerative diseases sharply increases. One of the most significant limitations of current neurodegenerative disease treatment is the inefficient delivery of neuroprotective drugs to the affected part of the brain. One of the promising methods to improve the pharmacokinetic and pharmacodynamic properties of antioxidants is their encapsulation in nanocarriers.

Materials and Methods

Encapsulation of carnosic acid into a chitosan-based nanoparticle system with ultrasound-assisted emulsification process was developed. The physicochemical properties (size, stability, concentration of nanoparticles) of obtained nanocapsules were analyzed. Also, the cytotoxicity and neuroprotective effect in SH-SY5Y cells exposed to toxic concentration of H2O2 of the obtained nanoparticles were evaluated in vitro.

Results and Discussion

The capsules with diameters between 90 and 150 nm and long-term stability were obtained. Cytotoxicity tests of empty capsules indicate that observed toxic effects were concentration dependent and lower concentrations (dilution above 500×) can be considered as safe for tested cells. Our study also indicates that encapsulation of carnosic acid decreased the cytotoxicity of empty nanocapsules and can efficiently protect SH-SY5Y cells from factors causing cell destruction. In addition, the neuroprotective efficacy of carnosic acid loaded nanocapsules was also demonstrated in SH-SY5Y cells exposed to toxic concentration of H2O2. The designed nanoparticles appear to possess sufficient biocompatibility to deserve their further evaluation in in vivo models.

An investigation of the effect of the protein corona on the cellular uptake of nanoliposomes under flow conditions using quartz crystal microgravimetry with dissipation

When nanoparticle delivery systems are immersed in biological fluids, a complex assembly of proteins forms on their surface, creating a protein corona. The protein corona alters the physicochemical properties, toxicity, biodistribution, cellular uptake, and immune response of the nanoparticles, and consequently, their therapeutic efficacy. Currently, there is a lack of in vitro methods to assess the effects of the protein corona on nanoparticle uptake under dynamic flow and assess their binding kinetics in real-time. Here, we introduce quartz crystal microbalance with dissipation (QCM-D) as an in vitro technique, capable of incorporating dynamic flow, to study the effect of the protein corona on the binding of nanoliposome (NLP) formulations to cell surfaces as a first step in their cellular uptake. The interactions of four NLP formulations (low PEGylated, high PEGylated, negatively charged and positively charged NLPs) with A375 melanoma and THP1 cell lines were assessed by QCM-D, before and after the formation of a protein corona. Through real-time recording of the frequency and dissipation shifts (Δf and ΔD, respectively), the QCM-D results provided strong evidence of the role of the protein corona in the cellular interaction of these NLP formulations, with a variation in their adsorption kinetics depending on their initial composition. NLP's attachment to the cell surface was the lowest for PEGylated NLPs (<5%), while the positively charged NLPs showed the highest cellular attachment (≈100%), regardless of the presence of the protein corona or cell type. The effect of the protein corona was more pronounced for the negatively charged NLPs, where a significant reduction in the NLP attachment was observed. To complement the QCM-D data on the NLP attachment and to determine whether the NLP attachment leads to cellular uptake, confocal microscopy and flow cytometry were used to confirm NLP uptake by A375 and THP1 cells. Proteomic analysis revealed a differential composition of the protein corona on the various NLPs with possible implications for their sequestration and cellular uptake. Collectively, the findings suggest that QCM-D can be an important tool to study the binding of NLP formulations or other nanoparticles with cell membranes under dynamic flow, which very often differs from nanoparticle uptake under static conditions.

In vivo bioaccumulation and responses of hemocytes of mussels Perna viridis to microplastics and nanoplastics exposure

Growing micro- and nano-plastic (MNPs) pollution in the environment poses a threat to marine animals. Due to their excellent filtration capacity, bivalves can easily ingest MNPs, which could be translocated to open circulation system with potential risks. In the present study, the accumulation and elimination of MNPs (200 nm and 1 µm) in the mussel hemolymph serum and hemocytes were firstly quantified, and the differential sensitiveresponses of two subpopulations of hemocytes were then explored by in vivo exposure under environmentally relevant concentration of MNPs (200 µg/L). We demonstrated that MNPs were readily translocated into hemolymph serum, but were immediately followed by efficient internalization by hemocytes. Remarkably, concentrations of MNPs in hemolymph were only 0.63 and 0.39 times lower than the ambient exposure concentration. Granulocytes displayed a much higher potential of accumulating MNPs than the agranulocytes. MPs were more readily internalized by granulocytes, with their estimated maximum bioaccumulation factor (BCF) of 0.29 L/g. Due to the primary function of phagocytic encapsulation of MNPs by granulocytes, lysosome features especially the decline of subsequent lysosome membrane potential could be a potential sensitive biomarker in response to MNPs exposure. Our results provided insights on the bioaccumulation of MNPs at the cellular levels in marine bivalves.

Deciphering the links: Fragmented polystyrene as a driver of skin inflammation

Nano- and microplastics (NMPs), ubiquitous in the environment, pose significant health risks. We report for the first time a comprehensive study using in-vitro, in-vivo, and ex-vivo models to investigate the penetration and inflammatory effects of fragmented polystyrene (fPS) on human skin, including the analysis of both penetration depth and fPS amounts that penetrate the skin. Human keratinocyte (HaCaT) and human dermal fibroblast (HDF) cells exposed to fPS exhibited notable internalization and cytotoxicity. In a 3D human skin model, fPS particles penetrated the dermal layer within one hour, with an average maximum penetration of 4.7 μg for particles smaller than 2 µm. Similarly, mouse dorsal skin and human abdominal skin models confirmed fPS penetration. RNA sequencing revealed substantial upregulation of inflammatory genes, including IL-1α, IL-1β, IL-18, IL-6, IL-8, ICAM-1, FOS, and JUN, following fPS exposure. These findings were validated at both the mRNA and protein levels, indicating a robust inflammatory response. Notably, the inflammatory response in both the 3D human skin and mouse models increased in a dose-dependent manner, underscoring the toxicological impact of fPS on skin health. This study provides crucial insights into the mechanisms through which NMPs affect human health and underscores the need for further research to develop effective mitigation strategies.

From Preformulative Design to In Vivo Tests: A Complex Path of Requisites and Studies for Nanoparticle Ocular Application. Part 1: Design, Characterization, and Preliminary In Vitro Studies

Ocular pathologies are widely diffused worldwide, and their effective treatment, combined with a high patient compliance, is sometimes challenging to achieve due to the barriers of the eye; in this context, the use of nanoparticles for topical ophthalmic application could represent a successful strategy. Aiming to develop nanoplatforms with potential clinical applications, great attention has to be paid to their features, in relation to the route of administration and to the pharmacopoeial requirements. This review (part 1) thus embraces the preliminary steps of nanoparticle development and characterization. At the beginning, the main barriers of the eye and the different administration routes are resumed, followed by a general description of the advantages of the employment of nanoparticles for ocular topical administration. Subsequently, the preformulative steps are discussed, deepening the choice of raw materials and determining the quantitative composition. Then, a detailed report of the physicochemical and technological characterization of nanoparticles is presented, analyzing the most relevant tests that should be performed on nanoparticles to verify their properties and the requisites (both mandatory and suggested) demanded by regulatory agencies. In conclusion, some preliminary noncellular in vitro evaluation methods are described. Studies from in vitro cellular assays to in vivo tests will be discussed in a separate (part 2) review paper. Hence, this overview aims to offer a comprehensive tool to guide researchers in the choice of the most relevant studies to develop a nanoplatform for ophthalmic drug administration.

