Prussian blue analogues improves the microenvironment after spinal cord injury by regulating Zn.

Mitochondrial injury, neuronal apoptosis and phenotypic transformation of macrophages are the main mechanisms of spinal cord injury. Based on the Prussian blue nanomase's strong ability to clear free radicals, the treatment of spinal cord injury with nano-zirconium (Pb-Zr) was carried out. The disease treatment strategy based on nanomaterials has excellent therapeutic effect, and Prussian blue analogs have good therapeutic properties, so the application prospects of Prussian blue analogs is broad. From the point of view of Prussian blue content, improving the presence of zirconium in the microenvironment significantly increased the activity of Prussian blue. Prussian Blue zirconium significantly improved lipopolysaccharide (LPS) and interferon (IFN-γ) induced neuronal cell (pc12 cells) and macrophage dysfunction by improving oxidative stress, inflammation, and apoptosis in the microenvironment. It can promote the recovery of motor function after spinal cord injury. In vivo experiments, it shows that Prussian blue zirconium can improve inflammation, apoptosis and oxidative stress of spinal cord tissue, promote regenerative therapy after spinal cord injury, and improve motor function. Moreover, it has been reported that high-priced Zr4+ cations can regulate the deposition and nucleation behavior of Zn2+ in high-performance zinc metal anodes. Therefore, we propose the hypothesis that Pb-Zr modulates Zn2+ be used to promote recovery from spinal cord injury. The results show that nanomaterial is beneficial in the treatment of spinal cord injury. This study provides a good prospect for the application of spinal cord injury treatment. It also provides an important feasibility for subsequent clinical conversions.

Cell Plasticity in a Mouse Model of Benign Prostate Hyperplasia Drives Amplification of Androgen-Independent Epithelial Cell Populations Sensitive to Antioxidant Therapy.

Benign prostate hyperplasia (BPH) is caused by the nonmalignant enlargement of the transition zone of the prostate gland, leading to lower urinary tract symptoms. Although current medical treatments are unsatisfactory in many patients, the limited understanding of the mechanisms driving disease progression prevents the development of alternative therapeutic strategies. The probasin-prolactin (Pb-PRL) transgenic mouse recapitulates many histopathological features of human BPH. Herein, these alterations parallel urodynamic disturbance reminiscent of lower urinary tract symptoms. Single-cell RNA-sequencing analysis of Pb-PRL mouse prostates revealed that their epithelium mainly includes low-androgen signaling cell populations analogous to Club/Hillock cells enriched in the aged human prostate. These intermediate cells are predicted to result from the reprogramming of androgen-dependent luminal cells. Pb-PRL mouse prostates exhibited increased vulnerability to oxidative stress due to reduction of antioxidant enzyme expression. One-month treatment of Pb-PRL mice with anethole trithione (ATT), a specific inhibitor of mitochondrial ROS production, reduced prostate weight and voiding frequency. In human BPH-1 epithelial cells, ATT decreased mitochondrial metabolism, cell proliferation, and stemness features. ATT prevented the growth of organoids generated by sorted Pb-PRL basal and LSCmed cells, the two major BPH-associated, androgen-independent epithelial cell compartments. Taken together, these results support cell plasticity as a driver of BPH progression and therapeutic resistance to androgen signaling inhibition, and identify antioxidant therapy as a promising treatment of BPH.

Synthesis of 1,3,4-oxadiazoles with 4-methoxynaphthalene ring: discovering new compounds with antimicrobial activity.

Background: Paracoccidioidomycosis (PCM) is a systemic infection caused by Paracoccidioides spp. (Pb). PCM can be associated or clinically confused with tuberculosis (TB), another pulmonary infection, caused by Mycobacterium tuberculosis (Mtb). Futhermore, the long treatment time of TB and PCM and the cases of TB drug resistance impose difficulties for the cure of these diseases. Results: New 1,3,4-oxadiazoles containing the 4-methoxynaphthalene ring were synthesized and their antimicrobial activity was evaluated against Pb and Mtb. The derivative 6n (with 2-hydroxy-5-nitrophenyl subunit) is the most promising of the series. Conclusion: The 1,3,4-oxadiazole 6n can be used as a prototype drug candidate, with anti-Pb and anti-MTb activities, showing a broad-spectrum profile for the treatment of both pulmonary infections.

