Zinc Anodes Modified by One-Molecular-Thick Self-Assembled Monolayers for Simultaneous Suppression of Side-Reactions and Dendrite-Formation in Aqueous Zinc-Ion Batteries.

Repeated charge/discharge in aqueous zinc-ion batteries (ZIBs) commonly results in surface corrosion/passivation and dendrite formation on zinc anodes, which is a major challenge for the commercialization of zinc-based batteries. In this work, metallic Zn modified by self-assembled monolayers is described as a viable anode for ZIBs. ω-mercaptoundecanoic acid that is spontaneously adsorbed on Zn (MUDA/Zn) contributes to the simultaneous suppression of side reactions and dendrite formation in ZIBs. Though one-molecular-thick, densely packed alkyl chains prohibit H2 O and H+ from making direct contact with the underlying Zn, and surface carboxylate moieties (-COO- ) effectively repel anionic species (OH- ) in a solution, which renders a Zn anode inert against zincate formation within a wide range of pH. In contrast, the electrostatic attraction between surface-carboxylates and cations increases the concentration of Zn2+ on the surface of MUDA/Zn to facilitate Zn plating/stripping with less overpotentials. The high concentration of Zn2+ also results in an increased number of nucleation sites, which enhances the lateral growth of Zn with no formation of dendrites. As a result, MUDA/Zn shows excellent stability during prolonged Zn plating/stripping within a wide range of pH. The advantageous properties of MUDA/Zn are also retained in full-cells coupled with δ-MnO2 cathodes.

Sodium dichloroisocyanurate toxicity in rats during a 90-day inhalation toxicity study.

Sodium dichloroisocyanurate-96% (NaDCC) is commonly used to treat drinking water, industrial water, and wastewater. However, exposure to NaDCC by inhalation can have toxic pulmonary effects in humans. In the present study, we evaluated the potential toxicity of NaDCC following a 90-day inhalation toxicity study in Sprague-Dawley/Crl:CD (SD) rats. The animals were exposed to 0.4, 2.0, or 10.0 mg/m3 NaDCC for 90 days. In addition, male and female rats from the 10.0 mg/m3 group were set up as the recovery group for 14 days. The bronchoalveolar lavage fluid showed a concentration-dependent increase in the total cell count, with a significant increase in neutrophils in both the sexes in the 10.0 mg/m3 group compared to the negative control group. In the 10.0 mg/m3 group, lung organ weight was significantly increased among the female rats. Histopathological examination showed eosinophilic droplets in the olfactory/respiratory epithelium, mucous cell hyperplasia, atrophy/degeneration of the tracheal branches, and wall thickening of the alveolar ducts in the nasal cavity of both sexes in the 10.0 mg/m3 group. The adverse effects of NaDCC exposure were observed to decrease during the 14-day recovery period in both sexes. Based on pathological observations, the "no observed adverse effect concentration (NOAEC)" of inhaled NaDCC was 2.0 mg/m3 for both sexes. These results are expected to provide a scientific basis for inhalation toxicity data of NaDCC.

Four-week repeated dose oral toxicity study of KDS2010, a novel selective monoamine oxidase B inhibitor, in Sprague Dawley rats.

Repeated dose oral toxicity and toxicokinetic of KDS2010, a new drug for Parkinson's disease, was investigated after 4-week repeated oral administration at 30, 50, 75, or 100 mg/kg/day in rats. Body weight and body weight gain decreased in rats of both sexes in the 75 and 100 mg/kg groups, and food consumption was reduced in male rats of the 75 and 100 mg/kg male groups. Histological alterations were observed in the kidney (urothelial hyperplasia, inflammatory cell infiltration in the renal pelvis, tubular vacuolation/degeneration, basophilic tubules, and hyaline droplets in the proximal tubules) of the 75 and 100 mg/kg male groups and the 50 and 100 mg/kg female groups. The 75 and 100 mg/kg male groups showed adverse effect in the testes (degeneration/exfoliation of germ cells, seminiferous tubules atrophy) and epididymis (cellular debris, oligospermia). These changes were partially recovered after a 2-week recovery period. However, basophilic tubules and hyaline droplets in the proximal tubules in the kidney and germ cell degeneration/exfoliation in the testis were not recovered. In toxicokinetics study, systemic exposure to KDS2010 increased proportionally in both sexes by in a dose -dependent manner. In addition, repeated administration for 4 weeks led to increased tendency of systemic exposure in both sexes compared with that in Day 1. In conclusion, KDS2010 was shown to target the kidney and testis with a no-observed-adverse-effect level of 50 and 30 mg/kg/day for males and females, respectively.

