Impact of nanoparticle surface functionalization on the protein corona and cellular adhesion, uptake and transport

The impact of micro- and nanoplastics on immune system development and functions: Current knowledge and future directions

The prevalence of microplastics (MPs)/ nanoplastics (NPs) in the environment has raised significant concerns regarding their potential toxicity, particularly their impact on biological systems. These particles, particularly NPs, possess unique properties due to their small size and high surface area, enabling them to more easily cross biological barriers and accumulate in tissues. Among various types of plastic materials, polystyrene (PS) is one of the most studied for its toxicological effects, given its widespread use and environmental persistence. This narrative review examines current research on the effects of MPs/NPs, on the immune system, with a focus on both the development of the immune system and its functional responses. Evidence from in vitro and in vivo studies suggests that MP/NP exposure can disrupt immune function, including hematopoiesis, immune cell activation, and the production of inflammatory cytokines. Although in vitro studies highlight cellular toxicity and altered immune cell behavior, in vivo studies reveal more complex outcomes, with some findings suggesting significant effects on organ systems such as the spleen and intestines, while others indicate minimal or no impact under environmentally relevant exposure conditions. Here, we aim to consolidate and summarize the current evidence on the topic, highlight key limitations in the field, and identify areas that warrant further investigation for immunotoxicologists. In addition, we emphasize the importance of using relevant exposure concentrations and complex in vitro or in vivo models to better understand the potential risks associated with MP/NP exposure and their long-term implications for immune health.

Proteomic characterization of particle-protein coronas shows differences between osteoarthritic and contralateral knees in a rat model

OBJECTIVE

When synthetic particles are injected into a biofluid, proteins nonspecifically adsorb onto the particle surface and form a protein corona. Protein coronas are known to alter how particles function in blood; however, little is known about protein corona formation in synovial fluid or how these coronas change with osteoarthritis (OA). In this study, protein coronas were characterized on particles incubated within OA-affected or healthy rat knees.

DESIGN

First, to evaluate particle collection techniques, magnetic polystyrene particles were placed in bovine synovial fluid and separated using either magnetics or centrifugation. In a second experiment, 12 male and 12 female Lewis rats received a simulated medial meniscal injury. At 2, 5, or 8 weeks post-surgery, operated and contralateral limbs were injected with clean magnetic particles (n = 8 per timepoint). After a 4-h incubation, animals were euthanized and particles were magnetically recovered. In both experiments, protein coronas were characterized using an Orbitrap fusion mass spectrometer.

RESULTS

In the first experiment, the particle separation method affected the identified proteins, likely due to centrifugation forces causing some large proteins to spin-down with the particles. In the OA model, 300-500 proteins were identified in the particle-protein coronas with 35, 59, and 13 proteins differing between the OA-affected and contralateral limbs at 2, 5, and 8 weeks, respectively. In particular, plectin, a serine (or cysteine) proteinase inhibitor, and cathepsin B were more prominent in the particle-protein coronas of OA-affected knees.

CONCLUSIONS

Synthetic particles nonspecifically adsorb proteins in synovial fluid, and these binding events differ with OA severity.

Microplastics in the Human Body: Exposure, Detection, and Risk of Carcinogenesis: A State-of-the-Art Review

Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation.

Plastic Fly: What Drosophila melanogaster Can Tell Us about the Biological Effects and the Carcinogenic Potential of Nanopolystyrene

Today, plastic pollution is one of the biggest threats to the environment and public health. In the tissues of exposed species, micro- and nano-fragments accumulate, leading to genotoxicity, altered metabolism, and decreased lifespan. A model to investigate the genotoxic and tumor-promoting potential of nanoplastics (NPs) is Drosophila melanogaster. Here we tested polystyrene, which is commonly used in food packaging, is not well recycled, and makes up at least 30% of landfills. In order to investigate the biological effects and carcinogenic potential of 100 µm polystyrene nanoparticles (PSNPs), we raised Oregon [R] wild-type flies on contaminated food. After prolonged exposure, fluorescent PSNPs accumulated in the gut and fat bodies. Furthermore, PSNP-fed flies showed considerable alterations in weight, developmental time, and lifespan, as well as a compromised ability to recover from starvation. Additionally, we noticed a decrease in motor activity in DNAlig4 mutants fed with PSNPs, which are known to be susceptible to dietary stressors. A qPCR molecular investigation of the larval intestines revealed a markedly elevated expression of the genes drice and p53, suggesting a response to cell damage. Lastly, we used warts-defective mutants to assess the carcinogenic potential of PSNPs and discovered that exposed flies had more aberrant masses than untreated ones. In summary, our findings support the notion that ingested nanopolystyrene triggers metabolic and genetic modifications in the exposed organisms, eventually delaying development and accelerating death and disease.

The potential of micro- and nanoplastics to exacerbate the health impacts and global burden of non-communicable diseases

Non-communicable diseases (NCD) constitute one of the highest burdens of disease globally and are associated with inflammatory responses in target organs. There is increasing evidence of significant human exposure to micro- and nanoplastics (MnPs). This review of environmental MnP exposure and health impacts indicates that MnP particles, directly and indirectly through their leachates, may exacerbate inflammation. Meanwhile, persistent inflammation associated with NCDs in gastrointestinal and respiratory systems potentially increases MnP uptake, thus influencing MnP access to distal organs. Consequently, a future increase in MnP exposure potentially augments the risk and severity of NCDs. There is a critical need for an integrated one-health approach to human health and environmental research for assessing the drivers of human MnP exposure and their bidirectional links with NCDs. Assessing these risks requires interdisciplinary efforts to identify and link drivers of environmental MnP exposure and organismal uptake to studies of impacted disease mechanisms and health outcomes.

Nanoplastic Size and Surface Chemistry Dictate Decoration by Human Saliva Proteins

Environmental pollution with plastic polymers has become a global problem, leaving no continent and habitat unaffected. Plastic waste is broken down into smaller parts by environmental factors, which generate micro- and nanoplastic particles (MNPPs), ultimately ending up in the human food chain. Before entering the human body, MNPPs make their first contact with saliva in the human mouth. However, it is unknown what proteins attach to plastic particles and whether such protein corona formation is affected by the particle's biophysical properties. To this end, we employed polystyrene MNPPs of two different sizes and three different charges and incubated them individually with saliva donated by healthy human volunteers. Particle zeta potential and size analyses were performed using dynamic light scattering complemented by nanoliquid chromatography high-resolution mass spectrometry (nLC/HRMS) to qualitatively and quantitatively reveal the protein soft and hard corona for each particle type. Notably, protein profiles and relative quantities were dictated by plastic particle size and charge, which in turn affected their hydrodynamic size, polydispersity, and zeta potential. Strikingly, we provide evidence of the latter to be dynamic processes depending on exposure times. Smaller particles seemed to be more reactive with the surrounding proteins, and cultures of the particles with five different cell lines (HeLa, HEK293, A549, HepG2, and HaCaT) indicated protein corona effects on cellular metabolic activity and genotoxicity. In summary, our data suggest nanoplastic size and surface chemistry dictate the decoration by human saliva proteins, with important implications for MNPP uptake in humans.

Nanozyme as a rising star for metabolic disease management

Nanozyme, characterized by outstanding and inherent enzyme-mimicking properties, have emerged as highly promising alternatives to natural enzymes owning to their exceptional attributes such as regulation of oxidative stress, convenient storage, adjustable catalytic activities, remarkable stability, and effortless scalability for large-scale production. Given the potent regulatory function of nanozymes on oxidative stress and coupled with the fact that reactive oxygen species (ROS) play a vital role in the occurrence and exacerbation of metabolic diseases, nanozyme offer a unique perspective for therapy through multifunctional activities, achieving essential results in the treatment of metabolic diseases by directly scavenging excess ROS or regulating pathologically related molecules. The rational design strategies, nanozyme-enabled therapeutic mechanisms at the cellular level, and the therapies of nanozyme for several typical metabolic diseases and underlying mechanisms are discussed, mainly including obesity, diabetes, cardiovascular disease, diabetic wound healing, and others. Finally, the pharmacokinetics, safety analysis, challenges, and outlooks for the application of nanozyme are also presented. This review will provide some instructive perspectives on nanozyme and promote the development of enzyme-mimicking strategies in metabolic disease therapy.

