scholarly journals Thermoresponsive Poly(ε-Caprolactone)-Poly(Ethylene/Propylene Glycol) Copolymers as Injectable Hydrogels for Cell Therapies

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 367 ◽  
Author(s):  
Kyle Brewer ◽  
Batjargal Gundsambuu ◽  
Paula Facal Marina ◽  
Simon C. Barry ◽  
Anton Blencowe
Keyword(s):  
Propylene Glycol ◽  
Adoptive Cell Therapy ◽  
Sol Gel ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Inversion Method ◽  
Scanning Calorimetry ◽  
Cell Therapies ◽  
Thermoresponsive Hydrogels ◽  
Poly Ethylene

Injectable, thermoresponsive hydrogels are promising candidates for the delivery, maintenance and controlled release of adoptive cell therapies. Therefore, there is significant interest in the development of cytocompatible and biodegradable thermoresponsive hydrogels with appropriate gelling characteristics. Towards this end, a series of thermoresponsive copolymers consisting of poly(caprolactone) (PCL), poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) segments, with various PEG:PPG ratios, were synthesised via ring-opening polymerisation (ROP) of ε-caprolactone and epoxy-functionalised PEG and PPG derivatives. The resultant PCL–PEG–PPG copolymers were characterised via proton nuclear magnetic resonance (1H NMR) spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The thermoresponsive characteristics of the aqueous copolymer solutions at various concentrations was investigated using the inversion method. Whilst all of the copolymers displayed thermoresponsive properties, the copolymer with a ratio of 1:2 PEG:PPG exhibited an appropriate sol–gel transition (28 °C) at a relatively low concentration (10 wt%), and remained a gel at 37 °C. Furthermore, the copolymers were shown to be enzymatically degradable in the presence of lipases and could be used for the encapsulation of CD4+ T-cell lymphocytes. These results demonstrate that the thermoresponsive PCL–PEG–PPG hydrogels may be suitable for use as an adoptive cell therapy (ACT) delivery vehicle.

scholarly journals Acrylate-Based Hybrid Sol-Gel Coating for Corrosion Protection of AA7075-T6 in Aircraft Applications: The Effect of Copolymerization Time

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 948 ◽  
Author(s):  
Peter Rodič ◽  
Romana Cerc Korošec ◽  
Barbara Kapun ◽  
Alenka Mertelj ◽  
Ingrid Milošev
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Condensation Reaction ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Gel Permeation Chromatography ◽  
Corrosion Attack ◽  
Scanning Calorimetry ◽  
Corrosion Properties ◽  
Pressure Differential Scanning Calorimetry

Pre-hydrolysed/condensed tetraethyl orthosilicate (TEOS) was added to a solution of methyl methacrylate (MMA) and 3-methacryloxypropyltrimethoxysilane (MAPTMS), and then copolymerised for various times to study the influence of the latter on the structure of hybrid sol-gel coatings as corrosion protection of aluminium alloy 7075-T6. The reactions taking place during preparation were characterised using real-time Fourier transform infrared spectroscopy, dynamic light scattering and gel permeation chromatography. The solution characteristics were evaluated, using viscosimetry, followed by measurements of thermal stability determined by thermogravimetric analysis. The optimal temperature for the condensation reaction was determined with the help of high-pressure differential scanning calorimetry. Once deposited on 7075-T6 substrates, the coatings were evaluated using a field emission scanning electron microscope coupled to an energy dispersive spectrometer to determine surface morphology, topography, composition and coating thickness. Corrosion properties were tested in dilute Harrison’s solution (3.5 g/L (NH4)2SO4 and 0.5 g/L NaCl) using electrochemical impedance spectroscopy. The copolymerization of MMA and MAPTMS over 4 h was optimal for obtaining 1.4 µm thick coating with superior barrier protection against corrosion attack (|Z10 mHz| ~ 1 GΩ cm2) during three months of exposure to the corrosive medium.

