Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells:A systematic review

BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

A CuNi/C Nanosheet Array Based on a Metal–Organic Framework Derivate as a Supersensitive Non-Enzymatic Glucose Sensor

Bimetal catalysts are good alternatives for nonenzymatic glucose sensors owing to their low cost, high activity, good conductivity, and ease of fabrication. In the present study, a self-supported CuNi/C electrode prepared by electrodepositing Cu nanoparticles on a Ni-based metal–organic framework(MOF) derivate was used as a non-enzymatic glucose sensor. The porous construction and carbon scaffold inherited from the Ni-MOF guarantee good kinetics of the electrode process in electrochemical glucose detection. Furthermore, Cu nanoparticles disturb the array structure of MOF derived films and evidently enhance their electrochemical performances in glucose detection. Electrochemical measurements indicate that the CuNi/C electrode possesses a high sensitivity of17.12 mA mM^(-1) cm^(-2), a low detection limit of 66.67 nM,and a wider linearity range from 0.20 to 2.72 mM. Additionally, the electrode exhibits good reusability, reproducibility, and stability, thereby catering to the practical use of glucose sensors. Similar values of glucose concentrations in human blood serum samples are detected with our electrode and with the method involving glucose-6-phosphate dehydrogenase; the results further demonstrate the practical feasibility of our electrode.

Response of enzymatic and non-enzymatic antioxidant defense systems of Polygonum hydropiper to Mn stress

The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper （P. hydropiper）, to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly （p〈0.05） decreased with increasing Mn treatment levels （0, 0.5, 1, 2, 4, and 8 mg/L） in hydroponics. The concentrations of malondialdehyde （MDA） and hydrogen peroxide （H202） in the root and shoot of P hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase （SOD）, catalase （CAT）, ascorbate peroxidase （APX） and peroxidase （POD） in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group （--SH） and glutathion （GSH） were likely involved in Mn detoxification ofP. hydropiper under high Mn stress.

A novel sensitive non-enzymatic glucose sensor

Cu nanoclusters were electrochemically deposited on the film of a Nafion-solubilized multi-wall carbon nanotubes (CNTs) modified glassy carbon electrode (CNTs-GCE), which fabricated a Cu-CNTs composite sensor (Cu-CNTs-GCE) to detect glucose with non-enzyme. The linear range is 7.0 × 10?7 to 3.5 × 10?3 mol/L with a high sensitivity of 17.76 μA/(mmol L), with a low detection limit 2.1 × 10?7 mol/L, fast response time (within 5 s), good reproducibility and stability.

Novel insights into conjugation of antitumor-active unsymmetrical bisacridine C-2028 with glutathione:Characteristics of non-enzymatic and glutathione S-transferase-mediated reactions

Unsymmetrical bisacridines(UAs) are a novel potent class of antitumor-active therapeutics.A significant route of phase II drug metabolism is conjugation with glutathione(GSH),which can be non-enzymatic and/or catalyzed by GSH-dependent enzymes.The aim of this work was to investigate the GSHmediated metabolic pathway of a representative UA,C-2028.GSH-supplemented incubations of C-2028 with rat,but not with human,liver cytosol led to the formation of a single GSH-related metabolite.Interestingly,it was also revealed with rat liver microsomes.Its formation was NADPH-independent and was not inhibited by co-incubation with the cytochrome P450(CYP450) inhibitor 1-aminobenzotriazole.Therefore,the direct conjugation pathway occurred without the prior CYP450-catalyzed bioactivation of the substrate.In turn,incubations of C-2028 and GSH with human recombinant glutathione S-transferase(GST) P1-1 or with heat-/ethacrynic acid-inactivated liver cytosolic enzymes resulted in the presence or lack of GSH conjugated form,respectively.These findings proved the necessary participation of GST in the initial activation of the GSH thiol group to enable a nucleophilic attack on the substrate molecule.Another C-2028-GSH S-conjugate was also formed during non-enzymatic reaction.Both GSH S-conjugates were characterized by combined liquid chromatography/tandem mass spectrometry.Mechanisms for their formation were proposed.The ability of C-2028 to GST-mediated and/or direct GSH conjugation is suspected to be clinically important.This may affect the patient’s drug clearance due to GST activity,loss of GSH,or the interactions with GSH-conjugated drugs.Moreover,GST-mediated depletion of cellular GSH may increase tumor cell exposure to reactive products of UA metabolic transformations.

