Cellular Barriers Research Articles

Exploring the role of Müller cells-derived exosomes in diabetic retinopathy

Exosomes are nanosized vesicles that have been reported as cargo-delivering vehicles between cells. Müller cells play a crucial role in the pathogenesis of diabetic retinopathy (DR). Activated Müller cells in the diabetic retina mediate disruption of barrier integrity and neovascularization. Endothelial cells constitute the inner blood-retinal barrier (BRB). Herein, we aim to evaluate the effect of Müller cell-derived exosomes on endothelial cell viability and barrier function under normal and hyperglycemic conditions. Müller cell-derived exosomes were isolated and characterized using Western blotting, nanoparticle tracking, and electron microscopy. The uptake of Müller cells-derived exosomes by the human retinal endothelial cells (HRECs) was monitored by labeling exosomes with PKH67. Endothelial cell vitality after treatment by exosomes under normo- and hypoglycemic conditions was checked by MTT assay and Western blot for apoptotic proteins. The barrier function of HRECs was evaluated by analysis of ZO-1 and transcellular electrical resistance (TER) using ECIS. Additionally, intracellular Ca+2 in HRECs was assessed by spectrofluorimetry. Analysis of the isolated exosomes showed a non-significant change in the number of exosomes isolated from both normal and hyperglycemic condition media, however, the average size of exosomes isolated from the hyperglycemic group showed a significant rise when compared to that of the normoglycemic group. Müller cells derived exosomes from hyperglycemic condition media markedly reduced HRECs cell count, increased caspase-3 and Annexin V, decreased ZO-1 levels and TER, and increased intracellular Ca+ when compared to other groups. However, treatment of HRECs under hyperglycemia with normo-glycemic Müller cells-derived exosomes significantly decreased cell death, preserved cellular integrity and barrier function, and reduced intracellular Ca+2. Collectively, Müller cell-derived exosomes play a remarkable role in the pathological changes associated with hyperglycemia-induced inner barrier dysfunction in DR. Further in vivo research will help in understanding the role of exosomes as therapeutic targets and/or delivery systems for DR.

Regulation of fadR on the ROS defense mechanism in Shewanalla oneidensis.

Protein FadR is known as a fatty acid metabolism global regulator that sustains cell envelope integrity by changing the profile of fatty acid. Here, we present its unique participation in the defense against reactive oxygen species (ROS) in the bacterium. FadR contributes to defending extracellular ROS by maintaining the permeability of the cell membrane. It also facilitates the ROS detoxification process by increasing the expression of ROS neutralizers (KatB, KatG, and AhpCF). FadR also represses the leakage of ROS by alleviating the respiratory action conducted by terminal cytochrome cbb3-type heme-copper oxidases (ccoNOQP). These findings suggest that FadR plays a comprehensive role in modulating the bacterial oxidative stress response, instead of merely strengthening the cellular barrier against the environment. This study sheds light on the complex mechanisms of bacterial ROS defense and offers FadR as a novel target for ROS control research.

Exploring Bimetallic Nanoparticles in Alzheimer's Therapy: A Novel Bio-Assisted Synthesis with Multitarget Potential.