Role of identified proteins in the proteome profiles of CDK4/6 inhibitor-resistant breast cancer cell lines.

Abemaciclib (Ab) and palbociclib (Pb) are CDK4/6 inhibitors used to cure advanced breast cancer (BC). However, acquired resistance is a major challenge. The molecular mechanisms and signature proteins of therapy resistance for Ab and Pb drugs need to be explored. Here we developed resistant cells for Ab and Pb drugs in MCF-7 cell lines and explored the mechanisms and signature proteins of therapy resistance in BC. Proteome profiling was performed using the label-free proteome-orbitrap-fusion-MS-MS technique. Gene ontology (GO)-terms, KEGG pathways and network analysis were performed for the proteome data. Drug-resistant cells showed increased drug tolerance, enhanced colony formation potential and an increased gap-healing tendency for the respective drug. Up-regulation of survival genes (BCL-2 and MCL-1) and down-regulation of apoptosis inducers were observed. Drug-resistance markers (MDR-1 and ABCG2 (BCRP)) along with ESR-1, CDK4, CDK6, and cyclin-D1 genes were up-regulated in resistant cells. A total of 237 and 239 proteins were found to be differentially expressed in the Ab and Pb-resistant cells, respectively. Down-regulated proteins induce apoptosis signalling and nucleotide metabolisms and restrict EGFR signalling; however, up-regulated proteins induce Erk, wnt-ß-catenin, VEGFR-PI3K-AKT, glucose transportation, and hypoxia signalling pathways and regulate hydrogen peroxide signalling pathways. The panel of identified proteins associated with these pathways might have characteristics of molecular signature and new drug targets for overcoming drug resistance in breast cancer.

A Review on the Natural Components Applied as Lead Compounds for Potential Multi-target Anti-AD Theranostic Agents.

Alzheimer's disease (AD) is a neurodegenerative disease that seriously affects the health and quality of life of the elderly. Its pathogenesis is very complex and there is still a lack of effective clinical drugs to treat or control the development of AD. Studies have shown that ß-amyloid (Aß) deposition, tau protein hyperphosphorylation, reduced levels of brain cholinergic transmitters, and oxidative stress are the main causes of AD. Furthermore, recent studies showed that metal dyshomeostasis could relate to all the above pathogenesis of AD and was a key factor in the development of AD. Natural compounds and their derivatives have multi-target therapeutic effects on AD, and they also have the advantages of low toxicity, and low cost, which are important directions for anti- AD drugs. Meanwhile, early detection may play an important role in preventing the development of AD. The concept of "theranostic agent" combining molecular imaging probes and therapeutic drugs has emerged in recent years. Fluorescence imaging has been widely studied and applied because of its non-invasive, high resolution, high sensitivity, rapid imaging, and low cost. However, at present, most of the research methods in this field use individual therapeutic or diagnostic reagents, which is not conducive to exploring the optimal treatment time window and drug efficacy. Therefore, this work reviewed the natural compounds and their derivatives which all have been studied for both the in vitro and in vivo therapeutic and diagnostic anti-AD activities. At last, structure and activity relationship (SAR) was discussed and potential AD theranostic natural agents were put forwarded to provide a more detailed theoretical basis for the further development of drugs with diagnostic and therapeutic effects in AD.

Discovery of Potent Cholinesterase Inhibition-Based Multi-Target-Directed Lead Compounds for Synaptoprotection in Alzheimer's Disease.

Drug development efforts that focused on single targets failed to provide effective treatment for Alzheimer's disease (AD). Therefore, we designed cholinesterase inhibition (ChEI)-based multi-target-directed ligands (MTDLs) to simultaneously target AD-related receptors. We built a library of 70 compounds, sequentially screened for ChEI, and determined σ1R, σ2R, NMDAR-GluN2B binding affinities, and P2X7R antagonistic activities. Nine fulfilled in silico drug-likeness criteria and did not display toxicity in three cell lines. Seven displayed cytoprotective activity in two stress-induced cellular models. Compared to donepezil, six showed equal/better synaptic protection in a zebrafish model of acute amyloidosis-induced synaptic degeneration. Two P2X7R antagonists alleviated the activation state of microglia in vivo. Permeability studies were performed, and four did not inhibit CYP450 3A4, 2D6, and 2C9. Therefore, four ChEI-based lead MTDLs are promising drug candidates for synaptic integrity protection and could serve as disease-modifying AD treatment. Our study also proposes zebrafish as a useful preclinical tool for drug discovery and development.