Mechanistic Insights into Toxicity of Titanium Dioxide Nanoparticles at the Micro- and Macro-levels

Titanium oxide nanoparticles (TiO2 NPs) have been regarded as a legacy nanomaterial due to their widespread usage across multiple fields. The TiO2 NPs have been and are still extensively used as a food and cosmetic additive and in wastewater and sewage treatment, paints, and industrial catalysis as ultrafine TiO2. Recent developments in nanotechnology have catapulted it into a potent antibacterial and anticancer agent due to its excellent photocatalytic potential that generates substantial amounts of highly reactive oxygen radicals. The method of production, surface modifications, and especially size impact its toxicity in biological systems. The anatase form of TiO2 (<30 nm) has been found to exert better and more potent cytotoxicity in bacteria as well as cancer cells than other forms. However, owing to the very small size, anatase particles are able to penetrate deep tissue easily; hence, they have also been implicated in inflammatory reactions and even as a potent oncogenic substance. Additionally, TiO2 NPs have been investigated to assess their toxicity to large-scale ecosystems owing to their excellent reactive oxygen species (ROS)-generating potential compounded with widespread usage over decades. This review discusses in detail the mechanisms by which TiO2 NPs induce toxic effects on microorganisms, including bacteria and fungi, as well as in cancer cells. It also attempts to shed light on how and why it is so prevalent in our lives and by what mechanisms it could potentially affect the environment on a larger scale.

What if you eat nanoplastics? Simulating nanoplastics fate during gastrointestinal digestion

Despite our growing awareness of micro-and nanoplastics presence in food and beverages, the fate of nanoplastics (NPs) in the human gastrointestinal tract (GIT) remains poorly investigated. Changes of nanoplastics size upon digestive conditions influence the potential of absorption through the intestine. In this study, polymer nanoparticles with different physicochemical properties (size, surface and chemistry) were submitted to gastrointestinal digestion (GID) simulated in vitro. Their agglomeration behaviour was measured with a unique set of analytical approaches, allowing to study NPs' interactions with the digestive enzymes. Smaller NPs agglomerated more, narrowing the overall particle size distribution of smaller and larger NPs. NPs of different polymers exhibited heteroagglomeration. Digestive enzymes interact with the NPs, forming large but fragile agglomerates. In presence of the enzymes, even acid-functionalized NPs, typically stable in harsh conditions, agglomerated similarly to the non-functionalized PS NPs. These results highlight the role of the GID in increasing the effective size of ingested NPs, potentially reducing their ability to pass through the cell membranes. Our findings address a critical knowledge gap in nanoplastics oral uptake potential, providing a solid technical foundation for their characterization.

Model for random internalization of nanoparticles by cells

We propose a stochastic model for the internalization of nanoparticles by cells formulating cellular uptake as a compound Poisson process with a random probability of success. This is an alternative approach to the one presented by Rees et al. [Nat. Commun. 10, 2341 (2019)2041-172310.1038/s41467-018-07882-8] who explained overdispersion in nanoparticle uptake and associated negative binomial distribution by considering a Poisson distribution for particle arrival and a gamma-distributed cell area. In our stochastic model, the formation of new pits is represented by the Poisson process, whereas the capturing process and the population heterogeneity are described by a random Bernoulli process with a beta-distributed probability of success. The random probability of success generates ensemble-averaged conditional transition probabilities that increase with the number of newly formed pits (self-reinforcement). As a result, an ensemble-averaged nanoparticle uptake can be represented as a Polya process. We derive an explicit formula for the distribution of the random number of pits containing nanoparticles. In the limit of the fast nucleation and low probability of nanoparticle capture, we find the negative binomial distribution.

Biofabricated nanomaterials in sustainable agriculture: insights, challenges and prospects

One ever-evolving and ever-demanding critical human endeavour is the provision of food security for the growing world population. This can be done by adopting sustainable agriculture through horizontal (expanding the arable land area) and vertical (intensifying agriculture through sound technological approaches) interventions. Customized formulated nanomaterials have numerous advantages. With their specialized physico-chemical properties, some nanoparticulated materials improve the plant's natural development and stress tolerance and some others are good nanocarriers. Nanocarriers in agriculture often coat chemicals to form composites having utilities with crop productivity enhancement abilities, environmental management (such as ecotoxicity reduction ability) and biomedicines (such as the ability to control and target the release of useful nanoscale drugs). Ag, Fe, Zn, TiO2, ZnO, SiO2and MgO nanoparticles (NPs), often employed in advanced agriculture, are covered here. Some NPs used for various extended purposes in modern farming practices, including disease diagnostics and seed treatment are also covered. Thus, nanotechnology has revolutionized agrotechnology, which holds promise to transform agricultural (ecosystems as a whole to ensure food security in the future. Considering the available literature, this article further probes the emergent regulatory issues governing the synthesis and use of nanomaterials in the agriculture sector. If applied responsibly, nanomaterials could help improve soil health. This article provides an overview of the nanomaterials used in the distribution of biomolecules, to aid in devising a safer and eco-friendly sustainable agriculture strategy. Through this, agri-systems that depend on advanced farming practices might function more effectively and enhance agri-productivity to meet the food demand of the rising world population.

Lack of cytotoxic and genotoxic effects of mPEG-silane coated iron(III) oxide nanoparticles doped with magnesium despite cellular uptake in cancerous and noncancerous lung cells

Cytotoxic and genotoxic effects of novel mPEG-silane coated iron(III) oxide nanoparticles doped with magnesium (Mg0.1-γ-Fe2O3(mPEG-silane)0.5) have been investigated on human adenocarcinomic alveolar basal epithelial (A549) and human normal bronchial epithelial (BEAS-2B) cells. In the studies several molecular and cellular targets addressing to cell membrane, cytoplasm organelles and nucleus components were served as toxicological endpoints. The as-synthesized nanoparticles were found to be stable in the cell culture media and were examined for different concentration and exposure times. No cytotoxicity of the tested nanoparticles was found although these nanoparticles slightly increased reactive oxygen species in both cell types studied. Mg0.1-γ-Fe2O3(mPEG-silane)0.5 nanoparticles did not produce any DNA strand breaks and oxidative DNA damages in A549 and BEAS-2B cells. Different concentration of Mg0.1-γ-Fe2O3(mPEG-silane)0.5 nanoparticles and different incubation time did not affect cell migration. The lung cancer cells' uptake of the nanoparticles was more effective than in normal lung cells. Altogether, the results evidence that mPEG-silane coated iron(III) oxide nanoparticles doped with magnesium do not elucidate any deleterious effects on human normal and cancerous lung cells despite cellular uptake of these nanoparticles. Therefore, it seems reasonable to conclude that these novel biocompatible nanoparticles are promising candidates for further development towards medical applications.