Unlocking the potential of metal nanoparticles (NPs) in biomedical applications represents a leading endeavor in contemporary research. Among these, gold NPs (AuNPs) and silver NPs (AgNPs) have shown promising strides in combatting complex neurodegenerative ailments like Alzheimer's disease. Yet, the unexplored realm of bimetallic Au/Ag-NP harbors immense potential, concealing undiscovered opportunities for enhanced therapeutic effectiveness through the synergistic interaction of metal ions. Nonetheless, the limitations of traditional synthesis methods have restricted the preparation, biocompatibility, and versatility of these NPs, prompting an urgent requirement for innovative approaches. Biobased synthetic methodologies have emerged as a noteworthy solution to address these challenges. Our study ventures into uncharted terrain, harnessing collagen-mimicking peptide nanofibers as a bioactive template for the synthesis of bimetallic NPs. These green NPs exhibit remarkable activity in inhibiting amyloid β (Aβ) protein aggregation with almost 74% inhibition, surpassing the individual impacts of Au and Ag NPs, which show inhibition percentages of 66 and 43, respectively. The bimetallic Au/Ag-NPs not only demonstrate powerful inhibition of Aβ, but they also demonstrate inhibitory activity against esterase (∼50%) and against reactive oxygen species (ROS) (∼75%), metamorphosing into multifaceted therapeutic agents for Alzheimer's disease. Au/Ag-NPs have proven highly beneficial in surpassing cellular barriers, as evidenced by studies on tissue penetration, 3D uptake, and endosomal escape, and these attributes also hold promise for the future treatment modalities. The findings indicate that the intrinsic traits of Au/Ag-NPs provide numerous mechanistic benefits, such as inhibiting Aβ and acetylcholinesterase (AChE), and reducing stress related to ROS, in addition to their advantageous internalization properties. This research represents a notable advancement in the development of multitargeted treatments for neurodegenerative disorders using bimetallic NPs, diverging from the prevalent emphasis on AuNPs in the current literature.

Deficiency of the BKCa potassium channel displayed significant implications for the physiology of the human bronchial epithelium

Plasma membrane large-conductance calcium-activated potassium (BKCa) channels are important players in various physiological processes, including those mediated by epithelia. Like other cell types, human bronchial epithelial (HBE) cells also express BKCa in the inner mitochondrial membrane (mitoBKCa). The genetic relationships between these mitochondrial and plasma membrane channels and the precise role of mitoBKCa in epithelium physiology are still unclear. Here, we tested the hypothesis that the mitoBKCa channel is encoded by the same gene as the plasma membrane BKCa channel in HBE cells. We also examined the impact of channel loss on the basic function of HBE cells, which is to create a tight barrier. For this purpose, we used CRISPR/Cas9 technology in 16HBE14o- cells to disrupt the KCNMA1 gene, which encodes the α-subunit responsible for forming the pore of the plasma membrane BKCa channel. Electrophysiological experiments demonstrated that the disruption of the KCNMA1 gene resulted in the loss of BKCa-type channels in the plasma membrane and mitochondria. We have also shown that HBE ΔαBKCa cells exhibited a significant decrease in transepithelial electrical resistance which indicates a loss of tightness of the barrier created by these cells. We have also observed a decrease in mitochondrial respiration, which indicates a significant impairment of these organelles.In conclusion, our findings indicate that a single gene encodes both populations of the channel in HBE cells. Furthermore, this channel is critical for maintaining the proper function of epithelial cells as a cellular barrier.

Ezrin Contributes to the Damage of Airway Epithelial Barrier Related to Diabetes Mellitus.

Diabetes mellitus predisposes individuals to respiratory infections. The airway epithelial barrier provides defense against inhaled antigens and pathogens. Ezrin, is a component of the membrane-cytoskeleton that maintains the cellular morphology, intercellular adhesion, and barrier function of epithelial cells. This study aimed to explore the role of ezrin in airway epithelial barrier damage and correlate its expression and activation with diabetes mellitus. This study was performed in a murine model of diabetes mellitus and with human bronchial epithelial BEAS-2B cells using real-time PCR, Western blotting, immunohistochemical and immunofluorescence staining. Ezrin was knocked down in BEAS-2B cells using siRNA. Ezrin phosphorylation levels were measured to determine activation status. The integrity of the airway epithelial barrier was assessed in vivo by characterizing morphological structure, and in vitro in BEAS-2B cells by measuring tight junction protein expression, transepithelial electrical resistance (TER) and permeability. We demonstrated that ezrin expression levels were lower in the lung tissue and airway epithelium of diabetic mice than those in control mice. The morphological structure of the airway epithelium was altered in diabetic mice. High glucose levels downregulated the expression and distribution of ezrin and connexin 43, reduced the expression of tight junction proteins, and altered the epithelial barrier characteristics of BEAS-2B cells. Ezrin knockdown had effects similar to those of high glucose levels. Moreover, a specific inhibitor of ezrin Thr567 phosphorylation (NSC305787) inhibited epithelial barrier formation. These results demonstrate that ezrin expression and activation are associated with airway epithelial damage in diabetes mellitus. These findings provide new insights into the molecular pathogenesis of pulmonary infections in diabetes mellitus and may lead to novel therapeutic interventions for airway epithelial barrier damage.