RNA-seq-based transcriptome analysis of the anti-inflammatory effect of artesunate in the early treatment of the mouse cerebral malaria model.

BACKGROUND: cerebral malaria (CM) is an important complication of malaria with a high mortality rate. Artesunate is recommended as the first-line artemisinin compound treatment for severe malaria. Due to the difficulty of obtaining brain tissue samples clinically, the use of animals to research host responses to CM parasite infections is necessary. Rodent malaria models allow for detailed time series studies of host responses in multiple organs. To date, studies on the transcriptome of severe malaria are only limited to the parasites in the peripheral blood of patients, and there is little data on the transcriptional changes in brain tissue in mice with CM treated with artesunate. METHOD AND RESULT: in this study, fresh tissue samples (three biological replicates per mouse) from the same area of the brain in each animal were collected from the uninfected, Plasmodium berghei ANKA-infected and artesunate-treated C57BL/6 mice, and then transcriptome research was performed by the RNA-seq technique. Differentially expressed genes (DEGs) included Il-21, Tnf, Il-6, Il-1ß, Il-10, Ifng, and Icam-1. Among which, Il-6, Il-10, Tnf-α and Il-1ß were further verified and validated via qRT-PCR and ELISA. This revealed that Il-1ß (p < 0.0001), Il-10 (p < 0.05) and Tnf-α (p < 0.05) were significantly up-regulated in the Pb ANKA-infected versus uninfected group, while Il-1ß (p < 0.0001) and Tnf-α (p < 0.05) were significantly down-regulated after artesunate treatment. All DEGs were closely related to the top 3 artesunate treatment pathways, including the JAK-STAT signaling pathway, apoptosis, and Toll-like receptor signaling pathway. CONCLUSION: the mechanism of improving the prognosis of cerebral malaria by artesunate may not only involve the killing of plasmodium but also the inhibition of a cytokine storm in the host. This study provides new insights into the molecular mechanism by which artesunate improves the prognosis of cerebral malaria.

Phytochemical screening, cytotoxicity assessment and evaluation of in vitro antiplasmodial and in vivo antimalarial activities of Mentha spicata L. methanolic leaf extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria causes extensive morbidity and mortality, and the decreasing efficacy of artemisinin and its partner drugs has posed a serious concern. Therefore, it is important to identify new antimalarials, and the natural compounds from plants provide a promising platform. Mentha spicata L. representing the Lamiaceae family has been used in traditional medicine for various diseases including malaria. AIM OF THE STUDY: This study was aimed at evaluating the antiplasmodial activity of M. spicata methanolic leaf extract using Plasmodium falciparum (Pf) cultures (Pf3D7 and artemisinin (ART)-resistant PfCam3.IR539T strains) and antimalarial activity using Plasmodium berghei (Pb)-infected mice. Dry leaf powder and methanolic leaf extract were examined for in vivo antimalarial activity and the efficacy of oral versus parenteral administration was compared. MATERIALS AND METHODS: Leaves of M. spicata were collected and extracted using 70% methanol in water (v/v). [3H]-hypoxanthine incorporation assays and Giemsa-stained smears were used to assess the in vitro antiplasmodial activity of M. spicata methanolic extract against Pf3D7 and ART-resistant PfCam3.IR539T strains. Cytotoxicity was evaluated in HeLa and HEK-293T cell lines using MTT assays. Hemolysis assays were performed using red blood cells (RBCs). In vivo antimalarial activities of M. spicata dry leaf powder and methanolic leaf extract were examined in P. berghei-infected mice by Rane's curative test and Peters' 4-day suppressive test. RESULTS: Phytochemical screening of M. spicata methanolic leaf extract indicated the presence of reducing sugars, phenolic compounds, flavonoids, glycosides, sterols, saponins, alkaloids, coumarins, tannins, carbohydrates, and proteins. In vitro studies carried out using Pf cultures showed that M. spicata methanolic leaf extract had significant antiplasmodial activity against Pf3D7 cultures with a 50% inhibitory concentration (IC50) of 57.99 ± 2.82 µg/ml. The extract was also effective against ART-resistant PfCam3.IR539T strain with an IC50 of 71.23 ± 3.85 µg/ml. The extract did not show significant in vitro cytotoxicity, hemolysis, and in vivo toxicity. In vivo studies performed using Pb-infected mice treated with M. spicata dry leaf powder and methanolic leaf extract showed ∼50% inhibition in parasite growth at 1500 mg/kg and 1000 mg/kg doses, respectively. There was also a significant delay in the mortality of treated mice. Parenteral administration was found to be appropriate for the in vivo treatment. CONCLUSIONS: Our in vitro and in vivo findings from Pf and Pb parasites suggested the therapeutic potential of M. spicata leaf extract as an antimalarial. M. spicata leaf extract could also inhibit the growth of ART-resistant Pf strain. Further studies on fractionation and active component analysis of M. spicata leaf extract would be required to identify the bioactive phytochemicals having pharmaceutical and therapeutic values. Such efforts would help us in developing new antimalarials to combat malaria.