Adapting the in vitro micronucleus assay (OECD Test Guideline No. 487) for testing of manufactured nanomaterials: recommendations for best practices

The current Organisation for Economic Co-Operation and Development test guideline number 487 (OECD TG No. 487) provides instruction on how to conduct the in vitro micronucleus assay. This assay is one of the gold standard approaches for measuring the mutagenicity of test items; however, it is directed at testing low molecular weight molecules and may not be appropriate for particulate materials (e.g. engineered nanoparticles [ENPs]). This study aimed to adapt the in vitro micronucleus assay for ENP testing and underpins the development of an OECD guidance document. A harmonized, nano-specific protocol was generated and evaluated by two independent laboratories. Cell lines utilized were human lymphoblastoid (TK6) cells, human liver hepatocytes (HepG2) cells, Chinese hamster lung fibroblast (V79) cells, whole blood, and buffy coat cells from healthy human volunteers. These cells were exposed to reference ENPs from the Joint Research Council (JRC): SiO2 (RLS-0102), Au5nm and Au30nm (RLS-03, RLS-010), CeO2 (NM212), and BaSO4 (NM220). Tungsten carbide-cobalt (WC/Co) was used as a trial particulate positive control. The chemical controls were positive in all cell cultures, but WC/Co was only positive in TK6 and buffy coat cells. In TK6 cells, mutagenicity was observed for SiO2- and both Au types. In HepG2 cells, Au5nm and SiO2 showed sub-two-fold increases in micronuclei. In V79 cells, whole blood, and buffy coat cells, no genotoxicity was detected with the test materials. The data confirmed that ENPs could be tested with the harmonized protocol, additionally, concordant data were observed across the two laboratories with V79 cells. WC/Co may be a suitable particulate positive control in the in vitro micronucleus assay when using TK6 and buffy coat cells. Detailed recommendations are therefore provided to adapt OECD TG No. 487 for testing ENP.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

The Translation of Nanomedicines in the Contexts of Spinal Cord Injury and Repair

PURPOSE OF THIS REVIEW

Manipulating or re-engineering the damaged human spinal cord to achieve neuro-recovery is one of the foremost challenges of modern science. Addressing the restricted permission of neural cells and topographically organised neural tissue for self-renewal and spontaneous regeneration, respectively, is not straightforward, as exemplified by rare instances of translational success. This review assembles an understanding of advances in nanomedicine for spinal cord injury (SCI) and related clinical indications of relevance to attempts to design, engineer, and target nanotechnologies to multiple molecular networks.

RECENT FINDINGS

Recent research provides a new understanding of the health benefits and regulatory landscape of nanomedicines based on a background of advances in mRNA-based nanocarrier vaccines and quantum dot-based optical imaging. In relation to spinal cord pathology, the extant literature details promising advances in nanoneuropharmacology and regenerative medicine that inform the present understanding of the nanoparticle (NP) biocompatibility-neurotoxicity relationship. In this review, the conceptual bases of nanotechnology and nanomaterial chemistry covering organic and inorganic particles of sizes generally less than 100 nm in diameter will be addressed. Regarding the centrally active nanotechnologies selected for this review, attention is paid to NP physico-chemistry, functionalisation, delivery, biocompatibility, biodistribution, toxicology, and key molecular targets and biological effects intrinsic to and beyond the spinal cord parenchyma.

SUMMARY

The advance of nanotechnologies for the treatment of refractory spinal cord pathologies requires an in-depth understanding of neurobiological and topographical principles and a consideration of additional complexities involving the research's translational and regulatory landscapes.

Micro(nano)plastics and Their Potential Impact on Human Gut Health: A Narrative Review

Microplastics and nanoplastics (MNPs) are becoming an increasingly severe global problem due to their widespread distribution and complex impact on living organisms. Apart from their environmental impact, the effects of MNPs on living organisms have also continued to attract attention. The harmful impact of MNPs has been extensively documented in marine invertebrates and larger marine vertebrates like fish. However, the research on the toxicity of these particles on mammals is still limited, and their possible effects on humans are poorly understood. Considering that MNPs are commonly found in food or food packaging, humans are primarily exposed to them through ingestion. It would be valuable to investigate the potential harmful effects of these particles on gut health. This review focuses on recent research exploring the toxicological impacts of micro- and nanoplastics on the gut, as observed in human cell lines and mammalian models. Available data from various studies indicate that the accumulation of MNPs in mammalian models and human cells may result in adverse consequences, in terms of epithelial toxicity, immune toxicity, and the disruption of the gut microbiota. The paper also discusses the current research limitations and prospects in this field, aiming to provide a scientific basis and reference for further studies on the toxic mechanisms of micro- and nanoplastics.

Application of Nanoparticles for Magnetic Hyperthermia for Cancer Treatment-The Current State of Knowledge

Hyperthermia (HT) is an anti-cancer therapy commonly used with radio and chemotherapies based on applying heat (39-45 °C) to inhibit tumor growth. However, controlling heat towards tumors and not normal tissues is challenging. Therefore, nanoparticles (NPs) are used in HT to apply heat only to tumor tissues to induce DNA damage and the expression of heat shock proteins, which eventually result in apoptosis. The aim of this review article is to summarize recent advancements in HT with the use of magnetic NPs to locally increase temperature and promote cell death. In addition, the recent development of nanocarriers as NP-based drug delivery systems is discussed. Finally, the efficacy of HT combined with chemotherapy, radiotherapy, gene therapy, photothermal therapy, and immunotherapy is explored.

Package delivered: folate receptor-mediated transporters in cancer therapy and diagnosis

Neoplasias pose a significant threat to aging society, underscoring the urgent need to overcome the limitations of traditional chemotherapy through pioneering strategies. Targeted drug delivery is an evolving frontier in cancer therapy, aiming to enhance treatment efficacy while mitigating undesirable side effects. One promising avenue utilizes cell membrane receptors like the folate receptor to guide drug transporters precisely to malignant cells. Based on the cellular folate receptor as a cancer cell hallmark, targeted nanocarriers and small molecule-drug conjugates have been developed that comprise different (bio) chemistries and/or mechanical properties with individual advantages and challenges. Such modern folic acid-conjugated stimuli-responsive drug transporters provide systemic drug delivery and controlled release, enabling reduced dosages, circumvention of drug resistance, and diminished adverse effects. Since the drug transporters' structure-based de novo design is increasingly relevant for precision cancer remediation and diagnosis, this review seeks to collect and debate the recent approaches to deliver therapeutics or diagnostics based on folic acid conjugated Trojan Horses and to facilitate the understanding of the relevant chemistry and biochemical pathways. Focusing exemplarily on brain and breast cancer, recent advances spanning 2017 to 2023 in conjugated nanocarriers and small molecule drug conjugates were considered, evaluating the chemical and biological aspects in order to improve accessibility to the field and to bridge chemical and biomedical points of view ultimately guiding future research in FR-targeted cancer therapy and diagnosis.

The in vitro gastrointestinal digestion-associated protein corona of polystyrene nano- and microplastics increases their uptake by human THP-1-derived macrophages

BACKGROUND

Micro- and nanoplastics (MNPs) represent one of the most widespread environmental pollutants of the twenty-first century to which all humans are orally exposed. Upon ingestion, MNPs pass harsh biochemical conditions within the gastrointestinal tract, causing a unique protein corona on the MNP surface. Little is known about the digestion-associated protein corona and its impact on the cellular uptake of MNPs. Here, we systematically studied the influence of gastrointestinal digestion on the cellular uptake of neutral and charged polystyrene MNPs using THP-1-derived macrophages.