Non-enzymatic Glucose Sensor Based on Porous Foam Au/MXene Nanocomposites

A novel electrochemical non-enzymatic glucose sensor based on three-dimensional Au/MXene nanocomposites was developed.MXenes were prepared using the mild etched method,and the porous foam of Au nanoparticles was combined with the MXene by means of in situ synthesis.By controlling the mass of MXene in the synthesis process,porous foam with Au nanoparticles was obtained.The three-dimensional foam structure of nanoparticles was confirmed by scanning electron microscopy.Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical performance of the Au/MXene nanocomposites.The Au/MXene nanocomposites acted as a fast redox probe for nonenzymatic glucose oxidation and showed good performance,including a high sensitivity of 22.45μA·(mmol/L)^(-1)·cm^(-1)and a wide linear range of 1-12 mmol/L.Studies have shown that MXene as a catalyst-supported material is beneficial to enhance the conductivity of electrons and increase the loading rate of the catalyst materials.The foam structure with Au nanoparticles can provide a larger surface area,increase the contact area with the molecule in the catalytic reaction,and enhance the electrochemical reaction signal.In summary,this study shows that Au/MXene nanoparticles have the potential to be used in non-enzymatic glucose sensors.

The Non-Enzymatic Antioxidant and Level of Oxidative Stress of Tuberculosis Patients in Selected Treatment Center in Addis Ababa Ethiopia

Introduction: Non-enzymatic antioxidants are good scavengers of free radicals preventing their overproduction there by reducing the level of oxidative stress. This work was undertaken at Saint Peter TB specialized hospital and TekleHaimanot health center from March 2012 to May 2013.Aim: To determine changes in Non-Enzymatic Antioxidants and level of oxidative stress of tuberculosis Patients before and after taking anti tuberculosis treatment.Materials and Methods: In this comparative cross sectional study, a total of 210 individuals including: newly diagnosed TB patients as group-I (n = 70), TB patients who completed treatment as group-II (n = 70), and healthy volunteers as group-III (n = 70) were enrolled. Different methods were used to determine the parameters;vit-C (HPLC method), lipid peroxidation (thiobarbuituric acid method), and bilirubin (Colorimetric assay). Results: Vitamin-C (Vit-C) and of group-I showed a significant reduction (p < 0.001) as compared with both group-II and group-III whereas Malondialdehyde (MDA) level was increased. However, the total and direct bilirubin was not different among the groups. In group-III, there was a positive correlation between BMI and serum Vit-C (r = -0.305, p = 0.010). Vit-C showed a negative correlation with serum MDA in all the groups with values (r = -0.265, p = 0.027), (r = -0.389, p = 0.001) and (r = -0.375, p = 0.001) for group-I, group-II and group-III respectively. In addition to this Vit-C was negatively correlated with serum UA (r = -0.285, p = 0.017) in group-I. Conclusion: The findings of the current study suggest that the amount of Vit-C in the newly diagnosed TB patients and those who finished their treatment is much lower than the healthy volunteers. In contrast to this, the MDA value was significantly higher both in the newly diagnosed TB patients and TB patients who completed treatment than in healthy volunteers suggesting higher degree of oxidative stress.

Non-Enzymatic Glucose Sensor Based on the Novel Flower Like Morphology of Nickel Oxide

In this study, novel nickel oxide (NiO) flowers like nanostructures were fabricated onto gold coated glass substrate by hydrothermal method using high alkaline pH medium. The structural study of nickel oxide nanostructures was performed by scanning electron microscopy (SEM) and X-ray differaction (XRD) techniques. Nickel oxide nanostructures are highly dense, uniform and possess good crystalline quality. The so prepared structures were investigated for their electrochemical properties by cyclic voltammetry and amperometric techniques. The nickel oxide flower like morphology has shown good electrochemical performances for the oxidation of glucose. The presented sensing material was able to detected glucose in a wide range of concentration of 0.001 mM to 8 mM with a high sensitivity (123 μmA/mM) and regression coefficient of 0.99. Moreover, the NiO nanostructures based sensor is highly reproducible, stable, exhibiting a fast response time and selective in the response. All the obtained results indicate the potential use of this material in the development of enzyme free sensors for the detection of glucose.