Novel inhibitors of AChE and Aß aggregation with neuroprotective properties as lead compounds for the treatment of Alzheimer's disease.

A series of sulfone analogs of donepezil were designed and synthesized as novel acetylcholinesterase (AChE) inhibitors with the potent inhibiting Aß aggregation and providing neuroprotective effects as potential modalities for Alzheimer's disease (AD). Most of the target compounds displayed effective inhibition of AChE, especially compound 24r which displayed powerful inhibitory activity (IC50 = 2.4 nM). Kinetic and docking studies indicated that compound 24r was a mixed-type inhibitor. Furthermore, in glyceraldehyde (GA)-exposed SH-SY5Y differentiated neuronal cells, compound 24r could potently inhibit AChE, reduce tau phosphorylation at S396 residue, provide neuroprotection by rescuing neuronal morphology and increasing cell viability. It was also found to reduce amyloid aggregation in the presence of AChE. In addition, compound 24r showed evident protections from mitochondrial membrane dysfunction and oxidative stress in okadaic acid-induced pharmacological models. Moreover, compound 24r exhibited more effective treatment prospects in vivo than donepezil, including a moderate blood-brain barrier permeability, a more potent AChE inhibitory activity and behavioral improvement in scopolamine-induced cognition-impaired mice model at a much lower dose. Collectively, compound 24r is a promising lead compound for further investigation to discovery and development of new anti-AD agents.

Abdominal pain caused by lead toxicity due to over the counter herbal medicines: A case series.

In the last three decades, the use of herbal medications has been increasing for the treatment of various chronic disorders. Studies in the past have shown that many of these medicines could contain high levels of heavy metals, including lead. Therefore, we planned this study to evaluate the possibility of lead toxicity as the underlying cause in patients consuming these unnamed herbal medicines among patients presenting with significant abdominal pain. (Unexplained abdominal pain means pain in abdomen in which no etiology could be ascertained after all possible routine and specialized investigations including computerized axial tomography [CT] of the abdomen and upper gastrointestinal [UGI] endoscopy/colonoscopy). This is an observational case series of prospectively maintained data of all patients having unexplained abdominal pain and found to have an elevated blood lead level from 2011 to 2019. Lead toxicity was diagnosed when its blood lead level was >25 µg/dL. Total sixty-six patients with unexplained abdominal pain from 2011 to 2019 were recruited. Out of the sixty-six patients, seventeen had elevated blood lead levels. All seventeen patients had a history of ingestion of herbal medicines for more than 6 months. Among the seventeen patients, eight were taking it for infertility and sexual dysfunction, six for diabetes, two for arthritis and one for hypertension. Basophilic stippling was seen in one patient. Fourteen patients had low hemoglobin with a median value of 9.7 g/dL. Mean serum blood lead level was 87.1 µg/dL. None of them required anti-chelating agent. Lead toxicity owing to herbal medicine is not uncommon cause of unexplained abdominal pain. Most of these patients do not require a chelating agent for treatment. There is a need to bring these herbal medicines under strict regulations for displaying its constituents and their concentrations.

