Zinc oxide nanoparticles disrupt the mammary epithelial barrier via Z-DNA binding protein 1-triggered PANoptosis.

Lactation women, a highly concerned demographic in society, face health risks that deserve attention. Zinc oxide nanoparticles (ZnO NPs) are widely utilized in food and daily products due to their excellent physicochemical properties, leading to the potential exposure of lactating women to ZnO NPs. Hence, assessing the potential risks associated with ZnO NP exposure during lactation is critical. While studies have confirmed that exposure to ZnO NPs during lactation can induce toxic responses in multiple organs through blood circulation, the effects of lactational exposure on mammary tissue remain unclear. This research investigated the impairment of mammary tissue induced by ZnO NPs and its potential mechanisms. Through administering multiple injections of ZnO NPs into the tail vein of lactating ICR mice, our study revealed that ZnO NPs can deposit in the mammary tissues, downregulating key components of mammary epithelial barrier such as ZO-1, occludin, and claudin-3. In vivo, we also found that ZnO NPs can simultaneously induce apoptosis, necroptosis, and pyroptosis, called PANoptosis. Additionally, using EpH4-Ev cells to simulate an in vitro mammary epithelial barrier model, we observed that ZnO NPs effectively disrupted the integrity of mammary epithelial barrier and induced PANoptosis. Furthermore, we confirmed that PANoptosis was responsible for the mammary epithelial barrier disruption induced by ZnO NPs. Moreover, we identified that ZBP1 was the primary mechanism of ZnO NPs inducing PANoptosis. These discoveries are designed to enhance our comprehension of the mechanisms underlying mammary epithelial barrier disruption caused by ZnO NPs, and we aim to highlight the potential hazards associated with daily usage and therapeutic exposure to ZnO NPs during lactation.

A multifunctional integrated biomimetic spore nanoplatform for successively overcoming oral biological barriers.

The biological barriers have seriously restricted the efficacious responses of oral delivery system in diseases treatment. Utilizing a carrier based on the single construction means is hard to overcome these obstacles simultaneously because the complex gastrointestinal tract environment requires carrier to have different or even contradictory properties. Interestingly, spore capsid (SC) integrates many unique biological characteristics, such as high resistance, good stability etc. This fact offers a boundless source of inspiration for the construction of multi-functional oral nanoplatform based on SC without further modification. Herein, we develop a type of biomimetic spore nanoplatform (SC@DS NPs) to successively overcome oral biological barriers. Firstly, doxorubicin (DOX) and sorafenib (SOR) are self-assembled to form carrier-free nanoparticles (DS NPs). Subsequently, SC is effectively separated from probiotic spores and served as a functional vehicle for delivering DS NPs. As expect, SC@DS NPs can efficaciously pass through the rugged stomach environment after oral administration and further be transported to the intestine. Surprisingly, we find that SC@DS NPs exhibit a significant improvement in the aspects of mucus penetration and transepithelial transport, which is related to the protein species of SC. This study demonstrates that SC@DS NPs can efficiently overcome multiple biological barriers and improve the therapeutic effect.

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.

Transport of microplastics in the body and interaction with biological barriers, and controlling of microplastics pollution.

Microplastics (MPs) are one novel environmental pollutant sized < 5 mm that is ubiquitously present in numerous environmental media and particularly susceptible to interact with various toxic chemicals. Importantly, MPs can enter the food chain, and are bio-enriched and bio-accumulated with trophic levels, eventually endangering ecosystems and human health. However, there need to be more understanding regarding the bio-interaction of MPs with the host, particularly for biological barriers. This review aimed to summarize the latest findings regarding the main exposure routes of MPs that generated health burdens on humans. Furthermore, their interactions with biological barriers that generate adverse health effects and the underlying mechanisms were also reviewed. Additionally, we provided a comprehensive overview of recent advances regarding the removing and controlling of MPs. Finally, we discussed the future directions for MPs hazard prevention to provide helpful information for regulating decision-making and guiding safer plastics applications.

Discoidin domain receptor 1 may be involved in biological barrier homeostasis.