Electrochemistry and DFT study of galvanic interaction on the surface of monoclinic pyrrhotite(001)and galena(100)

The electrochemical interaction between galena and monoclinic pyrrhotite was investigated to examine its impact on the physical and chemical properties of the mineral micro-surface.This investigation employed techniques such as electrochemistry,metal ion stripping,X-ray photoelectron spectroscopy,and quantum chemistry.The electrochemical test results demonstrate that the galena surface in the electro-couple system exhibits a lower electrostatic potential and higher electrochemical activity compared to the monoclinic pyrrhotite surface,rendering it more susceptible to oxidation dissolution.Monoclinic pyrrhotite significantly amplifies the corrosion rate of the galena surface.Mulliken charge population calculations indicate that electrons are consistently transferred from galena to monoclinic pyrrhotite,with the number of electron transfers on the mineral surface increasing as the interaction distance decreases.The analysis of state density revealed a shift in the surface state density of galena towards lower energy levels,resulting in decreased reactivity and increased difficulty for the reagent to adsorb onto the mineral surface.Conversely,monoclinic pyrrhotite exhibited an opposite trend.The X-ray photoelectron spectroscopy(XPS)test results indicate that galvanic interaction leads to the formation of hydrophilic substances,PbS_(x)O_(y) and Pb(OH)_(2),on the surface of galena.Additionally,the surface of monoclinic pyrrhotite not only adsorbs Pb^(2+)but also undergoes S^(0) formation,thereby augmenting its hydrophobic nature.

Ionic liquid modified GC electrode for the direct electrochemistry of chloroperoxidase

Chloropcroxidase （CPO） was immobilized by konjac glucomannan （KGM） on the 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4]/Nafion modified glassy carbon eloctrode. The electrochemical behaviors of the immobilized CPO were investigated by cyclic voltammetry. The results showed that CPO was successfully immobilized on the GCE and underwent fast direct electron transfer reactions with the formal potential at -0.3 V vs. SCE. The modified electrode showed a good catalytic activity for elcctrocatalytical reduction of O2 and H2O2.

A semiconductor-electrochemistry model for design of high-rate Li ion battery

For designing batteries with high-rate and long-life, electronic/ionic transport and reaction must be unified for metal oxide electrodes. However, it remains challenging for effectively integrating the whole substrate/active materials/electrolyte interfaces. Herein by taking Li ion battery as example, we propose a semiconductor-electrochemistry model by which a general but novel insight has been gained into interfacial effect in batteries. Different from those traditional viewpoints, this derived model lies across from physics to electrochemistry. A reaction driving force can be expressed in terms of Fermi energy change,based on the tradeoff between electronic and ionic concentration at the reaction interfacial region. Therefore, at thermodynamic-controlled interface I of substrate/electrode, increasing contact areas can afford higher activity for active materials. Whereas at kinetically-governed interface II of electrode/electrolyte or inside active materials, it is crucial to guarantee high-reaction Li ionic concentration, with which some sufficient reaction degrees can reach.

Understanding oxygen electrochemistry in aprotic Li-O_2 batteries

In the past decade, the aprotic lithium-oxygen(Li-O_2) battery has generated a great deal of interest because theoretically it can store more energy than today's lithium-ion batteries. Although considerable research efforts have been devoted to the R&D of this potentially disruptive technology, many scientific and engineering obstacles still remain to be addressed before a practical device could be realized. In this review, we summarize recent advances in the fundamental understanding of the O_2 electrochemistry in Li-O_2 batteries, including the O_2 reduction to Li_2O_2 on discharge and the reverse Li_2 O_2 oxidation on recharge and factors that exert strong influences on the redox of O_2/Li_2O_2. In addition,challenges and perspectives are also provided for the future study of Li—O_2 batteries.

INVESTIGATION ON ELECTROCHEMISTRY INSIDE STRESS CORROSION CRACKS OR PITS

Techniques are developed for studying the mechanism of localized corrosion and protectivemeasures against such corrosion are suggested.The pH values and composition of the occluded sol-ution at different propagation stages are determined.Measurements of the critical pH value and cor-rosion rate inside the occluded cells are conducted.Potential-pH diagrams depicting kinetic andthermodynamic behaviors of occluded cell corrosion are being established.The mechanism of inhibi-tion of pitting and stress corrosion cracking have also been investigated.

THE PULP ELECTROCHEMISTRY OF FLOTATION SEPARATION FOR STIBNITE-ARSENOPYRITE BULK CONCENTRATE

In the thermodynamics, for flotation separation of the SbAs bulk concentrate system there is no potential extent using butyl xanthate as collector. However in the kinetics, there exists 150 mV in reducing potential of butyl dixanthogen on the surface of stibnite and arsenopyrite. In this paper, their reducing kinetic difference of electrochemistry was confirmed by pure mineral flotation under controlled potential, the artificial SbAs bulk concentrate flotation separation and UVspectrophotometic analysis. The electrochemical separation of SbAs bulk concentrate has been carried out. qualified concentrate has been obtained. Sbconcentrate contains Sb 4944 %, As 044 %, Sbrecovery is 8783 % and Asconcentrate contains As 1096 %, Asrecovery is 9466 %.