RESULTS

The protein corona composition was quantified using LC‒MS-MS-based proteomics, and the cellular uptake of MNPs was determined using flow cytometry and confocal microscopy. Gastrointestinal digestion resulted in a distinct protein corona on MNPs that was retained in serum-containing cell culture medium. Digestion increased the uptake of uncharged MNPs below 500 nm by 4.0-6.1-fold but did not affect the uptake of larger sized or charged MNPs. Forty proteins showed a good correlation between protein abundance and MNP uptake, including coagulation factors, apolipoproteins and vitronectin.

CONCLUSION

This study provides quantitative data on the presence of gastrointestinal proteins on MNPs and relates this to cellular uptake, underpinning the need to include the protein corona in hazard assessment of MNPs.

Supported Erythrocyte Membranes on Piezoelectric Sensors for Studying the Interactions with Nanoparticles

Applications of nanoparticles (NPs) in nanodrugs, food additives, and cosmetics can result in the presence of nanomaterials in the human circulatory system and their attachment to red blood cells (RBCs), which may lead to cytotoxic effects. To investigate the interactions of NPs with RBC membranes (RBCm), supported erythrocyte membranes (SRBCm) were developed on piezoelectric sensors in a quartz crystal microbalance with dissipation (QCM-D) at 25 °C. A well-dispersed RBCm suspension at 1 mM NaCl and 0.2 mM NaHCO3 was obtained from whole blood and comprised colloidal membrane fragments with the average hydrodynamic diameter and zeta potential of 390 nm and -0.53 mV, respectively, at pH 7.0. The thin and rigid SRBCm was formed mainly through the deposition of RBCm fragments on the poly-l-lysine-modified crystal sensor, leading to the average frequency shift of -26.2 Hz and the low ratio of the dissipation to frequency shift (7.2 × 10-8 Hz-1). The complete coverage of SRBCm was indicated by the plateau of the frequency shift in the stage of SRBCm formation and no deposition of negatively charged 106 nm polystyrene nanoparticles (PSNPs) on the SRBCm. Atomic force microscopy and immunofluorescence microscopy images showed that RBCm aggregates with the average size of 420 nm and erythrocyte membrane proteins existed on SRBCm, respectively. The methods of determining attachment efficiencies of model positively charged NPs (i.e., hematite NPs or HemNPs) and model negatively charged NPs (i.e., PSNPs) on SRBCm were demonstrated in 1 mM NaCl solution at pH 5.1 and pH 7.0, respectively. HemNPs exhibited a favorable deposition with an attachment efficiency of 0.99 while PSNPs did not show any attachment propensity toward SRBCm.

Hydrophobicity-enhanced ferritin nanoparticles for efficient encapsulation and targeted delivery of hydrophobic drugs to tumor cells

Ferritin, a naturally occurring iron storage protein, has gained significant attention as a drug delivery platform due to its inherent biocompatibility and capacity to encapsulate therapeutic agents. In this study, we successfully genetically engineered human H ferritin by incorporating 4 or 6 tryptophan residues per subunit, strategically oriented towards the inner cavity of the nanoparticle. This modification aimed to enhance the encapsulation of hydrophobic drugs into the ferritin cage. Comprehensive characterization of the mutants revealed that only the variant carrying four tryptophan substitutions per subunit retained the ability to disassemble and reassemble properly. As a proof of concept, we evaluated the loading capacity of this mutant with ellipticine, a natural hydrophobic indole alkaloid with multimodal anticancer activity. Our data demonstrated that this specific mutant exhibited significantly higher efficiency in loading ellipticine compared to human H ferritin. Furthermore, to evaluate the versatility of this hydrophobicity-enhanced ferritin nanoparticle as a drug carrier, we conducted a comparative study by also encapsulating doxorubicin, a commonly used anticancer drug. Subsequently, we tested both ellipticine and doxorubicin-loaded nanoparticles on a promyelocytic leukemia cell line, demonstrating efficient uptake by these cells and resulting in the expected cytotoxic effect.

Formation and detection of biocoronas in the food industry and their fate in the human body

The rapid advancement of nanotechnology has opened up new avenues for applications in all stages of the food industry. Over the past decade, extensive research has emphasized that when nanoparticles (NPs) enter organisms, they spontaneously adsorbed biomolecules, leading to the formation of biocorona. This paper provided a detailed review of the process of biocorona formation in the food industry, including their classification and influencing factors. Additionally, various characterization methods to investigated the morphology and structure of biocoronas were introduced. As a real state of food industry nanoparticles in biological environments, the biocorona causes structural transformations of biomolecules bound to NPs, thus affecting their fate in the body. It can either promote or inhibit enzyme activity in the human environment, and may also positively or negatively affect the cellular uptake and toxicity of NPs. Since NPs present in the food industry will inevitably enter the human body, further investigations on biocoronas will offer valuable insights and perspectives on the safety of incorporating more NPs into the food industry.

Influence of drug molecular weight on self-assembly and intestinal permeation of polymer-based nanocarriers

For oral delivery, the physicochemical properties of nanocarriers are decisive factors for permeation through the intestinal epithelium. These properties are determined by the composition of the nanocarriers as well as by the process parameters during their self-assembly. For macromolecular drugs, there is still little understanding of the drug-polymer interactions during nanocarrier self-assembly and the effects on carrier properties. In this study, the effect of drug molecular weight on nanocarrier self-assembly, physicochemical properties of nanocarriers as well as their permeation across the intestinal epithelium was investigated. Our results show that the drug molecular weight impacts the physicochemical properties of nanocarriers. Further, the physicochemical properties of the nanocarriers, governed by the molecular weight of the drug, determine their permeation properties across the intestinal epithelium. Comparative in vitro and ex vivo studies revealed that intestinal absorption is dependent on both, the properties of the tissue as well as properties of the carrier system. In conclusion, the molecular weight of drug payload is a key factor determining the physiochemical properties of polymeric nanocarriers and is closely linked to their oral absorption. Using different preclinical models to evaluate intestinal permeation of nanocarriers allows for novel insights into key formulation properties governing oral bioavailability.

High-Throughput Single-Cell Analysis of Nanoparticle-Cell Interactions

Understanding nanoparticle-cell interactions at single-nanoparticle and single-cell resolutions is crucial to improving the design of next-generation nanoparticles for safer, more effective, and more efficient applications in nanomedicine. This review focuses on recent advances in the continuous high-throughput analysis of nanoparticle-cell interactions at the single-cell level. We highlight and discuss the current trends in continual flow high-throughput methods for analyzing single cells, such as advanced flow cytometry techniques and inductively coupled plasma mass spectrometry methods, as well as their intersection in the form of mass cytometry. This review further discusses the challenges and opportunities with current single-cell analysis approaches and provides proposed directions for innovation in the high-throughput analysis of nanoparticle-cell interactions.

Determinants and mechanisms of inorganic nanoparticle translocation across mammalian biological barriers

Biological barriers protect delicate internal tissues from exposures to and interactions with hazardous materials. Primary anatomical barriers prevent external agents from reaching systemic circulation and include the pulmonary, gastrointestinal, and dermal barriers. Secondary barriers include the blood-brain, blood-testis, and placental barriers. The tissues protected by secondary barriers are particularly sensitive to agents in systemic circulation. Neurons of the brain cannot regenerate and therefore must have limited interaction with cytotoxic agents. In the testis, the delicate process of spermatogenesis requires a specific milieu distinct from the blood. The placenta protects the developing fetus from compounds in the maternal circulation that would impair limb or organ development. Many biological barriers are semi-permeable, allowing only materials or chemicals, with a specific set of properties, that easily pass through or between cells. Nanoparticles (particles less than 100 nm) have recently drawn specific concern due to the possibility of biological barrier translocation and contact with distal tissues. Current evidence suggests that nanoparticles translocate across both primary and secondary barriers. It is known that the physicochemical properties of nanoparticles can affect biological interactions, and it has been shown that nanoparticles can breach primary and some secondary barriers. However, the mechanism by which nanoparticles cross biological barriers has yet to be determined. Therefore, the purpose of this review is to summarize how different nanoparticle physicochemical properties interact with biological barriers and barrier products to govern translocation.