Guanidinium-based Integrated Peptide Dendrimers: Pioneer Nanocarrier in Cancer Therapy.

The landscape of cancer therapy has witnessed a paradigm shift with the emergence of innovative delivery systems, and Guanidinium-based Peptide Dendrimers have emerged as a vanguard in this transformative journey. With their unique molecular architecture and intrinsic biocompatibility, these dendrimers offer a promising avenue for the targeted delivery of therapeutic cargo in cancer treatment. This comprehensive review delves into the intricate world of Guanidinium- based Peptide Dendrimers, unraveling their structural intricacies, mechanisms of action, and advancements that have propelled them from laboratory curiosities to potential clinical champions. Exploiting the potent properties of guanidinium, these dendrimers exhibit unparalleled precision in encapsulating and transporting diverse cargo molecules, ranging from conventional chemotherapeutics to cutting-edge nucleic acids. The review navigates the depths of their design principles, investigating their prowess in traversing the complex terrain of cellular barriers for optimal cargo delivery. Moreover, it delves into emerging trends, such as personalized therapeutic approaches, multimodal imaging, and bioinformatics-driven design, highlighting their potential to redefine the future of cancer therapy. Crucially, the review addresses the pivotal concerns of biocompatibility and safety, examining cytotoxicity profiles, immune responses, and in vivo studies. It underscores the importance of aligning scientific marvels with the stringent demands of clinical applications. Through each section, the narrative underscores the promises and possibilities that Guanidinium-based Peptide Dendrimers hold and how they can potentially reshape the landscape of precision cancer therapy.

Innovative Cellular Insulation Barrier on the Basis of Voronoi Tessellation-Influence of Internal Structure Optimization on Thermal Performance.

The optimization of structure and thermal properties in 3D-printed insulation materials remains an underexplored area in the literature. This study aims to address this gap by investigating the impact of 3D printing on the thermal properties of manufactured cellular composites. The materials studied were closed-cell foams with a complex cell structure based on the Voronoi cell model, manufactured using incremental technology (3D printing). The influence of the cellular structure of the composite, the type of material used, and the number of layers in the composite structure on its thermal properties, i.e., thermal conductivity coefficient, thermal resistance, and coefficient of heat transfer, was analyzed. Samples of different types of thermosetting resins, characterized by different values of emissivity coefficient, were analyzed. It was shown that both the type of material, the number of layers of the composite, and the number of pores in its structure significantly affect its thermal insulating properties. Thermal conductivity and permeability depended on the number of layers and decreased up to 30% as the number of layers increased from one to four, while thermal resistance increased to 35%. The results indicate that material structure is key in regulating thermal conduction. Controlling the number of cells in a given volume of composite (and thus the size of the air cells) and the number of layers in the composite can be an effective tool in designing materials with high insulation performance. Among the prototype composites produced, the best thermal performance was that of the metalized four-layer cellular composites (λ = 0.035 ± 0.002 W/m·K, Rc = 1.15 ± 0.02 K·m2/W, U = 0.76 ± 0.01 W/m2·K).

Electroacupuncture stimulation enhances the permeability of the blood-brain barrier: A systematic review and meta-analysis of preclinical evidence and possible mechanisms.

