Nano- and microscaled particles for drug targeting to inflamed intestinal mucosa—A first in vivo study in human patients

Biosimilars versus biological therapy in inflammatory bowel disease: challenges and targeting strategies using drug delivery systems

Inflammatory bowel disease (IBD) is a multifactorial illness with a climbing prevalence worldwide. While biologics are commonly prescribed especially for severe cases, they may worsen patients' outcomes due to financial burden. Consequently, there has been an increased focus on biosimilars to improve overall disease outcomes by maintaining similar efficacy and safety while minimizing the cost of therapy. Infliximab-dyyb was the first biosimilar approved by US-FDA for IBD. Since that, the US-FDA approved 14 biosimilars with different mechanisms of action and different routes of administration for IBD patients (four infliximab biosimilars, nine adalimumab biosimilars, and most recently one ustekinumab biosimilar). It should be noted that more biologics are in the pipeline as golimumab and natalizumab patents are set to expire in the near future, and biosimilars are now in pre-clinical to phase 3 trials. Different studies have evaluated biologics' effectiveness and safety and concluded that the majority of available biosimilars are efficacious and have similar adverse effect profiles compared to their reference biologics. It is worth mentioningthat post-marketing surveillance reports revealed some risks associated with biosimilars which should be taken into consideration in future research and clinical trials to avoid health hazards. Most biologics and biosimilars are administered parenterally which results in several drawbacks such as raised risk of infections, hypersensitivity, autoimmunity, development of malignancies, liver toxicity as well as worsening of heart failure. Several drug delivery systems based on passive and active targeting mechanisms are under active investigation to overcome these limitations. This review sheds light on the emergence of biologics and biosimilars as alternatives in IBD management, the differences between them, challenges and risks, and future perspectives in IBD therapy and new trends in drug delivery systems.

Mechanisms of microplastics on gastrointestinal injury and liver metabolism disorder (Review)

With the high production and use of plastic products, a large amount of microplastics (MPs) is generated by degradation, which causes environmental pollution. MPs are particles with a diameter <5 mm; further degradation of MPs produces nano‑plastics (NPs), which could further increase the damage to cells when entering the human body. Therefore, the present review summarizes the effect of MP and NP deposition on the human gastrointestinal tract and the underlying injury mechanism of oxidative stress, inflammation and apoptosis, as well as the potential mechanism of glucose and liver lipid metabolism disorder. The present review provides a theoretical basis for research on the mechanisms of MPs in gastrointestinal injury and liver metabolism disorder. Further studies are needed for prevention and treatment of gastrointestinal diseases caused by MPs and NPs.

From food-to-human microplastics and nanoplastics exposure and health effects: A review on food, animal and human monitoring data

This review figures out the overall status on the presence of microplastics (MPs) and nanoplastics (NPs) in food and their bioaccumulation in animal and human tissues, providing critical insights into possible human health impacts. Data are discussed on both in-vivo and ex-vivo animal and human studies, and the role of physicochemical properties in determining the biological fate and toxicological effects of MPs and NPs. Particular attention is given to dietary exposure assessments, specifically evaluating daily intake through the consumption of contaminated food items. The current limitations in the body of knowledge and some considerations for future assessments are also reported. Overall, there is a pressing need to establish more robust biomarker research and develop standardized methodologies, for a better understanding of MPs and NPs fate and associated effects in more realistic scenarios for their safe consumption. The review underscores the importance of integrating the human biomonitoring into monitoring programs and interdisciplinary research to ultimately inform on MPs and NPs real burden in the human body.

Biotransport and toxic effects of micro- and nanoplastics in fish model and their potential risk to humans: A review

The growing body of scientific evidence suggests that micro- and nanoplastics (MPs/NPs) pose a significant threat to aquatic ecosystems and human health. These particles can enter organisms through ingestion, inhalation, dermal contact, and trophic transfer. Exposure can directly affect multiple organs and systems (respiratory, digestive, neurological, reproductive, urinary, cardiovascular) and activate extensive intracellular signaling, inducing cytotoxicity involving mechanisms such as membrane disruption, extracellular polymer degradation, reactive oxygen species (ROS) production, DNA damage, cellular pore blockage, lysosomal instability, and mitochondrial depolarization. This review focuses on current research examining the in vivo and in vitro toxic effects of MPs/NPs on aquatic organisms, particularly fish, in relation to particulate toxicity aspects (such as particle transport mechanisms and structural modifications). Meanwhile, from the perspectives of the food chain and environmental factors, it emphasizes the comprehensive threats of MPs/NPs to human health in terms of both direct and indirect toxicity. Additionally, future research needs and strategies are discussed to aid in mitigating the potential risks of particulate plastics as carriers of toxic trace elements to human health.

Revisiting the potential of natural antimicrobial peptides against emerging respiratory viral disease: a review

This review assesses the antiviral capabilities of antimicrobial peptides (AMPs) against SARS-CoV-2 and other respiratory viruses, focussing on their therapeutic potential. AMPs, derived from natural sources, exhibit promising antiviral properties by disrupting viral membranes, inhibiting viral entry, and modulating host immune responses. Preclinical studies demonstrate that peptides such as defensins, cathelicidins, and lactoferrin can effectively reduce SARS-CoV-2 replication and inhibit viral spread. In addition, AMPs have shown potential in enhancing the host's antiviral immunity. Despite these promising outcomes, several challenges require assessments before transforming into clinical translation. Several issues related to peptide stability, cytotoxicity, and efficient delivery systems pose significant limitations to their therapeutic application. Recent advancements in peptide engineering, nanotechnology-based delivery systems, and peptide conjugation strategies have improved AMPs stability and bioavailability; however, further optimization is essential. Moreover, whilst AMPs are safe, their effects on host cells and tissues need a thorough investigation to minimise potential adverse reactions. This review concludes that whilst AMPs present a promising route for antiviral therapies, particularly in targeting SARS-CoV-2, extensive clinical trials and additional studies are required to overcome current limitations. Future research should focus on developing more stable, less toxic AMPs formulations with enhanced delivery mechanisms, aiming to integrate AMPs into viable therapeutic options for respiratory viral diseases, including COVID-19 and other emerging infections.