Exploring the Therapeutic Potential of Fe3O4@Glu-Oleuropein Nanoparticles in Targeting KRAS Pathway-Regulating lncRNAs in Colorectal Cancer Cells

Cancer, the leading cause of death worldwide, has witnessed significant advancements in treatment through targeted therapies. Among the proto-oncogenes prevalent in human cancers, KRAS stands out, and recent research has focused on long noncoding RNAs (lncRNAs) as regulators of miRNAs targeting the KRAS oncogene. This study specifically explores lncRNAs involved in the KRAS pathway in colorectal cancer (CRC). To investigate this, researchers employed iron oxide nanoparticles coated with glucose and conjugated with Oleuropein (Fe3O4@Glu-Oleuropein NPs) to evaluate their impact on candidate lncRNAs associated with KRAS pathway deregulation. The study utilized TCGA data to identify genes affected by KRAS mutation and lncRNAs linked to KRAS in CRC. Enrichr and MsigDB databases helped identify relevant pathways. Genes with a correlation coefficient above 0.5 and a P-value less than 0.01 with candidate lncRNAs were selected. MTT and flow cytometry assays determined the anti-proliferative and apoptotic effects of Fe3O4@Glu-Oleuropein NPs on CRC cells (SW480) and normal cells (HEK293). The findings showed that increased expression of FEZF1-AS1, GAS6-AS1, and LINC00920 correlated with mutated KRAS, and co-expressed genes were significantly involved in hypoxia, KRAS signaling, DNA repair, and IL-2/STAT5 signaling pathways. Fe3O4@Glu-Oleuropein NPs exhibited higher toxicity toward cancer cells, with IC50 values of 92 μg/ml for SW480 and 281 μg/ml for HEK293. Flow cytometry analysis revealed a substantial increase in necrotic and apoptotic cells when treated with Fe3O4@Glu-Oleuropein, along with down-regulation of GAS6-AS1, LINC00920, and FEZF1-AS1 lncRNAs in treated cells. In conclusion, this study highlights the therapeutic potential of Fe3O4@Glu-Oleuropein on colon cancer cells in vitro. The identification of lncRNAs involved in the KRAS pathway provides insights into the underlying mechanisms and offers avenues for further research in targeted cancer therapies.

Understanding Human Health Impacts Following Microplastic Exposure Necessitates Standardized Protocols

Microplastics (MPs; 1 µm to 5 mm) are a persistent and pervasive environmental pollutant of emergent and increasing concern. Human exposure to MPs through food, water, and air has been documented and thus motivates the need for a better understanding of the biological implications of MP exposure. These impacts are dependent on the properties of MPs, including size, morphology, and chemistry, as well as the dose and route of exposure. This overview offers a perspective on the current methods used to assess the bioactivity of MPs. First, we discuss methods associated with MP bioactivity research with an emphasis on the variety of assays, exposure conditions, and reference MP particles that have been used. Next, we review the challenges presented by common instrumentation and laboratory materials, the lack of standardized reference materials, and the limited understanding of MP dosimetry. Finally, we propose solutions that can help increase the applicability and impact of future studies while reducing redundancy in the field. The excellent protocols published in this issue are intended to contribute toward standardizing the field so that the MP knowledge base grows from a reliable foundation. © 2024 Wiley Periodicals LLC.

Apoptosis induction in colon cancer cells (SW480) by BiFe2O4@Ag nanocomposite synthesized from Chlorella vulgaris extract and evaluation the expression of CASP8, BAX and BCL2 genes

BACKGROUND

The use of nanomaterials in cancer diagnosis and treatment has received considerable interest. Preparation of nanoscale complex molecules could be considered to improve the efficacy and minimize toxicity of the product. This work aimed to biosynthesize BiFe2O4@Ag nanocomposite using the Chlorella vulgaris extract and its cytotoxic effect on colon cancer cell line.

METHODS

The physicochemical properties of the bioengineered BiFe2O4 @Ag were investigated by Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FE-SEM), Zeta potential, Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive X-ray Spectroscopy (EDX), Vibrating-sample Magnetometer (VSM) and X-ray Diffraction Analysis (XRD). The cytotoxic potential of BiFe2O4 @Ag was evaluated by MTT assay against SW480 colon cancer cell line. The expression levels of apoptotic genes including BAX, BCL2 and CASP8 were determined by Real-time PCR. The rate of apoptosis and necrosis of the cancer cells as well as the cell cycle analysis were evaluated by flow cytometry.

RESULTS

Physicochemical assays indicated the nanoscale synthesis (10-70 nm) and functionalization of BiFe2O4 nanoparticles by Ag atoms. The VSM analysis revealed the magnetism of BiFe2O4 @Ag nanocomposite. According to the MTT assay, colon cancer cells (SW480) were considerably more sensitive to BiFe2O4 @Ag nanocomposite than normal cells. Apoptotic cell percentage increased from 1.93% to 73.66%, after exposure to the nanocomposite. Cell cycle analysis confirmed an increase in the number of the cells in subG1 and G0/G1 phases among nanocomposite treated cells. Moreover, treating the colon cancer cells with BiFe2O4 @Ag caused an increase in the expression of CASP8, BAX, and BCL2 genes by 3.1, 2.6, and 1.2 folds, respectively. Moreover, activity of Caspase-3 protein increased by 2.4 folds and apoptotic morphological changes appeared which confirms that exposure to the nanocomposite induces extrinsic pathway of apoptosis in colon cancer cells.

CONCLUSION

The considerable anticancer potential of the synthesized BiFe2O4 @Ag nanocomposite seems to be related to the induction of oxidative stress which leads to inhibit cell cycle progression and cell proliferation. This study reveals that the BiFe2O4 @Ag is a potent compound to be used in biomedical fields.