An important cellular barrier to maintain the stability of the brain's internal and external environment is the blood-brain barrier (BBB). It also prevents harmful substances from entering brain tissue through blood circulation while providing protection for the central nervous system. It should be noted, however, that the intact BBB can be a barrier to the transport of most drugs into the brain via the conventional route of administration, which can prevent them from reaching effective concentrations for the treatment of disorders affecting the central nervous system. Electroacupuncture stimulation has been shown to be effective at opening the BBB in a series of experimental studies. This study systematically analyzes the possibility and mechanism by which electroacupuncture opens the BBB. In PubMed, Web of Science, VIP Database, Wanfang Database, and the Chinese National Knowledge Infrastructure, papers have been published for nearly 22 years aimed at opening the BBB and its associated structures. A comparison of EB content between electroacupuncture and control was selected as the primary outcome. There were also results on vascular endothelial growth factor (VEGF), nerve growth factor (NGF), P-Glycoprotein (P-gp), Matrix Metalloproteinase 9 (MMP-9), and glial fibrillary acidic protein (GFAP). We utilized Review Manager software analysis to analyze correlations between studies with a view to exploring the mechanisms of similarity. Evans Blue infiltration forest plot: pooled effect size of 2.04, 95% CI: 1.21 to 2.87, P < 0.01. These results indicate that electroacupuncture significantly increases EB penetration across the BBB. Most studies have reported that GFAP, MMP-9, and VEGF were upregulated after treatment. P-gp expression decreased as well. Electroacupuncture can open the BBB, and the sparse-dense wave is currently the most effective electroacupuncture frequency for opening the BBB. VEGF plays an important role in opening the BBB. It is also important to regulate the expression of MMP-9 and GFAP and inhibit the expression of P-gp.

Abstract 5752: Enhanced cancer therapy strategies utilizing gelatin-lipidoid hybrid nanoparticles for RNA delivery

Abstract Nanoparticle delivery platforms have provided impetus for the emergence of novel RNA-based cancer therapeutics due to their ability to circumvent the physiological and cellular barriers in the delivery. The clinical success of these strategies hinges primarily on the safety and efficacy of the delivery vehicle. Here, we have developed a gelatin-lipidoid hybrid nanoparticle (GLNP) that utilizes gelatin's biocompatibility, biodegradability, and lipidoids' high transfection efficiency. With GLNP, we have demonstrated the efficacy of delivering siRNA and silencing AXL, a receptor tyrosine kinase commonly associated with cancer progression, metastasis, and drug resistance. siRNA is attached to the surface of GLNP through covalent conjugation with gelatin, while the lipidoid on the system's interior electrostatically complexes with the siRNA. siRNAs are well protected by the GLNP when exposed to serum for at least 48 hours. The GLNP's bivalency significantly enhanced the downregulation of target genes in vitro and in vivo. Furthermore, the bivalent GLNP can simultaneously target and downregulate two oncogenes. Apart from siRNA, GLNP was also able to encapsulate and deliver mRNA, thereby suggesting the potential to simultaneously deliver RNA therapeutics to effect knockdown and expression of target proteins and maximize therapeutic effect. The length of the carbon chain of the lipidoid can be manipulated to influence the physico-chemical properties of the GLNP and its efficiency in encapsulating and delivering RNA drugs. Importantly, gelatin was found to effectively shield the cationic lipidoid and negate its toxicity. Toxicity studies indicate that high doses of GLNPs (up to 48 mg/kg BW) are well-tolerated with no significant changes in body weight, hematology, or serum chemistry. The co-administration of GLNP-siAXL and TKI in PDX models has shown notable control of tumor growth. It is important to note that immune checkpoint blockade (ICB) therapy has shown significant survival benefits in NSCLC patients. However, the therapeutic effect is limited to only 20% of patients due to several resistance mechanisms, such as increased expression of oncogenic proteins. Therefore, our future study will explore GLNP's ability to sensitize NSCLC tumors to immune therapy. Citation Format: Abilash Gangula, Dhananjay Suresh, Agasthya Suresh Babu, Zhaohui Li, Anandhi Upendran, Raghuraman Kannan. Enhanced cancer therapy strategies utilizing gelatin-lipidoid hybrid nanoparticles for RNA delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5752.

