scholarly journals Modified Chitosan Hydrogels and Nano Hydrogels for Congo Red Removal from Aqueous System

2021 ◽  
Vol 38 (1) ◽  
pp. 91-117
Author(s):  
Shimaa Khaled ◽  
Abir S. Nasr ◽  
Howida T. Zaky ◽  
Nadia G. Kandile
Keyword(s):  
Congo Red ◽  
Aqueous System ◽  
Modified Chitosan ◽  
Chitosan Hydrogels

Modified Chitosan Hydrogels and Nano Hydrogels for Congo Red Removal from Aqueous System

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
shimaa khaled ◽  
Howaida Zaky ◽  
Abeer Salah Nasr ◽  
nadia hassan
Keyword(s):  
Congo Red ◽  
Aqueous System ◽  
Modified Chitosan ◽  
Chitosan Hydrogels

scholarly journals Sulphate-Crosslinked Chitosan as an Adsorbent for the Removal of Congo Red Dye From Aqueous Solution

2018 ◽  
Vol 11 ◽  
pp. 117862211881168 ◽  
Author(s):  
Christine Jeyaseelan ◽  
Nisha Chaudhary ◽  
Ravin Jugade
Keyword(s):  
Adsorption Capacity ◽  
Congo Red ◽  
Water Bodies ◽  
X Ray ◽  
Modified Chitosan ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Crosslinked Chitosan ◽  
Wastewater Samples ◽  
Red Dye

Dyes are a major cause of concern nowadays as large quantities are being released into water bodies causing pollution. In this article, modified chitosan (sulphate crosslinked) has been studied for the removal of Congo red (a benzidine-based anionic diazo dye) which is a toxic dye introduced into water bodies from textile industries. Sulphate-crosslinked chitosan (SCC) was prepared in the laboratory and the characterization of SCC was done by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Various parameters such as pH, contact time, adsorbent dosage, and concentration of adsorbent were optimized. The adsorption capacity was determined at pH 3.0, at which the percentage recovery was about 90% and followed Freundlich adsorption isotherm with an adsorption capacity of 91.8 mg/g. The adsorption followed pseudo-second-order kinetics. Various thermodynamic parameters were also determined for the change in adsorption with temperature. The SCC was regenerated with NaOH and showed good recycling capacity. The modified chitosan was applied for the removal of Congo red from industrial wastewater samples (spiked).

scholarly journals Adsorption of tetracycline by a tailor- made adsorbent in aqueous system

2019 ◽  
Vol 6 (1) ◽  
pp. 30-36
Author(s):  
Adelagun Ruth Olubukola Ajoke ◽  
Neelam Yadav ◽  
Ajar Nath Yadav
Keyword(s):  
Municipal Wastewater ◽  
Growth Promotion ◽  
Active Form ◽  
Animal Husbandry ◽  
Freundlich Isotherm ◽  
Aqueous System ◽  
Isotherm Models ◽  
Municipal Wastewater Treatment ◽  
Input Concentration ◽  
Modified Chitosan

Tetracyclines are frequently used antibiotics for growth promotion and therapeutic pharmaceuticals both by humans and animal husbandry, and commonly encountered in municipal wastewater treatment plants and in the environment in their active form. This implies their continuous release into the environment may facilitate toxic effects both on humans and the environment including development of resistance strains, among others. This research was focused on the synthesis, characterisation and assessment of a tailor- made adsorbent: modified chitosan flakes, using several materials for the modification of chitosan to enhance its sorption properties thereby facilitating a higher percentage of TC removal from a synthetic pharmaceutical wastewater. TC adsorption onto the modified chitosan flakes was relatively fast (equilibrium time = 2h). Sorption studies revealed that TC removal by the adsorbent followed pseudo second order kinetics and Freundlich isotherm models. At higher TC input concentration, the amount of TC removed was also higher, this implied the sorption was concentration dependent. Insight into mechanism of sorption revealed cation exchange was an active means of interaction between the adsorbate and adsorbents moieties.