[Severe lead poisoning caused by ayurvedic medicine]. / Schwere Bleivergiftung durch ayurvedisches Heilmittel.

HISTORY: We report the case of a young patient who presented to our emergency department with reduced general condition, anemia, and crampy abdominal pain. A previous inpatient workup including abdominal imaging and bone marrow aspiration had not yielded a diagnosis. On inquiry, the patient reported oral ingestion of an Ayurvedic remedy over the course of one month. FINDINGS: 24-year-old circulatory stable patient in reduced general condition with gray skin coloration and a dark gingival margin. Laboratory testing revealed an increase in transaminases and normocytic anemia. A peripheral blood smear showed basophilic stippling of the erythrocytes. Significantly elevated lead levels were detected in the patient's blood and hair. Toxic lead levels were detected in the ingested preparation. DIAGNOSIS: Severe lead poisoning caused by self-medication with an Ayurvedic remedy. Analysis revealed a daily oral lead load of 136 times the maximum permissible dose. THERAPY AND COURSE: By means of chelation therapy, the blood lead levels were significantly reduced, and there was a complete regression of the complaints as well as a normalization of the laboratory findings. CONCLUSION: Lead has toxic effects on all organ systems of the body and is stored in the bone for decades. Symptoms of poisoning are nonspecific; a thorough history and generous indication for measuring lead levels are helpful for the diagnosis.

Preclinical study of 212Pb alpha-radioimmunotherapy targeting CD20 in non-Hodgkin lymphoma.

BACKGROUND: Despite therapeutic advances, Non-Hodgkin lymphoma (NHL) relapses can occur. The development of radioimmunotherapy (RIT) with α-emitters is an attractive alternative. In this study, we investigated the potential of α-RIT in conjunction with 212Pb-rituximab for the treatment of NHL. METHODS: EL4-hCD20-Luc cells (mouse lymphoma cell line) were used for in vitro and in vivo studies. Biodistribution and efficacy studies were performed on C57BL/6 mice injected intravenously with 25 × 103 cells. RESULTS: 212Pb-rituximab (0.925-7.4 kBq/mL) inhibit proliferation of EL4-hCD20-Luc cells in vitro. Biodistribution of 203/212Pb-rituximab in mice showed a significant tumour uptake and suggested that the liver, spleen, and kidneys were the organs at risk. For efficacy studies, mice were treated at either 11 days (early stage) or 20-30 days after injection of tumour cells (late stage). Treatment with 277.5 kBq 212Pb-rituximab significantly prolonged survival. Even at an advanced tumour stage, significant tumour regression occurred, with an increase in the median survival time to 28 days, compared with 9 days in the controls. CONCLUSIONS: These results show the efficacy of 212Pb-rituximab in a murine syngeneic lymphoma model, in terms of significant tumour regression and increased survival, thereby highlighting the potency of α-RIT for the treatment of NHL.

Cheminformatic Characterization of Natural Antimicrobial Products for the Development of New Lead Compounds.

The growing antimicrobial resistance (AMR) of pathogenic organisms to currently prescribed drugs has resulted in the failure to treat various infections caused by these superbugs. Therefore, to keep pace with the increasing drug resistance, there is a pressing need for novel antimicrobial agents, especially from non-conventional sources. Several natural products (NPs) have been shown to display promising in vitro activities against multidrug-resistant pathogens. Still, only a few of these compounds have been studied as prospective drug candidates. This may be due to the expensive and time-consuming process of conducting important studies on these compounds. The present review focuses on applying cheminformatics strategies to characterize, prioritize, and optimize NPs to develop new lead compounds against antimicrobial resistance pathogens. Moreover, case studies where these strategies have been used to identify potential drug candidates, including a few selected open-access tools commonly used for these studies, are briefly outlined.

Changes in inflammatory cytokines, antioxidants and liver stiffness after chelation therapy in individuals with chronic lead poisoning.