Abstract 2054: A sensitive and specific human primary stem cell-based in vitro assay for predicting the gastrointestinal toxicity risk of therapeutic agents

Abstract Gastrointestinal (GI) toxicities are the most common drug-induced adverse events in human clinical trials. Drugs that cause GI toxicities often affect the proliferative stem and progenitor cell populations responsible for maintaining the cellular composition, self-renewing capacity, and barrier function of the intestinal epithelium. This disruption leads to impaired GI barrier integrity, culminating in a broad range of clinical symptoms, including diarrhea, inflammation, and increased risk of infection. The impact of GI toxicity is substantial and can cause dose-limiting clinical side-effects that may affect patient compliance and dosing adherence. Common nonclinical animal models, including rats, mice and dogs are often poor predictors of human GI toxicity and safety outcomes. Furthermore, in vivo animal testing poses limited screening throughput, which is particularly important in fields such as oncology, where matrices of double or triple drug combinations represent the standard of care. Additionally, existing cell-based model systems, such as Caco-2 cells, are of limited predictive value as they are tumor-derived and do not reprise native epithelium. Thus, there is a need for the development of assay systems that more accurately recapitulate human biology, have higher throughput testing capabilities, and ultimately improve clinical predictability. To this end, we have developed an assay to assess GI toxicity potential using the RepliGut Planar platform, which consists of a primary human stem cell-derived epithelium in a 96-well Transwell format. Quantitative dose-response curves were generated on proliferative and/or differentiated GI cultures for various test articles utilizing endpoints that assess GI proliferative capacity, cell viability, and epithelial barrier formation and maintenance. An initial set of marketed drugs (including diverse anti-proliferative, cytotoxic, or anti-inflammatory mechanisms) with known clinical incidence of diarrhea were over a 5-log dose range to enable modeling of the Toxic Concentration 50% (TC50). When benchmarked against the known human plasma concentrations (Cmax), this model was able to accurately predict clinical outcomes for diarrheagenic-drugs, as well as non-toxic negative controls, within 30-fold of the clinical Cmax. Overall, this model system provides straightforward and informative screening for GI toxicity that integrates sensitive and robust endpoints, enables screening to support early nonclinical development, and uniquely allows for mechanistic insights. Citation Format: James Levi, Reganne Lorichon, Lauren Boone, Maureen Bunger, Elizabeth Boazak, William R. Thelin. A sensitive and specific human primary stem cell-based in vitro assay for predicting the gastrointestinal toxicity risk of therapeutic agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2054.

Enhanced Cellular Uptake through Nanotopography‐Induced Macropinocytosis

AbstractEfficient cellular uptake of biomolecules, including genetic material, mRNA, proteins, and nanoparticles, requires novel approaches to overcome inherent cellular barriers. Here, the study investigates how nanotopographical cues from nanoporous surfaces impact the uptake efficiency by cells. The results demonstrate notable enhancements in cellular uptake efficiency across a range of vectors when cells are exposed to nanoporous surfaces. The uptake process is found to be dependent on the size and morphology of the nanopores, reaching a peak efficacy with blind pores of 400 nm in size. Enhanced genetic transduction on nanoporous surfaces are observed for multiple vectors, including lentiviruses, baculoviruses, and mRNA molecules. The versatile nature of this approach allows co‐transfection of cells with multiple mRNA vectors. Moreover, the nanoporous platform is used for efficient and fast manufacturing of Chimeric Antigen Receptor (CAR)‐T cells through lentiviral transduction. Furthermore, the study pinpoints macropinocytosis as the predominant mechanism driving increased cellular uptake induced by the nanoporous surfaces. The introduced method for enhancing genetic transduction of cells has applications in immunotherapy research, drug delivery, and cell engineering.

A highly stable, pressure-driven, flow control system based on Coriolis mass flow sensors for organs-on-chips

