scholarly journals An investigation of PS-b-PEO polymersomes for the oral treatment and diagnosis of hyperammonemia

2019 ◽  
Author(s):  
Simon Matoori ◽  
Yinyin Bao ◽  
Aaron Schmidt ◽  
Eric J. Fischer ◽  
Rafael Ochoa-Sanchez ◽  
...  

AbstractAmmonia-scavenging transmembrane pH-gradient poly(styrene)-b-poly(ethylene oxide) polymersomes were investigated for the oral treatment and diagnosis of hyperammonemia, a condition associated with serious neurologic complications in patients with liver disease as well as in infants with urea cycle disorders. While these polymersomes were highly stable in simulated intestinal fluids at extreme bile salt and osmolality conditions, they unexpectedly did not reduce plasmatic ammonia levels in cirrhotic rats after oral dosing. Incubation in dietary fiber hydrogels mimicking the colonic environment suggested that the vesicles were probably destabilized during the dehydration of the intestinal chyme. Our findings question the relevance of commonly used simulated intestinal fluids for studying vesicular stability. With the encapsulation of a pH-sensitive dye in the polymersome core, the local pH increase upon ammonia influx could be exploited to assess the ammonia concentration in the plasma of healthy and cirrhotic rats as well as in other fluids. Due to its high sensitivity and selectivity, this novel polymersome-based assay could prove useful in the monitoring of hyperammonemic patients and in other applications such as drug screening tests.Graphical abstract

2020 ◽  
Vol 10 ◽  
Author(s):  
Bianca Peterson ◽  
Henrico Heystek ◽  
Josias H. Hamman ◽  
Johan D. Steyn

Background:: Knowledge of the permeation characteristics of new chemical entities across biological membranes is essential to drug research and development. Transport medium composition may affect the absorption of compounds during in vitro drug transport testing. To preserve the predictive values of screening tests, the possible influence of transport media on the solubility of model drugs, and on the activities of tight junctions and efflux transporter proteins (e.g. P-glycoprotein) must be known. Objective:: The aim of this study was to compare the impact of different transport media on the bi-directional transport of standard compounds, selected from the four classes of the Biopharmaceutical Classification System (BCS), across excised pig intestinal tissue. Methods:: The Sweetana-Grass diffusion apparatus was used for the transport studies. Krebs-Ringer bicarbonate (KRB) buffer and simulated intestinal fluids in the fed (FeSSIF) and fasted (FaSSIF) states were used as the three transport media, while the chosen compounds were abacavir (BCS class 1), dapsone (BCS class 2), lamivudine (BCS class 3) and furosemide (BCS class 4). Results:: Abacavir exhibited lower permeability in both the simulated intestinal fluids than in the KRB buffer. Dapsone showed similar permeability in all media. Lamivudine exhibited lower permeability in FaSSIF than in the other two media. Furosemide exhibited improved transport with pronounced efflux in FaSSIF. Conclusion:: Different permeation behaviors were observed for the selected drugs in the respective media, which may have resulted from their different physico-chemical properties, as well as from the effects that dissimilar transport media components had on excised pig intestinal tissue.


Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.


2019 ◽  
Vol 11 (10) ◽  
pp. 1405-1409 ◽  
Author(s):  
Haoshuang Shen ◽  
Baoxia Liu ◽  
Daosheng Liu ◽  
Xu Zhu ◽  
Xiuhua Wei ◽  
...  

GMP ligand based LCP sensor for Cit with high sensitivity and selectivity was constructed.


2020 ◽  
Vol 12 (8) ◽  
pp. 1122-1130
Author(s):  
Yan Liu ◽  
Lu-Lu Peng ◽  
Wei-Xiong Huang ◽  
Hui-Zhuo Zhou ◽  
Li Xu

A luminescent nucleotide/Tb3+ coordination polymer (CP) was synthesized using adenosine triphosphate (ATP) molecules as a bridge ligand and Phen as a sensitizer, which showed high sensitivity and selectivity for Fe2+.


2021 ◽  
Author(s):  
Luis David Rosales-Vazquez ◽  
Alejandro Dorazco-González ◽  
Victor Sanchez-Mendieta

Optical sensors with high sensitivity and selectivity, as important analytical tools for chemical and environmental research, can be accomplished by straightforward synthesis of luminescent one-, two- and three-dimensional Zn(II) and...


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1922
Author(s):  
Gwang Su Kim ◽  
Yumin Park ◽  
Joonchul Shin ◽  
Young Geun Song ◽  
Chong-Yun Kang

The breath gas analysis through gas phase chemical analysis draws attention in terms of non-invasive and real time monitoring. The array-type sensors are one of the diagnostic methods with high sensitivity and selectivity towards the target gases. Herein, we presented a 2 × 4 sensor array with a micro-heater and ceramic chip. The device is designed in a small size for portability, including the internal eight-channel sensor array. In2O3 NRs and WO3 NRs manufactured through the E-beam evaporator’s glancing angle method were used as sensing materials. Pt, Pd, and Au metal catalysts were decorated for each channel to enhance functionality. The sensor array was measured for the exhaled gas biomarkers CH3COCH3, NO2, and H2S to confirm the respiratory diagnostic performance. Through this operation, the theoretical detection limit was calculated as 1.48 ppb for CH3COCH3, 1.9 ppt for NO2, and 2.47 ppb for H2S. This excellent detection performance indicates that our sensor array detected the CH3COCH3, NO2, and H2S as biomarkers, applying to the breath gas analysis. Our results showed the high potential of the gas sensor array as a non-invasive diagnostic tool that enables real-time monitoring.


Author(s):  
Rocío Cabra-Rodríguez ◽  
Guadalupe Bueno Rodríguez ◽  
Cristina Santos Rosa ◽  
Miguel Ángel Castaño López ◽  
Sonia Delgado Muñoz ◽  
...  

AbstractObjectivesNon-invasive prenatal screening (NIPS) is a test for the detection of major fetal chromosomal abnormalities in maternal blood during pregnancy. The purpose of this study was to assess the performance of NIPS implemented within the framework of the Screening Program for Congenital Abnormalities of the Andalusian Health System.MethodsA retrospective observational study was undertaken to determine the number of NIPS tests performed since its introduction. The number of invasive diagnostic tests done after the implementation of NIPS in the patients included in the program between March 2016 and August 2017 was also quantified.ResultsA total of 6,258 combined first- and second trimester screening tests were performed, covering 95% of the population. In total, 250 subjects were identified as high risk, of whom 200 underwent NIPS after loss to follow-up. NIPS showed a sensitivity of 100% (95% CI: 76.84–100%) and a specificity of 99.46% (95% CI: 97.04–99.99%).ConclusionsThis test has proven to have a very high sensitivity and specificity. The results obtained demonstrate that the incorporation of NIPS in clinical practice minimizes the rate of miscarriages and reduces the frequency of invasive procedures by 70%.


Sign in / Sign up

Export Citation Format

Share Document