Advancing Inflammatory Bowel Disease Treatment by Targeting the Innate Immune System and Precision Drug Delivery

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, involves chronic inflammation of the gastrointestinal tract. Current immune-modulating therapies are insufficient for 30-50% of patients or cause significant side effects, emphasizing the need for new treatments. Targeting the innate immune system and enhancing drug delivery to inflamed gut regions are promising strategies. Neutrophils play a central role in IBD by releasing reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) -DNA-based structures with cytotoxic proteins-that contribute to mucosal damage and inflammation. Recent studies linking ROS production, DNA repair, and NET formation have identified NETs as potential therapeutic targets, with preclinical models showing positive outcomes from NET inhibition. Innovative oral drug delivery systems designed to target gut inflammation directly-without systemic absorption-could improve treatment precision and reduce side effects. Advanced formulations utilize properties such as particle size, surface modifications, and ROS-triggered release to selectively target the distal ileum and colon. A dual strategy that combines a deeper understanding of IBD pathophysiology to identify inflammation-related therapeutic targets with advanced drug delivery systems may offer significant promise. For instance, pairing NET inhibition with ROS-responsive nanocarriers could enhance treatment efficacy, though further research is needed. This synergistic approach has the potential to greatly improve outcomes for IBD patients.

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.

Physical and chemical food safety hazards and associated health risks in seafood: A Mediterranean perspective (Part 1)

Several risks to food safety are associated with seafood. The marine environment is heavily affected by various materials, both of physical and chemical nature, which have significant impact on the safety of seafood. Recently, there has been a concerning discovery regarding seafood contamination. As it appears, there are physical hazards present, specifically in the form of nano- and micro-plastic materials. Additionally, chemicals from various sources have been detected. These chemicals are commonly used in the production of convenience goods, antimicrobials, antibiotics, heavy metals and industrial effluents. This chapter has focused on the various hazards that can influence the safety of seafood in the marine environment. It covers both physical and chemical sources of these hazards, ensuring a comprehensive understanding of the potential risks involved. There are indications that the consumption of polluted seafood in the Mediterranean region can have negative impact on human health.

Toxicity of gold nanoparticles complicated by the co-existence multiscale plastics

Introduction

Gold nanoparticles (AuNPs) have been developed as treatment materials for various diseases and shown magnificent potential. By contrast to the broad toxicological studies on the single exposure (AuNPs), how the other health risks modulate the toxicological profile of AuNPs remains to be investigated. Plastics are among the most common health risks in daily life due to the broad utilization of plastic products. Therefore, in this study, we aimed to reveal the toxicological effects induced by co-exposure of gold nanorod (AuR) and polystyrene micro- and nano-plastics (hereinafter, referred to as AuRmPS and AuRnPS, respectively) in mice.

Methods

Systematic biochemical characterizations were performed to investigate the hepatotoxicity, nephrotoxicity, neurotoxicity, inflammatory responses, alterations in gut microbiota induced by co-exposure, and to analyze the toxicological phenomena from the roles of reactive oxygen species and gut-organ axis.

Results

It has been found that hepatotoxicity, nephrotoxicity, neurotoxicity, and inflammation were exacerbated in AuRnPS and AuRmPS, and gut microbiota composition was more severely altered in AuRnPS exposure. These results suggest the necessity of reducing plastics exposure in AuNPs-based therapies. Moreover, protection against the nano-sized plastic particles holds higher priority.

Conclusion

These findings will facilitate the explorations of methods to reduce therapeutic toxicity and improve biosafety for specific treatments by referring to the orders of importance in protecting different organs.

Lipid- and polymer-based formulations containing TNF-α inhibitors for the treatment of inflammatory bowel diseases

Monoclonal antibodies inhibiting tumor necrosis factor-alpha (iTNF-α) have revolutionized the therapeutic regimen of inflammatory bowel disease, but their main drawback is the parenteral route of administration they require. An alternative approach lies in the delivery of these molecules to the area involved in the inflammatory process by means of innovative formulations able to promote their localization in affected tissues while also decreasing the number of administrations required. This review describes the advantages deriving from the use of lipid- and polymer-based systems containing iTNF-α, focusing on their physicochemical and technological properties and discussing the preclinical results obtained in vivo using rodent models of colitis.

Mucoadhesive Mesalamine Prodrug Nanoassemblies to Target Intestinal Macrophages for the Treatment of Inflammatory Bowel Disease

While mesalamine, a 5-aminosalicylic acid (5-ASA), is pivotal in the management of inflammatory bowel disease (IBD) through both step-up and top-down approaches in clinical settings, its widespread utilization is limited by low bioavailability at the desired site of action due to rapid and extensive absorption in the upper gastrointestinal (GI) tract. Addressing mesalamine's pharmacokinetic challenges, here, we introduce nanoassemblies composed exclusively of a mesalamine prodrug that pairs 5-ASA with a mucoadhesive and cathepsin B-cleavable peptide. In an IBD model, orally administered nanoassemblies demonstrate enhanced accumulation and sustained retention in the GI tract due to their mucoadhesive properties and the epithelial enhanced permeability and retention (eEPR) effect. This retention enables the efficient uptake by intestinal pro-inflammatory macrophages expressing high cathepsin B, triggering a burst release of the 5-ASA. This cascade fosters the polarization toward an M2 macrophage phenotype, diminishes inflammatory responses, and simultaneously facilitates the delivery of active agents to adjacent epithelial cells. Therefore, the nanoassemblies show outstanding therapeutic efficacy in inhibiting local inflammation and contribute to suppressing systemic inflammation by restoring damaged intestinal barriers. Collectively, this study highlights the promising role of the prodrug nanoassemblies in enhancing targeted drug delivery, potentially broadening the use of mesalamine in managing IBD.

The potential impact of nano- and microplastics on human health: Understanding human health risks

Plastics are used all over the world. Unfortunately, due to limited biodegradation, plastics cause a significant level of environmental pollution. The smallest recognized to date are termed nanoplastics (1 nm [nm] up to 1 μm [μm]) and microplastics (1 μm-5 mm). These nano- and microplastics can enter the human body through the respiratory system via inhalation, the digestive tract via consumption of contaminated food and water, or penetration through the skin via cosmetics and clothes contact. Bioaccumulation of plastics in the human body can potentially lead to a range of health issues, including respiratory disorders like lung cancer, asthma and hypersensitivity pneumonitis, neurological symptoms such as fatigue and dizziness, inflammatory bowel disease and even disturbances in gut microbiota. Most studies to date have confirmed that nano- and microplastics can induce apoptosis in cells and have genotoxic and cytotoxic effects. Understanding the cellular and molecular mechanisms of plastics' actions may help extrapolate the risks to humans. The article provides a comprehensive review of articles in databases regarding the impact of nano- and microplastics on human health. The review included retrospective studies and case reports of people exposed to nanoplastics and microplastics. This research highlights the need for further research to fully understand the extent of the impact of plastics on human health.

