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Biopreservation and Biobanking Dec 2023Two physicochemical effects occur during vitrification: nucleation and crystallization. Nucleation is a statistical occurrence by its nature. Thus, the more water...
Two physicochemical effects occur during vitrification: nucleation and crystallization. Nucleation is a statistical occurrence by its nature. Thus, the more water molecules that are present the higher are the chances for nucleation to occur. Crystallization is a first-order transition where a water molecule is incorporated into ice crystal. Intracellular viscosity, which is the combination of water, salts, and cryoprotectants (CPs), affects both the nucleation and crystal growth rates. Ice velocity is inversely correlated with the viscosity and directly proportional to the function of the system's supercooling. However, little is known about the speed of ice crystal propagation in vitrification solutions containing different concentrations of CPs. This article describes the ice crystal propagation velocity while referring to vitrification. Ice crystal propagation velocity was measured in solutions containing different CP (dimethyl sulfoxide [DMSO], propylene glycol [PG], ethylene glycol [EG], and glycerol) concentrations at a supercooled temperature. The different CPs solutions were inserted into 0.25 mL straws and placed in different temperatures of an alcohol bath () at supercooling temperatures of -8°C to -10°C. We found that ice crystal propagation is inversely correlated to CP concentrations. Interestingly, PG showed, with statistically significant results, lower ice crystal growth velocities up to concentrations of 30% (v/v), compared with DMSO, and EG at the same concentrations. The combination of EG with PG showed better results (0.25 mm/s) than EG with DMSO (0.39 mm/s) in terms of decreasing the ice crystal growth velocity. When the concentration was increased to 40% (v/v), EG showed the lowest ice crystal propagation velocity (0.09 mm/s), although not significantly different than PG and glycerol but significantly lower than DMSO (0.13 mm/s). These results suggest that current vitrification solutions are not optimized. Based on our results, we suggest that combining PG with EG has advantages over the combination of DMSO and EG, which might promote successful cell and tissue vitrification.
Topics: Dimethyl Sulfoxide; Glycerol; Ice; Cryopreservation; Cryoprotective Agents; Vitrification; Propylene Glycol; Water; Ethylene Glycol
PubMed: 36383132
DOI: 10.1089/bio.2022.0144 -
Scientific Reports Jun 2024Propolis extracts have been used in traditional medicines since ages due to its advantageous complex chemical composition. However, the antibacterial and antifungal...
Propolis extracts have been used in traditional medicines since ages due to its advantageous complex chemical composition. However, the antibacterial and antifungal activity of poplar propolis extracts prepared in Natural Deep Eutectic Solvent (NADES) are seldom studied. This study investigates suitable alternate for ethanol as a solvent for extraction for Polish poplar propolis. It also attempts to identify suitable extraction condition for the efficient transfer of compounds from propolis to the solvents. The extraction efficiency of NADES extracts was assessed in terms of total phenolic content, antioxidant activity and antimicrobial activity. The chemical composition of the extracts was analysed using UHPLC-DAD-QqTOF-MS. Four extracts, prepared in Propylene Glycol, Choline Chloride:Propylene Glycol (1:3), Choline Chloride:Propylene Glycol (1:4) and Choline Chloride:Glycerol (1:2), demonstrated activity and properties similar to ethanolic extract and extraction at 50 °C was found the most suitable for propolis. HPLC analysis confirmed that the chemical cocktail extracted by these solvents from propolis were identical with minor variations in their concentration as compared to its ethanolic extract. Thus, extracts of propolis at 50 °C in Propylene Glycol, Choline Chloride:Propylene Glycol (1:3) and Choline Chloride:Propylene Glycol (1:4) can be alternates for ethanolic extracts.
Topics: Propolis; Antifungal Agents; Anti-Bacterial Agents; Microbial Sensitivity Tests; Chromatography, High Pressure Liquid; Plant Extracts; Antioxidants; Propylene Glycol; Solvents; Choline; Deep Eutectic Solvents; Phenols
PubMed: 38871855
DOI: 10.1038/s41598-024-64111-7 -
Journal of Chromatography. A Apr 2024The solvation parameter model uses five system independent descriptors to characterize compound properties defined as excess molar refraction, E,...