scholarly journals Modified chitosan hydrogels as drug delivery and tissue engineering systems: present status and applications

2012 ◽  
Vol 2 (5) ◽  
pp. 439-449 ◽  
Author(s):  
Tapan Kumar Giri ◽  
Amrita Thakur ◽  
Amit Alexander ◽  
Ajazuddin ◽  
Hemant Badwaik ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Present Status ◽  
Engineering Systems ◽  
Modified Chitosan ◽  
Chitosan Hydrogels

scholarly journals Comparison of Rheological, Drug Release, and Mucoadhesive Characteristics upon Storage between Hydrogels with Unmodified or Beta-Glycerophosphate-Crosslinked Chitosan

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Emilia Szymańska ◽  
Anna Czajkowska-Kośnik ◽  
Katarzyna Winnicka
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Physicochemical Characteristics ◽  
Vaginal Mucosa ◽  
Drug Release Profile ◽  
Modified Chitosan ◽  
Long Term Storage ◽  
Crosslinked Chitosan ◽  
Chitosan Hydrogels ◽  
The Impact

The physicochemical characteristics of beta-glycerophosphate-crosslinked chitosan hydrogels were investigated upon long-term storage at ambient, accelerated, and refrigerated conditions and compared to unmodified chitosan formulations. Additionally, the impact of chitosan modification on the ex vivo mucoadhesive performance in contact with porcine vaginal mucosa and on the drug release profile from hydrogels was evaluated. Viscosity and mechanical properties of formulations with unmodified chitosan decreased significantly upon storage regardless of tested conditions as a result of hydrolytic depolymerization. Introduction of ion crosslinker exerted stabilizing effect on physicochemical performance of chitosan hydrogels but only upon storage at refrigerated conditions. Beta-glycerophosphate-modified chitosan formulations preserved organoleptic, rheological behavior, and hydrogel structure up to 3-month storage at 4 ± 2°C. Viscosity variations upon storage influenced markedly mucoadhesive properties and drug release rate from hydrogels.

scholarly journals Facile Preparation of Tunicate-Inspired Chitosan Hydrogel Adhesive with Self-Healing and Antibacterial Properties

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4322
Author(s):  
Xiang He ◽  
Ruyue Liu ◽  
Huiqing Liu ◽  
Ruixiao Wang ◽  
Zhenhao Xi ◽  
...  
Keyword(s):  
Protein A ◽  
Gelation Time ◽  
Antibacterial Properties ◽  
Tissue Adhesive ◽  
Self Healing ◽  
Tissue Adhesion ◽  
E Coli ◽  
Modified Chitosan ◽  
Non Invasive ◽  
Chitosan Hydrogels

In order to replace traditional wound treatments such as sutures, tissue adhesives with strong wet tissue adhesion and biocompatibility have attracted more attention to the applications of non-invasive wound closure. Herein, inspired by tunicate adhesive protein, a series of 2,3,4-trihydroxybenzaldehyde (TBA)-modified chitosan hydrogels (CS-TBA-Fe) were prepared by easily mixing the solutions of chitosan-FeCl3 and TBA via the Schiff-base reaction and the coordination between Fe3+ and pyrogallol groups. The gelation time was greatly shortened to only several seconds after induced even trace Fe3+. The hydrogel (CS-TBA-Fe) exhibited ~12-fold enhanced wet tissue adhesion strength (60.3 kPa) over the commercial fibrin glue. Meanwhile, the hydrogel also showed robust adhesion to various substrates such as wood, PMMA, and aluminum. The swelling ratio and rheological property can be simply controlled by changing the concentrations of chitosan, TBA, and Fe3+. Moreover, the hydrogel displayed a rapid and highly efficient self-healing ability and an excellent antibacterial activity against E. coli. The overall results show that the CS-TBA-Fe hydrogel with enhanced wet adhesiveness will be a promising tissue adhesive material.