Sonicated polyethylene terephthalate nano- and micro-plastic-induced inflammation, oxidative stress, and autophagy in vitro

The environmental presence of nano- and micro-plastic particles (NMPs) is suspected to have a negative impact on human health. Environmental NMPs are difficult to sample and use in life science research, while commercially available plastic particles are too morphologically uniform. Additionally, this NMPs exposure exhibited biological effects, including cell internalization, oxidative stress, inflammation, cellular adaptation, and genotoxicity. Therefore, developing new methods for producing heterogenous NMPs as observed in the environment is important as reference materials for research. Thus, we aimed to generate and characterize NMPs suspensions using a modified ultrasonic protocol and to investigate their biological effects after exposure to different human cell lines. To this end, we produced polyethylene terephthalate (PET) NMPs suspensions and characterized the particles by dynamic light scattering and scanning electron microscopy. Ultrasound treatment induced polymer degradation into smaller and heterogeneous PET NMPs shape fragments with similar surface chemistry before and after treatment. A polydisperse suspension of PET NMPs with 781 nm in average size and negative surface charge was generated. Then, the PET NMPs were cultured with two human cell lines, A549 (lung) and HaCaT (skin), addressing inhalation and topical exposure routes. Both cell lines interacted with and have taken up PET NMPs as quantified via cellular granularity assay. A549 but not HaCaT cell metabolism, viability, and cell death were affected by PET NMPs. In HaCaT keratinocytes, large PET NMPs provoked genotoxic effects. In both cell lines, PET NMPs exposure affected oxidative stress, cytokine release, and cell morphology, independently of concentration, which we could relate mechanistically to Nrf2 and autophagy activation. Collectively, we present a new PET NMP generation model suitable for studying the environmental and biological consequences of exposure to this polymer.

Encapsulation of short-chain bioactive peptides (BAPs) for gastrointestinal delivery: a review

The majority of known peptides with high bioactivity (BAPs) such as antihypertensive, antidiabetic, antioxidant, hypocholesterolemic, anti-inflammatory and antimicrobial actions, are short-chain sequences of less than ten amino acids. These short-chain BAPs of varying natural and synthetic origin must be bioaccessible to be capable of being adsorbed systemically upon oral administration to show their full range of bioactivity. However, in general, in vitro and in vivo studies have shown that gastrointestinal digestion reduces BAPs bioactivity unless they are protected from degradation by encapsulation. This review gives a critical analysis of short-chain BAP encapsulation and performance with regard to the oral delivery route. In particular, it focuses on short-chain BAPs with antihypertensive and antidiabetic activity and encapsulation methods via nanoparticles and microparticles. Also addressed are the different wall materials used to form these particles and their associated payloads and release kinetics, along with the current challenges and a perspective of the future applications of these systems.

Cell-Surface Binding of DNA Nanostructures for Enhanced Intracellular and Intranuclear Delivery

DNA nanostructures (DNs) have found increasing use in biosensing, drug delivery, and therapeutics because of their customizable assembly, size and shape control, and facile functionalization. However, their limited cellular uptake and nuclear delivery have hindered their effectiveness in these applications. Here, we demonstrate the potential of applying cell-surface binding as a general strategy to enable rapid enhancement of intracellular and intranuclear delivery of DNs. By targeting the plasma membrane via cholesterol anchors or the cell-surface glycocalyx using click chemistry, we observe a significant 2 to 8-fold increase in the cellular uptake of three distinct types of DNs that include nanospheres, nanorods, and nanotiles, within a short time frame of half an hour. Several factors are found to play a critical role in modulating the uptake of DNs, including their geometries, the valency, positioning and spacing of binding moieties. Briefly, nanospheres are universally preferable for cell surface attachment and internalization. However, edge-decorated nanotiles compensate for their geometry deficiency and outperform nanospheres in both categories. In addition, we confirm the short-term structural stability of DNs by incubating them with cell medium and cell lysate. Further, we investigate the endocytic pathway of cell-surface bound DNs and reveal that it is an interdependent process involving multiple pathways, similar to those of unmodified DNs. Finally, we demonstrate that cell-surface attached DNs exhibit a substantial enhancement in the intranuclear delivery. Our findings present an application that leverages cell-surface binding to potentially overcome the limitations of low cellular uptake, which may strengthen and expand the toolbox for effective cellular and nuclear delivery of DNA nanostructure systems.

Imidazolium-based zwitterionic liquid-modified PEG-PLGA nanoparticles as a potential intravenous drug delivery carrier

Zwitterionic-based systems offer promise as next-generation drug delivery biomaterials capable of enhancing nanoparticle (NP) stimuli-responsiveness, biorecognition, and biocompatibility. Further, imidazole-functionalized amphiphilic zwitterions are able to readily bind to various biological macromolecules, enabling antifouling properties for enhanced drug delivery efficacy and bio-targeting. Herein, we describe structurally tuned zwitterionic imidazole-based ionic liquid (ZIL)-coated PEG-PLGA nanoparticles made with sonicated nanoprecipitation. Upon ZIL surface modification, the hydrodynamic radius increased by nearly 20 nm, and the surface charge significantly shifted closer to neutral. 1H NMR spectra suggests that the amount of ZIL on the nanoparticle surface is controlled by the structure of the ZIL and that the assembly occurs as a result of non-covalent interactions of ZIL-coated nanoparticle with the polymer surface. These nanoparticle-zwitterionic liquid (ZIL) constructs demonstrate selective affinity towards red blood cells in whole mouse blood and show relatively low human hemolysis at ∼5%. Additionally, we observe higher nanoparticle accumulation of ZIL-NPs compared with unmodified NP controls in human triple-negative breast cancer cells (MDA-MB-231). Furthermore, although the ZIL shows similar protein adsorption by SDS-PAGE, LC-MS/MS protein analysis data demonstrate a difference in the relative abundance and depletion of proteins in mouse and human serum. Hence, we show that ZIL-coated nanoparticles provide a new potential platform to enhance RBC-based drug delivery systems for cancer treatments.

Influence of the polymer type of a microplastic challenge on the reaction of murine cells

Due to global pollution derived from plastic waste, the research on microplastics is of increasing public interest. Until now, most studies addressing the effect of microplastic particles on vertebrate cells have primarily utilized polystyrene particles (PS). Other studies on polymer microparticles made, e.g., of polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), or poly (ethylene terephthalate) (PET), cannot easily be directly compared to these PS studies, since the used microparticles differ widely in size and surface features. Here, effects caused by pristine microparticles of a narrow size range between 1 - 4 µm from selected conventional polymers including PS, PE, and PVC, were compared to those of particles made of polymers derived from biological sources like polylactic acid (PLA), and cellulose acetate (CA). The microparticles were used to investigate cellular uptake and assess cytotoxic effects on murine macrophages and epithelial cells. Despite differences in the particles' properties (e.g. ζ-potential and surface morphology), macrophages were able to ingest all tested particles, whereas epithelial cells ingested only the PS-based particles, which had a strong negative ζ-potential. Most importantly, none of the used model polymer particles exhibited significant short-time cytotoxicity, although the general effect of environmentally relevant microplastic particles on organisms requires further investigation.

