Dimethyl Sulfoxide Solution Research Articles

Quantitative Analysis of Ice Crystal Growth During Freezing of Dimethyl Sulfoxide Solutions Under Alternating Current Electric Fields.

During cryopreservation, the growth of ice crystals can cause mechanical damage to samples, which is one of the important factors limiting the quality of preserved samples. To enhance the preservation quality of biological samples, scholars have tried various engineering methods. Among them, an electric field is an essential factor affecting solution freezing. Dimethyl sulfoxide, as a commonly used cryoprotectant, can cause mechanical damage to cells due to ice crystals even when freezing at the optimal freezing rate. Water is a strongly polar dielectric material, and the applied alternating current (AC) electric field will affect the water freezing performance. Therefore, a quantitative study of ice crystal nucleation and growth during freezing of dimethyl sulfoxide solutions under different AC electric field conditions is needed to try to reduce ice crystal damage. We created a liquid-film device to approximate the ice crystal growth process as a two-dimensional image. The frequency of the AC voltage was set from 0 to 50 kHz. We measured the supercooling of the dimethyl sulfoxide solution under AC electric field conditions. As an objective and accurate quantitative analysis of the ice crystal growth process, we propose a Dilated Convolutional Segmentation Transformer for semantic segmentation of ice crystal images. It is concluded that the average area and the growth rate of single ice crystals decrease with increasing electric field frequency at a certain concentration of dimethyl sulfoxide solution. Lower concentrations of dimethyl sulfoxide solution in combination with an AC electric field can achieve similar ice suppression effects as when higher concentrations of dimethyl sulfoxide solution act alone. We believe that AC electric fields are expected to be an aid to cryopreservation and provide some theoretical basis and experimental foundation for its development.

Proton tautomerism and stereoisomerism in 5-[(dimethylamino)methylidene]-4-[3/4-(trifluoromethylphenyl)amino]-1,3-thiazol-2(5H)-ones: synthesis, crystal structure and spectroscopic studies.

5-[(Dimethylamino)methylidene]-4-{[3-(trifluoromethyl)phenyl]amino}-1,3-thiazol-2(5H)-one and the [4-(trifluoromethyl)phenyl]amino derivative, both C13H12F3N3OS, with the trifluoromethyl group substituted at the arene ring at the meta and para positions, were synthesized to study the structural changes associated with proton tautomerism of the amidine system. The studied compounds were found to be in the amine tautomeric form in both the solid and the liquid (dimethyl sulfoxide solutions) phase. In both isomers, the [(trifluoromethyl)phenyl]amino residue assumes a synperiplanar conformation with respect to the thiazolone system, while the 5-[(dimethylamino)methylidene] residue adopts the Z configuration. Density functional theory (DFT) calculations correctly predicted that the synperiplanar arrangement is favoured in both isomers. In the crystal, the whole independent molecule of the para compound is disordered over two alternative positions, with occupancy factors of 0.926 (3) and 0.074 (3).

Concentration effect of DMSO-dry bonding on the stability of etch-and-rinse bonds

ObjectivesTo examine whether lower dimethyl sulfoxide (DMSO) concentrations would affect long-term bond stability of simplified or multistep water-based adhesives to dry-etched dentin. MethodsH3PO4-etched mid-coronal dentin surfaces from human molars were randomly blot- or air-dried for 30 s and pretreated or not with 5 or 50 % (v/v) ethanolic DMSO solutions. Untreated samples served as control. Samples were bonded with a two-step or a three-step etch-and-rinse adhesive. Restored crown segments (n = 5/group) were stored in distilled water for 24 h and sectioned for microtensile bond strength testing. Resin-dentin beams (0.8 mm2) were tested under tension until fracture (0.5 mm/min) after 24 h and one year of storage in artificial saliva at 37 °C. Nanoleakage evaluation and hybrid layer characterization were performed by SEM. Bond strength data was examined by three-way ANOVA followed by the Tukey test (α = 0.05). Results: Dry bonding produced significantly lower bond strengths than conventional wet bonding for both water-based adhesive systems (p < 0.05). DMSO-dry bonding restored bond strengths and reduced nanoleakage levels, regardless of adhesive type or DMSO concentration (p < 0.05). Bond strengths of DMSO-dry bonded samples were not significantly affected by long-term ageing regardless of adhesive type or DMSO concentration (p < 0.05). SignificanceAlthough bonding methacrylate-based resins to etched dentin is normally performed under wet conditions, hybridization of air-dried collagen can outperform conventional wet bonding by employing water-free DMSO solutions with concentrations as low as 5 %. Reduced moisture-related technique sensitivity, higher bonding performance and improved hybrid layer stability may contribute to extend the service life of resin-dentin bonding.