scholarly journals Kinetics, Isotherm and Thermodynamic Studies for Efficient Adsorption of Congo Red Dye from Aqueous Solution onto Novel Cyanoguanidine-Modified Chitosan Adsorbent

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4446
Author(s):  
Nouf F. Al-Harby ◽  
Ebtehal F. Albahly ◽  
Nadia A. Mohamed
Keyword(s):  
Aqueous Solution ◽  
Congo Red ◽  
Adsorption Process ◽  
Ph Value ◽  
Dye Adsorption ◽  
Order Kinetic ◽  
Amino Groups ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Modified Chitosan

Novel Cyanoguanidine-modified chitosan (CCs) adsorbent was successfully prepared via a four-step procedure; first by protection of the amino groups of chitosan, second by insertion of epoxide rings, third by opening the latter with cyanoguanidine, and fourth by restoring the amino groups through elimination of the protection. Its structure and morphology were checked using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The adsorption capacity of CCs for Congo Red (CR) dye was studied under various conditions. It decreased significantly with the increase in the solution pH value and dye concentration, while it increased with increasing temperature. The adsorption fitted to the pseudo-second order kinetic model and Elovich model. The intraparticle diffusion model showed that the adsorption involved a multi-step process. The isotherm of CR dye adsorption by CCs conforms to the Langmuir isotherm model, indicating the monolayer nature of adsorption. The maximum monolayer coverage capacity, qmax, was 666.67 mg g−1. Studying the thermodynamic showed that the adsorption was endothermic as illustrated from the positive value of enthalpy (34.49 kJ mol−1). According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The value of ΔS° showed an increase in randomness for the adsorption process. The value of activation energy was 2.47 kJ mol−1. The desorption percentage reached to 58% after 5 cycles. This proved that CCs is an efficient and a promising adsorbent for the removal of CR dye from its aqueous solution.

scholarly journals Peptide-Modified Chitosan Hydrogels Accelerate Skin Wound Healing by Promoting Fibroblast Proliferation, Migration, and Secretion

2017 ◽  
Vol 26 (8) ◽  
pp. 1331-1340 ◽  
Author(s):  
Xionglin Chen ◽  
Min Zhang ◽  
Shixuan Chen ◽  
Xueer Wang ◽  
Zhihui Tian ◽  
...  
Keyword(s):  
Wound Healing ◽  
Growth Factors ◽  
Skin Wound ◽  
Skin Wounds ◽  
Skin Wound Healing ◽  
Promote Cell Proliferation ◽  
Modified Chitosan ◽  
Chitosan Hydrogels ◽  
Positive Controls

Skin wound healing is a complicated process that involves a variety of cells and cytokines. Fibroblasts play an important role in this process and participate in transformation into myofibroblasts, the synthesis of extracellular matrix (ECM) and fibers, and the secretion of a variety of growth factors. This study assessed the effects of peptide Ser-Ile-Lys-Val-Ala-Val (SIKVAV)--modified chitosan hydrogels on skin wound healing. We investigated the capability of peptide SIKVAV to promote cell proliferation and migration, the synthesis of collagen, and the secretion of a variety of growth factors using fibroblasts in vitro. We also treated skin wounds established in mice using peptide SIKVAV-modified chitosan hydrogels. Hematoxylin and eosin staining showed that peptide-modified chitosan hydrogels enhanced the reepithelialization of wounds compared with negative and positive controls. Masson’s trichrome staining demonstrated that more collagen fibers were deposited in the wounds treated with peptide-modified chitosan hydrogels compared with the negative and positive controls. Immunohistochemistry revealed that the peptide-modified chitosan hydrogels promoted angiogenesis in the skin wound. Taken together, these results suggest that peptide SIKVAV-modified chitosan hydrogels may be useful in wound dressing and the treatment of skin wounds.

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