WHAT IS KNOWN AND OBJECTIVE: Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase involved in the pathological processes of several diseases, such as keloid formation, renal fibrosis, atherosclerosis, tumours, and inflammatory processes. The biological barrier is the first line of defence against pathogens, and its disruption is closely related to diseases. In this review, we attempt to elucidate the relationship between DDR1 and the biological barrier, explore the potential biological value of DDR1, and review the current research status and clinical potential of DDR1-selective inhibitors. METHODS: We conducted an extensive literature search on PubMed to collect studies on the relevance of DDR1 to biological barriers and DDR1-selective inhibitors. With these studies, we explored the relationship between DDR1 and biological barriers and briefly reviewed representative DDR1-selective inhibitors that have been reported in recent years. RESULTS AND DISCUSSION: First, the review of the potential mechanisms by which DDR1 regulates biological barriers, including the epithelial, vascular, glomerular filtration, blood-labyrinth, and blood-brain barriers. In the body, DDR1 dysfunction and aberrant expression may be involved in the homeostasis of the biological barrier. Secondly, the review of DDR1 inhibitors reported in recent years shows that DDR1-targeted inhibition is an attractive and promising pharmacological intervention. WHAT IS NEW AND CONCLUSIONS: This review shows that DDR1 is involved in various physiological and pathological processes and in the regulation of biological barrier homeostasis. However, studies on DDR1 and biological barriers are still scarce, and further studies are needed to elucidate their specific mechanisms. The development of targeted inhibitors provides a new direction and idea to study the mechanism of DDR1.

Self-Assembling Drug Formulations with Tunable Permeability and Biodegradability.

This review focuses on key topics in the field of drug delivery related to the design of nanocarriers answering the biomedicine criteria, including biocompatibility, biodegradability, low toxicity, and the ability to overcome biological barriers. For these reasons, much attention is paid to the amphiphile-based carriers composed of natural building blocks, lipids, and their structural analogues and synthetic surfactants that are capable of self-assembly with the formation of a variety of supramolecular aggregates. The latter are dynamic structures that can be used as nanocontainers for hydrophobic drugs to increase their solubility and bioavailability. In this section, biodegradable cationic surfactants bearing cleavable fragments are discussed, with ester- and carbamate-containing analogs, as well as amino acid derivatives received special attention. Drug delivery through the biological barriers is a challenging task, which is highlighted by the example of transdermal method of drug administration. In this paper, nonionic surfactants are primarily discussed, including their application for the fabrication of nanocarriers, their surfactant-skin interactions, the mechanisms of modulating their permeability, and the factors controlling drug encapsulation, release, and targeted delivery. Different types of nanocarriers are covered, including niosomes, transfersomes, invasomes and chitosomes, with their morphological specificity, beneficial characteristics and limitations discussed.

Oral Insulin Delivery Platforms: Strategies To Address the Biological Barriers.

Diabetes mellitus is a lifelong metabolic disease that requires frequent subcutaneous injections of insulin. However, this method of administration can be associated with patient discomfort and local tissue infection. Oral delivery of insulin has been pursued as a more convenient method for diabetes treatment, given its likely superior patient compliance and convenience as well as cost-effectiveness. However, various biological barriers hinder the clinical translation of oral insulin. The rapid development of nanotechnology over the last decade offers great promise in improving the bioavailability of oral insulin. This Minireview provides an overview of biological barriers to oral insulin delivery, summarizes significant technological advances, and outlines future perspectives in oral insulin formulations as well as their hypoglycaemic effects.

The effect of saliva on the fate of nanoparticles.

OBJECTIVES: The design of nanocarriers for local drug administration to the lining mucosa requires a sound knowledge of how nanoparticles (NPs) interact with saliva. This contact determines whether NPs agglomerate and become immobile due to size- and interaction-filtering effects or adsorb on the cell surface and are internalized by epithelial cells. The aim of this study was to examine the behavior of NPs in saliva considering physicochemical NP properties. MATERIALS AND METHODS: The salivary pore-size distribution was determined, and the viscosity of the fluid inside of the pores was studied with optical tweezers. Distinct functionalized NPs (20 and 200 nm) were dispersed in saliva and salivary buffers and characterized, and surface-bound MUC5B and MUC7 were analyzed by 1D electrophoresis and immunoblotting. NP mobility was recorded, and cellular uptake studies were performed with TR146 cells. RESULTS: The mode diameter of the salivary mesh pores is 0.7 µm with a peak width of 1.9 µm, and pores are filled with a low-viscosity fluid. The physicochemical properties of the NPs affected the colloidal stability and mobility: compared with non-functionalized particles, which did not agglomerate and showed a cellular uptake rate of 2.8%, functionalized particles were immobilized, which was correlated with agglomeration and increased binding to mucins. CONCLUSION: The present study showed that the salivary microstructure facilitates NP adsorption. However, NP size and surface functionalization determine the colloidal stability and cellular interactions. CLINICAL RELEVANCE: The sound knowledge of NP interactions with saliva enables the improvement of current treatment strategies for inflammatory oral diseases.