Electrochemistry of Hydroquinone Derivatives at Metal and Iodine-modified Metal Electrodes

The difference in the electrochemical behavior of hydroquinone and pyrocatechol at platinum and gold surfaces was analyzed using voltammetry and attenuated total reflection Fourier transform infrared spectroscopy. The results show that the hydroquinone derivatives are adsorbed on a gold surface with vertical orientation, which makes the electron transfer between the bulk species and the electrode surface easier than that in the case of flat adsorption of hydroquinone derivatives that occurs at a platinum electrode. The formation of the vertical conformation and the rapid process of electron transfer were also confirmed by quantum chemistry calculations. In addition, the pre-adsorbed iodine on the electrodes played a key role on the adsorbed configuration and electron transfer of redox species.

Predominating stable adsorption and direct electrochemistry of glucose oxidase on carbon nanotubes by oxygen-containing groups

Stable adsorption and direct electrochemistry of glucose oxidase （COx） occurred on nitric acid （HNO3）-treated multi-walled carbon nanotubcs （MWNTs） instead of as-received MWNTs, demonstrating the critical roles of oxygen-containing groups in stable adsorption and direct electrochemistry of GOx on carbon nanotubcs （CNTs）.

Recent development in researches of electrochemistry of sulphide flotation at Central South University of Technology

The recent development on flotation electrochemistry of sulphide minerals at Central South University of Technology is briefly summarized. General behavior of natural floatability, self and sulphur induced, and collector induced floatability of sulphide minerals are described. The mechanism is discussed based on Eh pH diagrams, voltammograms, energy band theory and molecular orbital theory.

Direct Electrochemistry of Hemoglobin Immobilized in Sodium Alginate Film on the Ionic Liquid [BMIM]PF_6 Modified Carbon Paste Electrode

Room temperature ionic liquid （RTILs） [BMIM]PF6 was used as a new kind of binder to construct a chemical modified carbon paste electrode （CPE） and the direct electrochemistry of hemoglobin （Hb）, which was immobilized on the surface of RTIL/CPE with the film of sodium alginate hydrogel, was studied by cyclic voltammetry. The presence of RTILs improved the direct electron transfer of Hb and a pair of well-defined quasi-revesible redox peaks appeared in pH 7.0 B-R buffer solution. The cathodic and anodic peak potentials were located at -0.383 V and -0.305 V with the formal potential （E^0） at -0.344 V （vs. SCE）. In addition the immobilized Hb showed good electrocatalytic activity to the reduction of H2O2.

Synthesis, Fluorescence and Electrochemistry of Three New Ruthenium(Ⅱ) Complexes

ＩｎｔｒｏｄｕｃｔｉｏｎＥＬＣｉｓａｔｅｃｈｎｉｑｕｅｂｙｗｈｉｃｈａｃｈｅｍｉｌｕｍｉｎｅｓｃｅｎｔｒｅａｃｔｉｏｎｉｓｇｅｎｅｒａｔｅｄｆｒｏｍｔｈｅｒｅａｇｅｎｔｓｐｒｏｄｕｃｅｄｉｎｔｈｅｖｉｃｉｎｉｔｙｏｆａｎｅｌｅｃｔｒｏｄｅｓｕｒｆａｃ...

Metal-organic frameworks-derived metal phosphides for electrochemistry application

Metal-organic frameworks(MOFs)with high porosity and variable structure have attracted extensive attention in the field of electrochemistry,but their poor conductivity and stability have limited their development.Materials derived from MOFs can maintain the structural diversity and porosity characteristics of MOFs while improving their electrical conductivity and stability.Metal phosphides play an important role in electrochemistry because they possess rich active sites,unique physicochemical properties,and a porous structure.Published results show that MOF-derived metal-phosphides materials have great promise in the field of electrochemistry due to their controllable structure,high specific surface area,high stability and excellent electrical conductivity.MOF-derived metal-phosphides with significant electrochemical properties can be obtained by simply,economical and scalable synthetic methods.This work reviews the application of MOF-derived metal phosphides in electrochemistry.Specifically,the synthesis methodology and morphological characterization of MOFs derived metal-phosphides and their application in electrochemistry are described.Based on recent scientific advances,we discuss the challenges and opportunities for future research on MOF-derived metal-phosphides materials.