Quantum chemical investigation of predominant conformation of the antibiotic azithromycin in water and DMSO solutions: thermodynamic and NMR analysis.

Azithromycin (AZM) is a macrolide-type antibiotic used to prevent and treat serious infections (mycobacteria or MAC) that significantly inhibit bacterial growth. Knowledge of the predominant conformation in solution is of fundamental importance for advancing our understanding of the intermolecular interactions of AZM with biological targets. We report an extensive density functional theory (DFT) study of plausible AZM structures in solution considering implicit and explicit solvent effects. The best match between the experimental and theoretical nuclear magnetic resonance (NMR) profiles was used to assign the preferred conformer in solution, which was supported by the thermodynamic analysis. Among the 15 distinct AZM structures, conformer M14, having a short intramolecular C6-OH … N H-bond, is predicted to be dominant in water and dimethyl sulfoxide (DMSO) solutions. The results indicated that the X-ray structure backbone is mostly conserved in solution, showing that large flexible molecules with several possible conformations may assume a preferential spatial orientation in solution, which is the molecular structure that ultimately interacts with biological targets.

Quantum Chemical Investigation of the Interaction of Thalidomide Monomeric, Dimeric, Trimeric, and Tetrameric Forms with Guanine DNA Nucleotide Basis in DMSO and Water Solution: A Thermodynamic and NMR Spectroscopy Analysis.

Thalidomide (TLD) was used worldwide as a sedative, but it was revealed to cause teratogenicity when taken during early pregnancy. It has been stated that the (R) enantiomer of TLD has therapeutic effects, while the (S) form is teratogenic. Clinical studies, however, demonstrated the therapeutic efficacy of thalidomide in several intractable diseases, so TLD and its derivatives have played an important role in the development and therapy of anticancer drugs. Therefore, it is important to know the molecular mechanism of action of the TLD, although this is still not clear. In what molecular interactions are concerned, it is known that drug molecules can interact with DNA in different ways, for example, by intercalation between base pairs. Furthermore, the ability of the TLD to interact with DNA has been confirmed experimentally. In this work, we report a theoretical investigation of the interaction of the R and S enantiomers of TLD, in its monomeric, dimeric, trimeric, and tetrameric forms, with guanine (GUA) DNA nucleotide basis in solution using density functional theory (DFT). Our initial objective was to evaluate the interaction of TLD-R/S with GUA through thermodynamic and spectroscopic study in dimethyl sulfoxide (DMSO) solvent and an aqueous solution. Comparison of the experimental 1H nuclear magnetic resonance (NMR) spectrum in DMSO-d6 solution with calculated DFT-PCM-DMSO chemical shifts revealed that TLD can undergo molecular association in solution, and interaction of its dimeric form with a DNA base ((TLD)2-GUA and (TLD)2-2GUA, for example) through H-bond formation is likely to take place. Our results strongly indicated that we must consider the plausibility of the existence of TLD associations in solution when modeling the complexation of the TLD with biological targets. This is new information that may provide further insight into our understanding of drug binding to biological targets at the molecular level.

