Recent advances in poly(3,4-ethylenedioxyselenophene) and related polymers

This review highlights the recent progress in synthesis, properties, applications and future outlook of PEDOS based conjugated polymers.

Poly(3,4-ethylenedioxyselenophene): effect of solvent and electrolyte on electrodeposition, optoelectronic and electrochromic properties

In this article, we report the effect of electropolymerization conditions such as solvent and supporting electrolyte on the redox, optoelectronic and electrochromic properties of PEDOS. Monomer EDOS was synthesized by new and simple route and its electropolymerization was investigated by employing six different combinations of solvent–electrolyte namely TBAClO₄/MeCN, TBAPF₆/MeCN, TBABF₄/MeCN, TBAClO₄/PC, TBAPF₆/PC and TBABF₄/PC. Further, the electrochemical, spectroelectrochemistry, morphology and electrochromic properties of resultant PEDOS films were systematically studied. A pronounced effect of both solvent and supporting electrolyte on the electropolymerization, redox, optoelectronic and electrochromic properties on PEDOS film is noted. Among all solvent–electrolyte systems, MeCN and TBAClO₄ were found to be the most suitable medium for electropolymerization of EDOS. Further, PEDOS films prepared in PC showed red shifted absorption maxima, narrow absorption peaks in UV-vis-NIR spectra, slightly more smooth morphologies, and high optical contrasts ratio and coloration efficiency in comparison to MeCN. PEDOS films prepared in TBABF₄/PC exhibited longer λ_max (670 nm), smooth morphology, and the highest optical contrasts ratio (44.6%) and coloration efficiency (141.8 cm² C⁻¹) compared to the other solvent–electrolyte medium.

In this article, we report the effect of electropolymerization conditions such as solvent and supporting electrolyte on the redox, optoelectronic and electrochromic properties of PEDOS.

Etiology and characteristics of pediatric urethral strictures in a developing country in the 21st century

BACKGROUND

Urethral stricture disease in children is not uncommon as assumed; however, most of the information about the etiology, features, and natural history of pediatric strictures is extrapolations from adult series as the literature on this common entity is sparse, and most of the studies are small series.

OBJECTIVE

The current etiology and clinical features of urethral stricture disease in the pediatric population in the developing world were determined.

MATERIALS AND METHODS

The data of children with urethral stricture disease, who had undergone treatment in the tertiary center from 2001 to 2017, were retrospectively analyzed. After excluding girls, the database was analyzed for clinical presentation, possible causes of stricture, site and number of strictures, and length of stricture and for previous interventions. Subanalysis was performed for stricture etiology by patient age, stricture length, site, previous treatments, and presentation with paraurethral abscess.

RESULTS

A total of 195 boys with strictures were identified. The common causes of pediatric urethral stricture were traumatic (36.9%), iatrogenic (31.8%), and idiopathic (28.7%). The anterior urethra was the location of the stricture in 141 patients (72.3%). Iatrogenic causes (due to catheterization, hypospadias repair, and valve fulguration) accounted for the majority of anterior urethral strictures (61/141 or 43.2%). Younger children had a tendency to have an iatrogenic and idiopathic cause for strictures, whereas older children had a traumatic etiology; 18.6% of strictures in children younger than 10 years were secondary to trauma, whereas 44.9% of the strictures in patients older than 10 years were traumatic in origin. Trauma was the major cause of posterior urethral strictures (53/54 or 98.1%) and was always associated with pelvic fracture. Strictures due to lichen sclerosus or infectious cause were rare (5 patients or 2.6%). The length of strictures was longer in pan anterior urethral strictures (mean: 82.0 mm) than that of those due to lichen sclerosus (mean: 42.5 mm) and in patients who had undergone previous treatment (mean: 28.7 mm).

CONCLUSION

Iatrogenic causes such as catheterization and hypospadias repair account for the majority of anterior urethral stricture disease in the pediatric population, especially the younger age-group. However, as the child grows, there is a gradual preponderance of traumatic urethral strictures, including posterior urethral strictures.