Iron oxide nanoparticles coated with Glucose and conjugated with Safranal (Fe3O4@Glu-Safranal NPs) inducing apoptosis in liver cancer cell line (HepG2)

Magnetic nanoparticles can be considered a reliable tool for targeted drug delivery to cancer tissues. Based on this, in this study, the anticancer effect of iron oxide nanoparticles coated with glucose and conjugated with Safranal (Fe3O4@Glu-Safranal NPs) on a liver cancer cell line (HepG2) was investigated. Physicochemical properties of nanoparticles were characterized using FT-IR, XRD, VSM, EDS-mapping, SEM and TEM imaging, zeta potential, and DLS analyses. MTT test was used to investigate the inhibitory effect of nanoparticles on cancer and normal cell lines. Also, the reactive oxygen species (ROS) level, the population of apoptotic cells, and cell cycle analysis were evaluated in control and nanoparticle-treated cells. The synthesized particles were spherical, in a size range of 17-49 nm, without impurities, with a surface charge of - 13 mV and hydrodynamic size of 129 nm, and with magnetic saturation of 22.5 emu/g. The 50% inhibitory concentration (IC50) of Safranal, Fe3O4, Fe3O4@Glu-Safranal and Cisplatin drug on liver cancer cells were 474, 1546, 305 and 135 µg/mL, respectively. While, the IC50 of Fe3O4@Glu-Safranal for normal cell line was 680 µg/mL. Treating liver cancer cells with nanoparticles significantly increased the population of apoptotic cells from 2.5% to 34.7%. Furthermore, the population of the cells arrested at the G2/M phase increased in nanoparticle-treated cells. Due to the biocompatibility of the constituent compounds of these nanoparticles, their magnetic properties, and their inhibitory effects on cancer cells, Fe3O4@Glu-Safranal NPs can be further considered as a promising anticancer compound.

Fluorescent hydrophobic ion pairs: A powerful tool to investigate cellular uptake of hydrophobic drug complexes via lipid-based nanocarriers

HYPOTHESIS

Hydrophobic ion pairs (HIPs) between two fluorescent components and incorporation into nanoemulsions (NE) allows tracking in cellular uptake studies.

EXPERIMENTS

HIPs were formed between propidium iodide and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) (NBD-PE), azure A chloride and NBD-PE or coumarin 343 and 4-(4-dihexadecylaminostyryl)-N-methylpyridinium iodide) (DiA). Fluorescence spectra of the resulting complexes were recorded. HIPs were loaded into zwitterionic NE and their size, stability in different media, haemolytic properties and cytotoxicity were evaluated. Furthermore, cellular uptake at 37 °C and 4 °C was investigated via flow cytometry and confocal microscopy.

FINDINGS

HIP-formation increased lipophilicity of the hydrophilic model drugs. NE exhibited a size between 80 and 150 nm and were not toxic in concentrations up to 0.1 % but showed high haemolytic properties. Cellular uptake of propidium, azure A and coumarin 343 were 8-fold, 115-fold and 1.3-fold improved by the formation of HIPs and up to 59-fold, 120-fold and 50-fold by incorporating these HIPs in NE, respectively. Lower uptake was observed at 4 °C. In case of propidium/ NBD-PE and azure A/ NBD-PE HIPs, propidium and azure A were delivered into the cytosol, whereas NBD-PE was unable to enter cells. In case of coumarin 343/ DiA HIPs, both components accumulated in the cell membrane. Therefore, HIPs between two fluorescent compounds are a powerful tool to investigate cellular uptake of hydrophobic complexes via nanocarriers by visualization of their cellular distribution.

Guar gum series affect nanostructured lipid carriers via electrostatic assembly or steric hindrance: Improving their oral delivery for phytosterols

Surface modification of nanostructured lipid carriers (NLCs) can be an effective way to improve their oral delivery for active ingredients. In this study, four type of guar gum series modified NLCs for the delivery of phytosterols (PS) were constructed and the effects of the polysaccharides on their structure and physicochemical properties were studied. DLS and AFM results revealed that positively charged polysaccharides could bind to PS-NLCs through electrostatic attraction and made the complexes finally take positive charges, while negatively charged polysaccharides were more likely to fill in the gaps of NLC systems to achieve a balance between electrostatic repulsion and intermolecular forces. Although all four polysaccharides exhibited good storage stability and controlled release of PS in simulated intestinal digestion, PS-NLCs modified with partially hydrolyzed cationic guar gum (PHCG) at medium or high concentrations exhibited better gastric stability, mucoadhesion, and cellular uptake, which had considerable significance for improving the oral bioavailability of PS. This might be related to the coating structure of PHCG-PS-NLCs confirmed by AFM, FTIR, and Raman characterization. This study provide a reference value for designing suitable PS-NLC complexes without synthetic surfactants.

Microneedle-Assisted Transfersomes as a Transdermal Delivery System for Aspirin

Transdermal drug delivery systems offer several advantages over conventional oral or hypodermic administration due to the avoidance of first-pass drug metabolism and gastrointestinal degradation as well as patients' convenience due to a minimally invasive and painless approach. A novel transdermal drug delivery system, comprising a combination of transfersomes with either solid silicon or solid polycarbonate microneedles has been developed for the transdermal delivery of aspirin. Aspirin was encapsulated inside transfersomes using a "thin-film hydration sonication" technique, yielding an encapsulation efficiency of approximately 67.5%. The fabricated transfersomes have been optimised and fully characterised in terms of average size distribution and uniformity, surface charge and stability (shelf-life). Transdermal delivery, enhanced by microneedle penetration, allows the superior permeation of transfersomes into perforated porcine skin and has been extensively characterised using optical coherence tomography (OCT) and transmission electron microscopy (TEM). In vitro permeation studies revealed that transfersomes enhanced the permeability of aspirin by more than four times in comparison to the delivery of unencapsulated "free" aspirin. The microneedle-assisted delivery of transfersomes encapsulating aspirin yielded 13-fold and 10-fold increases in permeation using silicon and polycarbonate microneedles, respectively, in comparison with delivery using only transfersomes. The cytotoxicity of different dose regimens of transfersomes encapsulating aspirin showed that encapsulated aspirin became cytotoxic at concentrations of ≥100 μg/mL. The results presented demonstrate that the transfersomes could resolve the solubility issues of low-water-soluble drugs and enable their slow and controlled release. Microneedles enhance the delivery of transfersomes into deeper skin layers, providing a very effective system for the systemic delivery of drugs. This combined drug delivery system can potentially be utilised for numerous drug treatments.