BACKGROUND: Chronic exposure to lead causes lead to accumulate mainly in the liver. In vivo studies have shown that lead toxicity is related to alterations in the inflammatory response. We aimed to evaluate the association between lead poisoning and liver fibrosis as well as the change in the degree of liver fibrosis, levels of inflammatory mediators and glutathione (GSH) after chelation therapy. METHODS: Workers from a battery factory who were exposed to lead for > 12 months and had a blood lead level (BLL) > 70 µg/dL were enrolled (n = 86) in the study. Participants underwent chelation therapy with intravenous CaNa2EDTA for 2 days followed by treatment with oral D-penicillamine for 90 days. The primary outcome was the change in the degree of liver fibrosis, which was presented as liver stiffness (LS) measured by FibroScan®. Secondary outcomes were the changes in the levels of serum GSH and inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) after chelation therapy. RESULTS: Among the 86 participants, there was a positive correlation between the duration of lead exposure and LS (r = 0.249, p = 0.021). To avoid the confounding effect of obesity-related steatosis, only 70 individuals who had controlled attenuation parameters < 296 dB/m, BMI < 25 kg/m2 and normal waist circumference were included in the interventional analysis. After chelation, the mean LS significantly decreased from 5.4 ± 0.9 to 4.8 ± 1.4 kPa (p = 0.001). Similarly, all of the inflammatory cytokines studied significantly decreased after chelation (p < 0.001); TNF-α decreased from 371.6 ± 211.3 to 215.8 ± 142.7; the levels of IL-1ß decreased from 29.8 ± 1.7 to 25.9 ± 4.3; and the levels of IL-6 decreased from 46.8 ± 10.2 to 35.0 ± 11.9. On the other hand, the mean GSH level increased significantly from 3.3 ± 3.3 to 13.1 ± 3.7 (p < 0.001) after chelation therapy. CONCLUSION: The duration of lead exposure was significantly correlated with the degree of liver fibrosis. Chelation treatment was associated with increased levels of GSH and decreased levels of proinflammatory cytokines and could potentially reduce the degree of LS. TRIAL REGISTRATION: This study was retrospectively registered and approved by the Thai Clinical Trial Registry (TCTR) on 2019-11-07. The TCTR identification number is TCTR20191108001 .

Tubulin-Binding 3,5-Bis(styryl)pyrazoles as Lead Compounds for the Treatment of Castration-Resistant Prostate Cancer.

The microtubule-binding taxanes, docetaxel and cabazitaxel, are administered intravenously for the treatment of castration-resistant prostate cancer (CRPC) as the oral administration of these drugs is largely hampered by their low and highly variable bioavailabilities. Using a simple, rapid, and environmentally friendly microwave-assisted protocol, we have synthesized a number of 3,5-bis(styryl)pyrazoles 2a-l, thus allowing for their screening for antiproliferative activity in the androgen-independent PC3 prostate cancer cell line. Surprisingly, two of these structurally simple 3,5-bis(styryl)pyrazoles (2a and 2l) had concentrations which gave 50% of the maximal inhibition of cell proliferation (GI50) in the low micromolar range in the PC3 cell line and were thus selected for extensive further biologic evaluation (apoptosis and cell cycle analysis, and effects on tubulin and microtubules). Our findings from these studies show that 3,5-bis[(1E)-2(2,6-dichlorophenyl)ethenyl]-1H-pyrazole 2l 1) caused significant effects on the cell cycle in PC3 cells, with the vast majority of treated cells in the G2/M phase (89%); 2) induces cell death in PC3 cells even after the removal of the compound; 3) binds to tubulin [dissociation constant (Kd) 0.4 ± 0.1 µM] and inhibits tubulin polymerization in vitro; 4) had no effect upon the polymerization of the bacterial cell division protein FtsZ (a homolog of tubulin); 5) is competitive with paclitaxel for binding to tubulin but not with vinblastine, crocin, or colchicine; and 6) leads to microtubule depolymerization in PC3 cells. Taken together, these results suggest that 3,5-bis(styryl)pyrazoles warrant further investigation as lead compounds for the treatment of CRPC. SIGNIFICANCE STATEMENT: The taxanes are important components of prostate cancer chemotherapy regimens, but their oral administration is hampered by very low and highly variable oral bioavailabilities resulting from their poor absorption, poor solubility, high first-pass metabolism, and efficient efflux by P-glycoprotein. New chemical entities for the treatment of prostate cancer are thus required, and we report here the synthesis and investigation of the mechanism of action of some bis(styryl)pyrazoles, demonstrating their potential as lead compounds for the treatment of prostate cancer.