Waardenburg syndrome with dry eyes: A rare association

Waardenburg syndrome (WS) is a rare congenital disorder primarily characterized by characteristic facial abnormalities as dystopia canthorum and synophrys; depigmentation of the hair, skin (premature graying of hair), and/or the iris of both eyes; and/or congenital deafness. Here, we report a rare case of WS with associated dry eyes. A 4-year-old female presented with blue eyes and no tear and nasal secretion production since birth. She was also deaf and dumb since birth. On examination, it was recognized as an atypical case of WS type 2 clinically, with several classical features such as white forelock, bilateral blue iris, hypopigmented fundus, smooth philtrum, bilateral profound hearing loss, and a rare association of bilateral dry eyes. The patient was given proper refractive correction, treatment of her dry eyes, and subjected to multidisciplinary approach as for the management of sensorineural hearing loss. It was a case of WS type 2 with a rare association of bilateral dry eyes.

The Therapeutic and Preventive Efficacy of Curcumin and Its Derivatives in Esophageal Cancer

Esophageal cancer is the eighth most common occurring cancer type worldwide and 6th most common among the cancer related deaths of which the most common type is squamous cell carcinoma which comprise about 90% of esophageal cancer cases. The standard of care for esophageal cancer is neoadjuvant concurrent chemotherapy and radiation (NACRT) followed by surgery however the prognosis remains dismal with 5 year survival a meager 10-15%. The treatment modalities for esophageal cancer is associated with both long term and short term toxicities. Curcumin has been explored as a therapeutic modality as a chemo adjuvant in different cancers due to its low toxicity profile and potent anticancer effect however despite lot of promising preclinical data it has not progressed from bench side to bed side. The primary reason that has obstructed its application in clinic has been its low bioavailability which was seen in different clinical trials but there has been tremendous progress in developing formulations of curcumin which have significantly increased its bioavailability and are being tested in clinical trials. Esophageal cancer is associated with inflammation that’s why curcumin being a natural antioxidant offer a potential avenue to reduce toxicity of current therapeutic modalities in a chemo adjuvant setting while simultaneously targeting different pro oncogenic pathways. The present review tries to cover in depth different aspects of curcumin application in treatment of esophageal cancer and progress of this potent anticancer agent in its treatment and prevention.

Donor-Acceptor-Donor Copolymers with 3,4-Ethylenedioxythiophene Moiety: Electropolymerization and Effect on Optoelectronic and Electrochromic Properties

Three random copolymers PE- co -M1, PE- co -M2, and PE- co -M3 were obtained by electrochemical polymerization of donor-acceptor-donor monomers M1, M2, and M3 with 3,4-ethylenedioxythiophene moiety, respectively, using a 1:1 molar ratio of the corresponding monomers, to find new properties and a more effective way to control the optoelectronic properties in conjugated system. For comparison purpose, polymers P1, P2, and P3 were prepared from the corresponding monomer units M1-M3, respectively, by electrochemical polymerization. We also present efficient synthesis, characterization, and comparative density functional theory (DFT) calculations of the monomers M1-M3 and polymers P1-P3. Cyclic voltammetry, spectroelectrochemistry, and electrochromic properties of all of the polymers P1-P3 and copolymers PE- co -M1, PE- co -M2, and PE- co -M3 were carried out and a throughout comparison was made. We have shown that electrochemical copolymerization is a powerful strategy to tune the highest occupied molecular orbital energy level, band gap, and color of the copolymer. Thus, this finding clearly indicates that the copolymers show significantly different optoelectronic properties compared to their constituent polymers.

Abstract P6-20-10: Role of GPR110 in breast cancer

Our long-term goal is to discover adhesion GPCR targets in breast cancer. Our previous studies have found GPR110 to be overexpressed in tumorigenic cell population as well as in anti-HER2 drug-resistant derivatives of HER2+ breast cancer cells. In subsequent studies, we found that GPR110 knockdown inhibited anchorage-independent cell growth, mammosphere formation, and invasion/migration of HER2+ breast cancer cells. Conversely, overexpression of GPR110 by lentiviral delivery of cDNA enhanced anchorage-independent cell growth, mammosphere formation, and invasion/migration in HER2+ breast cancer cells. In addition, GPR110 overexpression led to increase in the % of Aldefluor-positive tumorigenic cell population, further emphasizing the role of GPR110 as a mediator of tumorigenesis in addition to the metastatic processes in HER2+ breast cancer. Among various subtypes of breast cancer, GPR110 expression was higher in HER2+ and basal subtypes, most of which are triple-negative (negative for ER, PR, and HER2), compared to luminal A and B subtypes. GPR110 was either gene amplified or upregulated in 4% of all breast cancers based on the publicly available TCGA dataset. GPR110 overexpression predicted poorer recurrence-free survival in triple-negative breast cancer. Furthermore, GPR110 was overexpressed in brain metastatic lesions compared to mammary tumors in patient-derived xenograft models of triple-negative breast cancer (WHIM2 and WHIM30). Knocking down GPR110 reduced anchorage-dependent and -independent cell growth, mammosphere formation, and invasion/migration of triple-negative breast cancer cells. Overall, our results suggest that GPR110 may be a potential drug target in HER2+ and triple-negative breast cancer. Drug discovery efforts to identify GPR110 antagonists will provide useful pharmacological tools for validating GPR110 as a drug target in breast cancer. Since GPR110 is also overexpressed in various other types of cancer, understanding the mechanism of GPR110 upregulation and signaling in cancer is an important future direction.