Earthworm Coelomocyte Internalization of MoS2 Nanosheets: Multiplexed Imaging, Molecular Profiling, and Computational Modeling

Fully understanding the cellular uptake and intracellular localization of MoS2 nanosheets (NSMoS2) is a prerequisite for their safe applications. Here, we characterized the uptake profile of NSMoS2 by functional coelomocytes of the earthworm Eisenia fetida. Considering that vacancy engineering is widely applied to enhance the NSMoS2 performance, we assessed the potential role of such atomic vacancies in regulating cellular uptake processes. Coelomocyte internalization and lysosomal accumulation of NSMoS2 were tracked by fluorescent labeling imaging. Cellular uptake inhibitors, proteomics, and transcriptomics helped to mechanistically distinguish vacancy-mediated endocytosis pathways. Specifically, Mo ions activated transmembrane transporter and ion-binding pathways, entering the coelomocyte through assisted diffusion. Unlike molybdate, pristine NSMoS2 (P-NSMoS2) induced protein polymerization and upregulated gene expression related to actin filament binding, which phenotypically initiated actin-mediated endocytosis. Conversely, vacancy-rich NSMoS2 (V-NSMoS2) were internalized by coelomocytes through a vesicle-mediated and energy-dependent pathway. Mechanistically, atomic vacancies inhibited mitochondrial transport gene expression and likely induced membrane stress, significantly enhancing endocytosis (20.3%, p < 0.001). Molecular dynamics modeling revealed structural and conformational damage of cytoskeletal protein caused by P-NSMoS2, as well as the rapid response of transport protein to V-NSMoS2. These findings demonstrate that earthworm functional coelomocytes can accumulate NSMoS2 and directly mediate cytotoxicity and that atomic vacancies can alter the endocytic pathway and enhance cellular uptake by reprogramming protein response and gene expression patterns. This study provides an important mechanistic understanding of the ecological risks of NSMoS2.

pH-Responsive Polypropylene Sulfide Magnetic Nanocarrier-Mediated Chemo-Hyperthermia Kills Breast Cancer Stem Cells by Long-Term Reversal of Multidrug Resistance and Chemotherapy Resensitization

Cancer stem cells (CSCs) present a formidable challenge in cancer treatment due to their inherent resistance to chemotherapy, primarily driven by the overexpression of ABC transporters and multidrug resistance (MDR). Despite extensive research on pharmacological small-molecule inhibitors, effectively managing MDR and improving chemotherapeutic outcomes remain elusive. On the other hand, magnetic hyperthermia (MHT) holds great promise as a cancer therapeutic, but there is limited research on its potential to reverse MDR in breast CSCs and effectively eliminate CSCs through combined chemo-hyperthermia. To address these gaps, we developed tumor microenvironment-sensitive, drug-loaded poly(propylene sulfide) (PPS)-coated magnetic nanoparticles (PPS-MnFe). These nanoparticles were employed to investigate hyperthermia sensitivity and MDR reversion in breast CSCs, comparing their performance to that of small-molecule inhibitors. Additionally, we explored the efficacy of combined chemo-hyperthermia in killing CSCs. CSC-enriched breast cancer cells were subjected to low-dose MHT at 42 °C for 30 min and then treated with the chemical MDR inhibitor salinomycin (SAL). The effectiveness of each treatment in inhibiting MDR was assessed by measuring the efflux of the MDR substrate, rhodamine 123 (R123) dye. Notably, MHT induced a prolonged reversal of MDR activity compared with SAL treatment alone. After successfully inhibiting MDR, the breast CSCs were exposed to chemotherapy using paclitaxel to trigger synergistic cell death. The combination of MHT and chemotherapy demonstrated remarkable reductions in stemness properties, MDR reversal, and the effective eradication of breast CSCs in this innovative dual-modality approach.

Enhancement of cellular uptake by increasing the number of encapsulated gold nanoparticles in polymeric micelles

We apply a combination of polycaprolactone (PCL)-thiol ligand functionalization with flow-controlled microfluidic block copolymer self-assembly to produce biocompatible gold nanoparticle (GNP)-loaded micellar polymer nanoparticles (GNP-PNPs) in which GNPs are encapsulated within PCL cores surrounded by an external layer of poly(ethylene glycol) (PEG). By varying both the relative amount of block copolymer and the microfluidic flow rate, a series of GNP-PNPs are produced in which the mean number of GNPs per PNP in the < 50-nm fraction (Zave,d< 50 nm) varies between 0.1 and 1.9 while the external PEG surface is constant. Zave,d< 50 nm values are determined by statistical analysis of TEM images and compared with the results of cell uptake experiments on MDA-MB-231 cancer cells. For Zave,d< 50 nm ≤ 1 (including a control sample of individual GNPs also with a PEG surface layer), cell uptake is relatively constant, but increases sharply for Zave,d< 50 nm > 1, with a factor of 7 enhancement as Zave,d< 50 nm increases from 1 to ∼2. Enabled by the shear processing control provided by the microfluidic chip, these results provide the first evidence that cellular uptake can be enhanced specifically by increasing the number of GNPs per vector, with other parameters, including polymeric material, internal structure, and external surface chemistry, held constant. They also demonstrate a versatile platform for packaging GNPs in biocompatible polymeric carriers with flow-controlled formulation optimization for various therapeutic and diagnostic applications.

Selective Endocytic Uptake of Targeted Liposomes Occurs within a Narrow Range of Liposome Diameters

Cell surface receptors facilitate signaling and nutrient uptake. These processes are dynamic, requiring receptors to be actively recycled by endocytosis. Due to their differential expression in disease states, receptors are often the target of drug-carrier particles, which are adorned with ligands that bind specifically to receptors. These targeted particles are taken into the cell by multiple routes of internalization, where the best-characterized pathway is clathrin-mediated endocytosis. Most studies of particle uptake have utilized bulk assays rather than observing individual endocytic events. As a result, the detailed mechanisms of particle uptake remain obscure. To address this gap, we employed a live-cell imaging approach to study the uptake of individual liposomes as they interact with clathrin-coated structures. By tracking individual internalization events, we find that the size of liposomes rather than the density of the ligands on their surfaces primarily determines their probability of uptake. Interestingly, targeting has the greatest impact on endocytosis of liposomes of intermediate diameters, with the smallest and largest liposomes being internalized or excluded, respectively, regardless of whether they are targeted. These findings, which highlight a previously unexplored limitation of targeted delivery, can be used to design more effective drug carriers.

Standardization of In Vitro Studies for Plasmonic Photothermal therapy

Lack of standardization is a systematic problem that impacts nanomedicine by challenging data comparison from different studies. Translation from preclinical to clinical stages indeed requires reproducible data that can be easily accessed and compared. In this work, we propose a series of experimental standards for in vitro plasmonic photothermal therapy (PPTT). This best practice guide covers the five main aspects of PPTT studies in vitro: nanomaterials, biological samples, pre-, during, and postirradiation characterization. We are confident that such standardization of experimental protocols and reported data will benefit the development of PPTT as a transversal therapy.