Stable delivery of liquids to microfluidic systems is essential for their reproducible functioning, especially when supplying flows to organs-on-chips – delicate living models that recreate human physiology on the microscale and thus can be used to reduce the need for animal testing. Most flow control systems are unable to sustain a robust and stable flow in longer experiments (>1 week), particularly those based on the ubiquitous syringe pump. Though easy to use, syringe pumps have no mechanism for actually measuring flow, let alone flow regulation with sensor feedback. We have developed a liquid delivery system based on the generation of flow by applying a constant air pressure to liquids in sealed containers. A flow of liquid is monitored by accurate measurement of mass flows (mg/min) using downstream Coriolis-based mass flow sensors. Measured mass flows provide fast feedback to integrated valves, with valves opening or closing slightly to increase or decrease solution flows to the organs-on-chips as required. This mass flow sensing principle is not affected by changes in the density, temperature, and viscosity of the liquids being displaced. This is in contrast to systems that use volumetric flow sensors, which require recalibration when these parameters change. The rationale behind using this principle for organs-on-chips, is that the stability provided by this flow control system allows for more control over growth of these mini-organs. We demonstrate the functionality of this system with three examples: 1) Fast stabilization (within seconds) under changing physical conditions; 2) Short-term stability (minutes to hours) of delivered flows in a microreactor with interconnected inlets; and 3) Long-term stability (>1 week) of cell medium flows to a living organ-on-a-chip. Two categories of organs-on-chips (OOCs) can be distinguished: 1) solid OOC are designed for three-dimensional cell or tissue constructs that interact with each other and their surroundings, and 2) barrier-type OOC contain a selective cellular barrier between two compartments as do many barriers in the body. The latter of these two types is the most challenging to culture and maintain as they are very sensitive to variations in flow and pressure surges. The flow control system presented in this work provides a great improvement compared to the use of syringe pumps and volumetric flow sensors in OOC studies. The novelty of this work lies in the long-term stability use of this system for organs-on-chips, maintaining stability for short to very long periods of time without compromising the barrier function of the organ-on-chip by pressure surges, bacterial contamination, or other undesired effects from the flow delivery system.

Synergistic Effect of B-Type Lotus Seedpod Oligomeric Procyanidin and Probiotics against Adhesion of Enterotoxigenic Escherichia coli In Vitro

Enterotoxigenic Escherichia coli (ETEC) adhesion to gut epithelial cells is a prerequisite for diarrhea. Here, we studied the synergistic effect and potential mechanism of B-type lotus seedpod oligomeric procyanidin (LSPC) combined with probiotics against adhesion of ETEC. The results indicated that LSPC exhibited an effective anti-ETEC adhesion effect. LSPC showed signally synergistic effects with probiotics, e.g., Streptococcus thermophilus (ST) and Lactobacillus rhamnosus (LGG) in response to ETEC adhesion, with the combination of LSPC and LGG being the most efficacious. This may be attributed to the restoration of transmembrane resistance of cells, the increased expression of anti-inflammatory factors (IL-10, 1.89-fold), and the reduction of cellular inflammatory factor levels (TNF-α and IL-8), regulated by LGG-LSPC, resulting in a better enhancement of cellular immune defense and barrier function. In addition, the results of gas chromatography showed that LSPC, as a prebiotic, could significantly increase the total amount of short-chain fatty acids (especially, butyric acid) produced by probiotics (e.g., LGG), thus better maintaining intestinal health against ETEC infection. In conclusion, the synergistic effect of LSPC and probiotics (represented by LGG) against ETEC adhesion in epithelial cells may be achieved through the enhancement of cellular immune defense, cellular barrier function, and maintenance of homeostasis in the gut.

Dynamic carriers for therapeutic RNA delivery

Carriers for RNA delivery must be dynamic, first stabilizing and protecting therapeutic RNA during delivery to the target tissue and across cellular membrane barriers and then releasing the cargo in bioactive form. The chemical space of carriers ranges from small cationic lipids applied in lipoplexes and lipid nanoparticles, over medium-sized sequence-defined xenopeptides, to macromolecular polycations applied in polyplexes and polymer micelles. This perspective highlights the discovery of distinct virus-inspired dynamic processes that capitalize on mutual nanoparticle–host interactions to achieve potent RNA delivery. From the host side, subtle alterations of pH, ion concentration, redox potential, presence of specific proteins, receptors, or enzymes are cues, which must be recognized by the RNA nanocarrier via dynamic chemical designs including cleavable bonds, alterable physicochemical properties, and supramolecular assembly–disassembly processes to respond to changing biological microenvironment during delivery.

Surface Functionalized Lipid Nanoparticles in Promoting Therapeutic Outcomes: An Insight View of the Dynamic Drug Delivery System.