Calcium Metabolism Profile in Rat Inner Ear Indicated by MRI After Tympanic Medial Wall Administration of Manganese Chloride.

OBJECTIVES: To evaluate the efficacy of the novel method for the targeted delivery of Mn(++) to the inner ear and monitor calcium metabolism activity in the inner ear. MATERIALS AND METHODS: Dynamic signal changes of Mn(++) in the rat inner ear were followed using T1-weighted magnetic resonance imaging (MRI) after administration of 2.5 µl MnCl2(500 mM) to the medial wall of the middle ear cavity. RESULTS: Mn(++) passed through both the oval and round windows and distributed in the perilymphatic compartments, where it formed bright sharp lines along the fluid-cellular borders 12 minutes post administration and entered the endolymph sufficiently after 45 minutes. After 6 hours, the distribution of Mn(++) shifted from a fluid-dominant pattern to a cell-dominant pattern. Mn(++) concentrated in the area of the basilar membrane, periphery process, and soma of the spiral ganglion on day 2; became more distinguishable on day 4; declined on day 8; and remained detectable for 16 days post administration. CONCLUSIONS: The novel targeted delivery method efficiently introduced Mn(++) into the inner ear. The dynamic distribution pattern of Mn(++) in the inner ear shown by MRI indicates that this method can be used to monitor calcium metabolism activity in the inner ear.

Transfer studies of polystyrene nanoparticles in the ex vivo human placenta perfusion model: key sources of artifacts.

Nanotechnology is a rapidly expanding and highly promising new technology with many different fields of application. Consequently, the investigation of engineered nanoparticles in biological systems is steadily increasing. Questions about the safety of such engineered nanoparticles are very important and the most critical subject with regard to the penetration of biological barriers allowing particle distribution throughout the human body. Such translocation studies are technically challenging and many issues have to be considered to obtain meaningful and comparable results. Here we report on the transfer of polystyrene nanoparticles across the human placenta using an ex vivo human placenta perfusion model. We provide an overview of several challenges that can potentially occur in any translocation study in relation to particle size distribution, functionalization and stability of labels. In conclusion, a careful assessment of nanoparticle properties in a physiologically relevant milieu is as challenging and important as the actual study of nanoparticle-cell interactions itself.

Accurate Spatio-Temporal Delivery of Nitric Oxide Facilitates the Programmable Repair of Avascular Dense Connective Tissues Injury.

Avascular dense connective tissues (e.g., the annulus fibrosus (AF) rupture, the meniscus tear, and tendons and ligaments injury) repair remains a challenge due to the "biological barrier" that hinders traditional drug permeation and limits self-healing of the injured tissue. Here, accurate delivery of nitric oxide (NO) to penetrate the "AF biological barrier" is achieved thereby enabling programmable AF repair. NO-loaded BioMOFs are synthesized and mixed in a modified polyvinyl alcohol and PCL-composited electrospun fiber membrane with excellent reactive oxygen species-responsive capability (LN@PM). The results show that LN@PM could respond to the high oxidative stress environment at the injured tissue and realize continuous and substantial NO release. Based on low molecular weight and lipophilicity, NO could penetrate through the "biological barrier" for accurate AF drug delivery. Moreover, the dynamic characteristics of the LN@PM reaction can be matched with the pathological microenvironment to initiate programmable tissue repair including sequential remodeling microenvironment, reprogramming the immune environment, and finally promoting tissue regeneration. This tailored programmable treatment strategy that matches the pathological repair process significantly repairs AF, ultimately alleviating intervertebral disc degeneration. This study highlights a promising approach for avascular dense connective tissue treatment through intelligent NO release, effectively overcoming "AF biological barriers" and programmable treatment.

