scholarly journals Development of Novel Superabsorbent Hybrid Hydrogels by E-Beam Crosslinking

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 189
Author(s):  
Ion Călina ◽  
Maria Demeter ◽  
Anca Scărișoreanu ◽  
Marin Micutz
Keyword(s):  
Sol Gel ◽  
Absorbed Dose ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Hybrid Hydrogel ◽  
Beam Radiation ◽  
Swelling Properties ◽  
Superabsorbent Hydrogel ◽  
Swelling Degree ◽  
Hybrid Hydrogels

In this study, several superabsorbent hybrid hydrogel compositions prepared from xanthan gum (XG)/sodium carboxymethylcellulose (CMC)/graphene oxide (GO) were synthesized by e-beam radiation crosslinking. We studied and evaluated the effects of GO content from the chemical structure of the hydrogels according to: sol-gel analysis, swelling degree, diffusion of water, ATR-FTIR spectroscopy, network structure, and dynamic mechanical analysis. The gel fraction and swelling properties of the prepared hydrogels depended on the polymer compositions and the absorbed dose. The hybrid XGCMCGO hydrogels showed superabsorbent capacity and reached equilibrium in less than 6 h. In particular, the XGCMCGO (70:30) hydrogel reached the highest swelling degree of about 6000%, at an irradiation dose of 15 kGy. The magnitude of the elastic (G′) and viscous (G″) moduli were strongly dependent on the absorbed dose. When the degree of crosslinking was higher, the G′ parameter was found to exceed 1000 Pa. In the case of the XGCMCGO (80:20) hydrogel compositions, the Mc and ξ parameters decreased with the absorbed dose, while crosslinking density increased, which demonstrated that we obtained a superabsorbent hydrogel with a permanent structure.

scholarly journals Synthesis and Performance of Hybrid Hydrogels Loaded with Methylene Blue and Its Use for Antimicrobial Photodynamic Inactivation

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Oksana Nadtoka ◽  
Pavlo Virych ◽  
Serhiy Nadtoka ◽  
Nataliya Kutsevol
Keyword(s):  
Methylene Blue ◽  
Chemical Nature ◽  
Red Light ◽  
Bactericidal Effect ◽  
Hybrid Hydrogel ◽  
Swelling Properties ◽  
Hybrid Hydrogels ◽  
Dye Sorption ◽  
And Performance

Development and characterization of hybrid hydrogels loaded with methylene blue, which are designed to apply for photodynamic therapy, are presented. Hybrid hydrogels were synthesized by grafting polyacrylamide onto dextran/dextran sulfate sodium salt using N, N′-methylene-bis-acrylamide as a cross-linker. The differences in microstructure of synthesized hydrogels were proved by scanning electron microscopy. FTIR spectra testify that the chemical nature of hydrogel components affects the hydrogel hydrophilicity. The swelling properties of hydrogels in water and absorption/desorption hydrogels’ ability towards methylene blue were studied. It was shown that dye sorption was dependent on the hydrogel type. The hydrogel based on dextran and polyacrylamide revealed the highest ability to release absorbed dye. The bactericidal effect of this hydrogel loaded with methylene blue and activated by red light in suspension and solid medium of S. aureus was tested. The increase of bactericidal activity of hybrid hydrogel was dependent on radiation doses.

scholarly journals Synthesis and characterization of new biodegradable gels based on 2,2 '-(ethylenedioxy) diethanethiol and pentaerythritol triacrylate

2022 ◽  
Vol 320 (1) ◽  
pp. 25-31
Author(s):  
R.A. Shulen ◽  
◽  
D.S. Kazybayeva ◽  
Keyword(s):  
Raman Spectroscopy ◽  
Ir Spectroscopy ◽  
Sol Gel ◽  
Polymer Network ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Synthesis And Characterization ◽  
Prolonged Release ◽  
Click Polymerization

The work is devoted to the synthesis and characterization of gels based on the monomers pentaerythritol triaacrylate (PETriA) and 2,2 '-(ethylenedioxy)diethanethiol (EDODET) by thiol-ene "click" polymerization. The properties of the obtained gels were investigated by IR, Raman spectroscopy, mechanical analysis. Sol-gel analysis of obtained networks was carried out and the degradability was investigated. The results of IR spectroscopy confirmed the presence of -C = O and -C-O-C- groups in the composition of the obtained gels. The presence of unreacted C = C bonds conjugated with C = O, as well as thiol groups, varies depending on the composition of the initial monomer mixture (IMM). Raman spectroscopy results correlate well with IR data. Raman spectra also show C-S, S-S and SH characteristic bands that are difficult to identify by IR spectroscopy. It was found that the composition of MM affects the physicochemical properties of the synthesized gels. The highest yield of the gel fraction of obtained polymers was found in samples with an equimolar composition of IMM. The analysis of mechanical properties showed that gels with an excess of PETriA exhibit more elastic properties, and an excess of EDODET leads to the formation of networks with a higher crosslinking density. The study of the ability of obtained PETria-EDODET gels to degrade in a 3% solution of hydrogen peroxide showed that the polymer network degrades by 12% within 60 days. This property of the obtained gels can find application in the creation of targeted drug delivery systems with their prolonged release.

