scholarly journals Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 547 ◽  
Author(s):  
Jiachang Feng ◽  
Jianpeng Dou ◽  
Youzhen Zhang ◽  
Zidan Wu ◽  
Dongxue Yin ◽  
...  
Keyword(s):  
Entrapment Efficiency ◽  
Honeycomb Structure ◽  
Aflatoxin Contamination ◽  
Biocontrol Agents ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Interpenetrating Network ◽  
Thermosensitive Hydrogel ◽  
Hydrogel Beads

Starch, alginate, and poly(N-isopropylacrylamide) (PNIPAAm) were combined to prepare a semi-interpenetrating network (IPN) hydrogel with temperature sensitivity. Calcium chloride was used as cross-linking agent, the non-toxigenic Aspergillus flavus spores were successfully encapsulated as biocontrol agents by the method of ionic gelation. Characterization of the hydrogel was performed by Fourier-transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetry analysis (TGA). Formulation characteristics, such as entrapment efficiency, beads size, swelling behavior, and rheological properties were evaluated. The optical and rheological measurements indicated that the lower critical solution temperature (LCST) of the samples was about 29–30 °C. TGA results demonstrated that the addition of kaolin could improve the thermal stability of the semi-IPN hydrogel. Morphological analysis showed a porous honeycomb structure on the surface of the beads. According to the release properties of the beads, the semi-IPN hydrogel beads containing kaolin not only have the effect of slow release before peanut flowering, but they also can rapidly release biocontrol agents after flowering begins. The early flowering stage of the peanut is the critical moment to apply biocontrol agents. Temperature-sensitive hydrogel beads containing kaolin could be considered as carriers of biocontrol agents for the control of aflatoxin in peanuts.

scholarly journals Particle and Gel Characterization of Irinotecan-Loaded Double-Reverse Thermosensitive Hydrogel

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 551
Author(s):  
Fakhar ud Din ◽  
Sung Giu Jin ◽  
Han-Gon Choi
Keyword(s):  
Entrapment Efficiency ◽  
Tween 80 ◽  
Rectal Administration ◽  
The Body ◽  
Poloxamer 407 ◽  
Gel Properties ◽  
Thermosensitive Hydrogel ◽  
Lipid Mixture ◽  
Dispersed System

The irinotecan-loaded double-reverse thermosensitive hydrogel (DRTH) is a dispersed system of irinotecan-loaded solid lipid nanoparticles (SLN) in a thermosensitive hydrogel. To optimise the particle and gel properties of DRTHs for rectal administration of irinotecan, SLNs and DRTHs were prepared with tricaprin, triethanolamine, Tween 80, and Span 20. Among the SLNs tested, an SLN composed of 1 g irinotecan, 0.5 g lipid mixture, and 0.5 g combined surfactant gave the highest entrapment efficiency and smallest particle size. A DRTH composed of (poloxamer 407/poloxamer 188/combined surfactant/SLN dispersion/H2O (10/15/17/4/54%)) showed easy administration, fast gelling, and strong gel-forming in the body.

Ultra Small Angle X-Ray Scattering Characterization of Temperature-Sensitive Ferrogels Prepared Using Magnetic Nanoparticles

2013 ◽  
Vol 1453 ◽  
Author(s):  
Kamlesh J. Suthar ◽  
Muralidhar K. Ghantasala ◽  
Derrick C. Mancini ◽  
Jan Ilavsky
Keyword(s):  
Small Angle ◽  
Quantum Interference ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Hydrogel Particle ◽  
Ray Scattering

ABSTRACTTemperature-sensitive ferrogel prepared using Fe3O4 nanoparticles are characterized under varying temperature conditions. The nanoparticles were distributed in Nisopropylacrylamide (NIPAm) during their polymerization to form hydrogel. Particle distribution and agglomeration characteristics of the prepared ferrogels were investigated using ultra small angle x-ray scattering (USAXS) at various temperatures through the Lower Critical Solution Temperature (LCST). Transmission electron microscopy (TEM) was used to estimate the particle size distribution. The magnetic property was investigated using direct current superconducting quantum interference device (DC-SQUID) under hydrated conditions. The USAXS analysis showed an increase in the volume of particles without changing the agglomeration characteristics as the temperature is increased during the measurements. The ferrogel did not show any sedimentation or particle detachment from the gel under thermal cycling. Details of our results and analysis are presented.

scholarly journals Fast-responsive temperature-sensitive hydrogels

BioResources ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 8543-8558
Author(s):  
Xiaohui Wang ◽  
Qingqing Dai ◽  
Haoquan Zhong ◽  
Xinxin Liu ◽  
Junli Ren
Keyword(s):  
Near Infrared ◽  
Reaction Medium ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Thermosensitive Hydrogel ◽  
Hydrogel Matrix ◽  
Hydrophilic Monomer ◽  
Responsive Behavior ◽  
Carboxymethyl Xylan

