Tailoring of an anti-diabetic drug empagliflozin onto zinc oxide nanoparticles: characterization and in vitro evaluation of anti-hyperglycemic potential

Diabetes is a serious health issue that can be a great risk factor related to numerous physical problems. A class of drugs "Gliflozin" especially Sodium Glucose Co. Transporter 2 was inhibited by a novel drug, which is known as "empagliflozin". While ZnO nanoparticles (NPs) had considerable promise for combating diabetes, it was employed in the treatment and management of type-2 diabetes mellitus. The new drug empagliflozin was initially incorporated into Zinc Oxide NPs in this study using the surface physio-sorption technique, and the degree of drug adsorption was assessed using the HPLC method. The tailored product was characterized by using the FTIR, EDX, Ultraviolet-Visible, XRD and SEM techniques. With an average particle size of 17 nm, SEM revealed mono-dispersion of NPs and sphere-like form. The Freundlich isotherm model best fits and explains the data for the physio-sorption investigation, which examined adsorption capabilities using adsorption isotherms. The enzymes α-amylase and α-glucosidase, which are involved in the human metabolism of carbohydrates, were used in the in-vitro anti-diabetic assays. It was discovered that the composite showed the highest levels of 81.72 and 92.77% inhibition of -α-amylase and -glucosidase at an absolute concentration of 1000 μg per ml with IC50 values of 30.6 μg per ml and 72 μg per ml.

Pyrimidine-morpholine hybrids as potent druggable therapeutics for Alzheimer's disease: Synthesis, biochemical and in silico analyses

The identification of effective and druggable cholinesterase inhibitors to treat progressive neurodegenerative Alzheimer's disorder remains a continuous drug discovery hunt. In this perspective, the present study investigates the design and discovery of pyrimidine-morpholine hybrids (5a-l) as potent cholinesterase inhibitors. Palladium-catalyzed Suzuki-Miyaura cross-coupling reaction was employed to introduce the structural diversity on the pyrimidine heterocyclic core. A range of commercially available boronic acids was successfully coupled showing a high functional group tolerance. In vitro cholinesterase inhibitory potential using Ellman's method revealed significantly strong potency. Compound 5h bearing a meta-tolyl substituent at 2-position of pyrimidine ring emerged as a lead candidate against AChE with an inhibitory potency of 0.43 ± 0.42 µM, ∼38-fold stronger value than neostigmine (IC50 = 16.3 ± 1.12 µM). Compound 5h also showed the lead inhibition against BuChE with an IC50 value of 2.5 ± 0.04 µM. The kinetics analysis of 5h revealed the non-competitive mode of inhibition against AChE whereas computational modelling results of potent leads depicted diverse contacts with the binding site amino acid residues. Molecular dynamics simulations revealed the stability of biomolecular system, while, ADME analysis demonstrated druglikeness behaviour of potent compounds. Overall, the investigated pyrimidine-morpholine scaffold presented a remarkable potential to be developed as efficacious anti-Alzheimer's drugs.

Investigation of novel bis-thiadiazole bearing schiff base derivatives as effective inhibitors of thymidine phosphorylase: Synthesis, in vitro bioactivity and molecular docking study

Thymidine phosphorylase (TP) is an angiogenic enzyme. It is crucial for the development, invasion and metastasis of tumors as well as angiogenesis. In our current research, we examine how structurally changing bis-thiadiazole bearing bis-schiff bases affects their ability to inhibit TP. Through the oxidative cyclization of pyridine-based bis-thiosemicarbazone with iodine, a series of fourteen analogs of bis-thiadiazole-based bis-imines with pyridine moiety were developed. Newly synthesized scaffolds were assessed in vitro for their thymidine phosphorylase inhibitory potential and showed moderate to good inhibition profile. Eleven scaffolds such as 4a-4d,4f-4 h and 4j-4 m were discovered to be more effective than standard drug at inhibiting the thymidine phosphorylase enzyme with IC50 values of 1.16 ± 1.20, 1.77 ± 1.10, 2.48 ± 1.30, 12.54 ± 1.60, 14.63 ± 1.70, 15.53 ± 1.80, 17.47 ± 1.70, 18.98 ± 1.70, 19.53 ± 1.50, 22.73 ± 2.40 and 24.87 ± 2.80 respectively, while remaining three analogs such as 4n, 4i and 4ewere found to be more potent, but they were less potent than the standard drug. All analogs underwent SAR studies based on the pattern of substitutions around the aryl part of the bis-thiadiazole skeleton. The most active analogs in the synthesized series were then molecular docking study performed to investigate their interactions of active part of enzyme. The results showed that remarkable interactions were exhibited by these analogs with the targeted enzymes active sites. Furthermore, to confirm the structure of synthesized analogs by employing spectroscopic tools such as HREI-MS and NMR.