Microplastics and environmental effects: investigating the effects of microplastics on aquatic habitats and their impact on human health

Microplastics (MPs) are particles with a diameter of <5 mm. The disposal of plastic waste into the environment poses a significant and pressing issue concern globally. Growing worry has been expressed in recent years over the impact of MPs on both human health and the entire natural ecosystem. MPs impact the feeding and digestive capabilities of marine organisms, as well as hinder the development of plant roots and leaves. Numerous studies have shown that the majority of individuals consume substantial quantities of MPs either through their dietary intake or by inhaling them. MPs have been identified in various human biological samples, such as lungs, stool, placenta, sputum, breast milk, liver, and blood. MPs can cause various illnesses in humans, depending on how they enter the body. Healthy and sustainable ecosystems depend on the proper functioning of microbiota, however, MPs disrupt the balance of microbiota. Also, due to their high surface area compared to their volume and chemical characteristics, MPs act as pollutant absorbers in different environments. Multiple policies and initiatives exist at both the domestic and global levels to mitigate pollution caused by MPs. Various techniques are currently employed to remove MPs, such as biodegradation, filtration systems, incineration, landfill disposal, and recycling, among others. In this review, we will discuss the sources and types of MPs, the presence of MPs in different environments and food, the impact of MPs on human health and microbiota, mechanisms of pollutant adsorption on MPs, and the methods of removing MPs with algae and microbes.

Selective Uptake Into Inflamed Human Intestinal Tissue and Immune Cell Targeting by Wormlike Polymer Micelles

Inflammatory bowel disease (IBD) has become a globally prevalent chronic disease with no causal therapeutic options. Targeted drug delivery systems with selectivity for inflamed areas in the gastrointestinal tract promise to reduce severe drug-related side effects. By creating three distinct nanostructures (vesicles, spherical, and wormlike micelles) from the same amphiphilic block copolymer poly(butyl acrylate)-block-poly(ethylene oxide) (PBA-b-PEO), the effect of nanoparticle shape on human mucosal penetration is systematically identified. An Ussing chamber technique is established to perform the ex vivo experiments on human colonic biopsies, demonstrating that the shape of polymeric nanostructures represents a rarely addressed key to tissue selectivity required for efficient IBD treatment. Wormlike micelles specifically enter inflamed mucosa from patients with IBD, but no significant uptake is observed in healthy tissue. Spheres (≈25 nm) and vesicles (≈120 nm) enter either both normal and inflamed tissue types or do not penetrate any tissue. According to quantitative image analysis, the wormlike nanoparticles localize mainly within immune cells, facilitating specific targeting, which is crucial for further increasing the efficacy of IBD treatment. These findings therefore demonstrate the untapped potential of wormlike nanoparticles not only to selectively target the inflamed human mucosa, but also to target key pro-inflammatory cells.

Review of emerging contaminants in green stormwater infrastructure: Antibiotic resistance genes, microplastics, tire wear particles, PFAS, and temperature

Green stormwater infrastructure is a growing management approach to capturing, infiltrating, and treating runoff at the source. However, there are several emerging contaminants for which green stormwater infrastructure has not been explicitly designed to mitigate and for which removal mechanisms are not yet well defined. This is an issue, as there is a growing understanding of the impact of emerging contaminants on human and environmental health. This paper presents a review of five emerging contaminants - antibiotic resistance genes, microplastics, tire wear particles, PFAS, and temperature - and seeks to improve our understanding of how green stormwater infrastructure is impacted by and can be designed to mitigate these emerging contaminants. To do so, we present a review of the source and transport of these contaminants to green stormwater infrastructure, specific treatment mechanisms within green infrastructure, and design considerations of green stormwater infrastructure that could lead to their removal. In addition, common removal mechanisms across these contaminants and limitations of green infrastructure for contaminant mitigation are discussed. Finally, we present future research directions that can help to advance the use of green infrastructure as a first line of defense for downstream water bodies against emerging contaminants of concern.

Chronic exposure to polystyrene nanoplastics induces intestinal mechanical and immune barrier dysfunction in mice

Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg·L-1) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin-eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1β, IL-6, and TNF-α) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg·L-1) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg·L-1 PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg·L-1 PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8+ T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-α and IL-1β were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.

Targeted delivery of budesonide in acetic acid induced colitis: impact on miR-21 and E-cadherin expression

Inflammatory bowel disease (IBD) is characterized by chronic inflammation along the gastrointestinal tract. For IBD effective treatment, developing an orally administered stable drug delivery system capable of targeting inflammation sites is a key challenge. Herein, we report pH responsive hyaluronic (HA) coated Eudragit S100 (ES) nanoparticles (NPs) for the targeted delivery of budesonide (BUD) (HA-BUD-ES-NPs). HA-BUD-ES-NPs showed good colloidal properties (274.8 ± 2.9 nm and - 24.6 ± 2.8 mV) with high entrapment efficiency (98.3 ± 3.41%) and pH-dependent release profile. The negative potential following incubation in simulated gastrointestinal fluids reflected the stability of HA coat. In vitro studies on Caco-2 cells showed HA-BUD-ES-NPs biocompatibility and enhanced cellular uptake and anti-inflammatory effects as shown by the significant reduction in IL-8 and TNF-α. The oral administration of HA-BUD-ES-NPs in an acetic acid induced colitis rat model significantly mitigated the symptoms of IBD, and improved BUD therapeutic efficacy compared to drug suspension. This was proved via the improvement in disease activity index and ulcer score in addition to refined histopathological findings. Also, the assessment of inflammatory markers, epithelial cadherin, and mi-R21 all reflected the higher efficiency of HA-BUD-ES-NPs compared to free drug and uncoated formulation. We thus suggest that HA-BUD-ES-NPs provide a promising drug delivery platform for the management and site specific treatment of IBD.

Polystyrene may alter the cooperation mechanism of gut microbiota and immune system through co-exposure with DCBQ

The toxicity of Polystyrene (PS) may be higher through co-exposure with other pollutants. Human can simultaneously face the challenges from the various pollutants. Nevertheless, little research has been done on the combined effects of PS and 2,6-dichloro-p-benzoquinone (DCBQ) disinfection byproduct. Considering the potential risk of PS and DCBQ, we aimed to illustrate the effects of PS in combination with DCBQ on the immune responses of mice. We found that cotreatment of DCBQ and PS may inhibit the activity of spleen CD4+ T cells and interfere with the normal function of the immune system. Further research found that DCBQ + PS resulted in increasing amount of the inflammatory cells in intestine via histopathological evaluation. The reason might be that DCBQ + PS has changed the composition of intestinal flora, abnormally activated intestinal macrophage, and inhibited the expression of immune-related genes, thus leading to intestinal immune disorders and triggering intestinal inflammation. In summary, PS may alter the cooperation mechanism of gut microbiota and immune system through co-exposure with DCBQ. Current results suggested that more attention should be paid to the combined toxic effects of environmental contaminants.