Lipid Corona Formation on Micro- and Nanoplastic Particles Modulates Uptake and Toxicity in A549 Cells

Plastic waste is a global issue leaving no continents unaffected. In the environment, ultraviolet radiation and shear forces in water and land contribute to generating micro- and nanoplastic particles (MNPP), which organisms can easily take up. Plastic particles enter the human food chain, and the accumulation of particles within the human body is expected. Crossing epithelial barriers and cellular uptake of MNPP involves the interaction of plastic particles with lipids. To this end, we generated unilamellar vesicles from POPC (1-palmitoyl-2-oleoyl-glycero-3-phosphocholine) and POPS (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine) and incubated them with pristine, carboxylated, or aminated polystyrene spheres (about 1 µm in diameter) to generate lipid coronas around the particles. Lipid coronas enhanced the average particle sizes and partially changed the MNPP zeta potential and polydispersity. In addition, lipid coronas led to significantly enhanced uptake of MNPP particles but not their cytotoxicity, as determined by flow cytometry. Finally, adding proteins to lipid corona nanoparticles further modified MNPP uptake by reducing the uptake kinetics, especially in pristine and carboxylated plastic samples. In conclusion, our study demonstrates for the first time the impact of different types of lipids on differently charged MNPP particles and the biological consequences of such modifications to better understand the potential hazards of plastic exposure.

The impact of amine and carboxyl functionalised microplastics on the physiology of daphnids

Plastic waste is considered a major threat for terrestrial, marine and freshwater ecosystems. Ingestion of primary or secondary microparticles resulting from plastic degradation can lead to their trophic transfer raising serious health concerns. In this study, the effect of amine and carboxy functionalized polystyrene microparticles on the physiology of daphnids was investigated with a combination of phenotypic and metabolic endpoints. Carboxy functionalized microparticles showed higher toxicity in acute exposures compared to their amine counterparts. Accumulation of both microparticles in animal gut was confirmed by stereo-microscopy as well as fluorescent microscopy which showed no presence of particles in the rest of the animal. Fluorescence based quantification of microparticles extracted from animal lysates validated their concentration-dependent uptake. Additionally, exposure of daphnids to amine and carboxy functionalized microparticles resulted in increased activities of key enzymes related to metabolism and detoxification. Finally, significant metabolic perturbations were discovered following exposure to microplastics. These findings suggest that polystyrene microparticles can hinder organism performance of the freshwater species and highlight the importance of seeking for holistic and physiological endpoints for pollution assessment.

Effects of nano and microplastics on the reproduction system: In vitro and in vivo studies review

Microplastics (MPs) and nanoplastics (NPs), as their name suggest, are tiny plastic particles. The negative impact of MPs as an emerging pollutant on humans is not hidden from anyone. Recent research on how this pollutant affects the reproductive system and how it enters the blood, placenta, and semen has attracted the attention of scientists. This review study deals with the reproductive toxicity of MPs particles in terrestrial animals, aquatic animals, soil fauna, human cells, and human placenta. In vitro and in vivo animal studies showed that MPs can lead to reduced fertility in men, reduced ovarian capacity, apoptosis of granulosa cells, or even reduced sperm motility. They cause oxidative stress and cell apoptosis and inflammatory effects. The results of these animal studies show that MPs may have similar effects on the human reproductive system. However, not much research has been done on human reproductive toxicity by MPs. Therefore, special attention should be paid to the toxicity of the reproductive system by MPs. The purpose of this comprehensive study is to express the importance of the impact of MPs on the reproductive system. These results provide new insight into the potential dangers of MPs.

Silver nanoparticles combat Salmonella Typhimurium: Suppressing intracellular infection and activating dendritic cells

Salmonella Typhimurium (ST) can hide inside cells, avoid antibiotic therapy and being killed by host's immune system to cause persistent infection in humans and animals. Metal nanoparticles are regarded as an alternative to overcome the above limitations, silver nanoparticles especially have been applied in combating drug-resistant bacteria. However, the therapeutic effects of silver nanoparticles against intracellular infection and their impacts on host immunity remain an area of further investigation. In this work, we synthesized Ganoderma extract-capped silver nanoparticles (Ag@Ge) and explored the therapeutic potential and immune adjuvant effects of Ag@Ge against intracellular ST. Firstly, Ag@Ge had a small particle size of 35.52±7.46 nm, good stability, and biocompatibility. Then, Ag@Ge effectively entered RAW 264.7 cells, suppressed intracellular ST infection. Furthermore, Ag@Ge activated mouse dendritic cells (DCs) in vitro, evidenced by increased phenotypic markers (CD80/CD86/CD40/major compatibility complex II (MHCII)) expression and cytokine and chemokine (interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand 2 (CCL-2), and chemokine (C-C motif) receptor-7 (CCR-7)) transcription. More notably, the combination of Ag@Ge with inactivated ST recruited intestinal DCs to mitigate ST infection in mice, evidenced by decreased body weight loss and bacterial loads in the tissues (liver, jejunum, and colon), and improved platelets count. The above findings indicate that Ag@Ge has the potential as an alternative nano-antibiotic against intracellular ST infection.

A human Caco-2-based co-culture model of the inflamed intestinal mucosa for particle toxicity studies

The intestinal barrier is a complex interface of the human body, possessing the largest contact surface to nutrients and antigens and containing a major part of the immune system. It has to deal with continuous exposure to a broad mixture of essential, harmful, or useless substances and particles. In the context of plastic pollution and the ubiquitous occurrence of micro- and nanoplastics, oral exposure to such particles is of particular interest. Standard intestinal in vitro models, however, are unable to mimic the role of the immune system in the particle-exposed intestine. To allow for a closer look on the effect of particles on the intestinal immune system, we here developed a co-culture model to enable investigation of the epithelial brush border monolayer in a healthy and inflamed state. The model is based on well-established Caco-2 intestinal epithelial cells cultured in a Transwell™ system. Intraepithelial immune cells were mimicked by THP-1-derived M0-macrophages and MUTZ-3-derived dendritic cells. To fulfill the requirements needed for the investigation of particles, the co-culture system was developed without an additional matrix layer. Cell-cell contacts were established between interstitial and immune cells, and the Caco-2 standard cell culture medium was used, which is well-characterized for its role in defining the identity of particle dispersions. The model was characterized using confocal microscopy, membrane integrity measurements, and cytokine release assays from inflamed and healthy cells. Finally, the new co-culture model was used for investigation on polylactic acid, melamine formaldehyde resin, and polymethylmethacrylate plastic micro- and nanoparticles.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44164-023-00047-y.

Polystyrene Microplastics of Varying Sizes and Shapes Induce Distinct Redox and Mitochondrial Stress Responses in a Caco-2 Monolayer

Currently, we lack crucial knowledge on how the physicochemical properties of particles affect cellular health, resulting in an important gap in our understanding of the human toxicity of microplastics (MPs). Our aim was to evaluate the impact of the size and the shape of MPs on uptake and the intracellular effects in a human epithelial colorectal adenocarcinoma (Caco-2) cell line. Spherical (200 nm and 2 µm) and fibre-/fragment-shaped (8.9 ± 10.1 µm by 1.14 ± 0.97 µm) polystyrene microplastics (PS-MPs) were used to study their uptake and the potential to induce redox and mitochondrial stress responses after 24 h of exposure. We demonstrated the cellular uptake of both spherical and fibre-/fragment-shaped MPs in a size-dependent manner. In response to 2 µm spheres, we observed differential expressions of redox-related genes, including HMOX1, CAT, and GPX1. All PS-MPs decreased the intracellular H2O2 levels, which can be attributed to mitochondrial stress responses, such as increased mitochondrial DNA content, footprint, and morphology. Altogether, we demonstrated uptakes and changes in redox and mitochondrial parameters for all PS-MPs, with the 200 nm spheres showing the most profound effects. This suggests that the induction of defensive responses in Caco-2 cells mainly correlates with the number of particles taken up.