A flexible wearable self-supporting hybrid supercapacitor device based on hierarchical nickel cobalt sulfide@C electrode

A flexible wearable electrode consisting of nickel-cobalt sulfide (NCS) nanowires was fabricated in this study. Self-supporting NCS was grown in situ on porous carbon nanofibers without a binder as a novel material for supercapacitor electrodes. The NCS nanowires were grown using cyclic voltammetry electrodeposition, which proved to be a fast and environmentally friendly method with good controllability of the material structure. One-dimensional carbon nanofibers (C) have high surface-area-to-volume ratios, short ion transmission distances, excellent mechanical strengths, and remarkable flexibilities. Moreover, the NCS@C flexible electrode exhibited a synergetic effect with the active compounds, and the dense active sites were uniformly distributed across the entire surface of the carbon fibers, enabling rapid electron transport and enhancing the electrochemical properties of the NCS@C nanowires. The NCS@C achieved specific capacitances of 334.7 and 242.0 mAh g-1 at a current density of 2 A g-1 and high current densities (up to 40 A g-1), respectively, corresponding to a 72.3% retention rate. An NCS@C-nanofilm-based cathode and an activated-carbon-based anode were used to fabricate a flexible asymmetric supercapacitor. The device exhibited high energy and power densities of 12.91 Wh kg-1 and 358 W kg-1, respectively.

Recent developments in natural biopolymer based drug delivery systems

Targeted delivery of drug molecules to diseased sites is a great challenge in pharmaceutical and biomedical sciences. Fabrication of drug delivery systems (DDS) to target and/or diagnose sick cells is an effective means to achieve good therapeutic results along with a minimal toxicological impact on healthy cells. Biopolymers are becoming an important class of materials owing to their biodegradability, good compatibility, non-toxicity, non-immunogenicity, and long blood circulation time and high drug loading ratio for both macros as well as micro-sized drug molecules. This review summarizes the recent trends in biopolymer-based DDS, forecasting their broad future clinical applications. Cellulose chitosan, starch, silk fibroins, collagen, albumin, gelatin, alginate, agar, proteins and peptides have shown potential applications in DDS. A range of synthetic techniques have been reported to design the DDS and are discussed in the current study which is being successfully employed in ocular, dental, transdermal and intranasal delivery systems. Different formulations of DDS are also overviewed in this review article along with synthesis techniques employed for designing the DDS. The possibility of these biopolymer applications points to a new route for creating unique DDS with enhanced therapeutic qualities for scaling up creative formulations up to the clinical level.

Study of Single and Multipass f-rGO Inkjet-Printed Structures with Various Concentrations: Electrical and Thermal Evaluation

Reduced graphene oxide (rGO) is a derivative of graphene, which has been widely used as the conductive pigment of many water-based inks and is recognized as one of the most promising graphene-based materials for large-scale and low-cost production processes. In this work, we evaluate a custom functionalised reduced graphene oxide ink (f-rGO) via inkjet-printing technology. Test line structures were designed and fabricated by the inkjet printing process using the f-rGO ink on a pretreated polyimide substrate. For the electrical characterisation of these devices, two-point (2P) and four-point (4P) probe measurements were implemented. The results showed a major effect of the number of printed passes on the resulting resistance for all ink concentrations in both 2P and 4P cases. Interesting results can be extracted by comparing the obtained multipass resistance values that results to similar effective concentration with less passes. These measurements can provide the ground to grasp the variation in resistance values due to the different ink concentrations, and printing passes and can provide a useful guide in achieving specific resistance values with adequate precision. Accompanying topography measurements have been conducted with white-light interferometry. Furthermore, thermal characterisation was carried out to evaluate the operation of the devices as temperature sensors and heaters. It has been found that ink concentration and printing passes directly influence the performance of both the temperature sensors and heaters.

In-vitro Activity of Ceftazidime-Avibactam Against Carbapenem-Resistant K. pneumoniae in a Tertiary-Care Center in Al-Ahsa, KSA

Introduction/Objective

Carbapenem-resistant Enterobacteriaceae (CRE) represents an urgent global threat. Klebsiella pneumoniae is a common cause of various clinical infections showing increased rates of resistance. Carbapenem-resistant Klebsiella pneumoniae (CR-KP) is often multi-drug resistant and sometimes becomes pan-drug resistant causing serious infections with substantial morbidity, mortality and cost. Ceftazidime-avibactam (CZA) is considered to be a good alternative to standard CRE therapy. In our region, CRE is mostly due to OXA-type carbapenemases which are inhibited by CZA, however, metallo-beta-lactamases (MBLs) are being increasingly reported and against which CZA is inactive. The aim of this study is to determine the activity of CZA against CRE-KP isolated in our hospital.