A Series of Planar Phosphorescent Cyclometalated Platinum(II) Complexes as New Anticancer Theranostic Agents That Induce Oncosis

Herein, four planar cyclometalated platinum(II) complexes with a main ligand of enlarged aromatic rings have been assessed as effective anticancer theranostic agents for the first time. With an increased number of aromatic rings in the N∧N ligand, 1a-1d exhibit increased lipophilicity and cytotoxicity selectivity. The intensity of the Pt-Pt interaction of each complex can be indicated by an enhanced near-infrared (NIR) emission in phosphate-buffered saline (PBS), their binding activity with biomolecules of bovine serum albumin (BSA) is accompanied by a vivid turn-on green emission, and the intensity gradually decreased from 1a to 1d, which is consistent with the docking of two complexes with BSA. Both "turn-on" NIR and green emission of 1d can be mainly observed in nuclei of living cell within 24 h, while two phosphorescence traces of 1b were recorded in lysosomes by confocal imaging. Moreover, 1d shows the highest efficiency in inducing oncosis of Hela cells, and the relative process was investigated.

Lewis acid-driven self-assembly of diiridium macrocyclic catalysts imparts substrate selectivity and glutathione tolerance

Molecular inorganic catalysts (MICs) tend to have solvent-exposed metal centers that lack substrate specificity and are easily inhibited by biological nucleophiles. Unfortunately, these limitations exclude many MICs from being considered for in vivo applications. To overcome this challenge, a strategy to spatially confine MICs using Lewis acid-driven self-assembly is presented. It was shown that in the presence of external cations (e.g., Li+, Na+, K+, or Cs+) or phosphate buffered saline, diiridium macrocycles spontaneously formed supramolecular iridium-cation species, which were characterized by X-ray crystallography and dynamic light scattering. These nanoassemblies selectively reduced sterically unhindered C[double bond, length as m-dash]O groups via transfer hydrogenation and tolerated up to 1 mM of glutathione. In contrast, when non-coordinating tetraalkylammonium cations were used, the diiridium catalysts were unable to form higher-ordered structures and discriminate between different aldehyde substrates. This work suggests that in situ coordination self-assembly could be a versatile approach to enable or enhance the integration of MICs with biological hosts.

Selective endocytic uptake of targeted liposomes occurs within a narrow range of liposome diameter

Cell surface receptors facilitate signaling and nutrient uptake. These processes are dynamic, requiring receptors to be actively recycled by endocytosis. Due to their differential expression in disease states, receptors are often the target of drug-carrier particles, which are adorned with ligands that bind specifically to receptors. These targeted particles are taken into the cell by multiple routes of internalization, where the best-characterized pathway is clathrin-mediated endocytosis. Most studies of particle uptake have utilized bulk assays, rather than observing individual endocytic events. As a result, the detailed mechanisms of particle uptake remain obscure. To address this gap, we have employed a live-cell imaging approach to study the uptake of individual liposomes as they interact with clathrin-coated structures. By tracking individual internalization events, we find that the size of liposomes, rather than the density of the ligands on their surfaces, primarily determines their probability of uptake. Interestingly, targeting has the greatest impact on endocytosis of liposomes of intermediate diameters, with the smallest and largest liposomes being internalized or excluded, respectively, regardless of whether they are targeted. These findings, which highlight a previously unexplored limitation of targeted delivery, can be used to design more effective drug carriers.

Protein Adsorption, Calcium-Binding Ability, and Biocompatibility of Silver Nanoparticle-Loaded Polyvinyl Alcohol (PVA) Hydrogels Using Bone Marrow-Derived Mesenchymal Stem Cells

Several approaches have evolved to facilitate the exploration of hydrogel systems in biomedical research. In this sense, poly(vinyl alcohol) (PVA) has been widely used in hydrogel (HG) fabrication for several therapeutic applications. The biological properties of PVA hydrogels (PVA-HGs) are highly dependent on their interaction with protein receptors and extracellular matrix (mainly calcium) deposition, for which there is not enough evidence from existing research yet. Thus, for the first time, the functional properties, like protein and mineral interactions, related to the proliferation of mesenchymal stem cells (MSCs) by silver nanoparticle (AgNP)-loaded PVA hydrogels (AgNPs-PVA-HGs) were investigated in the present study. The UV absorption spectrum and TEM microscopic results showed a maximum absorbance of synthesized AgNPs at 409 nm, with an average particle size of 14.5 ± 2.5 nm, respectively. The functional properties, such as the calcium-binding and the protein adsorption of PVA-HG, were accelerated by incorporating AgNPs; however, the swelling properties of the HGs were reduced by AgNPs, which might be due to the masking of the free functional groups (hydroxyl groups of PVA) by AgNPs. SEM images showed the presence of AgNPs with a more porous structure in the HGs. The proliferative effect of MSCs increased over culture time from day 1 to day 7, and the cell proliferative effect was upregulated by HGs with more pronounced AgNPs-PVA-HG. In addition, both HGs did not produce any significant cytotoxicity in the MSCs. The histological (bright light and H&E staining) and fluorescence microscopic images showed the presence of a cytoskeleton and the fibrillar structure of the MSCs, and the cells adhered more firmly to all HGs. More fibrillar bipolar and dense fibrillar structures were seen in the day 1 and day 7 cultures, respectively. Interestingly, the MSCs cultured on AgNPs-PVA-HG produced extracellular matrix deposition on day 7. Accordingly, the present results proved the biocompatibility of AgNPs-PVA-HG as a suitable system for culturing mammalian stem cells for regenerative tissue applications.

Nanoplastics exposure disrupts circadian rhythm associated with dysfunction of the endolysosomal pathway and autophagy in Caenorhabditis elegans

Nanoplastics (NPs), an emerging pollutant, have raised great safety concerns due to their widespread applications and continuous release into the environment, which lead to potential human and environmental risks. Recently, polystyrene NPs (100 nm; 100 mg/L) exposure has been reported to disrupt circadian rhythms under five days temperature entrainment and be associated with stress resistance decline in Caenorhabditis elegans. This study explored the possible relationship between circadian rhythm disruption and endocytosis and autophagy under polystyrene NPs exposure in C. elegans. We show that the disrupted circadian rhythm induced by NPs exposure reduced stress resistance via endocytosis and autophagy impairment. Furthermore, we found that most NPs taken up by intestinal cells were localized to early endosomes, late endosomes, and lysosomes and delivered to autophagosomes. In addition, the disruption of circadian rhythm inhibited NPs localization to these organelles. These findings indicate that NPs exposure disrupts circadian rhythm and alters its subcellular trafficking, leading to enhanced toxicity in C. elegans. Our results shed light on the prominent role of NPs exposure in circadian rhythm disruption associated with endocytosis and autophagy impairments, which may be conserved in higher animals such as humans.