This work was supported by the Department of Defense Grants W81XWH-14-1-0340 and W81XWH-14-1-0341 to Drs. Trivedi and Schiff, respectively.

Citation Format: Bhat R, Qin L, De Angelis C, Sahay D, Bhargava D, Creighton C, Yadav P, Yazdanfard S, Alrawi A, Yadav V, Vasaikar S, Nanda S, Sethunath V, Fu X, Zhang B, Narkar V, Schiff R, Trivedi M. Role of GPR110 in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-20-10.

Plasmodium palmitoylation machinery engineered in E. coli for high-throughput screening of palmitoyl acyl-transferase inhibitors

Lipid‐based palmitoylation is a post‐translation modification (PTM) which acts as a biological rheostat in life cycle progression of a deadly human malaria parasite, Plasmodium falciparum. P. falciparum palmitoylation is catalyzed by 12 putative palmitoyl acyl‐transferase enzymes containing the conserved DHHC‐CRD (DHHC motif within a cysteine‐rich domain) which can serve as a druggable target. However, the paucity of high‐throughput assays has impeded the design of drugs targeting palmitoylation. We have developed a novel strategy which involves engineering of Escherichia coli, a PTM‐null system, to enforce ectopic expression of palmitoyl acyl‐transferase in order to study Plasmodium‐specific palmitoylation and screening of inhibitors. In this study, we have developed three synthetic E. coli strains expressing Plasmodium‐specific DHHC proteins (PfDHHC7/8/9). These cells were used for validating acyl‐transferase activity via acyl‐biotin exchange (ABE) and clickable chemistry methods. E. coli proteome was found to be palmitoylated in PfDHHC‐expressing clones, suggesting that plasmodium DHHC can catalyze palmitoylation of E. coli proteins. Upon treatment with generic inhibitor 2‐bromopalmitate (2‐BMP), a predominant reduction in palmitic acid incorporation is detected. Overall, these findings suggest that synthetic E. coli strains expressing PfDHHCs can enforce global palmitoylation in the E. coli proteome. Interestingly, this finding was corroborated by our in silico palmitoylome profiling, which revealed that out of the total E. coli proteome, 108 proteins were predicted to be palmitoylated as represented by the presence of three cysteine consensus motifs (cluster type I, II, III). In summary, our study reports a proof of concept for screening of chemotherapeutics targeting the palmitoylation machinery using a high‐throughput screening platform.

Dendrimer-based micelles as cyto-compatible nanocarriers

The aim of the present study is to compare the synthesized dendritic architectures in terms of self-assembly and transport potential for hydrophobic guest molecules.

Deregulated AUF1 Assists BMP-EZH2-Mediated Delayed Wound Healing during Candida albicans Infection

Tissue repair is a complex process that necessitates an interplay of cellular processes, now known to be dictated by epigenetics. Intriguingly, macrophages are testimony to a large repertoire of evolving functions in this process. We identified a role for BMP signaling in regulating macrophage responses to Candida albicans infection during wound repair in a murine model. In this study, the RNA binding protein, AU-rich element-binding factor 1, was posttranslationally destabilized to bring about ubiquitin ligase, NEDD4-directed activation of BMP signaling. Concomitantly, PI3K/PKCδ mobilized the rapid phosphorylation of BMP-responsive Smad1/5/8. Activated BMP pathway orchestrated the elevated recruitment of EZH2 at promoters of genes assisting timely wound closure. In vivo, the repressive H3K27 trimethylation was observed to persist, accompanied by a robust upregulation of BMP pathway upon infection with C. albicans, culminating in delayed wound healing. Altogether, we uncovered the signaling networks coordinated by fungal colonies that are now increasingly associated with the infected wound microbiome, resulting in altered wound fate.