Temperature fast-responsive and magnetic poly(N-isopropylacrylamide-co-acrylamide) (CMX-MNP-PNIPAm/Fe3O4) hydrogels were developed using carboxymethyl xylan (CMX) as a pore-forming agent and a NaCl solution as the reaction medium, followed by fabricating Fe3O4 nanoparticles in situ within the hydrogel matrix. It was found that NaCl played a role in the phase separation and was used as the electrolyte to shield CMX molecular chains. The obtained hydrogels exhibited a fast, temperature-responsive behavior, and the water retention was less than 15% for 1 min under 60 °C. The prepared hydrogels showed enhanced mechanical properties and magnetic properties due to the presence of Fe3O4 particles. The lower critical solution temperature of the hydrogels was in the range of 35 to 39 °C, which was acquired through adjusting the amount of hydrophilic monomer (AM). The magnetic and thermosensitive hydrogel had the attractive photothermal conversion ability and could be heated to 40 °C within 2 min, and to 69 °C within 7 min under near infrared irradiation.

scholarly journals FORMULATION AND CHARACTERIZATION OF FLOATING BEADS OF ANTIBIOTIC BY EMULSION GELATION TECHNIQUE

2019 ◽  
pp. 57-62
Author(s):  
KHALIFA MY ◽  
SHAIKH SIRAJ N
Keyword(s):  
Drug Release ◽  
Entrapment Efficiency ◽  
Microscopy Study ◽  
Generation Cephalosporin ◽  
Electron Microscopy Study ◽  
Stability Studies ◽  
In Vitro Drug Release ◽  
Hydrogel Beads

Objective: The study aims at formulation and characterization of floating hydrogel beads of cefdinir for improving its bioavailability. Methods: Cefdinir is broad-spectrum, oral, third-generation cephalosporin antimicrobial agent active against Gram-positive and Gram-negative bacteria. The floating hydrogel beads of cefdinir were formulated with polymers such as sodium alginate and sodium carboxymethyl cellulose by emulsion gelation technique using olive oil/castor oil. The beads were evaluated for surface morphology, bead size, entrapment efficiency, floating characteristics, in vitro swelling, in vitro drug release, and stability studies. Results: On the basis of evaluation, all the beads show good swelling up to 12 h in 0.1 N hydrochloric acid. The swelling was followed by values in order of vegetable oil > mineral oil in case of emulsion gelation method. Scanning electron microscopy study shows that beads were spherical in shape. Comparing all the formulations, formulation FB12 was considered as optimized formulation which shows % yield 94.06±0.11, % floating 87.28±0.90, in vitro drug release 94.68, and also stable in stability studies. Conclusion: From the findings, it may be concluded that cefdinir-loaded floating beads were successfully prepared and proved to be useful for the better bioavailability and patient compliance for enhanced antimicrobial activity.

scholarly journals Synthesis of a New Phosphonate-Based Sorbent and Characterization of Its Interactions with Lanthanum (III) and Terbium (III)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1513
Author(s):  
Yuezhou Wei ◽  
Khalid A. M. Salih ◽  
Mohammed F. Hamza ◽  
Toyohisa Fujita ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
High Tech ◽  
Low Grade ◽  
Acid Solutions ◽  
Hydrogel Beads ◽  
Secondary Sources ◽  
Composite Sorbents ◽  
Synthesis Procedure ◽  
New Generation ◽  
Mild Acid

High-tech applications require increasing amounts of rare earth elements (REE). Their recovery from low-grade minerals and their recycling from secondary sources (as waste materials) are of critical importance. There is increasing attention paid to the development of new sorbents for REE recovery from dilute solutions. A new generation of composite sorbents based on brown algal biomass (alginate) and polyethylenimine (PEI) was recently developed (ALPEI hydrogel beads). The phosphorylation of the beads strongly improves the affinity of the sorbents for REEs (such as La and Tb): by 4.5 to 6.9 times compared with raw beads. The synthesis procedure (epicholorhydrin-activation, phosphorylation and de-esterification) is investigated by XPS and FTIR for characterizing the grafting route but also for interpreting the binding mechanism (contribution of N-bearing from PEI, O-bearing from alginate and P-bearing groups). Metal ions can be readily eluted using an acidic calcium chloride solution, which regenerates the sorbent: the FTIR spectra are hardly changed after five successive cycles of sorption and desorption. The materials are also characterized by elemental, textural and thermogravimetric analyses. The phosphorylation of ALPEI beads by this new method opens promising perspectives for the recovery of these strategic metals from mild acid solutions (i.e., pH ~ 4).

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