Thirteen-week oral toxicity study of fermented ginseng, GBCK25, in Sprague-Dawley rats.

Ginseng (Panax ginseng) is commonly used in Asia as a medicinal herb. In particular, fermented ginseng, GBCK25, has been recently developed to increase ginsenoside absorption. It also has other beneficial biological effects such as hemodynamic and anti-inflammation functions. Here, we investigated the potential toxicity of GBCK25 in Sprague-Dawley rats following 13 weeks of GBCK25 treatment by oral gavage at doses of 250, 500, or 1000 mg/kg/day and reversible toxic effects over a 4-week recovery phase. Ten male and female rats per group were randomly allocated to the main toxicology groups and five male and female rats per group were allocated to the 0 and 1000 mg/kg/day recovery groups, respectively. There was no mortality; significant clinical toxicity or microscopic findings; and changes in body weight, food consumption, hematological parameters, serum biochemistry, or absolute and relative organ weights in any of the groups. In conclusion, there were no toxicological changes upon repeated oral gavage of GBCK25 at doses of 250, 500, or 1000 mg/kg/day in Sprague-Dawley rats over 13 weeks. The no-observed-adverse-effect level of GBCK25 was 1000 mg/kg/day in both sexes of Sprague-Dawley rat.

Repeated injection of KMRC011, a medical countermeasure for radiation, can cause adverse health effects in cynomolgus monkeys.

High-dose radiation-induced tissue damage is a major limiting factor in the medical application of nuclear technology. Herein, we tested 28-day repeated-dose toxicity of KMRC011, an agonist of toll-like receptor (TLR) 5, which is being developed as a medical countermeasure for radiation, using cynomolgus monkeys. KMRC011 (0.01, 0.02 or 0.04 mg/kg/day) was intramuscularly injected once daily for 4 weeks, and each two monkeys in both control and 0.04 mg/kg/day group were observed for an additional 2-week recovery period. There were no dose-related toxicological changes in mortality, clinical observations, body weight, food consumption, ophthalmological findings, electrocardiographs, coagulation, serum chemistry, organ weights, or urinalysis and urine chemistry. Although treatment-related changes, such as increased white blood cells, increased absolute and relative neutrophils, decreased relative lymphocytes and inflammatory lesions, were noted in the maximum dose group, these findings were not observed after the 2-week recovery period. Further, we considered that the kidneys and heart may be target organs of TLR5 agonists, as well as the spleen, and that autophagic signals can be triggered in tissue damage and the repair process. Importantly, accumulation of p62 protein, an indicator of autophagy, and a decrease of caveolin-1 protein, a regulator of TLR5 protein half-life, were found in both tissues from the highest dose group. Therefore, we conclude that the no-observed-adverse-effect level for KMRC011 may be greater than 0.04 mg/kg/day in male and female monkeys. Additionally, we propose that further studies are needed to identify the molecular signals, which are related to KMRC011-induced adverse effects.

KCrS2 Cathode with Considerable Cyclability and High Rate Performance: The First K+ Stoichiometric Layered Compound for Potassium-Ion Batteries.

KCrS2 is presented as a stable and high-rate layered material that can be used as a cathode in potassium-ion batteries. As far as it is known, KCrS2 is the only layered material with stoichiometric amounts of K+ , which enables coupling with a graphite anode for full-cell construction. Cr(III)/Cr(IV) redox in KCrS2 is also unique, because LiCrS2 and NaCrS2 are known to experience S2- /S2 2- redox. O3-KCrS2 is first charged to P3-K0.39 CrS2 and subsequently discharged to O'3-K0.8 CrS2 , delivering an initial discharge capacity of 71 mAh g-1 . The following charge/discharge (C/D) shows excellent reversibility between O'3-K0.8 CrS2 and P3-K0.39 CrS2 , retaining ≈90% of the initial capacity during 1000 continuous cycles. The rate performance is also noteworthy. A C/D rate increase of 100-fold (0.05 to 5 C) reduces the reversible capacity only by 39% (71 to 43 mAh g-1 ). The excellent cyclic stability and high rate performance are ascribed to the soft sulfide framework, which can effectively buffer the stress caused by K+ deinsertion/insertion. During the transformation between P3-K0.39 CrS2 and O'3-K0.8 CrS2 , the material resides mostly in the P3 phase, which minimizes the abrupt dimension change and allows facile K+ diffusion through spacious prismatic sites. Structural analysis and density functional theory calculations firmly support this reasoning.