Colon-targeted delivery of polyphenols: construction principles, targeting mechanisms and evaluation methods

Polyphenols have received considerable attention for their promotive effects on colonic health. However, polyphenols are mostly sensitive to harsh gastrointestinal environments, thus, must be protected. It is necessary to design and develop a colon-targeted delivery system to improve the stability, colon-targeting and bioavailability of polyphenols. This paper mainly introduces research on colon-targeted controlled release of polyphenols. The physiological features affecting the dissolution, release and absorption of polyphenol-loaded delivery systems in the colon are first discussed. Simultaneously, the types of colon-targeted carriers with different release mechanisms are described, and colon-targeting assessment models that have been studied so far and their advantages and limitations are summarized. Based on the current research on polyphenols colon-targeting, outlook and reflections are proposed, with the goal of inspiring strategic development of new colon-targeted therapeutics to ensure that the polyphenols reach the colon with complete bioactivity.

Microplastics exposure and immunologic response

OBJECTIVE

To assess the impact of microplastics (MPs) on human health.

DATA SOURCE

The authors conducted a non-systematic review of articles published in English, Portuguese, French, and Spanish in the last decade in the following databases: PubMed, Google Scholar, EMBASE, and SciELO. The keywords used were: microplastics OR nanoplastics OR marine litter OR toxicology OR additives AND human health OR children OR adults.

DATA SUMMARY

MPs are a group of emerging contaminants that have attracted scientific interest and societal attention in the last decade due to their ubiquitous detection in all environments. Humans can primarily be exposed to MPs and nanoplastics via oral and inhalation routes, but dermal contact cannot be overlooked, especially in young children. The possible toxic effects of plastic particles are due to their potential toxicity, often combined with that of leachable additives and adsorbed contaminants.

CONCLUSIONS

Unless the plastic value chain is transformed over the next two decades, the risks to species, marine ecosystems, climate, health, economy, and communities will be unmanageable. However, along with these risks are the unique opportunities to help transition to a more sustainable world.

Harnessing polymer-derived drug delivery systems for combating inflammatory bowel disease

The inflammatory bowel disease (IBD) is incurable, chronic, recrudescent disorders in the inflamed intestines. Current clinic treatments are challenged by systemic exposure-induced severe side effects, inefficiency after long-term treatment, and increased risks of infection and malignancy due to immunosuppression. Fortunately, naturally bioactive small molecules, reactive oxygen species scavengers (or antioxidants), and gut microbiota modulators have emerged as promising candidates for the IBD treatment. Polymeric systems have been engineered as a delivery vehicle to improve the bioavailability and efficacy of these therapeutic agents through targeting the mucosa and enhancing intestinal adhesion and retention, and reduce their systemic toxicity. Herein we survey polymer-derived drug delivery systems for combating the IBD. Advanced delivery technologies, therapeutic intervention strategies, and the principles for the construction of hierarchical, mucosa-targeting, and bioresponsive systems are elaborated, providing insights into design and development of from-bench-to-bedside drug delivery polymeric systems for the IBD treatment.

PCB-126 spiked to polyethylene microplastic ingested by juvenile Atlantic cod (Gadus morhua) accumulates in liver and muscle tissues

In the present study, polyethylene (PE) microplastics (150-300 μm) were added to Atlantic cod (Gadus morhua) feeds at 1 %, either in their present form (Virgin PE) or spiked with PCB-126 (Spiked PE). The feeds were given to juvenile cod for a 4-week period. The fish grew from 11 to 23 g with no significant difference between dietary treatments. Cod fed spiked PE showed a significantly higher concentration of PCB-126 in liver and muscle samples compared to control and fish ingesting virgin PE. In accordance with the accumulation of PCB-126 in the liver, the expression of hepatic cyp1a was higher in cod fed spiked PE. Notably, we observed that spiked PE, as well as virgin PE, have an effect on skin. Overall changes indicated a reduced skin barrier in fish fed a diet containing PE. Indicating that PE itself through interaction with gut tissue may influence skin health in fish.

Efficient extraction of small microplastic particles from rat feed and feces for quantification

To date, microplastic is ubiquitously encountered in the environment. Studies analyzing microplastic in terrestrial ecosystems, including animal feces and feed, are few. Microplastic quantification method validation and harmonization are not yet far developed. For the analysis of small microplastic, approximately <0.5 mm, extraction from organic and inorganic materials is fundamental prior to quantitative and qualitative analysis. Method validation, including recovery studies, are necessary throughout the analytical chain. In this study, we developed an optimized, efficient protocol with a duration of 72 h for the digestion of laboratory rat feed and feces. A combination of a mild acidic (H₂O₂ 15%; HNO₃ 5%) and an alkaline treatment (10% KOH) dissolving the previous filter, followed by enzymatic digestion (Viscozyme®L) proved to be efficient for the extraction and identification of spiked polyamide (15-20 μm) and polyethylene (40-48 μm) from feed and feces samples from rats, showing high recovery rates. Extracted rat feces samples from an in vivo study in which Wistar rats were fed with feed containing microplastic were analyzed with pyrolysis-gas chromatography-Orbitrap™ mass spectrometry, quantifying recovered microplastic in rat feces in environmentally relevant concentrations. The presented three-step protocol provides a suitable, time and cost-effective method to extract microplastic from rat feed and feces.

The application of natural product-delivering micro/nano systems in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of recurrent intestinal diseases. Natural product molecules have been gradually developed into an important source of anti-inflammatory drugs for treating IBD owing to their high anti-inflammatory activity, well known safety, structural specificity and therapeutic mechanism diversity. However, most of the natural products are restricted by poor solubility in actual application. How to achieve satisfactory bioavailability during the treatment of IBD is one of the urgent problems to be solved in the current research. Micro/nano drug delivery systems could improve the solubility of drugs with targeted delivery of anti-inflammatory drugs to the colon with responsive release property. Therefore, using micro/nano drug delivery systems, the problems mentioned above involving natural product molecules in the treatment of IBD could be solved. According to the compositions of the intestinal tract and inflammatory characteristics of IBD, the strategies of using micro/nano drug delivery systems for natural products could be summarized in two steps: targeted delivery and responsive release. In this review, the targeted and responsive release strategies of the micro/nano drug delivery systems combined with their anti-inflammatory effects in IBD animal models to illustrate that the proposed strategies could be potential treatments for symptomatic IBD are described.