Methods/Case Report

Single-center, prospective study on consecutive non-duplicate CRE-KP isolates recovered from various clinical specimens in 2020 and 2021. BD Phoenix® system was used for initial Identification and susceptibility testing. E-test was done to confirm susceptibility and determine the minimum inhibitory concentration (MIC) for CZA. The standards of the Clinical and Laboratory Standards Institute were followed.

Results (if a Case Study enter NA)

95 CRE-KP isolates were collected. CRE-KP was mostly isolated from: Respiratory samples: 36% (n=34), bedsores: 28% (n=27), urine: 23% (n=22) and 11% (10 isolates) were retrieved from blood cultures. 65% of patients were admitted to the intensive care unit (ICU), 13% were in long-term care wards and 13% were admitted for management of infected bedsores. 88 isolates were susceptible to CZA (93%) with MIC50= 1.5 μg/mL and MIC90= 4.0 μg/mL. 26 isolates (27%) were sensitive only to CZA. Susceptibility to tigecycline was 54%, amikacin 18% and gentamicin 17%. Other antimicrocbials including ceftolozane-tazobactam were basically ineffective.

Conclusion

Ceftazidime-avibactam shows excellent in-vitro activity against CR-KP isolates tested in this study. Further clinical studies on treatment efficacy and emergence of resistance are needed. Moreover, with the recent increase in reported MBLs-mediated resistance in our region, infection control measures, resistance-surveillance programs, and molecular testing may prove essential in the fight against carbapenem-resistant Enterobacteriaceae.

In-vitro Activity of Ceftolozane-Tazobactam Against Multi-Drug ResistantPseudomonas aeruginosa in a Tertiary Care Center in Al-Ahsa, KSA

Introduction/Objective

Pseudomonas aeruginosa is a major nosocomial pathogen often causing serious multi-drug resistant (MDR) infections. Resistant strains, including carbapenem-resistant (CR), are increrasing especially in intensive care units (ICU) which limits treatment options to nephrotoxic aminoglycosides and polymyxins, and results in failure of initial therapy, significant mortality, morbidity and cost. Ceftolozane-tazobactam (CT) is a novel antimicrobial showing good activity against MDR and CR isolates; however, reports of resistance are increasing. Data from KSA is scarce. The aim of this study is to determine the in-vitro activity of CT against MDR and CR P. aeruginosa

Methods/Case Report

Single-center retrospective observational study of patients with P. aeruginosa infection in 2020 and 2021. Data including susceptibility to anti-pseudomonal drugs were retreived from medical records. Non-duplicate consecutive first isolates from all clinical specimens were included. MDR strains were labeled following international guidelines. Data was analyzed using the Statistical Package for the Social Sciences software (SPSS®).

Results (if a Case Study enter NA)

Out of 538 isolates collected, 98 (18.2%) were CR and 62 (11.5%) were MDR. MDR isolates were mainly retrieved from respiratory samples (44%), bedsores (29%) and urine (21%). 62% of CR and 76% of MDR isolates were from patients >60 years of age; significantly higher than younger patients. 85% (83/98) of CR and 81% (50/62) of MDR isolates came from ICU patients where the prevalence of CR and MDR was 34% and 20%, respectively; significantly higher than other areas. Overall sensitivity to CT was 97%, 85% for CR and 71% for MDR isolates. Only amikacin performed better with 98% sensitivity overall, 92% for CR and 86% for MDR. Sensitivity to CT in ICU was 94%. CT was effective against 83% of CR and 70% of MDR isolates second only to amikacin (90% and 84%, respectively). Other tested antimicrobials were ineffective against MDR and CR isolates.

Conclusion

CT shows good in-vitro activity against MDR and CR P. aeruginosa isolates. It may provide a therapeutic option to treat urinary tract infections and hospital-acquired or ventilator-associated pneumoniae especially in critically ill elderly patients. More studies on treatment responses and emergence of resistance are required to establish the role of CT as an effective treatment of serious P. aeruginosa infections.