Fabrication and evaluation of chitosan-coated nanostructured lipid carriers for co-delivery of paclitaxel and PD-L1 siRNA.

This study aimed to develop a nanostructured lipid carrier (NLC) capable of co-delivering paclitaxel (PTX) and programmed death-ligand 1 (PD-L1) small interfering RNA (siRNA) to enhance PTX bioavailability and bolster immunity through PD-L1 knockdown. We prepared a PTX-loaded NLC (P-NLC) and coated it with positively charged chitosan (Chi) to create P-NLC-Chi, which was subsequently conjugated to siRNA (P-NLC-Chi-siRNA). The P-NLC-Chi formulation was optimized using the Box-Behnken design. P-NLC-Chi measured 123.8 ± 0.52 nm (zeta potential, 22.71 ± 0.49 mV). By verifying the gel retardation assay and observing changes in the zeta potential, the optimal binding ratio of NLC to PD-L1 siRNA was identified as 50:1. The P-NLC-Chi-siRNA particle size was 181.97 ± 0.67 nm, with a zeta potential of 18.66 ± 0.23 mV. siRNA stability was observed in serum over a 24-h period. Enhanced cytotoxicity and intracellular uptake of the complex were evident in breast cancer cells and breast cancer-resistant cells (MCF-7 and MCF-7/ADR cells, respectively). Evaluation of P-glycoprotein-mediated efflux demonstrated that NLC mitigated drug efflux in MCF-7/ADR cells. Subcutaneous injection of P-NLC-Chi-siRNA into tumor-bearing BALB/c nude mice injected with MCF-7/ADR cells revealed a reduction in tumor size. In vitro and in vivo experiments indicated a significant reduction in PD-L1 mRNA expression levels. Additionally, an in vivo study revealed tumor-specific CD4 + and CD8 + T cell responses within the tumor tissue following the injection of P-NLC-Chi-siRNA. Our findings suggest that Chi-coated NLC for the co-delivery of PTX and PD-L1 siRNA has great potential as an innovative delivery system for chemoimmunotherapy.

Characterization of immune development of fetal and early-life of minipigs.

Fetal and child's immune systems differ from those of adults. Developing immune systems exhibit increased or decreased sensitivity to drugs, infection, or toxicants compared to adult immune systems. Understanding fetal and neonatal immune systems will help predict toxicity or the pathogenesis or prognosis of diseases. In this study, we evaluated whether the innate and adaptive immune system of fetal and young minipigs could respond to external stimuli compared to a medium-treated group and analyzed several immunological parameters for developmental immunotoxicity according to developmental stages. We performed a hematological analysis of fetal cord bloods and the bloods of neonatal and 4-week-old piglets. Splenocytes were isolated at each developmental stage and treated with lipopolysaccharide (LPS), R848, and concanavalin A (ConA). Various cytokines were measured in the cell supernatants. Total antibody production was also evaluated in serum. The percentage of lymphocytes was dominant in gestational weeks (GW) 10 and 12 and started to decrease from postnatal day (PND) 0. From PND0, the percentage of neutrophils increased. Interleukin (IL)-1ß, IL-6, and interferon (IFN)-α were induced from GW10 in response to LPS and R848 stimulation. Th1 cytokine induction was detected from PND0 upon ConA stimulation, whereas Th2 cytokine release was observed from GW10. IgM and IgG production was sustained at low levels at fetal stages and was significantly increased after birth. This study reconfirmed that the fetal immune system could respond to external stimuli and that hematological analysis, cytokine evaluation, and antibody subclass measurement can be useful parameters for developmental immunotoxicity using minipigs.

A phased array ultrasound system with a robotic arm for neuromodulation.