Thermosensitive hydrogel for in situ-controlled methotrexate delivery

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 910-920
Author(s):  
Teresa Darlen Carrillo-Castillo ◽  
Antonia Luna-Velasco ◽  
Erasto Armando Zaragoza-Contreras ◽  
Javier Servando Castro-Carmona
Keyword(s):  
Sol Gel ◽  
Proton Nuclear Magnetic Resonance ◽  
Infrared Spectrometry ◽  
Resonance Spectroscopy ◽  
Burst Release ◽  
Thermosensitive Hydrogel ◽  
Weight Analysis ◽  
Poly Ethylene ◽  
Copolymer Assembly

Abstract Methotrexate (MTX) is widely used for the treatment of various types of cancer; however, it has drawbacks such as low solubility, lack of selectivity, premature degradation, and side effects. To solve these weaknesses, a hydrogel with the ability to contain and release MTX under physiological conditions without burst release was synthesized. The hydrogel was fabricated with a poly(ɛ-caprolactone)-b-poly(ethylene glycol)-b-poly(ɛ-caprolactone) (PCL–PEG–PCL) triblock copolymer, synthesized by ring-opening polymerization. The characterizations by proton nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectrometry confirmed the copolymer assembly, whereas the molecular weight analysis validated the PCL2000–PEG1000–PCL2000 structure. The copolymer aqueous solution exhibited sol–gel phase transition at 37°C and injection capacity. The hydrogel supported a load of 1,000 μg MTX·mL−1, showing a gradual and sustained release profile of the drug for 14 days, with a delivery up to 92% at pH 6.7. The cytotoxicity of the MTX-loaded hydrogel was performed by the methyl thiazole tetrazolium assay, showing a mean inhibitory concentration of 50% of MCF-7 cells (IC50) at 43 µg MTX·mL−1.

Reduction-Degradable Shell Cross-Linked Micelle with pH-Responsive Cores Prepared via Click Chemistry

2016 ◽  
Vol 848 ◽  
pp. 527-531
Author(s):  
Lu Bin Lin ◽  
Qing Yun Yu ◽  
Zhuo Qun Gu ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu
Keyword(s):  
Click Chemistry ◽  
Self Assembly ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Poly Ethylene Glycol ◽  
H Nmr ◽  
Transmission Electron ◽  
Assembly Behavior ◽  
Poly Ethylene ◽  
Novel Drug

A well-defined poly [(ethylene glycol)-block-2-(dimethylamino) ethyl methacrylate-block-2-(diethylamino) methacrylate] (PEG-b-DMA-b-DEA) triblock copolymer was synthesized via atom transfer radical polymerization (ATRP) by successively polymerization of DMA and DEA monomers using a PEG-based macroinitiator, and obtained copolymer was then converted to be PEG-b-P(DMA-co-QDMA)-b-PDEA copolymer with “clickable” moieties in the middle block by the quaternization with propargyl bromide. Those copolymers prepared were characterized by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and its self-assembly behavior and subsequently fixation with bis-(azidoethyl) disulfide via click chemistry resulting reduction-sensitive shell-cross-linked (SCL) micelle in purely aqueous solution were investigated by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The results show the micellar structure could be effectively cross-linked via click chemistry and also be dissociated at reduction condition, which may realize it's potential application as novel drug delivery carriers.

On the structure alteration of crosslinkable gelatin coupled with methacrylic acid and its hydrogel

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaohong Hu ◽  
Dan Li ◽  
Feng Zhou ◽  
Changyou Gao
Keyword(s):  
Molecular Weight ◽  
Triple Helix ◽  
Sol Gel ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Small Range ◽  
Scanning Calorimetry ◽  
Physical Chemical ◽  
Substitution Degree

AbstractPhysical structures of a crosslinkable gelatin derivative (GM) were studied in terms of alteration of apparent molecular weight, triple helix content and mechanical strength. The GM with a substitution degree (DS) of 49% and 79% was prepared by grafting mechacrylic acid (MA), which was able to form injectable hydrogel by photoinitiating polymerization. The zeta potential was increased along the increase of DS. After modification, the apparent number-average molecular weight (Mn) detected by gel permeation chromatography was decreased to about 2/3 of gelatin, while the apparent weight-average molecular weight (Mw) was changed within a small range. Differential scanning calorimetry and circular dichroism (CD) revealed that ability of triple-helix formation of GM was decreased along with the increase of DS and decrease of GM concentration. After photocrosslinking, the sol-gel transition of GM49 physical-chemical hydrogel still existed, but completely disappeared for its chemical hydrogel. The physical-chemical hydrogel showed a larger storage modulus at 20°C than at 37°C as a result of additional physical crosslinking.

scholarly journals Facile Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Activities of Biscoumarin Copolyester Bearing Pendant 3-(Trifluoromethyl)Styrene