Potentials of ionic liquids to overcome physical and biological barriers.

Over the last decades, ionic liquids (IL) have shown great potential in non-invasive delivery starting from synthetic small molecules to biological large molecules. ILs are emerging as a particular class of drug delivery systems due to their unique physiochemical properties, simple surface modification, and functionalization. These features of IL help achieve specific design principles that are essential for a non-invasive drug delivery system. In this review, we have discussed IL and their applications in non-invasive drug delivery systems. We evaluated state-of-the-art development and advances of IL aiming to mitigate the biological and physical barriers to improve transdermal and oral delivery, summarized in this review. We also provided an overview of the various factors determining the systemic transportation of IL-based formulation. Additionally, we have emphasized how the ILs facilitate the transportation of therapeutic molecules by overcoming biological barriers.

Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers.

Nanoscale drug delivery systems (nDDS) have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects. Although several nDDS have been successfully approved for clinical use up to now, biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment. Polyethylene glycol (PEG)-modification (or PEGylation) has been regarded as the gold standard for stabilising nDDS in complex biological environment. However, the accelerated blood clearance (ABC) of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications. Zwitterionic polymer, a novel family of anti-fouling materials, have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility. Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues. More impressively, zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution, pressure gradients, impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications. The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS, which could facilitate their better clinical translation. Herein, we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlying mechanisms. Finally, prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.

Porous Membrane Electrical Cell-Substrate Impedance Spectroscopy for Versatile Assessment of Biological Barriers In Vitro.

Cell culture models of endothelial and epithelial barriers typically use porous membrane inserts (e.g., Transwell inserts) as a permeable substrate on which barrier cells are grown, often in coculture with other cell types on the opposite side of the membrane. Current methods to characterize barrier function in porous membrane inserts can disrupt the barrier or provide bulk measurements that cannot isolate barrier cell resistance alone. Electrical cell-substrate impedance sensing (ECIS) addresses these limitations, but its implementation on porous membrane inserts has been limited by costly manufacturing, low sensitivity, and lack of validation for barrier assessment. Here, we present porous membrane ECIS (PM-ECIS), a cost-effective method to adapt ECIS technology to porous substrate-based in vitro models. We demonstrate high fidelity patterning of electrodes on porous membranes that can be incorporated into well plates of a variety of sizes with excellent cell biocompatibility with mono- and coculture set ups. PM-ECIS provided sensitive, real-time measurement of isolated changes in endothelial cell barrier impedance with cell growth and barrier disruption. Barrier function characterized by PM-ECIS resistance correlated well with permeability coefficients obtained from simultaneous molecular tracer permeability assays performed on the same cultures, validating the device. Integration of ECIS into conventional porous cell culture inserts provides a versatile, sensitive, and automated alternative to current methods to measure barrier function in vitro, including molecular tracer assays and transepithelial/endothelial electrical resistance.

Herb-Nanoparticle Hybrid System for Improved Oral Delivery Efficiency to Alleviate Breast Cancer Lung Metastasis.

Background: Metastasis is a complex process involving multiple factors and stages, in which tumor cells and the tumor microenvironment (TME) play significant roles. A combination of orally bioavailable therapeutic agents that target both tumor cells and TME is conducive to prevent or impede the progression of metastasis, especially when undetectable. However, sequentially overcoming intestinal barriers, ensuring biodistribution in tumors and metastatic tissues, and enhancing therapeutic effects required for efficient therapy remain challenging. Methods: Inspired by the unique chemical features of natural herbs, we propose an oral herb-nanoparticle hybrid system (HNS) formed through the self-binding of Platycodon grandiflorum-Curcuma zedoaria (HG), a herb pair/group used in clinical practice to treat breast cancer metastasis, to lipid-polymer nanoparticles (LPNs) loaded with silibinin. The molecular structure responsible for HG association with LPNs was assessed using surface-enhanced Raman spectroscopy for HNS surface chemistry characterization. Moreover, the molecular class of HG was identified using UPLC-Orbitrap-MS/MS to further confirm the surface binding. Mucus diffusion and in vivo biodistribution were evaluated using in vitro multiple-particle tracking and environment-responsive fluorescence probe in 4T1 tumor-bearing mice, respectively. The alleviation of breast cancer metastasis was assessed in 4T1 tumor-bearing mice, and the underlying mechanism was investigated. Results: The HNS reduced particle-mucus interactions by altering hydrophilicity and surface characteristics compared to LPNs. The epithelium transportation of HNS and absorption through Peyer's patch in mice were improved, promoting their biodistribution in the lung and tumor tissues. Furthermore, the HNS alleviated lung metastasis by inducing cell apoptosis and regulating the expression of MMP-9 and TGF-ß1, which altered the TME in 4T1 tumor-bearing mice. Conclusion: HNS provides an appealing system with multi-component binding of herbal medicine to facilitate both oral nanoparticle delivery efficiency and the alleviation of lung metastasis. This strategy may potentially help improve treatment for patients with breast cancer.