Nanocarrier design–function relationship: The prodigious role of properties in regulating biocompatibility for drug delivery applications

The concept of drug delivery systems as a magic bullet for the delivery of bioactive compounds has emerged as a promising approach in the treatment of different diseases with significant advantages over the limitations of traditional methods. While nanocarrier-based drug delivery systems are the main advocates of drug uptake because they offer several advantages including reduced non-specific biodistribution, improved accumulation, and enhanced therapeutic efficiency; their safety and biocompatibility within cellular/tissue systems are therefore important for achieving the desired effect. The underlying power of "design-interplay chemistry" in modulating the properties and biocompatibility at the nanoscale level will direct the interaction with their immediate surrounding. Apart from improving the existing nanoparticle physicochemical properties, the balancing of the hosts' blood components interaction holds the prospect of conferring newer functions altogether. So far, this concept has been remarkable in achieving many fascinating feats in addressing many challenges in nanomedicine such as immune responses, inflammation, biospecific targeting and treatment, and so on. This review, therefore, provides a diverse account of the recent advances in the fabrication of biocompatible nano-drug delivery platforms for chemotherapeutic applications, as well as combination therapy, theragnostic, and other diseases that are of interest to scientists in the pharmaceutical industries. Thus, careful consideration of the "property of choice" would be an ideal way to realize specific functions from a set of delivery platforms. Looking ahead, there is an enormous prospect for nanoparticle properties in regulating biocompatibility.

Investigating nanoplastics toxicity using advanced stem cell-based intestinal and lung in vitro models

Plastic particles in the nanometer range-called nanoplastics-are environmental contaminants with growing public health concern. As plastic particles are present in water, soil, air and food, human exposure via intestine and lung is unavoidable, but possible health effects are still to be elucidated. To better understand the Mode of Action of plastic particles, it is key to use experimental models that best reflect human physiology. Novel assessment methods like advanced cell models and several alternative approaches are currently used and developed in the scientific community. So far, the use of cancer cell line-based models is the standard approach regarding in vitro nanotoxicology. However, among the many advantages of the use of cancer cell lines, there are also disadvantages that might favor other approaches. In this review, we compare cell line-based models with stem cell-based in vitro models of the human intestine and lung. In the context of nanoplastics research, we highlight the advantages that come with the use of stem cells. Further, the specific challenges of testing nanoplastics in vitro are discussed. Although the use of stem cell-based models can be demanding, we conclude that, depending on the research question, stem cells in combination with advanced exposure strategies might be a more suitable approach than cancer cell lines when it comes to toxicological investigation of nanoplastics.

Sleep matters: Neurodegeneration spectrum heterogeneity, combustion and friction ultrafine particles, industrial nanoparticle pollution, and sleep disorders-Denial is not an option

Sustained exposures to ubiquitous outdoor/indoor fine particulate matter (PM_2.5), including combustion and friction ultrafine PM (UFPM) and industrial nanoparticles (NPs) starting in utero, are linked to early pediatric and young adulthood aberrant neural protein accumulation, including hyperphosphorylated tau (p-tau), beta-amyloid (Aβ_{1 - 42}), α-synuclein (α syn) and TAR DNA-binding protein 43 (TDP-43), hallmarks of Alzheimer's (AD), Parkinson's disease (PD), frontotemporal lobar degeneration (FTLD), and amyotrophic lateral sclerosis (ALS). UFPM from anthropogenic and natural sources and NPs enter the brain through the nasal/olfactory pathway, lung, gastrointestinal (GI) tract, skin, and placental barriers. On a global scale, the most important sources of outdoor UFPM are motor traffic emissions. This study focuses on the neuropathology heterogeneity and overlap of AD, PD, FTLD, and ALS in older adults, their similarities with the neuropathology of young, highly exposed urbanites, and their strong link with sleep disorders. Critical information includes how this UFPM and NPs cross all biological barriers, interact with brain soluble proteins and key organelles, and result in the oxidative, endoplasmic reticulum, and mitochondrial stress, neuroinflammation, DNA damage, protein aggregation and misfolding, and faulty complex protein quality control. The brain toxicity of UFPM and NPs makes them powerful candidates for early development and progression of fatal common neurodegenerative diseases, all having sleep disturbances. A detailed residential history, proximity to high-traffic roads, occupational histories, exposures to high-emission sources (i.e., factories, burning pits, forest fires, and airports), indoor PM sources (tobacco, wood burning in winter, cooking fumes, and microplastics in house dust), and consumption of industrial NPs, along with neurocognitive and neuropsychiatric histories, are critical. Environmental pollution is a ubiquitous, early, and cumulative risk factor for neurodegeneration and sleep disorders. Prevention of deadly neurological diseases associated with air pollution should be a public health priority.

Microplastics in food: scoping review on health effects, occurrence, and human exposure

With most of the plastics ever produced now being waste, slowly degrading and fragmenting in the environment, microplastics (MPs) have become an emerging concern regarding their presence in food and influence on human health. While many studies on marine ecotoxicology and the occurrence of MPs in fish and shellfish exist, research on the occurrence of MPs in other foods and their effect on human health is still in early-stage, but the attention is increasing. This review aimed to provide relevant information on the possible health effect of ingested MPs, the occurrence, and levels of MPs contamination in various foods and estimated exposure to MPs through food. Potential toxic consequences from exposure to MPs through food can arise from MPs themselves, diffused monomers and additives but also from sorbed contaminants or microorganisms that colonise MPs. Recent publications have confirmed widespread contamination of our food with MPs including basic and life-essential constituents such as water and salt providing the basis for chronic exposure. Available exposure assessments indicate that we ingest up to several hundred thousand MPs particles yearly.

Macromolecules Absorbed from Influenza Infection-Based Sera Modulate the Cellular Uptake of Polymeric Nanoparticles

Optimizing the biological identity of nanoparticles (NPs) for efficient tumor uptake remains challenging. The controlled formation of a protein corona on NPs through protein absorption from biofluids could favor a biological identity that enables tumor accumulation. To increase the diversity of proteins absorbed by NPs, sera derived from Influenza A virus (IAV)-infected mice were used to pre-coat NPs formed using a hyperbranched polyester polymer (HBPE-NPs). HBPE-NPs, encapsulating a tracking dye or cancer drug, were treated with sera from days 3-6 of IAV infection (VS3-6), and uptake of HBPE-NPs by breast cancer cells was examined. Cancer cells demonstrated better uptake of HBPE-NPs pre-treated with VS3-6 over polyethylene glycol (PEG)-HBPE-NPs, a standard NP surface modification. The uptake of VS5 pre-treated HBPE-NPs by monocytic cells (THP-1) was decreased over PEG-HBPE-NPs. VS5-treated HBPE-NPs delivered a cancer drug more efficiently and displayed better in vivo distribution over controls, remaining stable even after interacting with endothelial cells. Using a proteomics approach, proteins absorbed from sera-treated HBPE-NPs were identified, such as thrombospondin-1 (TSP-1), that could bind multiple cancer cell receptors. Our findings indicate that serum collected during an immune response to infection is a rich source of macromolecules that are absorbed by NPs and modulate their biological identity, achieving rationally designed uptake by targeted cell types.

Investigation of Aggregation and Disaggregation of Self-Assembling Nano-Sized Clusters Consisting of Individual Iron Oxide Nanoparticles upon Interaction with HEWL Protein Molecules

In this paper, iron oxide nanoparticles coated with trisodium citrate were obtained. Nanoparticles self-assembling stable clusters were ~10 and 50-80 nm in size, consisting of NPs 3 nm in size. The stability was controlled by using multi-angle dynamic light scattering and the zeta potential, which was -32 ± 2 mV. Clusters from TSC-IONPs can be destroyed when interacting with a hen egg-white lysozyme. After the destruction of the nanoparticles and proteins, aggregates are formed quickly, within 5-10 min. Their sizes depend on the concentration of the lysozyme and nanoparticles and can reach micron sizes. It is shown that individual protein molecules can be isolated from the formed aggregates under shaking. Such aggregation was observed by several methods: multi-angle dynamic light scattering, optical absorption, fluorescence spectroscopy, TEM, and optical microscopy. It is important to note that the concentrations of NPs at which the protein aggregation took place were also toxic to cells. There was a sharp decrease in the survival of mouse fibroblasts (Fe concentration ~75-100 μM), while the ratio of apoptotic to all dead cells increased. Additionally, at low concentrations of NPs, an increase in cell size was observed.