Metformin Hydrochloride Mucosal Nanoparticles-Based Enteric Capsule for Prolonged Intestinal Residence Time, Improved Bioavailability, and Hypoglycemic Effect

Metformin hydrochloride enteric-coated capsule (MH-EC) is a commonly used clinical drug for the treatment of type 2 diabetes. In this study, we described a metformin hydrochloride mucosal nanoparticles enteric-coated capsule (MH-MNPs-EC) based on metformin hydrochloride chitosan mucosal nanoparticles (MH-CS MNPs) and its preparation method to improve the bioavailability and hypoglycemic effect duration of MH-EC. In intestinal adhesion study, the residue rates of free drugs and mucosal nanoparticles were 10.52% and 67.27%, respectively after cleaned with PBS buffer. MH-CS MNPs could significantly improve the efficacy of MH and promote the rehabilitation of diabetes rats. In vitro release test of MH-MNPs-EC showed continuous release over 12 h, while commercial MH-EC released completely within about 1 h in intestinal environment (pH 6.8). Pharmacokinetic study was performed in beagle dogs compared to the commercial MH-EC. The durations of blood MH concentration above 2 μg/mL were 9 h for MH-MNPs-EC versus 2 h for commercial MH-EC. The relative bioavailability of MH-MNPs-EC was determined as 185.28%, compared with commercial MH-EC. In conclusion, MH-CS MNPs have good intestinal adhesion and can significantly prolong the residence time of MH in the intestine. MH-MNPs-EC has better treatment effect compared with MH-EC, and it is expected to be a potential drug product for the treatment of diabetes because of its desired characteristics.

Preparation and Characterization of a Novel Multiparticulate Dosage Form Carrying Budesonide-Loaded Chitosan Nanoparticles to Enhance the Efficiency of Pellets in the Colon

An attempt was made to conquer the limitation of orally administered nanoparticles for the delivery of budesonide to the colon. The ionic gelation technique was used to load budesonide on chitosan nanoparticles. The nanoparticles were investigated in terms of size, zeta potential, encapsulation efficiency, shape and drug release. Then, nanoparticles were pelletized using the extrusion-spheronization method and were investigated for their size, mechanical properties, and drug release. Pellets were subsequently coated with a polymeric solution composed of two enteric (eudragit L and S) and time-dependent polymers (eudragit RS) for colon-specific delivery. All formulations were examined for their anti-inflammatory effect in rats with induced colitis and the relapse of the colitis after discontinuation of treatment was also followed. The size of nanoparticles ranged between 288 ± 7.5 and 566 ± 7.7 nm and zeta potential verified their positive charged surface. The drug release from nanoparticles showed an initial burst release followed by a continuous release. Pelletized nanoparticles showed proper mechanical properties and faster drug release in acidic pH compared with alkaline pH. It was interesting to note that pelletized budesonide nanoparticles released the drug throughout the GIT in a sustained fashion, and had long-lasting anti-inflammatory effects while rapid relapse was observed for those treated with conventional budesonide pellets. It seems that there is a synergistic effect of nanoformulation of budesonide and the encapsulation of pelletized nanoparticles in a proper coating system for colon delivery that could result in a significant and long-lasting anti-inflammatory effect.

Precise oral delivery systems for probiotics: A review

Probiotics have several health benefits to the host. However, low pH in the stomach, various digestive enzymes and bile salts in the intestine threaten their viability and function. Thus, probiotics need to be protected during gastric transit to address challenges associated with low viability and impaired function. At present, probiotic delivery systems with different trigger mechanisms have been constructed to successfully introduce numerous high-viability probiotics to the intestine. On this basis, the application of non-targeted/targeted probiotic delivery systems in different gut microenvironment and the adjuvant therapeutic effect of probiotic delivery systems on other disease were discussed in detail. It is important to also note that most of the current studies in this area focused on non-targeted probiotic delivery systems. Moreover, changes in intestinal microenvironment under disease state and discontinuous distribution of disease site limit their development. Thus, emphasis were made on the optimization of non-targeted probiotic delivery systems and the necessity of designing more precisely targeted ones.

Unraveling the potential human health risks from used disposable face mask-derived micro/nanoplastics during the COVID-19 pandemic scenario: A critical review

With the global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), disposable face masks (DFMs) have caused negative environmental impacts. DFMs will release microplastics (MPs) and nanoplastics (NPs) during environmental degradation. However, few studies reveal the release process of MPs/NPs from masks in the natural environment. This review presents the current knowledge on the abiotic and biotic degradation of DFMs. Though MPs and NPs have raised serious concerns about their potentially detrimental effects on human health, little attention was paid to their impacts on human health from DFM-derived MPs and NPs. The potential toxicity of mask-derived MPs/NPs, such as gastrointestinal toxicity, pneumotoxicity, neurotoxicity, hepatotoxicity, reproductive and transgenerational toxicity, and the underlying mechanism will be discussed in the present study. MPs/NPs serve as carriers of toxic chemicals and pathogens, leading to their bioaccumulation and adverse effects of biomagnification by food chains. Given human experiments are facing ethical issues and animal studies cannot completely reveal human characteristics, advanced human organoids will provide promising models for MP/NP risk assessment. Moreover, in-depth investigations are required to identify the release of MPs/NPs from discarded face masks and characterize their transportation through the food chains. More importantly, innovative approaches and eco-friendly strategies are urgently demanded to reduce DFM-derived MP/NP pollution.

The effect of polystyrene foam in different doses on the blood parameters and relative mass of internal organs of white mice

Due to their durability, versatility and economy, plastic products are widely used in all spheres of human life. Despite the inertness of polymers, recent studies show the ability of microplastic to overcome natural tissue barriers, accumulate in the animal’s body, affect metabolism and change the intestinal microbiota, negatively affecting it. In a 42-day experiment, changes in the internal organs’ relative mass, blood biochemical and morphological parameters of white mice were established under the influence of different doses of polystyrene foam in their diet. Four groups of white mice consumed crushed polystyrene foam particles (10%, 1% and 0.1% by weight of the feed, control group without the addition of polystyrene foam). At the end of the experiment, the morphofunctional state of the internal organs was determined by the organ mass index and blood biochemical parameters. Adding crushed polystyrene foam to the feed in an amount of 1% causes a significant decrease in the mass index of the heart and stomach, 10% – only the heart, and 0.1% – does not affect this indicator. Polystyrene foam had a significant effect on blood biochemical parameters, regardless of the dose, causing an increase in the activity of aspartate aminotransferase against the background of a decrease in the activity of alkaline phosphatase. The content of total bilirubin, urea, urea nitrogen and cholesterol decreased, and the concentration of creatinine and total protein increased (due to the albumin fraction). The use of crushed polystyrene foam in mice did not cause significant changes in the blood morphological composition, except for a dose-dependent increase in the number of monocytes. In the future, it is planned to determine histological, histochemical and immunohistochemical changes in the organs of laboratory animals under the influence of plastic in a laboratory experiment.