BACKGROUND: Ultrasonic neuromodulation (UNMOD) provides a non-invasive brain stimulation. However, the high-resolution region-specificity of UNMOD with a single element transducer combined with a mechanical positioning system could have limits due to the intrinsic positioning error from mechanical systems. OBJECTIVE/HYPOTHESIS: A phased array system could lead to highly selective neuromodulation with electronic control. METHODS: A specialized phased-array system with a robotic arm is implemented for a rhesus monkey model. Various primary motor cortex areas related to tail, hand, and mouth were stimulated with a 200 µm step size. The ultrasonic parameters were ISPTA of 840 mW/cm2, pulse repetition frequency of 100 Hz, and a 5% duty factor at 600 kHz. The induced movement were recorded and analyzed. RESULTS: Separate digits, mouth, and tongue motions were successfully induced by electronically controlling the focus. The identical body part movement could be induced when the focus was moved back to the identical primary motor cortex with electronic control. Accordingly, the reproducibility of UNMOD could be partially validated with rhesus monkey model. CONCLUSION: A phased-array system appears to have a potential for the non-invasive and region-selective neuromodulation method.

Development of a long-acting tablet with ticagrelor high-loaded nanostructured lipid carriers.

Ticagrelor (TCG), an antiplatelet agent, has low solubility and permeability; thus, there are many trials to apply the pharmaceutical technology for the enhancement of TCG solubility and permeability. Herein, we have developed the TCG high-loaded nanostructured lipid carrier (HL-NLC) and solidified the HL-NLC to develop the oral tablet. The HL-NLC was successfully fabricated and optimized with a particle size of 164.5 nm, a PDI of 0.199, an encapsulation efficiency of 98.5%, and a drug loading of 16.4%. For the solidification of HL-NLC (S-HL-NLC), the adsorbent was determined based on the physical properties of the S-HL-NLC, such as bulk density, tap density, angle of repose, Hausner ratio, Carr's index, and drug content. Florite R was chosen because of its excellent adsorption capacity, excellent physical properties, and solubility of the powder after manufacturing. Using an S-HL-NLC, the S-HL-NLC tablet with HPMC 4 K was prepared, which is showed a released extent of more than 90% at 24 h. Thus, we have developed the sustained release tablet containing the TCG-loaded HL-NLC. Moreover, the formulations have exhibited no cytotoxicity against Caco-2 cells and improved the cellular uptake of TCG. In pharmacokinetic study, compared with raw TCG, the bioavailability of HL-NLC and S-HL-NLC was increased by 293% and 323%, respectively. In conclusion, we successfully developed the TCG high-loaded NLC tablet, that exhibited a sustained release profile and enhanced oral bioavailability.

Antiviral Lipid Nanocarrier Loaded with Remdesivir Effective Against SARS-CoV-2 in vitro Model.

Introduction: The ongoing SARS-CoV-2 pandemic has affected public health, the economy, and society. This study reported a nanotechnology-based strategy to enhance the antiviral efficacy of the antiviral agent remdesivir (RDS). Results: We developed a nanosized spherical RDS-NLC in which the RDS was encapsulated in an amorphous form. The RDS-NLC significantly potentiated the antiviral efficacy of RDS against SARS-CoV-2 and its variants (alpha, beta, and delta). Our study revealed that NLC technology improved the antiviral effect of RDS against SARS-CoV-2 by enhancing the cellular uptake of RDS and reducing SARS-CoV-2 entry in cells. These improvements resulted in a 211% increase in the bioavailability of RDS. Conclusion: Thus, the application of NLC against SARS-CoV-2 may be a beneficial strategy to improve the antiviral effects of antiviral agents.

Two weeks dose range-finding and four weeks repeated dose oral toxicity study of a novel reversible monoamine oxidase B inhibitor KDS2010 in cynomolgus monkeys.