A Rapid and Quantitative Method for Determining Seed Viability Using 2,3,5-Triphenyl Tetrazolium Chloride (TTC): With the Example of Wheat Seed.

Current colorimetric methods for quantitative determination of seed viability (SV) with 2,3,5-triphenyl tetrazolium chloride (TTC) have been plagued by issues of being cumbersome and time-consuming during the experimental process, slow in extraction and staining, and exhibiting inconsistent results. In this work, we introduced a new approach that combines TTC-staining with high-temperature extraction using dimethyl sulfoxide (DMSO). The optimization of the germination stage, TTC-staining method, and 1,3,5-triphenylformazan (TTF) extraction method were meticulously carried out as follows: When the majority of wheat seeds had grown the radicle, and the length of radicles was approximately equal to the seed length (24 h-germination), 2 g germinating seeds were placed into a beaker (20 mL) containing 5 mL 10 g·L-1 TTC solution. The seeds were stained with TTC in the dark at 25 °C for 1 h. Following the staining, 1 mL 1 mol·L-1 H2SO4 was added to stop the reaction for 5 min. The H2SO4 solution was then removed, and the seeds were gently rinsed with deionized water. Subsequently, the TTF produced in the seeds was extracted directly with 5 mL DMSO solution at 55 °C for 1 h. The absorbance of the extract was measured at 483 nm, and the index of SV was calculated according to a predetermined TTC calibration curve and expressed by mg TTC·g-1 (seed)·h-1. The new method has been demonstrated to be rapid, stable, and highly sensitive, as evidenced by the accurate measurement of seed viability with different aging degrees.

Does dimethyl sulfoxide promote the bonding performance of different universal adhesives to dentin in etch-and-rinse approach?

This study examined the influence of dimethyl sulfoxide (DMSO) on the microtensile bond strength (μTBS) of universal adhesives to dry or wet dentin in the etch-and-rinse approach. Human third molars were cut to reveal the flat mid-coronal dentin surface. The specimens were randomly divided into 16 groups (n = 8) based on dentin condition (dry or wet), dentin pretreatment (with or without DMSO), and adhesive agents (Scotchbond Universal (SBU), Ambar Universal Bond (AUB), G-Premio Bond (GPB), and Clearfil Universal Bond (CUB). The etched-dentin surfaces were pretreated with a 50% DMSO solution before adhesive application. After 24 h or thermocycling, the resin-dentin beams were tested using the microtensile device. μTBS data were analyzed using a four-way ANOVA (α = 0.05). Scanning electron microscopy (SEM) was used to detect nanoleakage at adhesive interfaces. DMSO increased μTBS to wet and dry dentin of CUB, SBU, and AUB but not GPB. CUB, SBU, and AUB bonded better to wet dentin than dry dentin, but GPB bonded equally well to both. DMSO's nanoleakage effect dependent on dentin moisture and the adhesive agent used.

The Study of the Effect of Dimethylsulfoxide (or Diethylsulfoxide) on Quinine Sulfate-DNA Binding by UV-Vis and Steady-State Fluorescence Spectroscopies.

The effect of dimethylsulfoxide (DMSO) and diethylsulfoxide (DESO) on binding between quinine sulfate (QS) and DNA was studied by virtue of UV-Vis absorption, steady-state fluorescence spectroscopies, and fluorescence polarization measurements. The binding constant was determined at three different temperatures and the values of standard Gibbs energy change, enthalpy and entropy of binding were determined. The mechanism of binding and the effect of sulfoxides on this process was revealed. The values of binding constant, fluorescence polarization and iodide quenching studies confirmed that the main binding mode in QS-DNA system is groove binding. Addition of sulfoxides does not change the binding mechanism. Moreover, with addition of sulfoxides binding constant increases due to the removal of water molecules from DNA grooves making them more available for QS molecules.To explain the effect of DMSO and DESO on QS-DNA binding the photophysical properties of QS in aqueous solutions of DMSO and DESO were also studied. On the basis of quantum yield of QS in water, DMSO and DESO the types of intermolecular interactions were discussed. The obtained results show that quantum yield of QS in sulfoxides is lower compared with that in water and aqueous solution of 0.1M H2SO4. QS forms ground state complexes with both DMSO and DESO that are stronger fluorophores compared with free QS molecules.