Budesonide-Loaded Hyaluronic Acid Nanoparticles for Targeted Delivery to the Inflamed Intestinal Mucosa in a Rodent Model of Colitis

The aim of the present study was to investigate the therapeutic potential of budesonide- (BDS-) loaded hyaluronic acid nanoparticles (HANPs) for treatment of inflammatory bowel disease (IBD) using an acute model of colitis in rats. The therapeutic efficacy of BDS-loaded HANPs in comparison with an aqueous suspension of the drug with the same dose (30 μg/kg) was investigated 48 h following induction of colitis by intrarectal administration of acetic acid 4% in rats. Microscopic and histopathologic examinations were conducted in inflamed colonic tissue. Tissue concentration of tumor necrosis factor (TNF)-α was assessed by ELISA assay kit, while the activity of myeloperoxidase (MPO) was measured spectrophotometrically. Results from in vivo evaluations demonstrated that administrations of BDS-HANPs ameliorated the general endoscopic appearance, quite close to the healthy animals with no signs of inflammation and reduced the cellular infiltration, as well as the TNF-α level, and the MPO activity. It was found that delivery by BDS-loaded HANPSs alleviated the induced colitis significantly better than the same dose of the free drug. These data further suggest the potential of HANPs as a targeted drug delivery system to the inflamed colon mucosa.

Size-dependent transfer of microplastics across the intestinal wall of the echinoid Paracentrotus lividus

The fate and toxicity of ingested marine microplastics (MPs) have been of major concern in aquatic ecotoxicology for the last decade. Although their ingestion by a wide range of marine organisms has been proven, the uptake of MPs within organs is not yet fully understood and relies on the ability of ingested microplastics to transfer from the gut to tissues beyond the digestive wall (i.e., translocation). The present study investigates the in vitro transfer of fluorescent high-density polyethylene particles of different sizes classes (1-5 µm; 10-29 µm; 38-45 µm) across the intestinal wall of the sea urchin Paracentrotus lividus using Ussing chambers. Small microplastics (1-5 µm) were proven to be able to cross the intestinal wall of P. lividus and reach the coelomic fluid, while larger microplastics (≥ 10 µm) were not observed to cross the intestinal wall. Results demonstrate a size-dependent passage of polyethylene microparticles across the intestinal walls of P. lividus for the first time, highlighting the suitability of Ussing chamber systems to study the transfer of MPs across the intestinal wall of animals.

Phragmites rhizoma polysaccharide-based nanocarriers for synergistic treatment of ulcerative colitis

The purpose of this study was to construct Phragmites rhizoma polysaccharide-based nano-drug delivery systems (PRP2-SeNPs-H/Aza-Lips) for synergistically alleviating ulcerative colitis and to investigate the important roles of Phragmites rhizoma polysaccharide-based nanocarriers in PRP2-SeNPs-H/Aza-Lips. Phragmites rhizoma polysaccharide (PRP2) was isolated and used for the preparation of Phragmites rhizoma polysaccharide selenium nanoparticles with low selenium content (PRP2-SeNPs-L) and high selenium content (PRP2-SeNPs-H). Based on the electrostatic attraction between PRP2-SeNPs-H and azathioprine liposomes (Aza-Lips), PRP2-SeNPs-H/Aza-Lips were constructed for precise delivery of the model drug azathioprine (Aza) to colon lesions. Results showed that PRP2 significantly alleviated the clinical symptoms and colon tissue damage and down-regulated the levels of inflammatory factors in serum and colon, demonstrating beneficial effects on mice with ulcerative colitis. PRP2-SeNPs-L had better relieving effects on ulcerative colitis. Phragmites rhizoma polysaccharide-based nanocarriers may protect azathioprine liposomes against gastrointestinal digestion, enhance the therapeutic effects on ulcerative colitis, and significantly reduce liver damage from azathioprine, which helps to improve the efficacy and toxicity of clinical drugs.

Untoward Effects of Micro- and Nanoplastics: An Expert Review of Their Biological Impact and Epigenetic Effects

The production of plastic has dramatically increased in the last 50 y. Because of their stability and durability, plastics are ubiquitously incorporated in both marine and terrestrial ecosystems. Plastic is acted upon by biological, chemical, and physical agents, leading to fragmentation into small pieces [i.e., microplastics (MPs) or nanoplastics (NPs)], classified depending on their size. MPs range from 0.1 to 5000 μm and NPs are fragments between 0.001 to 0.1 μm. MPs and, especially NPs, are easily incorporated into living beings via ingestion. The penetration of MPs and NPs into the food system is an important issue, for both food security and health risk assessment. Ingestion of different MPs and NPs has been associated with different issues in the intestine, such as direct physical damage, increased intestinal permeability, diminished microbiota diversity, and increases in local inflammatory response. However, the potential harmful effects of low-dose dietary plastic are still unclear. Some evidence indicates that intestinal uptake of plastic particles is relatively low and is mostly dependent on the particle's size. However, other evidence highlights that NPs dysregulate key molecular signaling pathways, modify the gut microbiota composition, and may induce important epigenetic changes, including transgenerational effects that might be involved in the onset of many different metabolic disorders. Until now, experiments have been mostly performed on marine organisms, Caenorhabditis elegans, and mouse models, but some research indicates accidental plastic dietary consumption by humans, raising the issue of detrimental health effects of MPs and NPs. This review discusses the impact that MPs and NPs could have on the intestinal tract and the biodistribution and systemic, cellular, and molecular levels. Accumulated evidence of MPs' effects on the human gut suggests that large exposure to MPs and NPs may have phenotypical untoward effects in humans, calling for urgent research in this field.

Microplastics detected in cirrhotic liver tissue

Background

The contamination of ecosystem compartments by microplastics (MPs) is an ubiquitous problem. MPs have been observed in mice tissues, and recently in human blood, stool and placenta. However, two aspects remain unclear: whether MPs accumulate in peripheral organs, specifically in the liver, and if liver cirrhosis favours this process. We aimed to examine human liver tissue samples to determine whether MPs accumulate in the liver.

