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Advanced Formulation Techniques Including Innovative Materials
Published in Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters, Cosmetic Formulation, 2019
Bozena Michniak-Kohn, Tannaz Ramezanli, Frank Romanski, Cliff Milow, Kishore Shah
Evaluation of this family of polymers has shown that the triblock polymer PEG5K-b-oligo(desaminotyrosyl-tyrosine octyl ester suberate)-b-PEG5K (DTO-SA/5K) is optimal for encapsulation efficiency, has the lowest polydispersity index (0.17), a reproducible hydrodynamic diameter of 60–70 nm, and very low critical aggregation concentration (2.6 × 10–7 g/mL measured by static light scattering), making this polymer the lead candidate evaluated for nanosphere applications. The cytotoxicity of TyroSpheres was examined on a variety of cell lines and these nanospheres were found not toxic at concentrations up to 11.5 mg/mL (Sheihet et al., 2005, 2007).
Challenges of Investigation
Published in Golara Honari, Rosa M. Andersen, Howard Maibach, Sensitive Skin Syndrome, 2017
Lidia Maroñas-Jiménez, Elena González-Guerra, Aurora Guerra-Tapia
These types of tests relies on the measurement of structural or physiological cutaneous changes after the application of topical irritants, such as SLS or others. TEWL, cutaneous pH, and epidermal thickness, measured by ultrasonography, optical microscopy, or confocal microscopy, as well as skin penetrability, assessed with UV light, are the parameters most commonly used (13,14,24).
X-Ray Diffraction as a Tool for Studying Collagen Structure
Published in Marcel E. Nimni, Collagen, 1988
Barbara Brodsky, Shizuko Tanaka, Eric F. Eikenberry
Various methods tend to support the presence of some defined structure in the telopeptides,18 and experiments support their role in fibrillogenesis.19,20 The meridional intensities of the medium angle X-ray and neutron diffraction pattern.21,22 and the electron microscope banding patterns of SLS and native fibrils.23 place important constraints upon the proposed conformations of these peptides. Direct definition of the conformation of telopeptides would require crystallographic analysis, either of these regions alone (which would be difficult because of the structural instability of such small peptides) or while still linked to some of the triple-helix or propeptide regions.
Guanidine-modified albumin-MMAE conjugates with enhanced endocytosis ability
Published in Drug Delivery, 2023
Ce Yi, Fei Xie, Xin Xu, Dian Xiao, Xinbo Zhou, Maosheng Cheng
Tm and Tagg data were acquired by the Uncle, which running the Client software V5.03. A linear thermal ramp was performed from 15 to 95 °C at a rate of 0.3 °C/min. Before filling the sample into the loader, ensure that the volume of each sample is 9 μL. UV Filter 1 and Blue Filter 3 were used to illuminated the samples, which incubation time was 120 seconds. And then UNcle Analysis software V5.03 achieved Data analysis. Through analyzed the average center of gravity (BCM) between 300 and 430nm, the changes in intrinsic fluorescence with temperature were monitored, which excited using the 266 nm laser. Under appropriate conditions, detected changes in static light scattering by measuring the intensities of the peaks at 266 and 473 nm. At last, through identified by the differential of the maximum gradient of the BCM versus temperature traces to obtained Tm values. The above experimental methods refer to previously reported (Huang et al., 2022).
Quantification methods for viruses and virus-like particles applied in biopharmaceutical production processes
Published in Expert Review of Vaccines, 2022
Keven Lothert, Friederike Eilts, Michael W. Wolff
Light scattering has proven to be a fast and reliable technique to determine particle sizes and dimensions as well as particle counts. Measurements can be done either by static or by dynamic light scattering (SLS or DLS) analysis [134], with the respective methods being briefly explained in the following. The principle of measurement relies on a laser beam, which is directed at the sample. The data read-out for DLS is based on the fluctuations in scattering intensity, measured in very short time intervals (nanoseconds). The fluctuations are caused by particle displacement, either resulting from diffusion or from Brownian motion. By means of a scattering autocorrelation function, the average hydrodynamic diameter of the particles is calculated from the photon count rates. Multi-angle DLS (MADLS), a variation of the classical DLS, estimates the particle size by analyzing the scattering autocorrelation functions from different, usually three, angles. For both DLS methods, the intensity-weighted particle size is mathematically transformed into a particle concentration.
Influence of physiochemical properties on the subcutaneous absorption and bioavailability of monoclonal antibodies
Published in mAbs, 2020
Amita Datta-Mannan, Selina Estwick, Chen Zhou, Hiuwan Choi, Nicole E. Douglass, Derrick R. Witcher, Jirong Lu, Catherine Beidler, Rohn Millican
Fluorescence coupled with static light scattering was used to evaluate the onset temperature of tertiary structure unfolding. A UNit® (Unchained labs, Pleasanton, CA) system was used to measure the fluorescence and static light scattering simultaneously. During the measurement, ~8.8 uL protein sample at 1 mg/mL was loaded to the cuvette; the samples were held at 20°C for 120 s and then ramped to 95°C at the rate of 0.3°C/min. Both fluorescence and static light scattering (at 266 nm) were collected after excitation at 266 nm. After measurement, the data were loaded onto the UNit® analysis software, the raw fluorescence signals were extracted and further processed with excel. The onset of tertiary structure unfolding (Tonset) was defined as the temperature when center of mass (CM) of the fluorescence emission spectrum (agg) is defined as the first temperature at which the first derivative is larger than 0.