A novel reversible monoamine oxidase B inhibitor, KDS2010, has been developed as a therapeutic candidate for neurodegenerative diseases. This study investigated its potential toxicity in non-human primates before human clinical trials. Daily KDS2010 doses (25, 50, or 100 mg/kg) were orally administered to cynomolgus monkeys (1 animal/sex/group, 4 males and 4 females) for 2 weeks to determine the dose range. One male was moribund, and one female was found dead in the 100 mg/kg/day group. One male was also found dead in the 50 mg/kg/day group. The death was considered an adverse effect in both sexes since distal tubules/collecting duct dilation and hypertrophy in the epithelium of the papillary duct were observed in their kidneys. Based on dose range finding results, KDS2010 (10, 20, or 40 mg/kg/day) was administered orally for 4 weeks, and animals were given 2 weeks for recovery. No significant changes were observed during daily clinical observations and macro-and microscopic examinations, including body weight, food consumption, hematology, clinical chemistry, and organ weight. And, the kidney was seen as the primary target organ of KDS2010 in the 2 weeks study, but no adverse effect was observed in the 4 weeks study. Therefore, 40 mg/kg/day is considered the no-observed-adverse-effect level in both sexes of cynomolgus monkeys. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-023-00182-4.

Pharmacodynamics and subchronic toxicity in mice and monkeys of ISIS 388626, a second-generation antisense oligonucleotide that targets human sodium glucose cotransporter 2.

ISIS 388626, a 2'-methoxyethyl (MOE)-modified antisense oligonucleotide (ASO) that targets human sodium glucose cotransporter 2 (SGLT2) mRNA, is in clinical trials for the management of diabetes. SGLT2 plays a pivotal role in renal glucose reabsorption, and inhibition of SGLT2 is anticipated to reduce hyperglycemia in diabetic subjects by increasing urinary glucose elimination. To selectively inhibit SGLT2 in the kidney, ISIS 388626 was designed as a "shortmer" ASO, consisting of only 12 nucleotides with two 2'-MOE-modified nucleotides at the termini. Mice and monkeys received up to 30 mg/kg/week ISIS 388626 via subcutaneous injection for 6 or 13 weeks. Dose-dependent decreases in renal SGLT2 mRNA expression were observed, which correlated with dose-related increases in glucosuria without concomitant hypoglycemia. There were no histologic changes in the kidney attributed to SGLT2 inhibition after 6 or 13 weeks of treatment. The remaining changes observed in these studies were typical of those produced in these species by the administration of oligonucleotides, correlated with high doses of ISIS 388626, and were unrelated to the inhibition of SGLT2 expression. The kidney contained the highest concentration of ISIS 388626, and dose-dependent basophilic granule accumulation in tubular epithelial cells of the kidney, which is evidence of oligonucleotide accumulation in these cells, was the only histologic change identified. No changes in kidney function were observed. These results revealed only readily reversible changes after the administration of ISIS 388626 and support the continued investigation of the safety and efficacy of ISIS 388626 in human trials.

Claustral MeCP2 Regulates Methamphetamine-induced Conditioned Place Preference in Cynomolgus Monkey.

The claustrum, a brain nucleus located between the cortex and the striatum, has recently been highlighted in drug-related reward processing. Methyl CpG-binding protein-2 (MeCP2) is a transcriptional regulator that represses or activates the expression of the target gene and has been known to have an important role in the regulation of drug addiction in the dopaminergic reward system. The claustrum is an important region for regulating reward processing where most neurons receive dopamine input; additionally, in this region, MeCP2 is also abundantly expressed. Therefore, here, we hypothesized that MeCP2 would be involved in drug addiction control in the Claustrum as well and investigated how claustral MeCP2 regulates drug addiction. To better understand the function of human claustral MeCP2, we established a non-human primate model of methamphetamine (METH) - induced conditioned place preference (CPP). After a habituation of two days and conditioning of ten days, the CPP test was conducted for three days. Interestingly, we confirmed that virus-mediated overexpression of MECP2 in the claustrum showed a significant reduction of METH-induced CPP in the three consecutive days during the testing period. Moreover, they showed a decrease in visit scores (frequency for visit) for the METH-paired room compared to the control group although the scores were statistically marginal. Taken together, we suggest that the claustrum is an important brain region associated with drug addiction, in which MeCP2 may function as a mediator in regulating the response to addictive drugs.

SYNCRIP controls miR-137 and striatal learning in animal models of methamphetamine abstinence.