Synergistic effect of two metal porphyrins in a polymer catalyst for oxygen electroreduction

This work considers the formation and catalytic properties of films of individual hydroxyphenyl porphyrin complexes with manganese (manganese(III) acetate 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (MnAc(4-OHPh)P)) and iron (iron(III) chloride 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (FeCl(4-OHPh)P)) and their composites. The films of individual metalloporphyrins and bimetallic composites were obtained by superoxide-assisted electrochemical deposition in dimethylsulfoxide solutions. The formation of the bimetallic (Mn + Fe) porphyrin composite was confirmed by spectral methods. An analysis of the atomic-force microscopy results showed that the composite films consisted of larger globules and were rougher than those of individual porphyrins. The electroactive surface areas of the individual porphyrin films and the composite were significantly different from each other. The mechanism and kinetics of the oxygen electroreduction reaction (ORR) on the films of individual porphyrins and bimetallic composite were evaluated using a rotating disk electrode. The kinetic current density of the Tafel slope and the position of the ORR current wave on the surface of the poly-(MnAc(4-OHPh)P + FeCl(4-OHPh)P) composite indicate smaller kinetic limitations and lower overvoltage on this material than on carbositall and films of individual porphyrins. The smaller kinetic limitations and better energy characteristics can be explained by the synergistic effect produced by the combined action of the Mn- and Fe- catalytically active centers during ORR on the composite film.

Nematocidal Activity of Ethanol and Aqueous Extracts of Persea americana Seeds against Heligmosomoides polygyrus using the Worm Microtracker Method.

Infections with gastrointestinal helminths constitute a serious obstacle to the good health of the local population in most African Countries. The aim of this study was to evaluate the anthelminthic activity of Persea americana ethanol and aqueous extracts against Heligmosomoides polygyrus using the worm microtracker. Aqueous and ethanolic extracts of P. americana were prepared. Different concentrations of the extracts were tested against the egg and larvae stages of H. polygyrus using an automated high-throughput method. Briefly, embryonated eggs and larvae of this parasite were obtained after the incubation of fresh eggs at 25°C for 24, 48, and 96 hours for embryonated eggs, L1 and L2 larvae, respectively. One hundred microliters of the plant extracts at various concentrations were put in contact in a 96-well microplate with a suspension of 100 embryonated eggs in a total volume of 200 μL and incubated in a worm microtracker where the motility of the worms was recorded every 30 minutes for the ovicidal activity. The final tested extract concentration was 5, 2.5, 1.25, 0.625, and 0.3125 mg/mL, whereas ringer solution (0.95%) and 1.5% Dimethyl sulfoxide (DMSO) were used as negative controls and levamisole as positive control. The same method was used for larvicidal activities. The anthelmintic activity was determined using the average movement of the worms in the tested product compared with the negative control (1.5% DMSO and ringer solution). The egg hatching rates of H. polygyrus had IC50 of 0.49 mg/mL (95% confidence interval: 71.70-92.03) and 0.22 mg/mL (95% confidence interval: 74.28-86.18) for the ethanol and aqueous extract, respectively. These IC50 indicate that the aqueous extract is more active for the inhibition of hatching at a 95% confidence interval. The aqueous and ethanol extracts presented mean inhibitory hatching rates of 78.33 ± 1.67% and 75.67 ± 1.15% at 5 mg/mL, respectively, with no significant differences. The highest percentage of inhibition of L1 larva was observed at 5 mg/mL with 89 ± 2.3%and 85 ± 2.7% for the ethanol and aqueous extracts, respectively. The lowest percentage of inhibition was observed at 0.3125 mg/mL, with 54.67 ± 3.38% and 49 ± 2.64% for the ethanol and aqueous extract, respectively. No significant differences were observed between the two extracts at 5 mg/mL with an inhibitory percentage of 90.67 ± 3.05% (ethanol) and 89.33 ± 2.08% (aqueous). Extracts of P. americana seeds possess nematocidal activity, however, further in silico and in vivo investigations are necessary to confirm their anthelminthic activity.