Trigger of apoptosis in human liver cancer cell line (HepG2) by titanium dioxide nanoparticles functionalized by glutamine and conjugated with thiosemicarbazone

The incidence of liver cancer, the third cause of cancer-associated death, has been growing, worldwide. The increasing trend of liver cancer incidence and mortality indicates the inefficiency of current therapeutic approaches, especially anticancer chemotherapy. Owing to the promising anticancer potential of Thiosemicarbazone (TSC) complexes, this work was conducted to synthesize titanium oxide nanoparticles conjugated with TSC through glutamine functionalization (TiO2@Gln-TSC NPs) and characterize their anticancer mechanism in HepG2 liver cancer cells. Physicochemical analyses of the synthesized particles, including FT-IR, XRD, SEM, TEM, Zeta potential and DLS, and EDS-mapping confirmed the proper synthesis and conjugation of TiO2@Gln-TSC NPs. The synthesized NPs were almost spherical, with a size range of 10-80 nm, a zeta potential of - 57.8 mV, a hydrodynamic size of 127 nm, and without impurities. Investigation of the cytotoxic effect of TiO2@Gln-TSC in HepG2 and HEK293 human normal cells indicated significantly higher toxicity in cancer cells (IC50 = 75 µg/mL) than normal cells (IC50 = 210 µg/mL). Flow cytometry analysis of TiO2@Gln-TSC treated and control cells showed that the population of apoptotic cells considerably increased from 2.8 to 27.3% after treatment with the NPs. Moreover, 34.1% of the TiO2@Gln-TSC treated cells were mainly arrested at the sub-G1 phase of the cell cycle, which was significantly greater than control cells (8.4%). The Hoechst staining assay showed considerable nuclear damage, including chromatin fragmentation and the appearance of apoptotic bodies. This work introduced TiO2@Gln-TSC NPs as a promising anticancer compound that could combat liver cancer cells through apoptosis induction.

The toxicity of nanoparticles and their interaction with cells: an in vitro metabolomic perspective

Nowadays, nanomaterials (NMs) are widely present in daily life due to their significant benefits, as demonstrated by their application in many fields such as biomedicine, engineering, food, cosmetics, sensing, and energy. However, the increasing production of NMs multiplies the chances of their release into the surrounding environment, making human exposure to NMs inevitable. Currently, nanotoxicology is a crucial field, which focuses on studying the toxicity of NMs. The toxicity or effects of nanoparticles (NPs) on the environment and humans can be preliminary assessed in vitro using cell models. However, the conventional cytotoxicity assays, such as the MTT assay, have some drawbacks including the possibility of interference with the studied NPs. Therefore, it is necessary to employ more advanced techniques that provide high throughput analysis and avoid interferences. In this case, metabolomics is one of the most powerful bioanalytical strategies to assess the toxicity of different materials. By measuring the metabolic change upon the introduction of a stimulus, this technique can reveal the molecular information of the toxicity induced by NPs. This provides the opportunity to design novel and efficient nanodrugs and minimizes the risks of NPs used in industry and other fields. Initially, this review summarizes the ways that NPs and cells interact and the NP parameters that play a role in this interaction, and then the assessment of these interactions using conventional assays and the challenges encountered are discussed. Subsequently, in the main part, we introduce the recent studies employing metabolomics for the assessment of these interactions in vitro.

Enhanced toxicity of 2,2-bis(chloromethyl) trimethylene bis[bis(2-chloroethyl) phosphate] (V6) by nanopolystyrene particles towards HeLa cells

2,2-bis(chloromethyl) trimethylene bis[bis(2-chloroethyl) phosphate] (V6) has been widely used as an additive in a variety of plastics due to its extremely low toxicity. However, we showed in the study that once mixed with nanopolystyrene particles (NPs), the nontoxic V6 could exhibit significant toxicity to HeLa cells. The enhanced toxicity was much higher than the toxicity of NPs alone and was related to the size of NPs. The mixture of V6 and small polystyrene NPs (10 nm and 15 nm in radius) showed obvious toxicity to HeLa cells. The toxicity increased with the concentrations of both V6 and NPs. On the contrary, the mixture of V6 and larger NPs (25 nm, 50 nm, 100 nm, and 500 nm in radius) showed almost no toxicity even at extremely high concentrations (NPs: 100 mg/L; V6: 50 mg/L). The small NPs could enter the cells and accumulated in cytoplasm. However, the larger NPs did not distribute inside the cells. NPs efficiently adsorbed V6 on the surface. The mechanism of the enhanced toxicity was attributed to the increased intracellular reactive oxygen species (ROS) production and the regulation of gene expression concerning apoptosis and ROS scavenging. Our study not only showed that a safe chemical V6 could be turned to be toxic by NPs, but also pointed out a potential risk caused by the joint toxicity of 'safe' chemicals and plastic particles with small size.

Fighting Phytopathogens with Engineered Inorganic-Based Nanoparticles

The development of effective and ecofriendly agrochemicals, including bactericides, fungicides, insecticides, and nematicides, to control pests and prevent plant diseases remains a key challenge. Nanotechnology has provided opportunities for the use of nanomaterials as components in the development of anti-phytopathogenic agents. Indeed, inorganic-based nanoparticles (INPs) are among the promising ones. They may play an effective role in targeting and killing microbes via diverse mechanisms, such as deposition on the microbe surface, destabilization of cell walls and membranes by released metal ions, and the induction of a toxic mechanism mediated by the production of reactive oxygen species. Considering the lack of new agrochemicals with novel mechanisms of action, it is of particular interest to determine and precisely depict which types of INPs are able to induce antimicrobial activity with no phytotoxicity effects, and which microbe species are affected. Therefore, this review aims to provide an update on the latest advances in research focusing on the study of several types of engineered INPs, that are well characterized (size, shape, composition, and surface features) and show promising reactivity against assorted species (bacteria, fungus, virus). Since effective strategies for plant protection and plant disease management are urgently needed, INPs can be an excellent alternative to chemical agrochemical agents as indicated by the present studies.

Topical Delivery of Diacetyl Boldine in a Microemulsion Formulation for Chemoprotection against Melanoma

This study aimed to develop a microemulsion formulation for topical delivery of Diacetyl Boldine (DAB) and to evaluate its cytotoxicity against melanoma cell line (B16BL6) in vitro. Using a pseudo-ternary phase diagram, the optimal microemulsion formulation region was identified, and its particle size, viscosity, pH, and in vitro release characteristics were determined. Permeation studies were performed on excised human skin using Franz diffusion cell assembly. The cytotoxicity of the formulations on B16BL6 melanoma cell lines was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay. Two formulation compositions were selected based on the higher microemulsion area of the pseudo-ternary phase diagrams. The formulations showed a mean globule size of around 50 nm and a polydispersity index of <0.2. The ex vivo skin permeation study demonstrated that the microemulsion formulation exhibited significantly higher skin retention levels than the DAB solution in MCT oil (Control, DAB-MCT). Furthermore, the formulations showed substantially higher cytotoxicity toward B16BL6 cell lines than the control formulation (p < 0.001). The half-maximal inhibitory concentrations (IC50) of F1, F2, and DAB-MCT formulations against B16BL6 cells were calculated to be 1 µg/mL, 10 µg/mL, and 50 µg/mL, respectively. By comparison, the IC50 of F1 was 50-fold lower than that of the DAB-MCT formulation. The results of the present study suggest that microemulsion could be a promising formulation for the topical administration of DAB.