Compared to the conventional approach, nanoparticles (NPs) facilitate a non-hazardous, non-toxic, non-interactive, and biocompatible system, rendering them incredibly promising for improving drug delivery to target cells. When that comes to accomplishing specific therapeutic agents like drugs, peptides, nucleotides, etc., lipidic nanoparticulate systems have emerged as even more robust. They have asserted impressive ability in bypassing physiological and cellular barriers, evading lysosomal capture and the proton sponge effect, optimizing bioavailability, and compliance, lowering doses, and boosting therapeutic efficacy. However, the lack of selectivity at the cellular level hinders its ability to accomplish its potential to the fullest. The inclusion of surface functionalization to the lipidic NPs might certainly assist them in adapting to the basic biological demands of a specific pathological condition. Several ligands, including peptides, enzymes, polymers, saccharides, antibodies, etc., can be functionalized onto the surface of lipidic NPs to achieve cellular selectivity and avoid bioactivity challenges. This review provides a comprehensive outline for functionalizing lipid-based NPs systems in prominence over target selectivity. Emphasis has been put upon the strategies for reinforcing the therapeutic performance of lipidic nano carriers' using a variety of ligands alongside instances of relevant commercial formulations.

Molecular regulation of the key specialized metabolism pathways in medicinal plants.

The basis of modern pharmacology is the human ability to exploit the production of specialized metabolites from medical plants, for example, terpenoids, alkaloids, and phenolic acids. However, in most cases, the availability of these valuable compounds is limited by cellular or organelle barriers or spatio-temporal accumulation patterns within different plant tissues. Transcription factors (TFs) regulate biosynthesis of these specialized metabolites by tightly controlling the expression of biosynthetic genes. Cutting-edge technologies and/or combining multiple strategies and approaches have been applied to elucidate the role of TFs. In this review, we focus on recent progress in the transcription regulation mechanism of representative high-value products and describe the transcriptional regulatory network, and future perspectives are discussed, which will help develop high-yield plant resources.

Piceatannol Alleviates Deoxynivalenol-Induced Damage in Intestinal Epithelial Cells via Inhibition of the NF-κB Pathway.

Deoxynivalenol (DON) is a common mycotoxin that is widely found in various foods and feeds, posing a potential threat to human and animal health. This study aimed to investigate the protective effect of the natural polyphenol piceatannol (PIC) against DON-induced damage in porcine intestinal epithelial cells (IPEC-J2 cells) and the underlying mechanism. The results showed that PIC promotes IPEC-J2 cell proliferation in a dose-dependent manner. Moreover, it not only significantly relieved DON-induced decreases in cell viability and proliferation but also reduced intracellular reactive oxygen species (ROS) production. Further studies demonstrated that PIC alleviated DON-induced oxidative stress damage by increasing the protein expression levels of the antioxidant factors NAD(P)H quinone oxidoreductase-1 (NQO1) and glutamate-cysteine ligase modifier subunit (GCLM), and the mRNA expression of catalase (CAT), Superoxide Dismutase 1 (SOD1), peroxiredoxin 3 (PRX3), and glutathione S-transferase alpha 4 (GSTα4). In addition, PIC inhibited the activation of the nuclear factor-B (NF-κB) pathway, downregulated the mRNA expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) to attenuate DON-induced inflammatory responses, and further mitigated DON-induced cellular intestinal barrier injury by regulating the protein expression of Occludin. These findings indicated that PIC had a significant protective effect against DON-induced damage. This study provides more understanding to support PIC as a feed additive for pig production.

Transcellular Barriers to Glucose Delivery in the Body.