Pitfalls in methods to study colocalization of nanoparticles in mouse macrophage lysosomes

Background

In the field of nanoscience there is an increasing interest to follow dynamics of nanoparticles (NP) in cells with an emphasis on endo-lysosomal pathways and long-term NP fate. During our research on this topic, we encountered several pitfalls, which can bias the experimental outcome. We address some of these pitfalls and suggest possible solutions. The accuracy of fluorescence microscopy methods has an important role in obtaining insights into NP interactions with lysosomes at the single cell level including quantification of NP uptake in a specific cell type.

Methods

Here we use J774A.1 cells as a model for professional phagocytes. We expose them to fluorescently-labelled amorphous silica NP with different sizes and quantify the colocalization of fluorescently-labelled NP with lysosomes over time. We focus on confocal laser scanning microscopy (CLSM) to obtain 3D spatial information and follow live cell imaging to study NP colocalization with lysosomes.

Results

We evaluate different experimental parameters that can bias the colocalization coefficients (i.e., Pearson’s and Manders’), such as the interference of phenol red in the cell culture medium with the fluorescence intensity and image post-processing (effect of spatial resolution, optical slice thickness, pixel saturation and bit depth). Additionally, we determine the correlation coefficients for NP entering the lysosomes under four different experimental set-ups. First, we found out that not only Pearson’s, but also Manders’ correlation coefficient should be considered in lysosome-NP colocalization studies; second, there is a difference in NP colocalization when using NP of different sizes and fluorescence dyes and last, the correlation coefficients might change depending on live-cell and fixed-cell imaging set-up.

Conclusions

The results summarize detailed steps and recommendations for the experimental design, staining, sample preparation and imaging to improve the reproducibility of colocalization studies between the NP and lysosomes.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01670-9.

Broad-Spectrum Theranostics and Biomedical Application of Functionalized Nanomaterials

Nanotechnology is an important branch of science in therapies known as “nanomedicine” and is the junction of various fields such as material science, chemistry, biology, physics, and optics. Nanomaterials are in the range between 1 and 100 nm in size and provide a large surface area to volume ratio; thus, they can be used for various diseases, including cardiovascular diseases, cancer, bacterial infections, and diabetes. Nanoparticles play a crucial role in therapy as they can enhance the accumulation and release of pharmacological agents, improve targeted delivery and ultimately decrease the intensity of drug side effects. In this review, we discussthe types of nanomaterials that have various biomedical applications. Biomolecules that are often conjugated with nanoparticles are proteins, peptides, DNA, and lipids, which can enhance biocompatibility, stability, and solubility. In this review, we focus on bioconjugation and nanoparticles and also discuss different types of nanoparticles including micelles, liposomes, carbon nanotubes, nanospheres, dendrimers, quantum dots, and metallic nanoparticles and their crucial role in various diseases and clinical applications. Additionally, we review the use of nanomaterials for bio-imaging, drug delivery, biosensing tissue engineering, medical devices, and immunoassays. Understandingthe characteristics and properties of nanoparticles and their interactions with the biological system can help us to develop novel strategies for the treatment, prevention, and diagnosis of many diseases including cancer, pulmonary diseases, etc. In this present review, the importance of various kinds of nanoparticles and their biomedical applications are discussed in much detail.

The impact of nano/micro-plastics toxicity on seafood quality and human health: facts and gaps

Contamination of the food and especially marine environment with nano/micro-plastic particles has raised serious concern in recent years. Environmental pollution and the resulting seafood contamination with microplastic (MP) pose a potential threat to consumers. The absorption rate of the MP by fish is generally considered low, although the bioavailability depends on the physical and chemical properties of the consumed MP. The available safety studies are inconclusive, although there is an indication that prolonged exposure to high levels of orally administered MP can be hazardous for consumers. This review details novel findings about the occurrence of MP, along with its physical and chemical properties, in the marine environment and seafood. The effect of processing on the content of MP in the final product is also reviewed. Additionally, recent findings regarding the impact of exposure of MP on human health are discussed. Finally, gaps in current knowledge are underlined, and the possibilities for future research are indicated in the review. There is an urgent need for further research on the absorption and bioavailability of consumed MP and in vivo studies on chronic exposure. Policymakers should also consider the implementation of novel legislation related to MP presence in food.

Nanoparticle protein corona evolution: from biological impact to biomarker discovery

Nanoparticles exposed to biological fluids such as blood, quickly interact with their surrounding milieu resulting in a biological coating that results in large part as a function of the physicochemical properties of the nanomaterial. The large nanoparticle surface area-to-volume ratio further augments binding of biological molecules and the resulting biomolecular or protein corona, once thought of as problematic biofouling, is now viewed as a rich source of biological information that can guide the development of nanomedicines. This review gives an overview of the utility of the protein corona in proteomic profiling and discusses how a better understanding of nano-bio interactions can accelerate the clinical translation of nanomedicines and facilitate the identification of disease-specific biomarkers. With the FDA requirement of the protein corona analysis of nanoparticles in place, it is envisaged that analyzing the protein corona of nanoparticles on a case-by-case basis can provide highly valuable nano-bio interface information that can aid and improve their clinical translation.

Comparative study of the transcriptomes of Caco-2 cells cultured under dynamic vs. static conditions following exposure to titanium dioxide and zinc oxide nanomaterials

Due to the widespread application of food-relevant inorganic nanomaterials, the gastrointestinal tract is potentially exposed to these materials. Gut-on-chip in vitro systems are proposed for the investigation of compound toxicity as they better recapitulate the in vivo human intestinal environment than static models, due to the added shear stresses associated with the flow of the medium. We aimed to compare cellular responses of intestinal epithelial Caco-2 cells at the gene expression level upon TiO₂ (E171) and ZnO (NM110) nanomaterial exposure when cultured under dynamic and conventionally applied static conditions. Whole-genome transcriptome analyses upon exposure of the cells to TiO₂ and ZnO nanomaterials revealed differentially expressed genes and related biological processes that were culture condition specific. The total number of differentially expressed genes (p < 0.01) and affected pathways (p < 0.05 and FDR < 0.25) after nanomaterial exposure was higher under dynamic culture conditions than under static conditions for both nanomaterials. The observed increase in nanomaterial-induced responses in the gut-on-chip model indicates that shear stress might be a major factor in cell susceptibility. This is the first report on the application of a gut-on-chip system in which gene expression responses upon TiO₂ and ZnO nanomaterial exposure are evaluated and compared to a static system. It extends current knowledge on nanomaterial toxicity assessment and the influence of a dynamic environment on cellular responses. Application of the gut-on-chip system resulted in higher sensitivity of the cells and might thus be an attractive system for use in the toxicological hazard characterization of nanomaterials.

Polydopamine nanospheres coated with bovine serum albumin permit enhanced cell differentiation: fundamental mechanism and practical application for protein coating formation

Protein coating is a strategy for modifying and improving the surface functional properties of nanomaterials. However, the underlying mechanism behind protein coating formation, which is essential for its practical applications, remains largely unknown. Herein, we investigate the fundamental molecular mechanism of protein coating formation. Polydopamine nanospheres (PDANS) coated with bovine serum albumin (BSA) are examined in this study due to their wide biomedical potential. Our results demonstrate that BSAs can flexibly bind to PDANS and maintain their structural dynamicity. Our findings unveil that regular structure formation arises from BSAs lateral interactions via electrostatic forces. Notably, the protein coating modified PDANS surface enhances cell adhesion and proliferation as well as osteogenic differentiation. Such an enhancement is attributed to complementary surface properties provided by the dynamic PDANS-BSA complex and regular structure caused by BSA-BSA interactions in protein coating formation. This study provides a fundamental understanding of the molecular mechanism of protein coating formation, which facilitates the further development of functional protein-coated nanomaterials and guides the bioengineering decision making for biomedical applications, especially in bone tissue engineering.