Tungsten filled 3D printed field shaping devices for electron beam radiation therapy.

PURPOSE: Electron radiotherapy is a labor-intensive treatment option that is complicated by the need for field shaping blocks. These blocks are typically made from casting Cerrobend alloys containing lead and cadmium. This is a highly toxic process with limited precision. This work aims to provide streamlined and more precise electron radiotherapy by 3D using printing techniques. METHODS: The 3D printed electron cutout consists of plastic shells filled with 2 mm diameter tungsten ball bearings. Five clinical Cerrobend defined field were compared to the planned fields by measuring the light field edge when mounted in the electron applicator on a linear accelerator. The dose transmitted through the 3D printed and Cerrobend cutouts was measured using an IC profiler ion chamber array with 6 MeV and 16 MeV beams. Dose profiles from the treatment planning system were also compared to the measured dose profiles. Centering and full width half maximum (FWHM) metrics were taken directly from the profiler software. RESULTS: The transmission of a 16MeV beam through a 12 mm thick layer of tungsten ball bearings agreed within 1% of a 15 mm thick Cerrobend block (measured with an ion chamber array). The radiation fields shaped by ball bearing filled 3D printed cutout were centered within 0.4 mm of the planned outline, whereas the Cerrobend cutout fields had shift errors of 1-3 mm, and shape errors of 0.5-2 mm. The average shift of Cerrobend cutouts was 2.3 mm compared to the planned fields (n = 5). Beam penumbra of the 3D printed cutouts was found to be equivalent to the 15 mm thick Cerrobend cutout. The beam profiles agreed within 1.2% across the whole 30 cm profile widths. CONCLUSIONS: This study demonstrates that with a proper quality assurance procedure, 3D-printed cutouts can provide more accurate electron radiotherapy with reduced toxicity compared to traditional Cerrobend methods.

Organ-on-chip models: Implications in drug discovery and clinical applications.

Before a lead compound goes through a clinical trial, preclinical studies utilize two-dimensional (2D) in vitro models and animal models to study the pharmacodynamics and pharmacokinetics of that lead compound. However, these current preclinical studies may not accurately represent the efficacy and safety of a lead compound in humans, as there has been a high failure rate of drugs that enter clinical trials. All of these failures and the associated costs demonstrate a need for more representative models of human organ systems for screening in the preclinical phase of drug development. In this study, we review the recent advances in in vitro modeling including three-dimensional (3D) organoids, 3D microfabrication, and 3D bioprinting for various organs including the heart, kidney, lung, gastrointestinal tract (intestine-gut-stomach), liver, placenta, adipose, retina, bone, and brain as well as multiorgan models. The availability of organ-on-chip models provides a wealth of opportunities to understand the pathogenesis of human diseases and provide a potentially better model to screen a drug, as these models utilize a dynamic 3D environment similar to the human body. Although there are limitations of organ-on-chip models, the emergence of new technologies have refined their capability for translational research as well as precision medicine.

4-aminopyridyl-based lead compounds targeting CYP51 prevent spontaneous parasite relapse in a chronic model and improve cardiac pathology in an acute model of Trypanosoma cruzi infection.

