Magnetic and pH responsive composite hydrogel-based on poly(2-(diethylamino)ethyl methacrylate)/chitosan for fipronil removal from aqueous medium

2021 ◽  
Vol 168 ◽  
pp. 105050
Author(s):  
Marcella Matos Cordeiro Borges ◽  
Bruna Carneiro Pires ◽  
Sara Silveira Vieira ◽  
Keyller Bastos Borges ◽  
Luiz Gustavo de Lima Guimarães
Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 59
Author(s):  
Abeer M. Beagan ◽  
Ahlam A. Alghamdi ◽  
Shatha S. Lahmadi ◽  
Majed A. Halwani ◽  
Mohammed S. Almeataq ◽  
...  

Currently, chemotherapy is an important method for the treatment of various cancers. Nevertheless, it has many limitations, such as poor tumour selectivity and multi-drug resistance. It is necessary to improve this treatment method by incorporating a targeted drug delivery system aimed to reduce side effects and drug resistance. The present work aims to develop pH-sensitive nanocarriers containing magnetic mesoporous silica nanoparticles (MMSNs) coated with pH-responsive polymers for tumour-targeted drug delivery via the folate receptor. 2-Diethyl amino ethyl methacrylate (DEAEMA) was successfully grafted on MMSNs via surface initiated ARGET atom transfer radical polymerization (ATRP), with an average particle size of 180 nm. The end groups of poly (2-(diethylamino)ethyl methacrylate) (PDEAEMA) brushes were converted to amines, followed by a covalent bond with folic acid (FA) as a targeting agent. FA conjugated to the nanoparticle surface was confirmed by X-ray photoelectron spectroscopy (XPS). pH-Responsive behavior of PDEAEMA brushes was investigated by Dynamic Light Scattering (DLS). The nanoparticles average diameters ranged from ca. 350 nm in basic media to ca. 650 in acidic solution. Multifunctional pH-sensitive magnetic mesoporous nanoparticles were loaded with an anti-cancer drug (Doxorubicin) to investigate their capacity and long-circulation time. In a cumulative release pattern, doxorubicin (DOX) release from nano-systems was ca. 20% when the particle exposed to acidic media, compared to ca. 5% in basic media. The nano-systems have excellent biocompatibility and are minimally toxic when exposed to MCF-7, and -MCF-7 ADR cells.


2015 ◽  
Vol 815 ◽  
pp. 359-366 ◽  
Author(s):  
Qing Yun Yu ◽  
Lu Bin Lin ◽  
Xue Yu Xing ◽  
Hai Liang Dong ◽  
Xiao Ze Jiang ◽  
...  

Two pH-responsive block glycopolymers, poly (ethylene glycol)-b-Poly (2- (diethylamino) ethyl methacrylate-co-2-gluconamidoethyl methacrylate) (PEG113-b-P(DEA55-co-GAMA12)) and poly (ethylene glycol)-b-poly (2-(diethylamino) ethyl methacrylate)-b-poly (2-gluconamido ethyl methacrylate) (PEG113-b-PDEA55-b-PGAMA15), were synthesized via atom transfer radical polymerization (ATRP) by directly or successively polymerization of GAMA and DEA monomers using a PEG-based macroinitiator, respectively, without protecting group chemistry. Those block glycopolymers were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and their self-assembly behaviors were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta-potential. The results show both synthetic block glycopolymers were dissolved molecularly in aqueous solution at acidic pH (such as pH 3), thus it can reversibly convert to be two-layer micelles comprising DEA and GAMA cores, PEG coronas with size of around 50 nm, or micelles comprising DEA cores, GAMA and PEG outer coronas with bigger size of 70 nm for PEG113-b- P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15), respectively, at basic condition. Both glycopolymers have the micellization process at middle pH (pH 6-8), but possess different isoelectric points (pIs) (at pH 8.0 and 7.8) for their pH responsive block of PEG113-b-P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15 with DEA-co-GAMA random structure or DEA chain only, respectively. This study not only reveals the self-assembly of pH responsive block glycopolymers with different architectures by fixing similar degree polymerization (DP) of their blocks, but also provides a tool to investigate pH induced dynamic covalent interaction between glycopolymers and phenylboronic acid derivatives or a light for designing novel drug delivery carriers.


2021 ◽  
Vol 9 ◽  
Author(s):  
Nandita Srivastava ◽  
Anirban Roy Choudhury

Dyes are one of the most hazardous chemicals causing significant environmental pollution and affecting water quality. Majority of the existing methods for dye removal and degradation involve synthetic membranes and use of hazardous chemicals, further resulting in secondary pollution. The present study reports polysaccharide based novel composite hydrogel as biodegradable matrix for pH-responsive selective adsorption of cationic/anionic dyes. This membrane showed pH-responsive adsorption of methyl green (MG) and methyl orange (MO) with similar adsorption equilibrium, i.e., 315 and 276 mg g−1, respectively. Interestingly, selective adsorption at different pH has allowed separation of dye mixtures that holds incredible industrial importance for dyes recovery. The hydrogel matrix was able to completely separate MG, a model cationic dye at neutral pH from the dye mixture whereas, it was possible to remove 60% MO, a model anionic dye at acidic pH. Furthermore, comprehensive isothermal and kinetic studies of adsorption revealed that Freundlich isotherm describing the multilayer coverage and pseudo-second-order kinetics were followed. Thermodynamic studies indicated that the adsorption process was spontaneous and endothermic. In fact, the membrane was reusable for at least ten cycles and exhibited desorption efficiency of 80 and 60% for MO and MG, respectively, which may be further recycled to make the process environmentally sustainable. Overall, this study proposes an inexpensive, simple, biologically safe, and efficient adsorbent material for dye effluent treatment.


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