Methods

This proof-of-concept case series, conducted in Germany, Europe, analyzed tissue samples of 6 patients with liver cirrhosis and 5 individuals without underlying liver disease. A total of 17 samples (11 liver, 3 kidney and 3 spleen samples) were analyzed according to the final protocol. A reliable method for detection of MP particles from 4 to 30 µm in human tissue was developed. Chemical digestion of tissue samples, staining with Nile red, subsequent fluorescent microscopy and Raman spectroscopy were performed. Morphology, size and composition of MP polymers were assessed.

Findings

Considering the limit of detection, all liver, kidney and spleen samples from patients without underlying liver disease tested negative for MPs. In contrast, MP concentrations in cirrhotic liver tissues tested positive and showed significantly higher concentrations compared to liver samples of individuals without underlying liver disease. Six different microplastic polymers ranging from 4 to 30 µm in size were detected.

Interpretation

This proof-of-concept case series assessed the presence of MPs in human liver tissue and found six different MP polymers in the liver of individuals with liver cirrhosis, but not in those without underlying liver disease. Future studies are needed to evaluate whether hepatic MP accumulation represents a potential cause in the pathogenesis of fibrosis, or a consequence of cirrhosis and portal hypertension.

Funding

No funding was received for conducting this investigator driven study.

Pathological features-based targeted delivery strategies in IBD therapy: A mini review

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is characterized by a complex and dysfunctional immune response. Currently, IBD is incurable, and patients with IBD often need to take drugs for life. However, as the traditional systemic treatment strategies for IBD do not target the site of inflammation, only limited efficacy can be obtained from them. Moreover, the possibility of serious side effects stemming from the systemic administration or redistribution of drugs in the body is high when conventional drug formulations are used. Therefore, a targeted drug-delivery system for IBD should be considered. Based on the pathological features related to IBD, the new targeted drug-delivery strategy can directly transfer the drug to the inflammatory site, thus enhancing the accumulation of the drugs and reducing side effects. This article reviews the pathological features of IBD and the application of the IBD-targeted delivery system based on different pathological features, and discusses the challenges and new prospects in this field.

Novel drug delivery systems for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic illness characterized by relapsing inflammation of the intestines. The disorder is stratified according to the severity and is marked by its two main phenotypical representations: Ulcerative colitis and Crohn's disease. Pathogenesis of the disease is ambiguous and is expected to have interactivity between genetic disposition, environmental factors such as bacterial agents, and dysregulated immune response. Treatment for IBD aims to reduce symptom extent and severity and halt disease progression. The mainstay drugs have been 5-aminosalicylates (5-ASAs), corticosteroids, and immunosuppressive agents. Parenteral, oral and rectal routes are the conventional methods of drug delivery, and among all, oral administration is most widely adopted. However, problems of systematic drug reactions and low specificity in delivering drugs to the inflamed sites have emerged with these regular routes of delivery. Novel drug delivery systems have been introduced to overcome several therapeutic obstacles and for localized drug delivery to target tissues. Enteric-coated microneedle pills, various nano-drug delivery techniques, prodrug systems, lipid-based vesicular systems, hybrid drug delivery systems, and biologic drug delivery systems constitute some of these novel methods. Microneedles are painless, they dislodge their content at the affected site, and their release can be prolonged. Recombinant bacteria such as genetically engineered Lactococcus Lactis and eukaryotic cells, including GM immune cells and red blood cells as nanoparticle carriers, can be plausible delivery methods when evaluating biologic systems. Nano-particle drug delivery systems consisting of various techniques are also employed as nanoparticles can penetrate through inflamed regions and adhere to the thick mucus of the diseased site. Prodrug systems such as 5-ASAs formulations or their derivatives are effective in reducing colonic damage. Liposomes can be modified with both hydrophilic and lipophilic particles and act as lipid-based vesicular systems, while hybrid drug delivery systems containing an internal nanoparticle section for loading drugs are potential routes too. Leukosomes are also considered as possible carrier systems, and results from mouse models have revealed that they control anti- and pro-inflammatory molecules.

To Waste or Not to Waste: Questioning Potential Health Risks of Micro- and Nanoplastics with a Focus on Their Ingestion and Potential Carcinogenicity

Micro- and nanoplastics (MNPs) are recognized as emerging contaminants, especially in food, with unknown health significance. MNPs passing through the gastrointestinal tract have been brought in context with disruption of the gut microbiome. Several molecular mechanisms have been described to facilitate tissue uptake of MNPs, which then are involved in local inflammatory and immune responses. Furthermore, MNPs can act as potential transporters ("vectors") of contaminants and as chemosensitizers for toxic substances ("Trojan Horse effect"). In this review, we summarize current multidisciplinary knowledge of ingested MNPs and their potential adverse health effects. We discuss new insights into analytical and molecular modeling tools to help us better understand the local deposition and uptake of MNPs that might drive carcinogenic signaling. We present bioethical insights to basically re-consider the "culture of consumerism." Finally, we map out prominent research questions in accordance with the Sustainable Development Goals of the United Nations.

Impact of PEGylation on an antibody-loaded nanoparticle-based drug delivery system for the treatment of inflammatory bowel disease

Nanoparticle-based oral drug delivery systems have the potential to target inflamed regions in the gastrointestinal tract by specifically accumulating at disrupted colonic epithelium. But, delivery of intact protein drugs at the targeted site is a major challenge due to the harsh gastrointestinal environment and the protective mucus layer. Biocompatible nanoparticles engineered to target the inflamed colonic tissue and efficiently penetrate the mucosal layer can provide a promising approach for orally delivering monoclonal antibodies to treat inflammatory bowel disease. The study aims to develop mucus-penetrating nanoparticles composed of poly(lactic-co-glycolic acid, PLGA) polymers with two different polyethylene glycol (PEG) chain lengths (2 kDa and 5kDa) to encapsulate monoclonal antibody against tumor necrosis factor-α (TNF-α). The impact of different PEG chain lengths on the efficacy of the nanosystems was evaluated in vitro, ex vivo, and in vivo. Both PLGA-PEG2k and PLGA-PEG5k nanoparticles successfully encapsulated the antibody and significantly reduced TNF-α secretion from activated macrophages and intestinal epithelial cells. However, only antibody-loaded PLGA-PEG2k nanoparticles were able to alleviate the experimental acute colitis in mice demonstrated by improved colon weight/length ratio, histological score, and reduced tissue-associated myeloperoxidase activity and expression of proinflammatory cytokine TNF-α levels compared with the control group. The results suggest that despite having no significant differences in the in vitro cell-based assays, PEG chain length has a significant impact on the in vivo performance of the mucus penetrating nanoparticles. Overall, PLGA-PEG2k nanoparticles were presented as a promising oral delivery system for targeted antibody delivery to treat inflammatory bowel disease. STATEMENT OF SIGNIFICANCE: There is an unmet therapeutic need for oral drug delivery systems for safe and effective antibody therapy of inflammatory bowel disease. Therefore, we have developed PEGylated PLGA-based nanoparticulate drug delivery systems for oral targeted delivery of anti-TNF-α antibody as a potential alternative treatment strategy. The PEG chain length did not affect encapsulation efficiency or interaction with mucin in vitro but resulted in differences in in vitro release profile and in vivo efficacy study. We demonstrated the superiority of anti-TNF-α mAb-PLGA-PEG2k over mAb-PLGA-PEG5k nanoparticles to effectively exhibit anti-inflammatory responses in an acute murine colitis model. These nanoparticle-based formulations may be adjusted to encapsulate other drugs that could be applied to a number of disorders at different mucosal surfaces.