The solvation parameter model uses five system independent descriptors to characterize compound properties defined as excess molar refraction, E, dipolarity/polarizability, S, hydrogen-bond acidity, A, hydrogen-bond basicity, B, and McGowan's characteristic volume, V, to model transfer properties between condensed phases. The V descriptor is assigned from structure. For compounds liquid at 20 °C the E descriptor can be assigned from the characteristic volume and its refractive index. The E descriptor for compounds solid at 20 °C and the S, A, and B descriptors are experimental properties traditionally assigned from chromatographic, liquid-liquid partition, and solubility measurements. In this report liquid-liquid partition constants in totally organic and aqueous biphasic systems are evaluated as a standalone technique for descriptor assignments. Using six totally organic biphasic systems the S, A, and B descriptors were assigned with an average absolute deviation (AAD) of about 0.04, 0.03, and 0.04, respectively, compared with the best estimate of the true descriptor values for 65 compounds. The E descriptor for compounds solid at 20 °C can only be estimated with an AAD of approximately 0.1. For six aqueous biphasic systems the B descriptor is assigned with a lower AAD of 0.028 and higher AAD of 0.08 and 0.05 for the S and A descriptors, respectively, than for the totally organic biphasic systems for compounds with a reliable value for the E descriptor. The preferred system for descriptor assignments utilizes both totally organic biphasic systems (heptane-1,1,1-trifluoroethanol, isopentyl ether-propylene carbonate, isopentyl ether-ethanolamine, heptane-ethylene glycol, heptane-formamide, and 1,2-dichloroethane-ethylene glycol) and aqueous biphasic systems (octanol-water, cyclohexane-water) with the possible substitution of some systems with alternative systems of similar selectivity. For 55 varied compounds this combination of eight organic and aqueous biphasic systems resulted in an AAD of approximately 0.03, 0.02, and 0.02 for the S, A, and B descriptors compared to the best estimate of the true descriptor value. For 30 compounds solid at 20 °C the AAD for the E descriptor of 0.11 is poorly assigned. The relative average absolute deviation in percent (RAAD) corresponds to 9.7 %, 3.1 %. 4.0 % and 8.3 % for E, S, A, and B, respectively, for the eight biphasic systems. Liquid-liquid partition is compared to reversed-phase liquid and gas chromatography as a standalone technique for descriptor assignments.
Topics: Ethers; Ethylene Glycols; Heptanes; Hydrogen; Water; Cyclohexanes; Octanols
PubMed: 38564932
DOI: 10.1016/j.chroma.2024.464850 -
Ecotoxicology and Environmental Safety Dec 2023Chronic toxicity tests on adult and larval honey bees (Apis mellifera) can require the use of dietary additives (solvents, emulsifiers, adjuvants and viscosifier agents)...
Chronic toxicity tests on adult and larval honey bees (Apis mellifera) can require the use of dietary additives (solvents, emulsifiers, adjuvants and viscosifier agents) when the active ingredient of plant protection products cannot be dissolved or does not remain stable and homogeneous within the test diets. Acetone is the widely used and accepted solvent allowed within the international regulatory guidelines, but it can be ineffective in keeping certain compounds in solution and can cause toxicity to adults and larvae. In this publication, we present an evaluation of alternative additives in adult and larval diets. Six dietary additives including five solvents (ethanol, isopropanol, n-propanol, propylene glycol and triethylene glycol) and a viscosifier agent (xanthan gum) at five concentrations along with a negative control and a solvent control (acetone) were investigated at seven laboratories. The safe levels for bees were determined for each of the additives used in the 10-day chronic adult and 22-day chronic larval tests. In the 10-day chronic adult study, ethanol and isopropanol were found to be safe at concentrations ≤ 5.0 %, while xanthan gum can be reliably used at concentrations ≤ 0.1 %. Greater variability across laboratories was observed for N-propanol, propylene glycol, and triethylene glycol and these agents may cause mortality when added to diets at concentrations above 0.25-0.5 %. The safe levels of additives to larval diet in the 22-day chronic larval test had a greater variability and were generally lower than what were observed for adult diet. Our results do not recommend the inclusion of ethanol or n-propanol into the larval diet, and isopropanol, propylene glycol, and triethylene glycol may cause mortality at concentrations above 0.25-0.5 %. Safe levels for xanthan gum were more variable than what was observed for adults, but it can be used reliably at concentrations ≤ 0.05 %. Our analyses conclude that several additives can be integrated successfully in honey bee laboratory bioassays at levels that cause low mortality to adults and larvae.