Biological Barriers for Drug Delivery and Development of Innovative Therapeutic Approaches in HIV, Pancreatic Cancer, and Hemophilia A/B.

Biological barriers remain a major obstacle for the development of innovative therapeutics. Depending on a disease's pathophysiology, the involved tissues, cell populations, and cellular components, drugs often have to overcome several biological barriers to reach their target cells and become effective in a specific cellular compartment. Human biological barriers are incredibly diverse and include multiple layers of protection and obstruction. Importantly, biological barriers are not only found at the organ/tissue level, but also include cellular structures such as the outer plasma membrane, the endolysosomal machinery, and the nuclear envelope. Nowadays, clinicians have access to a broad arsenal of therapeutics ranging from chemically synthesized small molecules, biologicals including recombinant proteins (such as monoclonal antibodies and hormones), nucleic-acid-based therapeutics, and antibody-drug conjugates (ADCs), to modern viral-vector-mediated gene therapy. In the past decade, the therapeutic landscape has been changing rapidly, giving rise to a multitude of innovative therapy approaches. In 2018, the FDA approval of patisiran paved the way for small interfering RNAs (siRNAs) to become a novel class of nucleic-acid-based therapeutics, which-upon effective drug delivery to their target cells-allow to elegantly regulate the post-transcriptional gene expression. The recent approvals of valoctocogene roxaparvovec and etranacogene dezaparvovec for the treatment of hemophilia A and B, respectively, mark the breakthrough of viral-vector-based gene therapy as a new tool to cure disease. A multitude of highly innovative medicines and drug delivery methods including mRNA-based cancer vaccines and exosome-targeted therapy is on the verge of entering the market and changing the treatment landscape for a broad range of conditions. In this review, we provide insights into three different disease entities, which are clinically, scientifically, and socioeconomically impactful and have given rise to many technological advancements: acquired immunodeficiency syndrome (AIDS) as a predominant infectious disease, pancreatic carcinoma as one of the most lethal solid cancers, and hemophilia A/B as a hereditary genetic disorder. Our primary objective is to highlight the overarching principles of biological barriers that can be identified across different disease areas. Our second goal is to showcase which therapeutic approaches designed to cross disease-specific biological barriers have been promising in effectively treating disease. In this context, we will exemplify how the right selection of the drug category and delivery vehicle, mode of administration, and therapeutic target(s) can help overcome various biological barriers to prevent, treat, and cure disease.

Cell-Penetrating Peptide-Based Delivery of Macromolecular Drugs: Development, Strategies, and Progress.

Cell-penetrating peptides (CPPs), developed for more than 30 years, are still being extensively studied due to their excellent delivery performance. Compared with other delivery vehicles, CPPs hold promise for delivering different types of drugs. Here, we review the development process of CPPs and summarize the composition and classification of the CPP-based delivery systems, cellular uptake mechanisms, influencing factors, and biological barriers. We also summarize the optimization routes of CPP-based macromolecular drug delivery from stability and targeting perspectives. Strategies for enhanced endosomal escape, which prolong its half-life in blood, improved targeting efficiency and stimuli-responsive design are comprehensively summarized for CPP-based macromolecule delivery. Finally, after concluding the clinical trials of CPP-based drug delivery systems, we extracted the necessary conditions for a successful CPP-based delivery system. This review provides the latest framework for the CPP-based delivery of macromolecular drugs and summarizes the optimized strategies to improve delivery efficiency.