Supercapacitor performance of porous nickel cobaltite nanosheets

In this work, nickel cobaltite (NiCo2O4) nanosheets with a porous structure were fabricated on nickel foam as a working electrode for supercapacitor applications. The nanosheets were fabricated by electrochemical deposition of nickel-cobalt hydroxide on the nickel foam substrate at ambient temperature in a three-electrode cell followed by annealing at 300 °C to transform the coating into a porous NiCo2O4 nanosheet. Field emission scanning electron microscopy and transmission electron microscopy revealed a three-dimensional mesoporous structure, which facilitates ion transport and electronic conduction for fast redox reactions. For one cycle, the NiCo2O4 electrodeposited nickel foam has a high specific capacitance (1734.9 F g-1) at a current density (CD) of 2 A g-1. The electrode capacitance decreased by only approximately 12.7% after 3500 cycles at a CD of 30 A g-1. Moreover, a solid-state asymmetric supercapacitor (ASC) was built utilising the NiCo2O4 nanosheets, carbon nanotubes, and a polyvinyl alcohol-potassium hydroxide gel as the anode, cathode, and solid-state electrolyte, respectively. The ASC displayed great electrochemical properties with a 42.25 W h kg-1 energy density at a power density of 298.79 W kg-1.

Properties Investigation of GO/HA/Pt Composite Thin Film

Hydroxyapatite/graphene oxide/platinum (HA/GO/Pt) nanocomposite was synthesized and electrodeposited on a pure zirconium substrate. The coated zirconium was annealed at 200, 300, 400, and 600°C in vacuum furnace in presence of argon gas. The structure and morphology of the coated samples were characterized. Biocompatibility and wear and corrosion resistances of specimens were examined. The result of corrosion tests shows that the graphene into HA/Pt composites significantly improves their corrosion resistance. The wear tests results of uncoated and coated samples before and after annealing show that coated samples annealed at 300°C had better wear resistance compared with uncoated and coated samples at other temperatures. Furthermore, the biocompatibility test shows that the coatings improved the cell attachment and proliferation compared to the pure zirconium substrate.

A wireless oxygen saturation and heart rate monitoring and alarming system based on the Qatar Early Warning Scoring system

Background: Peripheral oxygen saturation (SpO2) and heart rate (HR) are important indicators for various medical conditions such as cardiopulmonary disorders and respiratory diseases. The main objectives of this study is to design and implement a portable embedded medical system. This system wirelessly obtains SpO2 and HR data from a patient as well as his/her coordination, and sends a short messaging service (SMS) alarm to the emergency control room to contact the patient and confirm his/her health status or dispatch an ambulance in case of his/her measurements are outside the normal range based on the Qatar Early Warning Scoring (QEWS) system.

Methods: The system mainly consists of a Bluetooth finger pulse oximeter, a Bluetooth-enabled microcontroller, a global positioning system (GPS) and a General Packet Radio Service (GPRS) module. It is divided into three main stages. In the first stage, the readings of SpO2 and HR are obtained from the patient in real time. During the second stage, the readings obtained are sent over Bluetooth to the signal acquisition and processing unit. The received data is processed and a decision is made whether a SMS alarm should be sent or not. The final stage is concerned with sending the alarming SMS to the emergency control room over the GPRS network based on the QEWS system.

Results: The system was implemented and successfully tested as a stand-alone unit by avoiding the use of a PC or a smartphone for data processing. The transmitted SMS alarm includes the SpO2 and HR readings, the QEWS score and the GPS coordinates.

Conclusions: The designed system is wireless, portable, and user-friendly. This system possibly promotes quality of care for the patient living outside hospital and could improve response time from an ambulance service point of view by determining the exact location of the patient.

Multiresidue analysis of 22 sulfonamides and their metabolites in animal tissues using quick, easy, cheap, effective, rugged, and safe extraction and high resolution mass spectrometry (hybrid linear ion trap-Orbitrap)

A new high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) method was developed for a simultaneous multi-residue analysis of 22 sulfonamides (SAs) and their metabolites in edible animal (pig, beef, sheep and chicken) tissues. Sample preparation was optimized on the basis of the "QuEChERS" protocol. The analytes were identified using their LC retention times and accurate mass; the identification was further confirmed by multi-stage high mass accuracy (<5ppm) mass spectrometry. The performance of the method was evaluated according to the EU guidelines for the validation of screening methods for the analysis of veterinary drugs residues. Acceptable values were obtained for: linearity (R(2)<0.99), limit of detection (LOD, 3-26μg/kg), limit of quantification (LOQ, 11-88μg/kg), accuracy (recovery 88-112%), intra- and inter-day precision 1-14 and 1-17%, respectively, decision limit (CCα) and detection capability (CCβ) around the maximum residue limits (MRL) of SAs (100μg/kg). The method was validated by analysis of a reference material FAPAS-02188 "Pig kidney" with ǀ Z-scoreǀ<0.63. The method was applied to various matrices (kidney, liver, muscle) originated from pig, beef, sheep, and chicken) allowing the simultaneous quantification of target sulfonamides at concentration levels above the MRL/2 and the identification of untargeted compounds such as N(4)-acetyl metabolites using multi-stage high mass accuracy mass spectrometry.