Topics: Bees; Animals; Larva; Acetone; 2-Propanol; 1-Propanol; Laboratories; Diet; Solvents; Ethanol; Propylene Glycols
PubMed: 38000305
DOI: 10.1016/j.ecoenv.2023.115718 -
Polymers Sep 2023In this work, the possibility of preparation of copolymers of three-dimensional crosslinked structure based on polypropylene glycol fumarate and acrylic acid is shown....
In this work, the possibility of preparation of copolymers of three-dimensional crosslinked structure based on polypropylene glycol fumarate and acrylic acid is shown. The initial reagent polypropylene glycol fumarate has been synthesized by polycondensation reaction of fumaric acid and propylene glycol. The curing process of polypropylene glycol fumarate and acrylic acid at various mole concentrations was studied using DSC method at isothermal and dynamic regimens. Curing in isothermal condition was carried out at temperatures of 60 °C, 70 °C, and 80 °C. Residual reactivity was evaluated at a dynamic regimen within the temperature range from 30 °C to 200 °C at a constant heating rate. On the basis of calorimetric studies, the thermal effects and kinetic parameters of the reaction (conversion, reaction rate, activation energy) have been determined. Thermal behavior of cured samples of p-PGF-AA was estimated using dynamic thermogravimetry (TGA). According to TGA data, the process of decomposition of the studied copolymers proceeds in several stages. Based on the results obtained, the activation energies of thermal decomposition were calculated using the iso-conversional methods of Kissinger-Akakhira-Sunose and Friedman.
PubMed: 37765607
DOI: 10.3390/polym15183753 -
Biopreservation and Biobanking Dec 2023In recent years, cells provided by cell banks and medical facilities have been used for cell therapy, regenerative therapy, and fundamental research. Cryopreservation is...
In recent years, cells provided by cell banks and medical facilities have been used for cell therapy, regenerative therapy, and fundamental research. Cryopreservation is an effective means of maintaining stable cell quality over a long period of time. The slow freezing method is most suitable for processing many human cells isolated simultaneously from organs and tissues, but it is necessary to develop a freezing solution for this method. In this study, we report the successful development of a dimethyl sulfoxide (DMSO)-free freezing medium for differentiated neuronal cells. Neuronal differentiation results in the differentiation of undifferentiated SK-N-SH cells into neuronal cells. A basic freezing medium (BFM) was prepared using Dulbecco's modified Eagle's medium, 1 M maltose, and 1% sericin as the essential ingredients, supplemented with 5%-40% propylene glycol (PG). Each BFM supplemented with 5%-40% PG was evaluated in undifferentiated cells. After thawing, BFM supplemented with 10% and 20% PG were 83% and 88% viable, respectively. There was no significant difference between the 10% and 20% PG groups. However, a significant difference was observed when the concentration of PG in the BFM decreased by 5% (5% PG vs. 10% PG; = 0.0026). Each DMSO-free BFM was evaluated using differentiated neuronal cells. There was no significant difference between the 10% PG BFM and stem-CB-free groups. Viability was significantly different in the 10% glycerol BFM (4.8%) and 10% PG BFM (45%) ( = 0.028). The differentiated cells with 10% PG BFM showed higher adherence to culture dishes than those with 10% glycerol BFM. These results show that BFM containing PG was effective in differentiating neuronal cells. DMSO affects the central nervous system at low concentrations. This report indicates that DMSO is unsuitable for neuronal cells with multipotent differentiation potential. Therefore, it is essential for cell banking and transplantation medicine services to select appropriate cell freezing media.
Topics: Humans; Dimethyl Sulfoxide; Glycerol; Cryopreservation; Freezing; Cell Differentiation; Cell Survival; Cryoprotective Agents
PubMed: 36827090
DOI: 10.1089/bio.2022.0180 -
RSC Advances Nov 2023Reversible thermochromism presents depth at low temperatures and brightness at high temperatures, which is not conducive to the application of the passive energy-saving...