SHARP hydrogel for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a relapsing and remitting inflammatory disease affecting millions of people worldwide. The active phase of IBD is characterized by excessive formation of reactive oxygen species (ROS) in the intestinal mucosa, which further accelerates the inflammatory process. A feasible strategy for the IBD treatment is thus breaking the oxidation-inflammation vicious circle by scavenging excessive ROS with the use of a suitable antioxidant. Herein, we have developed a novel hydrogel system for oral administration utilizing sterically hindered amine-based redox polymer (SHARP) incorporating covalently bound antioxidant SHA groups. SHARP was prepared via free-radical polymerization by covalent crosslinking of 2-hydroxyethyl methacrylate (HEMA), poly(ethylene oxide) methyl ether methacrylate (PEGMA) and a SHA-based monomer, N-(2,2,6,6-tetramethyl-piperidin-4-yl)-methacrylamide. The SHARP hydrogel was resistant to hydrolysis and swelled considerably (∼90% water content) under the simulated gastrointestinal tract (GIT) conditions, and exhibited concentration-dependent antioxidant properties in vitro against different ROS. Further, the SHARP hydrogel was found to be non-genotoxic, non-cytotoxic, non-irritating, and non-absorbable from the gastrointestinal tract. Most importantly, SHARP hydrogel exhibited a statistically significant, dose-dependent therapeutic effect in the mice model of dextran sodium sulfate (DSS)-induced acute colitis. Altogether, the obtained results suggest that the SHARP hydrogel strategy holds a great promise with respect to IBD treatment.

An inverted in vitro triple culture model of the healthy and inflamed intestine: Adverse effects of polyethylene particles

As environmental pollution with plastic waste is increasing, numerous reports show the contamination of natural habitats, food and drinking water with plastic particles in the micro- and nanometer range. Since oral exposure to these particles is virtually unavoidable, health concerns towards the general population have been expressed and risk assessment regarding ingested plastic particles is of great interest. To study the intestinal effects of polymeric particles with a density of <1 g/cm³ in vitro, we spatially inverted a triple culture transwell model of the healthy and inflamed intestine (Caco-2/HT29-MTX-E12/THP-1), which allows contact between buoyant particles and cells. We validated the inverted model against the original model using the enterotoxic, non-steroidal anti-inflammatory drug diclofenac and subsequently assessed the cytotoxic and pro-inflammatory effects of polyethylene (PE) microparticles. The results show that the inverted model exhibits the same distinct features as the original model in terms of barrier development and inflammatory parameters. Treatment with 2 mM diclofenac causes severe cytotoxicity, DNA damage and complete barrier disruption in both models. PE particles induced cytotoxicity and pro-inflammatory effects in the inverted model, which would have remained undetected in conventional in vitro approaches, as no effect was observed in non-inverted control cultures.

Colon-targeted drug delivery of polysaccharide-based nanocarriers for synergistic treatment of inflammatory bowel disease: A review

Drugs such as immunosuppressants and glucocorticoids used for the treatment of inflammatory bowel disease (IBD) have certain troubling side effects. Polysaccharide-based nanocarriers with high safety and bioavailability are often used in the construction of colon-targeted drug nanodelivery systems (DNSs). It can help the drug resist the harsh environment of gastrointestinal tract, improve stability and concentrate on the intestinal inflammation regions as much as possible, which effectively reduces drug side effects and enhances its bioavailability. Certain polysaccharides, as prebiotics, can not only endow DNSs with the ability to target the colon based on enzyme responsive properties, but also cooperate with drugs to alleviate IBD due to its good anti-inflammatory activity and intestinal microecological regulation. The changes in the gastrointestinal environment of patients with IBD, the colon-targeted drug delivery process of polysaccharide-based nanocarriers and its synergistic treatment mechanism for IBD were reviewed. Polysaccharides used in polysaccharide-based nanocarriers for IBD were summarized.

The reactive oxygen species as pathogenic factors of fragmented microplastics to macrophages

The presence of microplastics in the various food web raised concerns on human health, but little is known about the target cells and mechanism of toxicity of microplastics. In this study, we evaluated the toxicity of microplastics using relevant cell lines to the oral route of exposure. Approximately 100 μm-sized fragment-type polypropylene (PP) and polystyrene (PS) particles were prepared by sieving after pulverization and further applied the accelerated weathering using ultraviolet and heat. Thus, the panel of microplastics includes fresh PP (f-PP), fresh PS (f-PS), weathered PP (w-PP), and weathered PS (w-PS). The spherical PS with a similar size was used as a reference particle. Treatment of all types of PP and PS did not show any toxic effects to the Caco-2 cells and HepG2 cells. However, the treatment of microplastics to THP-1 macrophages showed significant toxicity in the order of f-PS > f-PP > w-PS > w-PP. The weathering process significantly reduced the reactive oxygen species (ROS) generation potential of both microplastics because the weathered microplastics have an increased affinity to bind serum protein which acts as a ROS scavenger. The intrinsic ROS generation potential of microplastics showed a good correlation with the toxicity endpoints including cytotoxicity and pro-inflammatory cytokines in THP-1 macrophages. In conclusion, the results of this study suggest that the target cell type of microplastics via oral administration can be macrophages and the pathogenic factor to THP-1 macrophages is the intrinsic ROS generation potential of microplastics. Nevertheless, the toxic effect of microplastics tested in this study was much less than that of nano-sized particles.