Controlling the reactivity of hydrophilic bark extractives as biopolyols in urethane-formation reactions using various catalysts

The composition, functionality, and reactivity of black alder (Alnus glutinosa) bark extractives as a biopolyol with polymeric diphenyl methane diisocyanate (PMDI) have been studied using a variety of methods, including HPLC, GPC, GC, wet chemistry, and isothermal calorimetry. The Black alder (BA) bark extractives were identified as a prospective polyol consisting mainly of the oregonin-xyloside form of diarylheptanoid, which contains OH groups that are almost equally represented by phenolic and aliphatic origins. To identify catalysts that effectively increase the reactivity of low-active phenolic OH groups in urethane formation reactions, the kinetics of extractives and model compounds' interaction with PMDI catalyzed with tin organic, dibutyl tin dilaurate (DBTDL) and tertiary amine, 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyst in dimethylsulfoxide (DMSO) solution were studied. The results showed that DABCO resulted in a fourfold higher reactivity of phenolic groups with PMDI compared to DBTDL catalyzed reactions. Furthermore, the reactivity of phenolic groups with PMDI catalyzed by DABCO was almost twofold greater than that of aliphatic OH catalyzed by DBTDL. The second-order constants of 31.9 × 10−4 mol·L−1·s−1 and 53.7 × 10−4 mol·L−1·s−1 were determined for the interaction of extractives with PMDI in the presence of DBTDL and DABCO, respectively. The disappearance of the radical scavenging effect of phenolic compounds in extractives derived PU elastomers obtained with DABCO catalyst indicates complete reactions of phenolic groups with isocyanate, while these groups remain partly free in the case of DBTDL catalysis. It is assumed that a combination of DBTDL and DABCO catalysts will be necessary to achieve high crosslinking while leaving a small portion of free phenolic groups in the bio-based PU network, thus obtaining material with high mechanical properties and thermal oxidative stability.

Mechanism of the surface-preferred crystal plane of CsPbBr3 single crystals in different solvents

CsPbBr3 single crystals have been grown by using solution method with hydrobromic acid (HBr) and dimethyl sulfoxide (DMSO), respectively. The same orthorhombic phase of crystals grown in these two solvents was confirmed by X-ray powder diffraction (XRD). A very interesting phenomenon is that the surface-preferred crystal plane of the CsPbBr3 single crystal would be (200) in HBr solution, while that would be (101) in DMSO solution. Remarkably, this growth mechanism can be explained effectively by the principle of opposite charges attraction, which would be likely to provide an approach to be extended to the regulation of surface-preferred crystal plane of other perovskite single crystals grown in different solvents, especially using solvent with original perovskite solute ions.

A new colorimetric sensor based on semithiocarbazone for some anions: 2-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)-N-phenylhydrazine-1-carbothioamide

Carbazones are molecules containing important functional groups in designing anion chemosensors due to proton donor and acceptor sites in their structures. In this paper, we synthesize a novel colorimetric receptor with 1,3-dioxo-indene and thiosemicarbazone moieties by the reaction of ninhydrin and 4-phenyl-thiosemicarbazide in quantitative yield. We then identify its structure by means of FT-IR, $^{1}$H-NMR, $^{13}$C-NMR, and MS spectroscopic techniques. Moreover, we observe the reaction of the title compound with biologically important F$^¯$, OAc$^¯$, CN$^¯$, H2PO4$^¯$, and OH$^¯$ anions in the presence of other anions, such as Cl$^¯$, Br$^¯$, I$^¯$, SCN$^¯$, and OCl$^¯$ in dimethylsulfoxide solution through a color change from yellow to orange-red that can easily be distinguished even by the naked eye under ambient light. Finally, we evaluate the anion-sensing ability of the title compound via UV-vis spectroscopic studies.