BACKGROUND: Chagas disease, caused by the protozoan Trypanosoma cruzi, is the leading cause of heart failure in Latin America. The clinical treatment of Chagas disease is limited to two 60 year-old drugs, nifurtimox and benznidazole, that have variable efficacy against different strains of the parasite and may lead to severe side effects. CYP51 is an enzyme in the sterol biosynthesis pathway that has been exploited for the development of therapeutics for fungal and parasitic infections. In a target-based drug discovery program guided by x-ray crystallography, we identified the 4-aminopyridyl-based series of CYP51 inhibitors as being efficacious versus T.cruzi in vitro; two of the most potent leads, 9 and 12, have now been evaluated for toxicity and efficacy in mice. METHODOLOGY/PRINCIPAL FINDINGS: Both acute and chronic animal models infected with wild type or transgenic T. cruzi strains were evaluated. There was no evidence of toxicity in the 28-day dosing study of uninfected animals, as judged by the monitoring of multiple serum and histological parameters. In two acute models of Chagas disease, 9 and 12 drastically reduced parasitemia, increased survival of mice, and prevented liver and heart injury. None of the compounds produced long term sterile cure. In the less severe acute model using the transgenic CL-Brenner strain of T.cruzi, parasitemia relapsed upon drug withdrawal. In the chronic model, parasitemia fell to a background level and, as evidenced by the bioluminescence detection of T. cruzi expressing the red-shifted luciferase marker, mice remained negative for 4 weeks after drug withdrawal. Two immunosuppression cycles with cyclophosphamide were required to re-activate the parasites. Although no sterile cure was achieved, the suppression of parasitemia in acutely infected mice resulted in drastically reduced inflammation in the heart. CONCLUSIONS/SIGNIFICANCE: The positive outcomes achieved in the absence of sterile cure suggest that the target product profile in anti-Chagasic drug discovery should be revised in favor of safe re-administration of the medication during the lifespan of a Chagas disease patient. A medication that reduces parasite burden may halt or slow progression of cardiomyopathy and therefore improve both life expectancy and quality of life.

3D-QSAR pharmacophore-based virtual screening, molecular docking and molecular dynamics simulation toward identifying lead compounds for NS2B-NS3 protease inhibitors.

NS2B-NS3 protease has been identified to serve as lead drug design target due to its significant role in West Nile viral (WNV) and dengue virus (DENV) reproduction and replication. There are currently no approved chemotherapeutic drugs and effective vaccines to inhibit DENV and WNV infections. In this work, 3D-QSAR pharmacophore model has been developed to discover potential inhibitory candidates. Validation through Fischer's model and decoy test indicate that the developed 3D pharmacophore model is highly predictive for DENV inhibitors, which was then employed to screen ZINC chemical library to obtain reasonable hits. Following ADMET filtering, 15 hits were subjected to further filter through molecular docking and CoMFA modeling. Finally, top three hits were identified as lead compounds or potential inhibitory candidates with IC50 values of ∼0.4637 µM and fitness of ∼57.73. It is implied from CoMFA modeling that substituents at the side site of benzotriazole such as a p-nitro group (e.g. biphenyl head) and a carbonyl (e.g. carboxylate function) at the side site of furan or amino group may improve bioactivity of ZINC85645245, respectively. Molecular dynamics simulations (MDS) were performed to discover new interactions and reinforce the binding modes from docking for the hits also. The QSAR and MDS results obtained from this work should be useful in determining structural requirements for inhibitor development as well as in designing more potential inhibitors for NS2B-NS3 protease.

Glu106 targeted inhibitors of ORAI1 as potential Ca2+ release-activated Ca2+ (CRAC) channel blockers - molecular modeling and docking studies.

Calcium release-activated calcium modulator 1(ORAI1) is an integral component of the calcium release-activated calcium channel (CRAC) channel complex and plays a central role in regulating Ca2 + concentrations in T-lymphocytes. It is critical for many physiological processes, including cell-proliferation, cytokine production and activation of the immune system. Loss of ORAI1 function is linked with rheumatoid arthritis (RA) and hence pharmacological blockers of ORAI1 could be potential therapeutic agents for the treatment of RA. In this study, we have used a high-throughput screening approach to inhibit the binding of Ca2+ toward ORAI1 and the interactions are verified through induced fit docking. The results hint that these compounds act by possibly binding with, and thereby blocking Ca2+-binding with ORAI1 (E106). The molecular dynamics (MD) simulations shows strong support toward the hit compounds by showing the ligand potency throughout the simulation timescale of 30 ns. We have thus identified a novel class of highly stable, potential lead compounds that directly bind with the selectivity filter region E106 and block Ca2+ binding on ORAI1. This resulting alteration in the pore geometry of ORAI1 due to the strong blocking mechanism of lead compounds will greatly diminish its function and the downstream activities that result from the same including decreased production of cytokines in autoimmune disorders. This study may lay the foundation for finding novel lead compounds for clinical trials that could positively modulate the course of autoimmune disorders with ORAI1 as its specific target.