scholarly journals The Effects of Monomer, Crosslinking Agent, and Filler Concentrations on the Viscoelastic and Swelling Properties of Poly(methacrylic acid) Hydrogels: A Comparison

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2305
Author(s):  
Claudia Mihaela Ninciuleanu ◽  
Raluca Ianchiş ◽  
Elvira Alexandrescu ◽  
Cătălin Ionuţ Mihăescu ◽  
Cristina Scomoroşcenco ◽  
...  
Keyword(s):  
Water Absorption ◽  
Methacrylic Acid ◽  
Crosslinking Agent ◽  
Monomer Concentration ◽  
Fold Increase ◽  
Crosslinking Density ◽  
Swelling Properties ◽  
Swelling Degree ◽  
Reinforcing Agent ◽  
Swelling Studies

The present work aims at comparatively studying the effects of the concentrations of a monomer (10–30 wt% based on the whole hydrogel composition), crosslinking agent (1–3 mol% based on the monomer), and reinforcing agent (montmorillonite-MMT, 1–3 wt.% based on the whole hydrogel composition) on the swelling and viscoelastic properties of the crosslinked hydrogels prepared from methacrylic acid (MAA) and N,N′-methylenebisacrylamide (BIS) in the presence of K2S2O8 in aqueous solution. The viscoelastic measurements, carried out on the as-prepared hydrogels, showed that the monomer concentration had the largest impact, its three-time enhancement causing a 30-fold increase in the storage modulus, as compared with only a fivefold increase in the case of the crosslinking agent and 1.5-fold increase for MMT in response to a similar threefold concentration increase. Swelling studies, performed at three pH values, revealed that the water absorption of the hydrogels decreased with increasing concentration of both the monomer and crosslinking agent, with the amplitude of the effect of concentration modification being similar at pH 5.4 and 7.4 in both cases, but very different at pH 1.2. Further, it was shown that the increased pH differently influenced the swelling degree in the case of the hydrogel series in which the concentrations of the monomer and crosslinking agent were varied. In contrast to the effect of the monomer and crosslinking agent concentrations, the increase in the MMT amount in the hydrogel resulted in an increased swelling degree at pH 5.4 and 7.4, while at pH 1.2, a slight decrease in the water absorption was noticed. The hydrogel crosslinking density determinations revealed that this parameter was most affected by the increase in the monomer concentration.

scholarly journals Preparation of covalently bonded silica-alginate hybrid hydrogels by SCHIFF base and sol-gel reactions

2021 ◽  
pp. 118186
Author(s):  
Aurora C. Hernández-González ◽  
Lucía Téllez-Jurado ◽  
Luis M. Rodríguez-Lorenzo
Keyword(s):  
Schiff Base ◽  
Sol Gel ◽  
Hybrid Hydrogels ◽  
Covalently Bonded

scholarly journals Superabsorbent poly(acrylic acid) and antioxidant poly(ester amide) hybrid hydrogel for enhanced wound healing

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Jianhua Zhang ◽  
Junfei Hu ◽  
Baoshu Chen ◽  
Tianbao Zhao ◽  
Zhipeng Gu
Keyword(s):  
Wound Healing ◽  
Acrylic Acid ◽  
Protein Denaturation ◽  
Healing Process ◽  
Antioxidant Properties ◽  
Skin Damage ◽  
Hybrid Hydrogel ◽  
Hydrogel Scaffolds ◽  
Hybrid Hydrogels ◽  
Poly Acrylic Acid