Medical micro- and nanomotors in the body.

Attributed to the miniaturized body size and active mobility, micro- and nanomotors (MNMs) have demonstrated tremendous potential for medical applications. However, from bench to bedside, massive efforts are needed to address critical issues, such as cost-effective fabrication, on-demand integration of multiple functions, biocompatibility, biodegradability, controlled propulsion and in vivo navigation. Herein, we summarize the advances of biomedical MNMs reported in the past two decades, with particular emphasis on the design, fabrication, propulsion, navigation, and the abilities of biological barriers penetration, biosensing, diagnosis, minimally invasive surgery and targeted cargo delivery. Future perspectives and challenges are discussed as well. This review can lay the foundation for the future direction of medical MNMs, pushing one step forward on the road to achieving practical theranostics using MNMs.

Co-Culture of Glomerular Endothelial Cells and Podocytes in a Custom-Designed Glomerulus-on-a-Chip Model Improves the Filtration Barrier Integrity and Affects the Glomerular Cell Phenotype.

Crosstalk between glomerular endothelial cells and glomerular epithelial cells (podocytes) is increasingly becoming apparent as a crucial mechanism to maintain the integrity of the glomerular filtration barrier. However, in vitro studies directly investigating the effect of this crosstalk on the glomerular filtration barrier are scarce because of the lack of suitable experimental models. Therefore, we developed a custom-made glomerulus-on-a-chip model recapitulating the glomerular filtration barrier, in which we investigated the effects of co-culture of glomerular endothelial cells and podocytes on filtration barrier function and the phenotype of these respective cell types. The custom-made glomerulus-on-a-chip model was designed using soft lithography. The chip consisted of two parallel microfluidic channels separated by a semi-permeable polycarbonate membrane. The glycocalyx was visualized by wheat germ agglutinin staining and the barrier integrity of the glomerulus-on-a-chip model was determined by measuring the transport rate of fluorescently labelled dextran from the top to the bottom channel. The effect of crosstalk on the transcriptome of glomerular endothelial cells and podocytes was investigated via RNA-sequencing. Glomerular endothelial cells and podocytes were successfully cultured on opposite sides of the membrane in our glomerulus-on-a-chip model using a polydopamine and collagen A double coating. Barrier integrity of the chip model was significantly improved when glomerular endothelial cells were co-cultured with podocytes compared to monocultures of either glomerular endothelial cells or podocytes. Co-culture enlarged the surface area of podocyte foot processes and increased the thickness of the glycocalyx. RNA-sequencing analysis revealed the regulation of cellular pathways involved in cellular differentiation and cellular adhesion as a result of the interaction between glomerular endothelial cells and podocytes. We present a novel custom-made glomerulus-on-a-chip co-culture model and demonstrated for the first time using a glomerulus-on-a-chip model that co-culture affects the morphology and transcriptional phenotype of glomerular endothelial cells and podocytes. Moreover, we showed that co-culture improves barrier function as a relevant functional readout for clinical translation. This model can be used in future studies to investigate specific glomerular paracrine pathways and unravel the role of glomerular crosstalk in glomerular (patho) physiology.

Non-viral vectors for RNA delivery.

RNA-based therapy is a promising and potential strategy for disease treatment by introducing exogenous nucleic acids such as messenger RNA (mRNA), small interfering RNA (siRNA), microRNA (miRNA) or antisense oligonucleotides (ASO) to modulate gene expression in specific cells. It is exciting that mRNA encoding the spike protein of COVID-19 (coronavirus disease 2019) delivered by lipid nanoparticles (LNPs) exhibits the efficient protection of lungs infection against the virus. In this review, we introduce the biological barriers to RNA delivery in vivo and discuss recent advances in non-viral delivery systems, such as lipid-based nanoparticles, polymeric nanoparticles, N-acetylgalactosamine (GalNAc)-siRNA conjugate, and biomimetic nanovectors, which can protect RNAs against degradation by ribonucleases, accumulate in specific tissue, facilitate cell internalization, and allow for the controlled release of the encapsulated therapeutics.