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Narendran Kandaswamy ◽  
Nanthini Raveendiran
Keyword(s):  
Gel Permeation Chromatography ◽  
Inherent Viscosity ◽  
Proton Nuclear Magnetic Resonance ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Anticancer Activities ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Agar Disc

Synthesis of random biscoumarin copolyester bearing pendant 3-(trifluoromethyl)styrene was prepared by the reaction of biscoumarin monomer 3 and hydroquinone 5 with azeloyl chloride. The influence of pendant 3-(trifluoromethyl)styrene unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and compared in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.15 dL/g and 1.36, respectively. The chemical structure of the copolyester was investigated by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The physical properties of copolyester were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and X-ray diffraction (XRD) technique. Agar disc diffusion method was employed to study the antimicrobial activity of the random copolyester. In vitro anticancer activity against lung cancer (Hep-2) cell line was also investigated.

scholarly journals Synthesis of Thermo-Responsive Block-Graft Copolymer Based on PCL and PEG Analogues, and Preparation of Hydrogel via Click Chemistry

2019 ◽  
Author(s):  
Pei Shang ◽  
Jie Wu ◽  
Xiaoyu Shi ◽  
Zhidan Wang ◽  
Fei Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Graft Copolymer ◽  
Water Solubility ◽  
Sol Gel ◽  
Cycloaddition Reaction ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Fluorescence Probes ◽  
Resonance Spectroscopy

The cross-linkable PCL-PEG analogues block-graft copolymer was designed and synthesized, which with the copolymer of the MEO2MA and OEGMA as graft chains to improve the mPEG-b-PCL-b-mPEG copolymer the aqueous solution properties. And successfully prepared two hydrogels via a copper-catalyzed 1, 3-dipolar azide-alkyne cycloaddition reaction of alkyne-terminated poly[glycidyl methacrylate-co-2-(2-methoxyethoxy) ethyl methacrylate-co-oligo (ethylene glycol) methacrylate] [P(GMA-co-MEO2MA-co-OEGMA)] with azide end-functionalized PCL-PEG analogues block-graft copolymer, and tetrakis (2-propynyloxymethyl) -methane (TPOM) and with azide end-functionalized PCL-PEG analogues block-graft copolymer. The copolymer's chemical structure was characterized by proton nuclear magnetic resonance spectroscopy and fourier transform infrared spectroscopy. The molecular weights of the copolymers were decided with gel permeation chromatography. The water solubility and temperature sensitivity of the copolymers were studied by taking digital photos and transmittance change measured by UV spectrophotometer at different temperatures. Fluorescence probes, surface tension, dynamic light scattering and transmission electron microscopy were used to analyze the micelles that copolymers self-assembly in aqueous solution. The sol-gel behavior of copolymer solutions at high concentrations was explored by vial inversion experiments. Finally, the network structure of the gels was observed by scanning electron microscopy. These conclusions indicate that these hydrogels are expected to be used as a new material in the field of biomedicine.

scholarly journals Extraction of Polyhydroxyalkanoates from Purple Non-Sulfur Bacteria by Non-Chlorinated Solvents

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4163
Author(s):  
Sara Filippi ◽  
Patrizia Cinelli ◽  
Andrea Mezzetta ◽  
Pietro Carlozzi ◽  
Maurizia Seggiani
Keyword(s):  
Chlorinated Solvents ◽  
Gel Permeation Chromatography ◽  
Photosynthetic Bacterium ◽  
Cellular Membrane ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Sulfur Bacteria ◽  
Working Volume ◽  
New Generation ◽  
Similar Yield

In this study, non-chlorinated solvents such as cyclohexanone (CYC) and three ionic liquids, (ILs) (1-ethyl-3-methylimidazolium dimethylphosphate, [EMIM][DMP], 1-ethyl-3-methylimidazolium diethylphosphate, [EMIM][DEP] and 1-ethyl-3-methylimidazolium methylphosphite, [EMIM][MP]) were tested to extract polyhydroxyalkanoates (PHAs) from the purple non-sulfur photosynthetic bacterium (PNSB) Rhodovulumsulfidophilum DSM-1374. The photosynthetic bacterium was cultured in a new generation photobioreactor with 4 L of working volume using a lactate-rich medium. The extracted PHAs were characterized using a thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy, proton nuclear magnetic resonance and gel permeation chromatography. The most promising results were obtained with CYC at 125 °C with an extraction time of above 10 min, obtaining extraction yields higher than 95% and a highly pure poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) with around 2.7 mol% of hydroxylvalerate (HV). A similar yield and purity were obtained with chloroform (CHL) at 10 °C for 24 h, which was used as the referent solvent Although the three investigated ILs at 60 °C for 4 and 24 h with biomass/IL up to 1/30 (w/w) obtained PHAs strongly contaminated by cellular membrane residues, they were not completely solubilized by the investigated ILs.

