Explore chapters and articles related to this topic
Seaweed Fucoidans and Their Marine Invertebrate Animal Counterparts
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Mauro Sérgio Gonçalves Pavão, Fernanda de Souza Cardoso
Similarly, the purification methods are diverse and depend on the degree of purity of the desired fucoidan extract. Deproteination might be carried out by protein precipitation (Zou et al. 2020; C. H. Wang and Chen 2016). The application of anion exchange or dye affinity chromatography using a salt gradient is usually followed by a chromatographic gel permeation (Zou et al. 2020) or a dialysis step against water using small molecular weight cut-off (MWCO) membranes (Zou et al. 2020; Sichert et al. 2021; Jayawardena et al. 2019) to remove salts, but this combination usually increases the production costs (Zayed and Ulber 2020). Dialysis might also be applied with different MWCO membranes to separate fucoidans according to their molecular weight, making it possible to separate the low-molecular-weight fucoidans (LMWF) from the high-molecular-weight fucoidans (HMWF) (Zayed and Ulber 2020). Another option is the application of ultrafiltration, which also allows the separation of different fucoidan sizes and the removal of low-molecular-weight impurities, such as laminarin (Zhang et al. 2021).
Bronchoalveolar Lavage in Inhalation Lung Toxicity
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
K. Randall Young, Herbert Y. Reynolds
The recovered fluid is filtered through sterile gauze to remove any large particulate matter and then centrifuged at 500 X g to pellet the cellular fraction. The fluid is then decanted and prepared for subsequent analysis of relevant substances (see below). Some or all of the fluid may be concentrated by positive pressure ultrafiltration through a membrane of approximately 10,000 dalton molecular weight cut-off and frozen for later measurement of proteins and other macromolecular constituents. Small molecules should be measured on the unconcentrated fluid.
Algal Polysaccharides
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
M Clemente-Carazo, V Sanchez, S Condon-Abanto, Garcia-Vaquero Marco
Filtration techniques seem well suited for initial extraction and purification steps at industrial scale as they can be automated; and permit to treat large volumes of samples (Patel et al. 2013). However, the widespread application of membranes has been hindered due to excessive membrane fouling which could result in reduced performance, severe flux decline, high energy consumption and frequent membrane cleaning or replacement (Feng et al. 2009). Recent studies focused on achieving a better understanding of anti-fouling agents (Feng et al. 2009) and other strategies to reduce fouling. For example the addition of an initial high-molecular weight cut-off membrane before the ultrafiltration step reduces the fouling of the membranes when extracting bacterial oligosaccharides (Mellal et al. 2008).
Application of zinc oxide and sodium alginate for biofouling mitigation in a membrane bioreactor treating urban wastewater
Published in Biofouling, 2020
Fatemeh Sokhandan, Maryam Homayoonfal, Fatemeh Davar
The mixed liquor suspended solid (MLSS) concentration was measured according to a standard method through filtering a specific volume of the sludge (V) via Whatman filter paper (2.5 µm) (Association APH et al. 1915). Furthermore, the chemical oxygen demand (COD) was measured using the vials of Merck Co. and through the standard method (Association APH et al. 1915). The COD removal was considered as the removal of input feed (COD in removal) and removal of supernatant (COD sup removal). In the COD determination, each analysis was replicated twice to ensure data reliability. The molecular weight cutoff (MWCO) of membranes was determined through filtering a 4 g l−1 solution of polyethylene glycol (PEG) with different molecular weights (6,000–15,000 g mole−1). The molecular weight corresponding to 90% PEG rejection was reported as MWCO. The PEG concentration was measured with a total organic carbon (TOC) analyzer (Analytic Jena, multi N/C series and CO2 NDIR detector, Jena, Germany).
In vitro and in vivo assessment of polymer microneedles for controlled transdermal drug delivery
Published in Journal of Drug Targeting, 2018
Bo Zhi Chen, Mohammad Ashfaq, Xiao Peng Zhang, Jia Nan Zhang, Xin Dong Guo
To further quantify controlled release properties in greater detail, a facile system involved dialysis bag was used to determine the cumulative release of sulforhodamine B from various drug-loaded MNs formulations. The dialysis membrane molecular weight cut-off was chosen on the basis of sulforhodamine B molecular weight. Figure 5(a) shows the cumulative release of drugs from different molecular weight of PVA based MNs. Approximately, 85% of drug was released within the first 30 min from PVA (≈2000 Da) based MNs, whereas ∼72 and 41% released from PVA (≈10,000 and ≈31,000 Da) based MNs, respectively. The significant changes in the release behaviour were observed in MNs fabricated from different molecular weight of PVA. The data clearly indicated the release of drugs increased with increasing time intervals. Moreover, rate of drug release increased with decreasing molecular weight of the PVA. Figure 5(b) shows the drug release behaviour of gelatine, chitosan and HA-based MNs. As observed from the data, all polymers based MNs exhibited similar trends and no significant changes were observed. Initially, robust release of drugs followed by steady release over the time. Approximately, 85% of drug was released from these polymer MNs samples within 1 h, indicating that gelatine, chitosan and HA MNs had robust release and that their release behaviour depended on dissolution of matrix materials. The robust release of drug into release medium can be attributed to the excellent water solubility of these polymers. In addition, the cumulative release behaviour data are consistent with microscopic analysis (Figure 4).
The Rhei radix rhizoma-based carbon dots ameliorates dextran sodium sulphate-induced ulcerative colitis in mice
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Yifan Zhang, Jie Zhao, Yusheng Zhao, Xue Bai, Yumin Chen, Yuhan Liu, Yue Zhang, Hui Kong, Huihua Qu, Yan Zhao
The RRR-CDs were prepared in the muffle furnace (TL0612 muffle furnace; Beijing Zhong Ke Aobo Technology Co., Ltd; Beijing, China) by one-step pyrolysis. First, the RRR samples were placed in separate crucibles and covered with aluminium foil paper with sealed lids. Then, the RRR was carbonised in a preheated muffle furnace at 350 °C for 1h. After cooling to room temperature, the RRR-carbon was ground to a fine powder and boiled twice in a water bath at 100 °C for 1h each time. Thereafter, the decoction solution was filtered (0.22 μm microfiltration membrane), concentrated, and dialysed (1000 Daltons molecular weight cut-off dialysis membrane). The obtained RRR-CDs were stored at 4 °C until further use. The preparation flow chart of RRR-CDs is shown in Figure 1.