Abstinence from prolonged psychostimulant use prompts stimulant withdrawal syndrome. Molecular adaptations within the dorsal striatum have been considered the main hallmark of stimulant abstinence. Here we explored striatal miRNA-target interaction and its impact on circulating miRNA marker as well as behavioral dysfunctions in methamphetamine (MA) abstinence. We conducted miRNA sequencing and profiling in the nonhuman primate model of MA abstinence, followed by miRNA qPCR, LC-MS/MS proteomics, immunoassays, and behavior tests in mice. In nonhuman primates, MA abstinence triggered a lasting upregulation of miR-137 in the dorsal striatum but a simultaneous downregulation of circulating miR-137. In mice, aberrant increase in striatal miR-137-dependent inhibition of SYNCRIP essentially mediated the MA abstinence-induced reduction of circulating miR-137. Pathway modeling through experimental deduction illustrated that the MA abstinence-mediated downregulation of circulating miR-137 was caused by reduction of SYNCRIP-dependent miRNA sorting into the exosomes in the dorsal striatum. Furthermore, diminished SYNCRIP in the dorsal striatum was necessary for MA abstinence-induced behavioral bias towards egocentric spatial learning. Taken together, our data revealed circulating miR-137 as a potential blood-based marker that could reflect MA abstinence-dependent changes in striatal miR-137/SYNCRIP axis, and striatal SYNCRIP as a potential therapeutic target for striatum-associated cognitive dysfunction by MA withdrawal syndrome.

Optimal Composition of Li Argyrodite with Harmonious Conductivity and Chemical/Electrochemical Stability: Fine-Tuned Via Tandem Particle Swarm Optimization.

A tandem (two-step) particle swarm optimization (PSO) algorithm is implemented in the argyrodite-based multidimensional composition space for the discovery of an optimal argyrodite composition, i.e., with the highest ionic conductivity (7.78 mS cm-1 ). To enhance the industrial adaptability, an elaborate pellet preparation procedure is not used. The optimal composition (Li5.5 PS4.5 Cl0.89 Br0.61 ) is fine-tuned to enhance its practical viability by incorporating oxygen in a stepwise manner. The final composition (Li5.5 PS4.23 O0.27 Cl0.89 Br0.61 ), which exhibits an ionic conductivity (σion ) of 6.70 mS cm-1 and an activation barrier of 0.27 eV, is further characterized by analyzing both its moisture and electrochemical stability. Relative to the other compositions, the exposure of Li5.5 PS4.23 O0.27 Cl0.89 Br0.61 to a humid atmosphere results in the least amount of H2 S released and a negligible change in structure. The improvement in the interfacial stability between the Li(Ni0.9 Co0.05 Mn0.05 )O2 cathode and Li5.5 PS4.23 O0.27 Cl0.89 Br0.61 also results in greater specific capacity during fast charge/discharge. The structural and chemical features of Li5.5 PS4.5 Cl0.89 Br0.61 and Li5.5 PS4.23 O0.27 Cl0.89 Br0.61 argyrodites are characterized using synchrotron X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. This work presents a novel argyrodite composition with favorably balanced properties while providing broad insights into material discovery methodologies with applications for battery development.

Enhancement of S(+)-zaltoprofen oral bioavailability using nanostructured lipid carrier system.

Zaltoprofen is a nonsteroidal anti-inflammatory drug with poor oral bioavailability. S(+)-zaltoprofen (SZPF)-loaded nanostructured lipid carriers (NLCs) were prepared to enhance oral bioavailability. SZPF-loaded NLCs (NLC-SZPF) were prepared using the hot-melting homogenization method and optimized using the Box-Behnken design. The characterization of optimized NLC-SZPF, in vitro release, cytotoxicity, cellular uptake, ex vivo permeability, and pharmacokinetic parameters were evaluated to confirm the advantages of NLC formulation. NLC-SZPF with a diameter of 105.5 ± 1.2 nm had a high encapsulation efficiency of 99.84 ± 0.01%. NLC-SZPF showed a sustained-release profile, high biocompatibility, and high permeability across the intestinal tract. The relative bioavailability of NLC-SZPF was 431.3% compared with that of SZPF after oral administration to experimental rats. NLC-SZPF was successfully optimized using experimental designs to enhance the oral bioavailability of SZPF. Hence, NLC-SZPF could be a promising approach to overcome the poor oral bioavailability of SZPF.

Transcriptomic Analysis of Polyhexamethyleneguanidine-Induced Lung Injury in Mice after a Long-Term Recovery.

