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Toxicity Analysis of Ag and Au Nanoparticles
Published in Suresh C. Pillai, Yvonne Lang, Toxicity of Nanomaterials, 2019
The NP flow rate in a solution (physiological liquids or incubation media) is a parameter that has often been neglected when studying the transport processes of NPs. NP transport experiments have been performed under static conditions in a Petri dish. Upright and inverted cell cultures have been studied by Cho et al., reporting that cellular uptake of Au-NPs depends on the sedimentation and diffusion velocities of the NPs [43]. Other researchers explored the gravitational settling of NPs [44] and the time linearity of the intracellular concentration of NPs. They showed also that the uptake of NPs is essentially irreversible [44]. These studies were performed under static conditions and the NPs were tested in a Petri dish following the NP settlement onto a cell culture. Quartz crystal microbalance with dissipation monitoring (QCM-D) was used in a flow chamber to follow the particles deposition/sedimentation under flow conditions [45]. Although the flow in a QCM-D chamber does not precisely depict how particles/NPs will move over a real human system, it brings researchers one step further in mimicking a real in vivo experiment in which the NPs are exposed to flow rates. To get a glimpse into understanding how the flow rate affects the NPs’ deposition rate, researchers studied the NPs’ behaviour under no-flow conditions and under different flow rates (from 50 to 250 µL/min).
General Properties and Characterization Methods of Biomaterials
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
On the other hand, several methods have been employed for understanding interactions between proteins, cell and material surfaces, which are critical when developing biomaterials; some of them are used for studying cell adhesion and include direct cell counting, centrifugation, and morphological observation. Although these techniques have been used for many years, they are time-consuming and may incur cell damage. Thus, other methods such as quartz crystal microbalance with dissipation monitoring (QCM-D) have been studied. Groups of researchers, like the one integrated by Kushiro, Lee, and Takai, studied QCM-D method and indicated that its main advantages are that, for protein analysis, it provides information about the viscoelastic properties of the adsorbed protein layer; and for cell studies, enables non-invasive, real-time in situ analyses and dynamic monitoring of the entire adhesion process. Therefore, they carried out a study to systematically analyse the influence of chemical functional groups on protein adsorption and consequent cell adhesion on various self-assembled monolayer (SAM) surfaces by means of QCM-D (Kushiro, Lee, and Takai, 2016). They were able to demonstrate that the characteristic features of the QCM-D plot – changes in frequency, ∆f, vs changes in dissipation factor, ∆D – can dynamically and quantitatively reflect the state of the proteins and the cells on the surface and distinguish the different modes of interactions. Hence, this highly sensitive and quantitative technique can be applied for in-vitro characterization of biomaterial–protein–cell interactions.
Antiproliferative drug-loaded multi-functionalized intraocular lens for reducing posterior capsular opacification
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Huiying Huang, Siqing Zhu, Dong Liu, Shimin Wen, Quankui Lin
The prepared HA-Pac was then used as one of the component to build-up the polyelectrolyte multilayer coating on the material surface via LbL deposition with positively charge CHI. The multilayer build-up process was followed by quartz crystal microbalance with dissipation monitoring (QCM-D) [32]. QCM-D is a versatile and ultra-sensitive tool to quantitatively monitor changes in film thickness and adsorbed mass without the addition of external labels. And it can provide a lot of information about key makeup of soft and solvated interfaces [33]. If a thin film attaches to the crystal surface rigidly, there exists a good linear relationship between the resonance of frequency and the mass of the film [34]. As shown in Figure 2, the frequency shift increases linearly with bilayer number, indicating a gradual deposition of HA-Pac/CHI bilayer. The result not only indicates that HA-Pac/CHI multilayer is rigidly thin attached to the substrate surfaces, but also shows a typical LbL build-up process of HA-Pac/CHI multilayer growth.
Fluoroalkyl polyhedral oligomeric silsesquioxane initiated methylmethacrylate polymer to produce hydrophobic coatings by low fluorine content
Published in Soft Materials, 2021
Yanan Li, Aizhao Pan, Ling He, Mengjun Jia
ap-FPOSS-PMMA polymer films were prepared with 1 wt% polymer THF solution by dropping it onto a glass substrate and drying the films in the air. Static contact angle (SCA) measurement was tested on a OCA20 contact angle goniometer (Data Physics, Germany) at 25°C. The surface free energy was calculated based on water contact angle .[40] Roughness of the film surfaces were tested by NT-MDT new Solver-Next atomic force microscope (AFM) under 38–42% R.H. The water adsorption behavior of the surfaces for polymer films was investigated using a Q-Sense E1 (Sweden) quartz crystal microbalance with dissipation monitoring (QCM-D) at 25°C. QCM-D measurement aims at study the film surface property about water absorption, which using AT-cut piezoelectric quartz crystals (fundamental frequency: 5 MHz). 0.2 μL of polymer solutions were dropped on the quartz crystal surface and drying in a vacuum oven at 25°C for 12 h before tests. The flow rate of deionized water is 150 μL/min. The baseline of Δf and ΔD with air: 15 MHz.
3D printing technology for textiles and fashion
Published in Textile Progress, 2020
Tanvir Mahady Dip, Ayesha Siddika Emu, Md Nafiul Hassan Nafiz, Puja Kundu, Hasnatur Rahman Rakhi, Abdullah Sayam, Md Akhtarujjman, Mohammad Shoaib, Md Shakil Ahmed, Swimi Tabassum Ushno, Abdullah Ibn Asheque, Enamul Hasnat, Mohammad Abbas Uddin, Abu Sadat Muhammad Sayem
Adhesion quality defines the degree of attraction between two dissimilar phases, such as cohesion between textiles and 3DP materials during the production of 3D-printed composites. 3DP composite structures require good adhesion quality, so adhesion testing is done to identify the adhesion quality of bonding between 3DP polymers and textile substances to find out the force required to cause fracture. The perpendicular tensile test, the peel test, and shear tests were conducted to identify the adhesion of a 3DP profile on textile substrates (Malengier et al., 2017). A peel strength test was carried out on polyester jersey weft-knitted fabric using polylactic acid (PLA) as printing material to identify the adhesion between printing materials and textile substrate. It was found that increasing fabric width ratio gives rise to higher peel strength or higher adhesion, but a reduction of the peel strength or adhesion happens if the width of the printing polymer increases (Narula et al., 2018). Using a quartz-crystal microbalance with dissipation monitoring, together with peeling and washability tests, it was observed that cellulose acetate shows better affinity and adhesion properties than acetoxypropyl cellulose. It is accountable not only for decent adsorption but also improved adhesion characters for the printed configurations (Tenhunen et al., 2018).