China
Africa
Explore chapters and articles related to this topic
Application of Next-Generation Plant-Derived Nanobiofabricated Drugs for the Management of Tuberculosis
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Charles Oluwaseun Adetunji, Olugbenga Samuel Michael, Muhammad Akram, Kadiri Oseni, Ajayi Kolawole Temidayo, Osikemekha Anthony Anani, Akinola Samson Olayinka, Olerimi Samson E, Wilson Nwankwo, Iram Ghaffar, Juliana Bunmi Adetunji
The optical characterization of nanoparticles is based on Beer–Lambert theory and the principle of basic light. The techniques commonly employed in the determination of optical characterization include UV-vis, null ellipsometer and photoluminescence. These take into consideration the absorption, luminescence, reflectance and phosphorescence (Khan et al., 2019).
Blood Cells and Rheology
Published in John H. Barker, Gary L. Anderson, Michael D. Menger, Clinically Applied Microcirculation Research, 2019
Dick W. Slaaf, Geert Jan Tangelder, Mirjam G. A. oude Egbrink, Robert S. Reneman
Various methods are available to measure deformability of individual RBCs. One way to measure its deformability is to aspirate an RBC by a micropipette.15 The negative pressure required to suck part of the RBC into a micropipette is evaluated. Deformability can also be assessed with the single erythrocyte rigidometer. The passage time of RBCs through a small pore under a shear stress of about 3 Pa is determined.30 The result is given as a histogram of passage times. Using a counter-rotating cone-plate Rheoscope, the deformations of individual RBCs can be observed directly.50 When a rotational viscometer is combined with laser diffraction ellipsometry, the average deformability of a sample of RBCs can be assessed from the ratio of the long and short axis of the resulting diffraction pattern8,24,25 (see Figure 5). The same instrument also may be modified to assess RBC aggregation.26
Polymer Adsorption: Fundamentals
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
If the polarization of the reflected light is also measured, the technique is known as ellipsometry. Measurements are usually carried out at the Brewster angle, where the parallel polarized, reflected light is at its minimum value. The measured quantity is the ellipticity—the ratio of the reflection coefficients of the parallel and perpendicularly polarized light:
Mucoadhesive drug delivery systems: a promising non-invasive approach to bioavailability enhancement. Part I: biophysical considerations
Published in Expert Opinion on Drug Delivery, 2023
Radha Kulkarni, Suraj Fanse, Diane J. Burgess
A review of the reported scientific literature suggests a lack of standardized methods for mucoadhesive testing (i.e. equipment and animal models used). Moreover, there is an emerging trend toward utilizing multiple techniques to gain more insights about the mechanism of mucoadhesion and the effect of formulation variables on product performance. The selection of a suitable analytical method along with tissues/animal models should be based on factors, such as the site of administration, duration of action, and the type of drug and polymers. For example, a texture analyzer can be used for evaluating semi-dry formulations such as buccal films. On the other hand, ellipsometry, rotating cylinder, and AFM are more useful for evaluating the interactions between mucoadhesive polymers [85]. MDDS designed to adhere to the GIT is best evaluated using specially designed flow channel apparatus and can be visualized using fluorescent probes. Rheological method is highly beneficial for evaluating nasal gels, which involves a thick mucus layer (nasal mucosa) and a dissolved polymer. On the other hand, BIACORE can be used to study the interactions between the polymer and the mucin substrate with great precision and sensitivity. Not only an innovative approach toward experiment design is necessary, but emphasis must also be laid on standardized output processing to ensure effective correlation of data. Associated cost as well as technical and ethical issues must also be considered.
Biosensors for the detection of mycotoxins
Published in Toxin Reviews, 2022
Akansha Shrivastava, Rakesh Kumar Sharma
Other optical biosensors include ellipsometric, surface-enhanced Raman scattering, optical waveguide interferometric, and reflectometric interference spectroscopy (RIFS) biosensors. Ellipsometry is a technique used to determine the thickness of an optical layer. It sensitively measures the changes in polarization when electromagnetic radiation is reflected or transmitted by the analyte. On the other hand, surface-enhanced Raman scattering is a biosensing technique that enhances the intensity of the vibration spectra of a molecule by several orders of magnitude when it is in close proximity to nanoparticles made up of gold or silver. A Raman spectroscopy-based demonstration of good potentials for nondestructive and rapid screening of DON contaminated wheat bran samples was developed. An optical waveguide interferometric is an integrated biosensor, a combination of evanescent field sensing and optical phase difference measurement methods. This technique is also known as resonant waveguide grating (RWG) and is suitable for detecting the redistribution of cellular contents, studying cellular responses, and cellular processes, and has also been applied for the detection of the avian influenza virus (Mignani et al. 2016). Reflectometric interference spectroscopy is a label-free and time-resolved method where the simple optical setup is based on white light interference at thin layers. Detection and quantification of diclofenac in bovine milk have been successfully achieved in the complex milk matrix (Maragos 2004, Damborský et al. 2016).
Quartz crystal microbalance based histidine sensor
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Merve Sönmezler, Erdoğan Özgür, Handan Yavuz, Adil Denizli
The synthesis of MIP was performed by two-phase mini-emulsion polymerization method [28]. Same synthesis approach was applied for the synthesis of non-imprinted nanoparticles (NIP) without using l-histidine. Prior to attaching of MIP onto the gold surface of QCM electrode, OCM electrode was immersed into the acidic piranha solution for 20 s then cleaned with deionized water and EtOH. Afterwards, 5 μL of MIP suspension was drop-casted on the QCM electrode and it was dried in a dust-free environment at 37 °C for 6 h. MIP attached QCM electrode was cleaned with DI and pure EtOH. FTIR-ATR characterization measurement of MIP biosensor was conducted by using the FTIR-ATR spectrophotometer. An auto-nulling imaging ellipsometer was used for thickness measument. All measurements were done at a wavelength of 532 nm with an incidence angle of 62°. Contact angle measurements were performed with Kruss DSA100 with sessile drop method.