Polyhexamethyleneguanidine phosphate (PHMG-P) is one of the causative agents of humidifier disinfectant-induced lung injury. Direct exposure of the lungs to PHMG-P causes interstitial pneumonia with fibrosis. Epidemiological studies showed that patients with humidifier disinfectant-associated lung injuries have suffered from restrictive lung function five years after the onset of the lung injuries. We investigated whether lung damage was sustained after repeated exposure to PHMG-P followed by a long-term recovery and evaluated the adverse effects of PHMG-P on mice lungs. Mice were intranasally instilled with 0.3 mg/kg PHMG-P six times at two weeks intervals, followed by a recovery period of 292 days. Histopathological examination of the lungs showed the infiltration of inflammatory cells, the accumulation of extracellular matrix in the lung parenchyma, proteinaceous substances in the alveoli and bronchiolar-alveolar hyperplasia. From RNA-seq, the gene expression levels associated with the inflammatory response, leukocyte chemotaxis and fibrosis were significantly upregulated, whereas genes associated with epithelial/endothelial cells development, angiogenesis and smooth muscle contraction were markedly decreased. These results imply that persistent inflammation and fibrotic changes caused by repeated exposure to PHMG-P led to the downregulation of muscle and vascular development and lung dysfunction. Most importantly, this pathological structural remodeling induced by PHMG-P was not reversed even after long-term recovery.

Assessment of acute and repeated pulmonary toxicities of oligo(2-(2-ethoxy)ethoxyethyl guanidium chloride in mice.

Oligo(2-(2-ethoxy)ethoxyethyl guanidinium chloride (PGH) and polyhexamethyleneguanidine phosphate (PHMG-P) are cationic biocides containing a guanidine group. Direct exposure of the lungs to PHMG-P is known to induce pulmonary inflammation and fibrotic changes. Few studies have assessed the pulmonary toxicity of PGH, another member of the guanidine family. In this study, we assessed the acute and repeated toxicity of PGH and PHMG-P to compare the pathological progression induced by both chemicals. PGH (1.5 mg/kg) or PHMG (0.6 mg/kg) was instilled intratracheally to mice once or three times every 4 days; subsequently, cytokine levels were quantified and a histopathological examination was performed. To verify the toxic mechanism of PGH, we quantified cell viability and cytokine production induced by PGH or PHMG-P in the presence or absence of anionic material in cells. Instillation of PGH and PHMG-P into the mouse lung increased cytokine production, immune cell infiltration, and pulmonary fibrotic changes. These pathological changes were exacerbated over time in the single- and the repeated-dose PHMG-P groups, but were resolved over time in the PGH groups. PGH or PHMG-P showed cytotoxic effects, IL-1ß secretion, and ROS production in a dose-dependent manner in human cell lines. However, the co-treatment of anionic materials with PGH or PHMG-P significantly reduced these toxic responses, which confirmed that the cation of PGH disrupted the plasma membrane via ionic interaction, as observed for PHMG-P. In addition, we suggest the disruption of plasma membrane as a molecular initiating event of cationic chemicals-induced adverse outcomes when exposed directly to the lungs.

Toxicity of diclofenac sodium salt in Yucatan minipigs (Sus scrofa) following 4 weeks of daily intramuscular administration.

Diclofenac sodium salt (DSS) is a widely used nonsteroidal anti-inflammatory drug. The present study was performed under good laboratory practice (GLP) regulations to investigate the toxicity of DSS after 4 weeks of repeated intramuscular administration at doses of 0, 2, 10, or 20 mg/kg/day in 32 minipigs and to evaluate the DSS effect following a 2-week recovery period. Dose-related clinical signs and alterations of hematological or clinical chemistry parameters, organ weight, and macroscopic as well as histopathological findings in hepatic, renal, gastrointestinal, skin and injection sites were observed in both sexes' animals of the 10 or 20 mg/kg/day group. With the exception of the skin-related findings, most symptoms showed a tendency to resolve after the 2-week recovery period. The systemic exposure (AUClast) of DSS in plasma showed similar pattern to the increase rate of the dose and similar values between males and females except for the female 20 mg/kg dose group (56 %) on Day1. The systemic exposure showed a decreasing trend in the 10 or 20 mg/kg group after 4-week of repeated administration compared to Day1. The no-observed-adverse-effect level of DSS in this study was considered to be 2 mg/kg/day in both male and female minipigs.