12.3% Efficient Low Voc Loss Pure Sulfide Kesterite Solar Cells from DMSO Solution via Cadmium Alloying

AbstractCd alloying has been theoretically proved to be an effective strategy to suppress Cu‐Zn antisite defects and related defect cluster for improving device performance of pure sulfide kesterite Cu2ZnSnS4 (CZTS) thin film solar cells. However, the potential of Cd alloying has not been fully realized by solely doping without further post heat‐treatment. Here, Cd alloying CZTS (Cu2(Zn,Cd)SnS4, CZCTS) is reported through dimethyl sulfoxide (DMSO) solution and how alloying concentration affects reaction path, grain growth, and electronic properties of the CZCTS absorbers is investigated. This study found that Cd can be incorporated into CZTS through direct phase transformation grain growth, which sufficiently suppresses band tailing. High quality CZCTS absorber films and efficient solar cells are fabricated within a wide range of alloy concentration. A champion CZCTS device with a power conversion efficiency of 12.3% is achieved at 35% Cd concentration without any post heat treatment, improved by over 70% compared to 7.0% of CZTS. This device exhibits a high VOC gain to the Shockley–Queisser (Voc/VocSQ = 59.7%), the lowest VOC deficit achieved in pure sulfide kesterite solar cells. The results demonstrate the importance of the Cd alloying strategy for mitigating band tailing and achieving high efficiency pure sulfide kesterite solar cells.

Crystallization and vitrification of solutions with weak intermolecular interaction of the components

An experimental study of the phenomenon of cluster crystallization and vitrification of solutions with weak intermolecular interaction of the components was performed with use of a purposely developed method of microvolumetric scanning tensodilatometry. Volumetric effects accompanying cooling and subsequent heating of aqueous solutions of glycerol and dimethyl sulfoxide were recorded within temperature range 300…135 K, and they are completely in line with patterns of cluster crystallization. The same phenomenon was used to analyze the structure of amorphous fractions of such solutions. Formation inside of them of ice nanocrystals without breakage of hydrogen bonds between water molecules and molecules of cryoprotectant dramatically reduces stability of amorphous fractions. Based on the resulted tensodilatograms, state diagrams for solutions, which include cluster phase, were for the first time plotted.

Evaluation of the effectiveness of allogeneic tendon graft sterilization with supercritical carbon dioxide