Glucose is the universal fuel of most mammalian cells, and it is largely replenished through dietary intake. Glucose availability to tissues is paramount for the maintenance of homeostatic energetics and, hence, supply should match demand by the consuming organs. In its journey through the body, glucose encounters cellular barriers for transit at the levels of the absorbing intestinal epithelial wall, the renal epithelium mediating glucose reabsorption, and the tight capillary endothelia (especially in the brain). Glucose transiting through these cellular barriers must escape degradation to ensure optimal glucose delivery to the bloodstream or tissues. The liver, which stores glycogen and generates glucose de novo, must similarly be able to release it intact to the circulation. We present the most up-to-date knowledge on glucose handling by the gut, liver, brain endothelium, and kidney, and discuss underlying molecular mechanisms and open questions. Diseases associated with defects in glucose delivery and homeostasis are also briefly addressed. We propose that the universal problem of sparing glucose from catabolism in favor of translocation across the barriers posed by epithelia and endothelia is resolved through common mechanisms involving glucose transfer to the endoplasmic reticulum, from where glucose exits the cells via unconventional cellular mechanisms.

Gelatin-Encapsulated Tetrahedral DNA Nanostructure Enhances Cellular Internalization for Treating Noise-Induced Hearing Loss.

Nanoparticle-based drug delivery strategies have emerged as a crucial avenue for comprehensive sensorineural hearing loss treatment. Nevertheless, developing therapy vectors crossing both biological and cellular barriers has encountered significant challenges deriving from various external factors. Herein, the rational integration of gelatin nanoparticles (GNPs) with tetrahedral DNA nanostructures (TDNs) to engineer a distinct drug-delivery nanosystem (designed as TDN@GNP) efficiently enhances the biological permeability and cellular internalization, further resolving the dilemma of noise-induced hearing loss via loading epigallocatechin gallate (EGCG) with anti-lipid peroxidation property. Rationally engineering of TDN@GNP demonstrates dramatic alterations in the physicochemical key parameters of TDNs that are pivotal in cell-particle interactions and promote cellular uptake through multiple endocytic pathways. Furthermore, the EGCG-loaded nanosystem (TDN-EGCG@GNP) facilitates efficient inner ear drug delivery by superior permeability through the biological barrier (round window membrane), maintaining high drug concentration within the inner ear. The TDN-EGCG@GNP actively overcomes the cell membrane, exhibiting hearing protection from noise insults via reduced lipid peroxidation in outer hair cells and spiral ganglion neurons. This work exemplifies how integrating diverse vector functionalities can overcome biological and cellular barriers in the inner ear, offering promising applications for inner ear disorders.

Analysis of the contributing role of drug transport across biological barriers in the development and treatment of chemotherapy-induced peripheral neuropathy

BackgroundChemotherapy-induced peripheral neuropathy (CIPN) represents a major unmet medical need that currently has no preventive and/or curative treatment. This is, among others, driven by a poor understanding of the contributive role of drug transport across biological barriers to target-site exposure.MethodsHere, we systematically investigated the transport of 11 small-molecule drugs, both, associated and not with CIPN development, at conventional (dorsal root ganglia, sciatic nerve) and non-conventional (brain, spinal cord, skeletal muscle) CIPN sites. We developed a Combinatory Mapping Approach for CIPN, CMA-CIPN, combining in vivo and in vitro elements.ResultsUsing CMA-CIPN, we determined the unbound tissue-to-plasma concentration ratio (Kp,uu) and the unbound intracellular-to-extracellular concentration ratio (Kp,uu,cell), to quantitatively assess the extent of unbound drug transport across endothelial interfaces and parenchymal cellular barriers of investigated CIPN-sites, respectively, in a rat model. The analysis revealed that unique pharmacokinetic characteristics underly time-dependent accumulation of the CIPN-positive drugs paclitaxel and vincristine at conventional (dorsal root ganglia and sciatic nerve) and non-conventional (skeletal muscle) CIPN sites. Investigated CIPN-positive drugs displayed intracellular accumulation contrary to CIPN-negative drugs nilotinib and methotrexate, which lacked this feature in all investigated tissues.ConclusionsHence, high unbound drug intracellular and extracellular exposure at target sites, driven by an interplay of drug transport across the endothelial and parenchymal cellular barriers, is a predisposing factor to CIPN development for CIPN-positive drugs. Critical drug-specific features of unbound drug disposition at various CIPN- sites provide invaluable insights into understanding the pharmacological/toxicological effects at the target-sites which will inform new strategies for monitoring and treatment of CIPN.