Abstract Wound healing dressing is increasingly needed in clinical owing to the large quantity of skin damage annually. Excessive reactive oxygen species (ROS) produced through internal or external environmental influences can lead to lipid peroxidation, protein denaturation, and even DNA damage, and ultimately have harmful effects on cells. Aiming to sufficiently contact with the wound microenvironment and scavenge ROS, superabsorbent poly (acrylic acid) and antioxidant poly (ester amide) (PAA/PEA) hybrid hydrogel has been developed to enhance wound healing. The physical and chemical properties of hybrid hydrogels were studied by Fourier-transform infrared (FTIR) absorption spectrum, compression, swelling, degradation, etc. Besides, the antioxidant properties of hybrid hydrogels can be investigated through the free radical scavenging experiment, and corresponding antioxidant indicators have been tested at the cellular level. Hybrid hydrogel scaffolds supported the proliferation of human umbilical vein endothelial cells and fibroblasts, as well as accelerated angiogenesis and skin regeneration in wounds. The healing properties of wounds in vivo were further assessed on mouse skin wounds. Results showed that PAA/PEA hybrid hydrogel scaffolds significantly accelerated the wound healing process through enhancing granulation formation and re-epithelialization. In summary, these superabsorbent and antioxidative hybrid hydrogels could be served as an excellent wound dressing for full-thickness wound healing.

EQUIVALENT UNIFORM DOSE SENSITIVITY TO CHANGES IN ABSORBED DOSE DISTRIBUTION

2013 ◽  
Vol 06 (01) ◽  
pp. 1250069
Author(s):  
FRANCISCO CUTANDA-HENRÍQUEZ ◽  
SILVIA VARGAS-CASTRILLÓN
Keyword(s):  
Treatment Planning ◽  
Dose Distribution ◽  
Absorbed Dose ◽  
Target Volume ◽  
Simple Expression ◽  
External Beam Radiation ◽  
Equivalent Uniform Dose ◽  
Beam Radiation ◽  
Dose Volume Histograms ◽  
Small Change

Treatment planning in external beam radiation therapy (EBRT) utilizes dose volume histograms (DVHs) as optimization and evaluation tools. They present the fraction of planning target volume (PTV) receiving more than a given absorbed dose, against the absorbed dose values, and a number of radiobiological indices can be computed with their help. Equivalent uniform dose (EUD) is the absorbed dose that, uniformly imparted, would yield the same biological effect on a tumor as the dose distribution described by the DVH. Uncertainty and missing information can affect the dose distribution, therefore DVHs can be modeled as samples from a set of possible outcomes. This work studies the sensitivity of the EUD index when a small change in absorbed dose distribution takes place. EUD is treated as a functional on the set of DVHs. Defining a Lévy distance on this set and using a suitable expansion of the functional, a very simple expression for a bound on the variation of EUD when the dose distribution changes is found. This bound is easily interpreted in terms of standard treatment planning practice.

Self-assembled three-dimensional hierarchical graphene hybrid hydrogels with ultrathin β-MnO2 nanobelts for high performance supercapacitors

2015 ◽  
Vol 3 (4) ◽  
pp. 1540-1548 ◽  
Author(s):  
Sheng Zhu ◽  
Hui Zhang ◽  
Ping Chen ◽  
Lin-Hui Nie ◽  
Chuan-Hao Li ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Three Dimensional ◽  
The Self ◽  
Mass Loading ◽  
Hybrid Hydrogel ◽  
Precise Control ◽  
Ultrafine Structure ◽  
Hybrid Hydrogels ◽  
Self Assembled

A facile protocol for the self-assembly of the rGO/β-MnO2 hybrid hydrogel with ultrafine structure and precise control of mass-loading for high performance supercapacitors is reported.

Safety and feasibility of rhenium-186 nanoliposome (186RNL) in recurrent glioma: The ReSPECT phase 1 trial.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2061-2061
Author(s):  
Andrew J. Brenner ◽  
Ande Bao ◽  
William Phillips ◽  
Gregory Stein ◽  
Vibhudutta Awasthi ◽  
...  
Keyword(s):  
Dose Escalation ◽  
Tumor Volume ◽  
Phase 1 ◽  
Absorbed Dose ◽  
External Beam Radiation ◽  
Whole Body ◽  
Recurrent Glioma ◽  
Normal Brain ◽  
Beam Radiation ◽  
The Mean