Eugenia jambolana extract reduces the systemic exposure of Sitagliptin and improves conditions associated with diabetes: A pharmacokinetic and a pharmacodynamic herb-drug interaction study

Eugenia jambolana (EJ) is an Indian traditional herb widely used for the treatment of diabetes mellitus. This herb is globally marketed as single or multi herb formulations. Many diabetes patients consume EJ extract oral hypoglycemic drugs together. This calls for a need to assess risks versus benefit of this co-administration.

In present investigation, pharmacodynamic and pharmacokinetic interactions of aqueous extract of EJ seeds at the dose of 400 mg/kg are studied with 10 mg/kg of oral hypoglycaemic drug sitagliptin (SITA) by co-administrating them for 28 days in streptozotocin (STZ) induced diabetic rats. The pharmacokinetic parameters of SITA were determined using HPLC-ESI-MS/MS and it was found that the combination treatment reduces the systemic exposure of SITA by showing 38.70% reduction in concentration maximum (Cmax) and 22.40% reduction in area under curve (AUC). Despite low levels of SITA, the combination demonstrated a significant reduction in blood glucose level when compared with individual drug and individual extract administered groups during pharmacodynamic study. In addition, the liver function, the kidney function and the lipid parameters were found to be significantly improved and beneficial effects were found with respect to food intake and water intake and urine output in case of combination treatment groups when compared with individual treatment groups. Histopathological examination of pancreatic tissue suggests its significant recovery of having normal acinus with better cell protection in combination treatment. In conclusion, the combination treatment demonstrated reduced systemic exposure of SITA without compromising on its antihyperglycemic activity and improvement in conditions associated with diabetes.

AA Homozygous Genotype of GSTP1 I105V Polymorphism in Oral Cancer: In Silico Screening, Molecular Dynamics Simulation and Activity Studies of Wild and Mutant GSTP1

Background: Highest incidence of oral squamous cell carcinoma (OSCC) has been reported in north-eastern India and causal association between cancer and raw areca-nut (RAN) consumption are well evident. Earlier studies revealed that monitoring the occurrence of precocious anaphase and expression of securin in blood lymphocytes can be a good biomarkers for cancer risk in RAN+lime chewers. Glutathione S-transferases (GSTs) are considered an important cellular detoxification system that provide protection against the effects of toxins and determine individual's cancer susceptibility. Aim: Although GST gene family has been extensively studied, its role as susceptibility factor in oral cancer risk in the RAN chewing population in Meghalaya state, India has not been explored. The association of polymorphisms in GSTP1 (Ile105Val) gene with OSCC risk in Meghalaya, India, was evaluated. Earlier both AA reference and the GG/AG mutant genotype of GSTP1 gene showed an association with different types of cancers. Methods: Genetic polymorphism was evaluated by genotyping 129 cases and 156 controls using PCR-RFLP method and validated by Sanger sequencing in a hospital-based case-control study. GSTP1's interaction status with c-Jun Kinase (JNK) was evaluated through protein-protein docking analysis and this was also validated experimentally by immunohistochemistry and qRT-PCR. Results: Individuals with AA allele of GSTP1 showed significant association with the risk of OSCC compared with individuals with AG/GG mutant genotypes in habit-matched “RAN-only” and “RAN+Tobacco” group. The binding geometry between JNK and GSTP1 was disrupted in mutant combinations. It was demonstrated that AA homozygous genotype of oral epithelial cells showed reduced c-Jun-phosphorylation and proapoptotic genes expression than AG/GG genotypes. In silico docking revealed that homodimeric GSTP1 with AA genotype showed weak catalytic activity in detoxification of RAN and tobacco toxins compared with the AG/GG mutant proteins. Interestingly, the quantitation of 8-Oxo-2´-deoxyguanosine in DNA digests by ELISA-kit showed no differences in these genotypes, however the frequency of sister-chromatid exchanges was significantly higher in individuals with GSTP1 AA genotype than GG genotype. Conclusion: Thus in this population, specific traditional habit along with GSTP1 AA genotype play a significant role in predisposition to oral cancer risk by showing higher DNA-lesions, might be caused by some specific RAN/tobacco metabolites, and lower c-Jun phosphorylation which may inhibit apoptosis.