Sol-gel synthesis of silica–based mesoporous powders

2004 ◽  
Vol 848 ◽  
Author(s):  
Lidia Armelao ◽  
Gregorio Bottaro ◽  
Renzo Campostrini ◽  
Stefano Gialanella ◽  
Marco Ischia ◽  
...  
Keyword(s):  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Structure Directing Agent ◽  
Template Removal ◽  
Guest Species ◽  
Poly Ethylene Oxide ◽  
Acidic Conditions ◽  
Poly Ethylene ◽  
Sol Gel Synthesis

ABSTRACTMesoporous silica powders have been synthesized starting from aqueous solutions of Si(OCH2CH3)4 (TEOS) under acidic conditions, using non-ionic alkyl poly(ethylene oxide) oligomer (Brij76) as a structure-directing agent. Template removal was performed by thermal treatment in air as well as by ethanol extraction. The annealing process (400 - 600°C) resulted in more efficient elimination of the organic molecules, thus yielding hexagonal (p6mm) mesopor-ous materials with pore volume and specific surface area ranging between 0.58 – 0.41 cm3/g and 900 – 700 m2/g, respectively. The systems were characterized by X-Ray Diffraction (XRD), N2 BET adsorption, Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Particular attention was focused on the evolution of the system mesostructural and porous features as a function of the template removal procedure. The obtained mesoporous networks are suitable as matrices for the development of nanocomposite systems in which the dispersion or the growth of various guest species (clusters, molecules…) can be addressed into the host mesopores.

scholarly journals Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Evaluation of Copolyester Bearing 4-Arylidene Curcumin in the Main Chain

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Narendran Kandaswamy ◽  
Nanthini Raveendiran
Keyword(s):  
Gel Permeation Chromatography ◽  
Inherent Viscosity ◽  
Proton Nuclear Magnetic Resonance ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polymer Backbone ◽  
H Nmr ◽  
Agar Disc

Synthesis of random copolyester bearing 4-arylidene curcumin M1 in the polymer backbone was prepared by solution polycondensation method. The influence of copolyester bearing 4-arylidene curcumin M1 unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and studied in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.19 dL/g and 1.38, respectively. The chemical structure of the copolyester was investigated by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The physical properties of copolyester were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and X-ray diffraction (XRD) technique. Agar disc diffusion method was employed to study the antimicrobial activity of the random copolyester. In vitro anticancer activity against lung cancer (Hep-2) cell line was investigated.

The Influence of Amount of Succinic Anhydride in Chain Extension Reaction on Increasing Molecular Weight of Poly(lactic acid)

2013 ◽  
Vol 747 ◽  
pp. 148-152
Author(s):  
Chaichana Piyamawadee ◽  
Duangdao Aht-Ong
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Succinic Anhydride ◽  
Gel Permeation Chromatography ◽  
Chain Extension ◽  
Proton Nuclear Magnetic Resonance ◽  
Poly Lactic Acid ◽  
Condensation Polymerization ◽  
Scanning Calorimetry ◽  
Molar Ratios

High molecular weight PLA was successfully synthesized by chain extension reaction of hydroxylated prepolymer using succinic anhydride as a chain extender. Hydroxylated prepolymer was prepared by direct condensation polymerization of L-lactic acid in the presence of 1,4-butanediol. Various molar ratios between hydroxylated prepolymer and succinic anhydride (i.e, 1:1, 1:2, 1:3) were investigated. The results showed that succinic anhydride can help increasing molecular weight of hydroxylated prepolymer approximately up to 47% as characterized by gel permeation chromatography (GPC) technique. Proton nuclear magnetic resonance (1H-NMR) was used to investigate structure of chain-extended PLA. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to examine thermal properties while the crystallinity was investigated by X-ray diffraction (XRD).

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