Elements of Polymer Science
E. Desmond Goddard, James V. Gruber in Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
Gel permeation chromatography (GPC) is a type of liquid-solid elution chromatography that separates polydisperse samples into fractions by means of the sieving action of a cross-linked gel. Such gels, which serve as the stationary phase, are commercially available with a wide distribution of pore sizes . Since the smaller molecules permeate the gels preferentially, the larger molecules elute faster than the smaller ones. Therefore, molecules are separated on the basis of their size. The separation can be carried out with polymers soluble in organic solvent, with calibration against polystyrene standard samples, or with water-soluble polymers, using poly(ethylene oxides) or dextrans standards.
Preclinical assessment of bioresorbable scaffolds and regulatory implication
Yoshinobu Onuma, Patrick W.J.C. Serruys in Bioresorbable Scaffolds, 2017
Bioresorbable metals or alloys degrade by erosion of the surface. Therefore, in vivo degradation processes can be monitored by morphometric assessment of tissue blocks embedded in methacrylate polymer [38]. The degradation analysis of polymeric material is more complex as degradation occurs by reduction of the length of the respective polymer chains, which is not accompanied by any macroscopic change. Mass loss can only be recognized during the final stage of degradation when the molecular mass of the produced oligomers is low enough to result in complete clearance of polymer residues. The onset of degradation can be detected by pH sensitive stains (e.g., May Grunwald staining), which results in colorimetric recognition of the polymer after generation of the first acidic degradation products [39]. Mass loss can be monitored by homogenizing the entire vessel including the stent, followed by complete chemical depolymerization of the stent into its monomers and quantitative analysis of the degradation product by HPLC [40]. The most versatile analysis method is GPC (gel permeation chromatography), which reveals important information to characterize the polymer by molecular weight distribution and polydispersity index (PDI) and is helpful to explain the observed biological behavior [41].
Algal Polysaccharides
Gokare A. Ravishankar, Ranga Rao Ambati in Handbook of Algal Technologies and Phytochemicals, 2019
After the extraction procedures, extra-cellular or cellular polysaccharides could go through one or several purification steps that do not differ to those described for other carbohydrates. The purification techniques commonly used in microalgal polysaccharides include the application of different solvents (hexane, ethyl acetate, acetone, ethanol, petroleum ether, methanol and water) to separate the molecules with respect to their polarity (Challouf et al. 2011, Jo et al. 2010). Other chromatographic techniques include ion-exchange chromatography (Guzmán et al. 2003, Huheihel et al. 2002, Huleihel et al. 2001, Sadovskaya et al. 2014, Sun et al. 2014) and gel permeation chromatography (Bae et al. 2006, Casano et al. 2015, Feng et al. 2009, Guzmán et al. 2003, Huleihel et al. 2001, Magaletti et al. 2004, Yim et al. 2004). The use of chromatographic and non-chromatographic techniques to purify and characterise carbohydrates was recently reviewed in detail by García-Vaquero (2019a).
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.
Phenylboronic ester-modified anionic micelles for ROS-stimuli response in HeLa cell
Published in Drug Delivery, 2020
Qi Y. Wang, Yi S. Xu, Nan X. Zhang, Zhi P. Dong, Bo N. Zhao, Lin C. Liu, Tao Lu, Yue Wang
1H NMR spectra of the polymers were recorded on a Bruker 400 MHz nuclear magnetic resonance instrument using DMSO 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 PEG-b-PAsp was measured at room temperature with a Waters 1525 chromatograph equipped with a Waters 2414 refractive index detector. H2O was used as eluents with a flow rate of 1.0 mL/min and narrowly distributed polyethylene glycol was used as standard. The size and surface charge of the nanocarrier was investigated on Malvern Zetasizer Nano ZS 90 zeta potential analyzer. Ultraviolet-visible (UV-vis) spectra were collected using a LAMBDA-35 spectrometer. Transmission electron microscopy (TEM) was performed on a JEOL-2100 with accelerating voltage of 200 kV. TEM samples were prepared by drop-casting dispersion onto copper grids covered by carbon film. Confocal images were acquired using a Zeiss confocal laser scanning unit mounted on an LSM 710 fixed-stage upright microscope (CLSM).
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).
Related Knowledge Centers
- Chromatography
- Dispersity
- Polymer
- Polystyrene
- Size-Exclusion Chromatography
- Analyte
- Molar Mass Distribution
- Van Der Waals Surface
- High-Performance Liquid Chromatography
- Gel