Reversible thermochromism presents depth at low temperatures and brightness at high temperatures, which is not conducive to the application of the passive energy-saving and shading effect. Here, we propose an innovative strategy for unconventional reversible thermochromic energy-storage flexible wood films (FT-PCMs-2) by the contribution of polyvinyl alcohol/propylene glycol (PVA/PG). Upon heating, the FT-PCMs-2 changes from light red/green to dark red/green, in contrast to the color change of the non-flexible composites without PVA/PG. The FT-PCMs-2 has good flexibility, mechanical strength and thermal stability. Among them, MSR-DEW-6PVA and MSG-DEW-6PVA have better comprehensive properties, including suitable phase change temperatures (38.6 °C and 37.2 °C), high latent heat values (59.79 J g and 73.02 J g), and low supercooling degrees (2 °C and 0.6 °C). FTIR, XRD and SEM analysis show that the binary fatty acid eutectics were successfully loaded into the eucalyptus fibre skeleton with physical interaction with PVA/PG. In addition, MSR-DEW-6PVA and MSG-DEW-6PVA have photothermal conversion rates of 48.3% and 36%, good cycling stability and anti-leakage performance after 50 cycles, and have promising applications in the fields of building energy saving, intelligent windows and decoration.
PubMed: 37954423
DOI: 10.1039/d3ra06336d -
Journal of Conservative Dentistry and... Feb 2024Calcium hydroxide, which is an intracanal medicament, is widely used in endodontics. Improvements can be made to its effectiveness, as calcium hydroxide is dependent on...
An comparison of calcium ions release and diffusion ability of calcium hydroxide-based intracanal medicament in combination with three different vehicles like propolis, chitosan, and propylene glycol.
CONTEXT
Calcium hydroxide, which is an intracanal medicament, is widely used in endodontics. Improvements can be made to its effectiveness, as calcium hydroxide is dependent on the vehicle.
AIM
The study aims to compare and evaluate the release and diffusion ability of calcium hydroxide when mixed with - propolis, chitosan, and propylene glycol.
METHODS
For this study, 33 single-rooted extracted premolar teeth have been decoronated. After the working length and enlargement of the canals had been established, different preparations of calcium hydroxide with vehicles such as propolis, chitosan, and propylene glycol were loaded into the canals. Atomic absorption spectrophotometry was used to analyze the release of calcium ions in three groups, while a digital pH meter was used to determine an acid change.
RESULTS
Atomic absorption spectrophotometry showed sustained releases of calcium ions and the digital pH meter showed increased diffusion capacity in the propylene glycol paste group in comparison to the other two groups.
CONCLUSION
Propylene glycol vehicle made it easier to enter calcium hydroxide into the dentinal tubules.
PubMed: 38463473
DOI: 10.4103/JCDE.JCDE_258_23 -
The Journal of Physical Chemistry. B Dec 2023The water microstructure around propofol plays a crucial role in controlling their solubility in the binary mixture. The unusual nature of such a water microstructure...
The water microstructure around propofol plays a crucial role in controlling their solubility in the binary mixture. The unusual nature of such a water microstructure can influence both translational and reorientational dynamics, as well as the water hydrogen bond network near propofol. We have carried out all-atom molecular dynamics simulations of five different compositions of the propylene glycol (PG)/water binary mixture containing propofol (PFL) molecules to investigate the differential behavior of water microsolvation shells around propofol, which is likely to control the propofol solubility. It is evident from the simulation snapshots for various compositions that the PG at high molecular ratio favors the water cluster and extended chainlike network that percolates within the PG matrix, where the propofol is in the dispersed state. We estimated that the radial distribution function indicates higher ordered water microstructure around propofol for high PG content, as compared to the lower PG content in the PG/water mixture. So, the hydrophilic PG regulates the stability of the water micronetwork around propofol and its solubility in the binary mixture. We observed that the translational and rotational mobility of water belonging to the propofol microsolvation shell is hindered for high PG content and relaxed toward the low PG molecular ratio in the PG/water mixture. It has been noticed that the structural relaxation of the hydrogen bond formed between the propofol and the water molecules present in the propofol microsolvation shell for all five compositions is found to be slower for high PG content and becomes faster on the way to low PG content in the mixture. Simultaneously, we calculated the intermittent residence time correlation function of the water molecules belonging to the microsolvation shell around the propofol for five different compositions and found a faster short time decay followed up with long time components. Again, the origin of such long time decay is primarily from the structural relaxation of the microsolvation shell around the propofol, where the high PG content shows the slower structural relaxation that turns faster as the PG content approaches to the other end of the compositions. So, our studies showed that the slower structural relaxation of the microsolvation shell around propofol for a high PG molecular ratio in the PG/water mixture correlate well with the extensive ordering of the water microstructure and restricted water mobility and facilitates the dissolution process of propofol in the binary mixture.
PubMed: 37972382
DOI: 10.1021/acs.jpcb.3c04932