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Industrial Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
The irradiation of pulp is of interest from different perspectives. Mainly it is required when a modification of cellulose is needed. Irradiation could bring many advantages, such as chemical savings and, therefore, cost savings and a reduction in environmental pollutants. In the work by Henniges et al. (2013), pulp and dissociated celluloses were analyzed before and after irradiation by EB. The focus of the analysis was the oxidation of hydroxyl groups to carbonyl and carboxyl groups in pulp and the degradation of cellulose causing a decrease in molar mass. For that purpose, the samples were labeled with a selective fluorescence marker and analyzed by gel permeation chromatography (GPC) coupled with multi-angle laser light scattering (MALLS), refractive index (RI), and fluorescence detectors. Degradation of the analyzed substrates was the predominant result of the irradiation; however, in the microcrystalline samples, oxidized cellulose functionalities were introduced along the cellulose chain, making this substrate suitable for further chemical modification (Henniges et al. 2013).
Promises, Facts and Challenges for Carbon Nanotubes in Imaging and Therapeutics
Published in Lajos P. Balogh, Nano-Enabled Medical Applications, 2020
Kostas Kostarelos, Alberto Bianco, Maurizio Prato
A further challenge is related to the lack of an accepted protocol to determine the degree of purity of the carbon nanotube material used [3]. Standard chromatographic techniques—such as thin-layer chromatography, high-pressure liquid chromatography and gel permeation chromatography—have achieved limited success, with no general or reproducible outcomes. Such technical limitations will need to be addressed, and standard procedures for the production and purification of nanotubes or functionalized nanotube materials should be developed to enable a move into large-scale multi-centre clinical trials.
Bioresponsive Hydrogels for Controlled Drug Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Tamgue Serges William, Dipali Talele, Deepa H. Patel
Gel Chromatography or Gel permeation chromatography (GPC) is considered to be the most important test method for the determination of molecular properties of synthetic and natural macromolecules in solution. Distribution properties of macromolecules such as molecular weight distribution, structure distribution, branching distribution are easily obtained by this mean. GPC coupled on line to a multi angle laser light scattering (GPC-MALLLS) is a widely used technique to determine the molecular distribution and parameters of a polymeric system. For example, this technique is widely used in quantifying the hydrogels of several hydrocolloids such as gum Arabic, gelatine, and pullulan [29].
Phenylboronic ester-modified polymeric nanoparticles for promoting TRP2 peptide antigen delivery in cancer immunotherapy
Published in Drug Delivery, 2022
Qiyan Wang, Zhipeng Dong, Fangning Lou, Yunxue Yin, Jiahao Zhang, Hanning Wen, Tao Lu, Yue Wang
The PEG-b-PAsp-g-PBE copolymer was synthesized via the amine-initiated ring-opening polymerization (ROP) and esterification reaction. With different molar ratio between BLA-NCA and m-PEG-NH2, we obtained different block copolymers with different molecular weight. According to the length of PAsp chain, PBE with proper molar ratio was added into reaction solution and we get PEG-b-PAsp-g-PBE with different grafting degree (Yang et al., 2015; Hu et al., 2017; Wang et al., 2020). 1H NMR spectra of the polymers were recorded on a Bruker 400 MHz nuclear magnetic resonance instrument using D2O as the solvents. Gel permeation chromatography (GPC) was used to analyze the molecular weights and molecular weight distributions (Mw/Mn) of the polymers. GPC of polymer (PEG-b-PAsp and PEG-b-PAsp-g-PBE) was measured by a Waters 1525 chromatograph equipped with a Waters 2414 refractive index detector.
Dual-functionalized liposome by co-delivery of paclitaxel with sorafenib for synergistic antitumor efficacy and reversion of multidrug resistance
Published in Drug Delivery, 2019
Meng Lei, Guanglan Ma, Sijia Sha, Xueyuan Wang, Haiting Feng, Yongqiang Zhu, Xiao Du
To deprotect the Z groups of PLL (Z) was dissolved in trifluoroacetic acid then HBr (2.64 g, 32.67 mmol) was added. The reaction was allowed to perform at room temperature for 2 h. Then the reaction was quenched with excess cold methyl tert-butyl ether and the precipitate was filtered and washed three times to obtain the resulting solid PLL. The average molecular weight was analyzed by gel permeation chromatography (GPC). The measurements were taken with a Shimadzu GPC with Shimadzu RI and UV/Vis detection, and two 300 mm Waters ultra-hydrogel GPC Columns using PEG standards. The dissolution solvent and mobile phase were composed of an aqueous solution containing 0.2 M NaNO3 and 0.01 NaH2PO4 and the mobile phase at a flow rate of 1.0 mL/min. The average molecular weight (6474 Da) and polydispersity index (1.00) were calculated from the GPC retention time (20.58 min) in Figure S2. 1 H NMR (300 MHz, D2O, ppm): 1.22-1.86 (-CH2- in PLL, and -CH2- in hexylamine), 3.08 (dd, ε-CH2), 4.36 (dd, α-CH) (Figure S1).
A perfect stimuli-responsive magnetic nanocomposite for intracellular delivery of doxorubicin
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Aliyeh Ghamkhari, Marjan Ghorbani, Samira Aghbolaghi
Fourier transform infrared (FT-IR) spectra of the samples were obtained by a Shimadzu 8101 M FT-IR (Shimadzu, Kyoto, Japan) at the wavenumber ranges of 4000 to 400 cm−1. Proton nuclear magnetic resonance (1HNMR) spectra were obtained at 25 °C using an FT-NMR (400 mHz) Bruker spectrometer (Bruker, Ettlingen, Germany). The samples were prepared in the deuterated dimethyl sulfoxide solvent (DMSO-d6) or water (D2O). The size exclusion analyses were carried out using a Waters 1515 (USA) gel permeation chromatography (GPC) instrument equipped with Breeze 1515 isocratic pump and 7725 manual injector. Ultraviolet-visible (UV–Vis) spectroscopy was taken in a Shimadzu 1650 PC UV-Vis spectrophotometer (Shimadzu, Kyoto, Japan). The magnetic properties of Fe3O4/poly(SEMA-b-NIPAM-b-DMAEMA) nanocomposites were evaluated by vibrating sample magnetometer (VSM, AGFM, Iran) at 25 °C temperature. The field emission scanning electron microscope (FESEM) type 1430 VP (LEO Electron Microscopy Ltd, Cambridge, UK) was applied to determine the morphologies of the synthesized samples. The structural properties were probed via using X-ray powder diffraction (XRD) with a X’pert-PRO advanced diffractometer by Cu (Kα) radiation (wavelength: 1.5406 Å), operated at 40 kV and 40 mA in the 2θ range of 20–70° at a room temperature. The particle size of nanocomposite was measured by a laser scattering technique (Zetasizer Nano ZS90; Malvern Instruments, Malvern, UK) at pH =4, 9 and 25, 40 and 50 °C.