Formation and biological effects of protein corona for food-related nanoparticles

The rapid development of nanoscience and nanoengineering provides new perspectives on the composition of food materials, and has great potential for food biology research and applications. The use of nanoparticle additives and the discovery of endogenous nanoparticles in food make it important to elucidate in vivo safety of nanomaterials. Nanoparticles will spontaneously adsorb proteins during transporting in blood and a protein corona can be formed on the nanoparticle surface inside the human body. Protein corona affects the physicochemical properties of nanoparticles and the structure and function of proteins, which in turn affects a series of biological reactions. This article reviewed basic information about protein corona of food-related nanoparticles, elucidated the influence of protein corona on nanoparticles properties and protein structure and function, and discussed the effect of protein corona on nanoparticles in vivo. The effects of protein corona on nanoparticles transport, cellular uptake, cytotoxicity, and immune response were reviewed, and the reasons for these effects were also discussed. Finally, future research perspectives for food protein corona were proposed. Protein corona gives food nanoparticles a new identity, which makes proteins bound to nanoparticles undergo structural transformations that affect their recognition by receptors in vivo. It can have positive or negative impacts on cellular uptake and toxicity of nanoparticles and even trigger immune responses. Understanding the effects of protein corona have potential in evaluating the fate of the food-related nanoparticles, providing physicochemical and biological information about the interaction between proteins and foodborne nanoparticles. The review article will help to evaluate the safety of protein coronas formed on nanoparticles in food, and may provide fundamental information for understanding and controlling nanotoxicity.

A Critical Review of the Use of Surfactant-Coated Nanoparticles in Nanomedicine and Food Nanotechnology

Surfactants, whose existence has been recognized as early as 2800 BC, have had a long history with the development of human civilization. With the rapid development of nanotechnology in the latter half of the 20th century, breakthroughs in nanomedicine and food nanotechnology using nanoparticles have been remarkable, and new applications have been developed. The technology of surfactant-coated nanoparticles, which provides new functions to nanoparticles for use in the fields of nanomedicine and food nanotechnology, is attracting a lot of attention in the fields of basic research and industry. This review systematically describes these "surfactant-coated nanoparticles" through various sections in order: 1) surfactants, 2) surfactant-coated nanoparticles, application of surfactant-coated nanoparticles to 3) nanomedicine, and 4) food nanotechnology. Furthermore, current progress and problems of the technology using surfactant-coated nanoparticles through recent research reports have been discussed.

Microfluidics-assisted conjugation of chitosan-coated polymeric nanoparticles with antibodies: Significance in drug release, uptake, and cytotoxicity in breast cancer cells

Nanoparticle-based drug delivery systems, in combination with high-affinity disease-specific targeting ligands, provide a sophisticated landscape in cancer theranostics. Due to their high diversity and specificity to target cells, antibodies are extensively used to provide bioactivity to a plethora of nanoparticulate systems. However, controlled and reproducible assembly of nanoparticles (NPs) with these targeting ligands remains a challenge. In this context, determinants such as ligand density and orientation, play a significant role in antibody bioactivity; nevertheless, these factors are complicated to control in traditional bulk labeling methods. Here, we propose a microfluidic-assisted methodology using a polydimethylsiloxane (PDMS) Y-shaped microreactor for the covalent conjugation of Trastuzumab (TZB), a recombinant antibody targeting HER2 (human epidermal growth factor receptor 2), to doxorubicin-loaded PLGA/Chitosan NPs (PLGA/DOX/Ch NPs) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysulfosuccinimide (sNHS) mediated bioconjugation reactions. Our labeling approach led to smaller and less disperse nanoparticle-antibody conjugates providing differential performance when compared to bulk-labeled NPs in terms of drug release kinetics (fitted and analyzed with DDSolver), cell uptake/labeling, and cytotoxic activity on HER2 + breast cancer cells in vitro. By controlling NP-antibody interactions in a laminar regime, we managed to optimize NP labeling with antibodies resulting in ordered coronas with optimal orientation and density for bioactivity, providing a cheap and reproducible, one-step method for labeling NPs with globular targeting moieties.

Investigations of acute effects of polystyrene and polyvinyl chloride micro- and nanoplastics in an advanced in vitro triple culture model of the healthy and inflamed intestine

The continuous degradation of plastic waste in the environment leads to the generation of micro- and nanoplastic fragments and particles. Due to the ubiquitous presence of plastic particles in natural habitats as well as in food, beverages and tap water, oral exposure of the human population with plastic particles occurs worldwide. We investigated acute toxicological effects of polystyrene (PS) and polyvinyl chloride (PVC) micro- and nanoparticles in an advanced in vitro triple culture model (Caco-2/HT29-MTX-E12/THP-1) mimicking the healthy and inflamed human intestine to study the effect of inflammatory processes on plastic particle toxicity. We monitored barrier integrity, cytotoxicity, cell layer integrity, DNA damage, the release of pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and TNF-α) and mucus distribution after 24 h of particle exposure. In addition, we investigated cytotoxicity, DNA damage and IL-1β release in monocultures of the three cell lines. Amine-modified polystyrene nanoparticles (PS-NH₂) served as a positive control for particle-induced toxicity. No acute effects in the investigated endpoints were observed in the model of the healthy intestine after PS or PVC exposure. However, during active inflammatory processes, exposure to PVC particles was found to augment the release of IL-1β and to cause a loss of epithelial cells. Our results suggest that prevalent intestinal inflammation might be an important factor to consider when assessing the hazard of ingested micro- and nanoplastic particles.

Research on the fate of polymeric nanoparticles in the process of the intestinal absorption based on model nanoparticles with various characteristics: size, surface charge and pro-hydrophobics

BACKGROUND

The use of drug nanocarriers to encapsulate drugs for oral administration may become an important strategy in addressing the challenging oral absorption of some drugs. In this study-with the premise of controlling single variables-we prepared model nanoparticles with different particle sizes, surface charges, and surface hydrophobicity/hydrophilicity. The two key stages of intestinal nanoparticles (NPs) absorption-the intestinal mucus layer penetration stage and the trans-intestinal epithelial cell stage-were decoupled and analyzed. The intestinal absorption of each group of model NPs was then investigated.

RESULTS

Differences in the behavioral trends of NPs in each stage of intestinal absorption were found to result from differences in particle properties. Small size, low-magnitude negative charge, and moderate hydrophilicity helped NPs pass through the small intestinal mucus layer more easily. Once through the mucus layer, an appropriate size, positive surface charge, and hydrophobic properties helped NPs complete the process of transintestinal epithelial cell transport.

CONCLUSIONS

To achieve high drug bioavailability, the basic properties of the delivery system must be suitable for overcoming the physiological barrier of the gastrointestinal tract.

Non-disruptive uptake of anionic and cationic gold nanoparticles in neutral zwitterionic membranes

The potential toxicity of ligand-protected nanoparticles (NPs) on biological targets is crucial for their clinical translation. A number of studies are aimed at investigating the molecular mechanisms shaping the interactions between synthetic NPs and neutral plasma membranes. The role played by the NP surface charge is still widely debated. We compare, via liposome leakage assays, the perturbation induced by the penetration of sub-6 nm anionic and cationic Au NPs into model neutral lipid membranes composed of the zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Our charged Au NPs are functionalized by a mixture of the apolar 1-octanethiol and a ω-charged thiol which is either the anionic 11-mercapto-1-undecanesulfonate or the cationic (11-mercaptoundecyl)-N,N,N-trimethylammonium. In both cases, the NP uptake in the bilayer is confirmed by quartz crystal microbalance investigations. Our leakage assays show that both negatively and positively charged Au NPs do not induce significant membrane damage on POPC liposomes when penetrating into the bilayer. By means of molecular dynamics simulations, we show that the energy barrier for membrane penetration is the same for both NPs. These results suggest that the sign of the NP surface charge, per se, does not imply different physicochemical mechanisms of interaction with zwitterionic lipid membranes.

