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Theory of Granulation
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Bryan J. Ennis, Michael Winn, Brandon Ennis, Naseem Jibrin
Charges can also exist at interfaces, as characterized by electrokinetic studies [34]. The total solid-fluid interfacial energy (i.e., both dispersion and polar components) is also referred to as the critical solid surface energy of the particulate phase. It is equal to the surface tension of a fluid, which just wets the solid with zero contact angle. This property of the particle feed may be determined by a third approach to characterize wetting, involving the penetration of particles into a series of fluids of varying surface tension [33,35], or by the variation of sediment height [36].
Disorders in tHemostasis System and Changes in the Rheological Properties of the Blood in Ischemic Heart Disease and Diabetes Mellitus Patients
Published in E.I. Sokolov, Obesity and Diabetes Mellitus, 2020
Aggregation of erythrocytes is an integrative process that is affected by changes in the protein and lipid composition of the blood. Disorder in the lipid composition of the plasma in DM patients (dyslipoproteinemia, hyperfibrinogenemia) alters the electrokinetic charge of the erythrocytes (drastically lowers it), especially in the presence of spherulized forms of the erythrocytes. In healthy persons, the erythrocytes have a considerable surface negative charge that repels the cells from one another. In DM, a growth in the level of fibrinogen and other high-molecular proteins lowers this potential, and this substantially accelerates aggregation (cohesion) of the erythrocytes.
Drug Monitoring by Capillary Electrophoresis
Published in Steven H. Y. Wong, Iraving Sunshine, Handbook of Analytical Therapeutic Drug Monitoring and Toxicology, 2017
Due to the availability of automated CE instruments, first examples of fully validated assays emerged, assays which have been applied to therapeutic and diagnostic drug monitoring (Table 1–1, Refs. 11–21) and to screening for and confirmation of drugs and metabolites in body fluids (Table 1–2, Refs. 22–42). Electrokinetic capillary technology is currently in the process of becoming applied to drug monitoring in routine laboratories.43 This chapter provides a brief review on drug monitoring by CE. The review is restricted to CZE and MECC separations of drugs and metabolites in body fluids, particularly serum (plasma), saliva, and urine (Tables 1–1 and 1–2). It does not deal with the determination of endogenous compounds, such as creatinine and uric acid,44 as well as the diagnosis of human diseases via monitoring of metabolic disorders,45 nor does it review the innumerable papers reporting the use of this emerging technology for the analysis of drugs in pharmaceutical preparations.10,46 Also, applications employing capillary isotachophoresis are not covered and interested readers are referred to the monograph of Boček et al47
An impedance flow cytometry with integrated dual microneedle for electrical properties characterization of single cell
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Muhammad Asraf Mansor, Mohd Ridzuan Ahmad, Michal Petrů, Seyed Saeid Rahimian Koloor
Label-free analysis in the microfluidic single-cell impedance technique is widely utilized for early cancer detection, disease development prediction and therapeutic intervention suggestions. The label-free analysis technique is a significant study due to how it reflects cell phenotype, such as biophysical electrical or mechanical properties. It is label-free means that the cells are not changed by chemical reagents or by extensive handling [1]. This label-free method protects cells from adverse effects associated with label production and is helpful in a wide range of applications. Microfluidic impedance spectroscopy is one commonly employed label-free method that is capable to measure the electrical characteristics of cells. Electrokinetic techniques based on alternating current (AC), particularly electrorotation and/or dielectrophoresis, have been utilized in the past [2–4]. The AC electrokinetic approach is a powerful tool capable of extracting the electrical properties of the cell; however, they lack high throughput, even though recent approaches have improved this [5–7].
Surface charge, glycocalyx, and blood-brain barrier function
Published in Tissue Barriers, 2021
Fruzsina R. Walter, Ana R. Santa-Maria, Mária Mészáros, Szilvia Veszelka, András Dér, Mária A. Deli
As far as biological barriers are concerned, however, it is not usually necessary to provide a detailed spatial information about the charge distribution at the interface, but an average value characteristic of surface charge density proves to be sufficient to understand the rule of thumb determining the relationship between surface charge properties and biological function. For this purpose, experiments utilizing electrokinetic phenomena can be applied. The measured electric parameter is generally the so-called zeta-potential (Vζ), that represents a sort of “damped” surface potential, due to the screening effect of the counterions in the diffuse double layer. By definition, the zeta-potential is the electric potential difference between the surface of the “shear layer” (that part of the interfacial fluid that remains attached to the surface under flow conditions, of a thickness δ) and the bulk, and it is proportional to the average surface charge density (σ), according to the linearized Grahame equation for low surface potentials: Vζ = (σ·λD/ε·ε0)·exp(-δ/λD), where ε0 and ε are absolute and relative electric permittivity, respectively.149
Intravesical electromotive administration of botulinum toxin type A in improving the bladder and bowel functions: Evidence for novel mechanism of action
Published in The Journal of Spinal Cord Medicine, 2021
Abdol-Mohammad Kajbafzadeh, Hamed Ahmadi, Laleh Montaser-Kouhsari, Shabnam Sabetkish, Sanam Ladi-Seyedian, Masoud Sotoudeh
In EMDA, drug transportation is accelerated by multiple electrokinetic forces.17 In optimal intravesical BoNTA delivery, EMDA, sufficient delivery time, adequate drug concentration with non-harmful intensity are of great value which should be taken into consideration.18 In the current study, functional density of 0.12 mA/cm2 and drug concentration of 1.2 IU/cm2 were applied which has been recommended to prevent tissue damage and burning sensation.19 It has also been demonstrated that drug can be penetrated efficiently within the first 15 min of EMDA.18 Although it has been reported that the bladder dome and the anterior wall are less susceptible to drug penetration in EMDA as they are far from electrical field,18 pathological specimens from BoNTA/EMDA group demonstrated that BoNTA has distributed to former areas in an identical pattern. In the current experimental study, a growing body of evidence has supported that the establishment of BoNTA/EMDA may have promising advantages for patients with bladder and bowel dysfunctions. By the application of this method, homogeneous distribution of BoNTA can be feasible in bladder and bowel segments.