2061 Background: While external beam radiation therapy (EBRT) remains a central component of the management of primary brain tumors, it is limited by tolerance of the surrounding normal brain tissue. Rhenium-186 NanoLiposome (186RNL) permits the delivery of beta-emitting radiation of high specific activity with excellent retention in the tumor. We report the results of the phase 1 study in recurrent glioma. Methods: A Phase 1 dose-escalation study of 186RNL in recurrent glioma utilizing a standard 3+3 design was undertaken to determine the maximum tolerated dose of 186RNL. 186RNL is administered by convection enhanced delivery (CED). Infusion is followed under whole body planar imaging and SPECT/CT. Repeat SPECT/CT imaging is performed immediately following, and at 1, 3, 5, and 8 days after 186RNL infusion to obtain dosimetry and distribution. Subjects were followed until disease progression by RANO criteria. Results: Eighteen subjects were treated across 6 cohorts. The mean tumor volume was 9.4 mL (range 1.1 – 23.4). The infused dose ranged from 1.0 mCi to 22.3 mCi and the volume of infusate ranged from 0.66 mL to 8.80 mL. From 1 – 4 CED catheters were used. The maximum catheter flow rate was 15 µl/min. The mean absorbed dose to the tumor volume was 239 Gy (CI 141 – 337; range 9 - 593), to normal brain was 0.72 Gy (CI 0.34 – 1.09; range 0.005 – 2.73), and to total body was 0.07 Gy (CI 0.04 – 0.10; range 0.001 – 0.23). The mean absorbed dose to the tumor volume when the percent tumor volume in the treatment volume was 75% or greater (n = 10) was 392 Gy (CI 306 – 478; range 143 – 593). Scalp discomfort and tenderness related to the surgical procedure did occur in 3 subjects. The therapy has been well tolerated, no dose-limiting toxicity has been observed, and no treatment-related serious adverse events have occurred despite markedly higher absorbed doses typically delivered by EBRT in patients with prior treatment. Responses have been observed supporting the clinical activity. Final results from the dose escalation will be presented. Conclusions: 186RNL administered by CED to patients with recurrent glioma results in a much higher absorbed dose of radiation to the tumor compared to EBRT without significant toxicity. The recommended Phase 2 dose is 22.3 mCi in 8.8 mL of infusate. Clinical trial information: NCT01906385. [Table: see text]

Preparation and characterization of acrylic polymer titania hybrid. A study of organicinorganic interactions in hybrid materials by micro-hardness Vickers

2002 ◽  
Vol 726 ◽  
Author(s):  
Van Nhan Nguyen ◽  
François Xavier Perrin ◽  
Jean-Louis Vernet
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Polymer Chains ◽  
Segmental Motion ◽  
Acrylic Polymer ◽  
Titania Content ◽  
Mineral Constituent ◽  
Free Films

AbstractMetal-oxide ceramer films have been developed using an acrylic polymer bearing a low amount of methacrylic acid units (ca. 4%mol) as the organic phase with titanium tetrabutoxide as the inorganic sol-gel precursor. The characterisation of free films was realized by various experimental methods. The formation of COOTi bonds prevents large scale phase separation between the organic component and the mineral network. Mechanical properties of the hybrid films have been investigated through dynamic mechanical analysis. The influence of the titania content on the damping peak amplitude suggests that titania is molecularly dispersed in the polymer matrix and that it significantly hinders the segmental motion of the polymer chains. However, the low content in potential carboxylic crosslinking sites explains why the glass transition temperature remains relatively unchanged when titania content increases. Vickers microhardness measurements used in this study allowed us to understand the contribution of the inorganic part (phase TiO2) to the mechanical properties of the polymer. The creep of hybrids has been studied carrying out hardness measurements under various indentation times. The mineral constituent leads to an important increase of the hardness and limits, in a significant way, the creep of polymer.

Development and Mechanical Characterization of a Collagen/Hydroxyapatite Bilayered Scaffold for Ostechondral Defect Replacement

2011 ◽  
Vol 493-494 ◽  
pp. 890-895 ◽  
Author(s):  
Francesca Gervaso ◽  
Francesca Scalera ◽  
Sanosh Kunjalukkal Padmanabhan ◽  
Antonio Licciulli ◽  
Daniela Deponti ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Sol Gel ◽  
Three Dimensional ◽  
Collagen Scaffold ◽  
Mechanical Analysis ◽  
Design Parameters ◽  
Compression Tests ◽  
Templating Method ◽  
Organic Part ◽  
Hydroxyapatite Scaffold

In this work a novel three-dimensional ostechondral substitute is proposed that is made of an inorganic/organic hybrid material, namely collagen/hydroxyapatite. The two components of the substitute have been characterized separately. The inorganic part, a hydroxyapatite scaffold, was fabricated by a polymer sponge templating method using a reactive sub-micron powder synthesized in our laboratory by hydroxide precipitation sol-gel route. The organic part, a collagen scaffold, was fabricated by a freeze-dying technique varying design parameters. Both the parts were analysed by scanning electron microscopy and their mechanical properties assessed by compression tests. The hydroxyapatite scaffold showed a high and highly interconnected porosity and a mechanical strength equal to 0.55 MPa, higher than those reported in literature. The collagen scaffolds were seeded by chondrocytes, processed for histology analysis and tested in compression. The biological tests proved the ability of the scaffolds to be positively populated by chondrocytes and the mechanical analysis showed that the mechanical strength of the scaffolds significantly increased after 3 weeks of culture.

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