Micro- and nanoplastics - current state of knowledge with the focus on oral uptake and toxicity

The production and use of plastics has constantly increased over the last 30 years. Over one third of the plastics is used in disposables, which are discarded within three years of their production. Despite efforts towards recycling, a substantial volume of debris has accumulated in the environment and is slowly degraded to micro- and nanoplastics by weathering and aging. It has recently been discovered that these small particles can enter the food chain, as for example demonstrated by the detection of microplastic particles in honey, beer, salt, sea food and recently in mineral water. Human exposure has further been documented by the detection of plastic microparticles in human feces. Potential toxic consequences of oral exposure to small plastic particles are discussed. Due to lacking data concerning exposure, biodistribution and related effects, the risk assessment of micro- and nanoplastics is still not possible. This review focuses on the oral uptake of plastic and polymer micro- and nanoparticles. Oral exposure, particle fate, changes of particle properties during ingestion and gastrointestinal digestion, and uptake and transport at the intestinal epithelium are reviewed in detail. Moreover, the interaction with intestinal and liver cells and possibly resulting toxicity are highlighted.

Preparation of the protein corona: How washing shapes the proteome and influences cellular uptake of nanocarriers

A protein coat, termed the protein corona, assembles around the nanocarriers´ surface once it gets in contact with a biological environment. We show that the media used for the washing of protein corona can be crucial. This is true for the downstream analysis as well as for the pre-coating used in in vitro or in vivo. This has been widely overlooked so far. In this paper we focus on eight different washing media and analyze how they influence the composition of the hard protein corona of several nanocarriers incubated with human blood plasma and serum. SDS-PAGE and LC-MS analysis showed major differences in protein corona profiles when using diverse washing media. While plasma and serum proteins already have different complexities, each washing media changes the composition of proteins detected by downstream methods with different key proteins bound to the nanocarriers´ surface. Furthermore, the protein structure of the most abundant blood proteins incubated in the different media was analyzed with nanoDSF. This also emphasized the importance of the washing media, which had a significant influence on the protein adsorption stability. Lastly, cell uptake experiments for HeLa and RAW 264.7 macrophages also indicated an influence of the washing media. In conclusion, picking a specific washing media is on the one hand an important factor for downstream detection of protein compositions and may on the other hand be used to deliberately tune the protein corona for pre-adsorbed proteins from complex protein compositions. This might further support a guided delivery of the nanocarrier to a desired location within a physiological environment. STATEMENT OF SIGNIFICANCE: The successfully application of nanocarriers as drug delivery vehicles is currently hampered by a limited understanding of the nanocarriers´ behavior in a complex biological environment. Once the nanocarrier comes into contact with blood plasma or serum, biomolecules rapidly adsorb onto their surface, covering the nanocarriers and forming a protein corona, which then dictates their biological identity. Analyzing the composition of this dynamic network of bound molecules, has already been shown to be influenced by various factors. However, the impact of the washing media used for the protein corona preparation has so far been neglected. In the present study, we demonstrate a quantitative influence of the washing media on the composition of the hard corona of different nanocarrier systems, which additionally affects protein stability and cellular uptake behavior.

Plasma proteins facilitates placental transfer of polystyrene particles

BACKGROUND

Nanoparticles, which are exposed to biological fluids are rapidly interacting with proteins and other biomolecules forming a corona. In addition to dimension, charge and material the distinct protein corona influences the interplay of nanoparticles with tissue barriers. In this study we were focused on the impact of in situ formed human plasma protein corona on the transfer of 80 nm polystyrene nanoparticles (PS-particles) across the human placenta. To study materno-to fetal PS transfer we used the human ex vivo placental perfusion approach, which represents an intact and physiological tissue barrier. To analyze the protein corona of PS particles we performed shotgun proteomics of isolated nanoparticles before and after tissue exposure.

RESULTS

Human plasma incubated with PS-particles of 80 nm and subsequent formed protein corona enhanced the transfer across the human placenta compared to PS-corona formed by bovine serum albumin and dextran which served as a control. Quantitative and qualitative changes of plasma proteins determined the changes in PS transfer across the barrier. Based on the analysis of the PS-proteome two candidate proteins, namely human albumin and immunoglobulin G were tested if these proteins may account for the enhanced PS-transfer across the placenta. Interestingly, the protein corona formed by human albumin significantly induced the transfer of PS-particles across the tissue compared to the formed IgG-corona.

CONCLUSION

In total we demonstrate the PS corona dynamically and significantly evolves upon crossing the human placenta. Thus, the initial composition of PS particles in the maternal circulation is not predictive for their transfer characteristics and performance once beyond the barrier of the placenta. The precise mechanism of these effects remains to be elucidated but highlights the importance of using well designed biological models when testing nanoparticles for biomedical applications.

Interactions between functionalised silica nanoparticles and Pseudomonas fluorescens biofilm matrix: A focus on the protein corona

Biofilms are microbial communities embedded in an extracellular polymeric matrix and display an enhanced tolerance to the action of antimicrobials. The emergence of novel functionalised nanoparticles is considered a promising avenue for the development of biofilm-specific antimicrobial technologies. However, there is a gap in the understanding of interactions between nanoparticles and the biofilm matrix. Particularly, questions are raised on how nanoparticle charge and surface groups play a role in aggregation when in contact with biofilm components. Herein we present the synthesis of four types of silica nanoparticles and undertake an analysis of their interactions with Pseudomonas fluorescens biofilm matrix. The effect of the biofilm matrix components on the charge and aggregation of the nanoparticles was assessed. Additionally, the study focused on the role of matrix proteins, with the in-depth characterisation of the protein corona of each nanoparticle by Liquid Chromatography with Tandem Mass Spectrometry experiments. The protein corona composition is dependent on the nanoparticle type; non-functionalised nanoparticles show less protein selectivity, whereas carboxylate-functionalised nanoparticles prefer proteins with a higher isoelectric point. These outcomes provide insights into the field of biofilm-nanoparticle interactions that can be valuable for the design of new nano-based targeting systems in future anti-biofilm applications.

Functionalized Surface-Charged SiO2 Nanoparticles Induce Pro-Inflammatory Responses, but Are Not Lethal to Caco-2 Cells

Nanoparticles (NPs) are widely used in food, and analysis of their potential gastrointestinal toxicity is necessary. The present study was designed to determine the effects of silica dioxide (SiO₂), titanium dioxide (TiO₂), and zinc oxide (ZnO) NPs on cultured THP-1 monocyte-derived macrophages and human epithelial colorectal adenocarcinoma (Caco-2) cells. Exposure to ZnO NPs for 24 h increased the production of redox response species (ROS) and reduced cell viability in a dose-dependent manner in THP-1 macrophages and Caco-2 cells. Although TiO₂ and SiO₂ NPs induced oxidative stress, they showed no apparent cytotoxicity against both cell types. The effects of functionalized SiO₂ NPs on undifferentiated and differentiated Caco-2 cells were investigated using fluorescently labeled SiO₂ NPs with neutral, positive, or negative surface charge. Exposure of both types of cells to the three kinds of SiO₂ NPs significantly increased their interaction in a dose-dependent manner. The largest interaction with both types of cells was noted with exposure to more negatively surface-charged SiO₂ NPs. Exposure to either positively or negatively, but not neutrally, surface-charged SiO₂ NPs increased NO levels in differentiated Caco-2 cells. Exposure of differentiated Caco-2 cells to positively or negatively surface-charged SiO₂ NPs also upregulated interleukin-8 expression. We conclude that functionalized surface-charged SiO₂ NPs can induce pro-inflammatory responses but are noncytotoxic.