Structural and functional properties of the human tendon tissue complicate process of tendon-based grafts preserving. In the process of preservation, it is necessary to maintain mechanical and functional parameters of the tendon tissue as well as to provide sterility and biological safety of the graft. One could conclude effectiveness of techniques, combining tendon conservation at low temperatures and sterilization with the supercritical carbon dioxide.Aim of work: to find optimal conditions for allogeneic tendon grafts sterilization with supercritical carbon dioxide.Materials and methods. Allogeneic tendons were prepared from the tissue donors, following the rules of asepsis and antisepsis. After quarantine and confirmation of the absence of blood-borne infections the tendon grafts were divided into 3 groups: in the control group the tendons were not subjected to cryopreservation and sterilization procedures; in 2 experimental groups tendons were treated with a cryoprotector 10 % dimethyl sulfoxide (DMSO) solution and sterilized with supercritical carbon dioxide with slow gas discharge (group 2) or with fast gas discharge (group 3); the duration of sterilization in both groups varied from 1 to 12 hours. The toxicity of the grafts was assessed in human mesenchymal multipotent stromal cells (MMSC) culture on the 3rd and 7th days. The sterility of the grafts was confirmed on the 7th and 14th day by bacteriological culture on thioglycol medium and Saburo broth. Mechanical tests were performed on testing machine LLOYD Instruments LR5K Plus with the tensile speed 5 mm/min.Results. Histological analysis showed, that in the group with slow gas discharge collagen fibers retained their integrity and topography and contained only local minor tears; in all terms of treatment, the tendon grafts were sterile and nontoxic. On the contrary, in the group with fast gas discharge there was marked damage of the collagen fibers and growth of bacterial and fungal flora was observed in the culture. The grafts of the control group and the group, where sterilization with supercritical carbon dioxide was performed with slow gas discharge for 1-12 hours, were used to evaluate mechanical characteristics. In the preserved tendons the stiffness and ultimate strain did not significantly differ from the similar values in the control (p &gt; 0.05), on the contrary, the level of ultimate strain in all experimental specimens was significantly reduced by 1.5-2.1 times comparing to the control. Young's modulus and load at rupture in the control grafts and grafts, sterilized for 1 hour, had similar values, whereas in grafts, sterilized from 3 to 12 hours, these parameters were 1.4-2.1 times lower (p &lt; 0.05).Conclusions. The suggested technique of tendon preservation, using cryoprotector DMSO and sterilization with the supercritical carbon dioxide, allows to obtain sterile and non-toxic grafts. The structure of cells and fibers of the preserved tendons did not significantly disturbed. For supercritical carbon dioxide sterilization of tendon grafts the most optimal processing time is 1 hour.

Topical Drug Delivery of Concentrated Cabazitaxel in an α-Tocopherol and DMSO Solution.

Topical chemotherapy approaches are relevant for certain skin cancer treatments. This study observes that cabazitaxel (CTX), a broad-spectrum second-generation taxane cytotoxic agent, can be dissolved in α-tocopherol at high concentrations exceeding 100mgmL-1 . 2D nuclear magnetic resonance (NMR) analysis and molecular dynamics (MD) are used to study this phenomenon. The addition of 30% dimethyl sulfoxide (DMSO) to the α-tocopherol/CTX solution improves its working viscosity and enhances CTX permeation through human skin in vitro (over 5µgcm-2 within 24h), while no detectable drug permeates when CTX is dissolved in α-tocopherol alone. In a transepidermal water loss assay, the barrier impairment induced by CTX in 30% DMSO in α-tocopherol, but not in pure DMSO, is reversible 8h after the formulation removal from the skin surface. Antitumor efficacy of the topical CTX formulation is evaluated in nude mice bearing A431 human squamous carcinoma skin cancer xenografts. With topical application of concentrated CTX solutions (75mgmL-1 ), tumor growth is significantly suppressed compared to lower concentration groups (0, 25, or 50mgmL-1 CTX). Taken together, these findings show that topical delivery of CTX using a DMSO and α-tocopherol solvent warrants further study as a treatment for skin malignancies.

Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

AbstractEndovascular embolization can selectively deploy embolic agents into diseased or injured blood vessels to complete the treatment. However, traditional embolic agents still face challenges, such as poor intravascular diffusivity, non‐biodegradable, unstable mechanical properties, radiolucency, and recanalization. Herein, we report a poly (lipoic acid‐tannic acid)/tromethamine/Galinstan (PLTTG) dimethyl sulfoxide (DMSO) solution‐derived hydrogel liquid embolic agent. By injecting PLTTG DMSO solution into body fluids, a PLTTG hydrogel can be formed in situ owing to the solvent exchange induced intra‐ and inter‐polymer hydrogen bonding and electrostatic interactions. Moreover, the gelation time and injection forces of the solution as well as the mechanical properties and embolic pressure of the obtained hydrogels can be adjusted by changing the concentration of PLTTG. The PLTTG hydrogel can effectively embolize the renal artery and femoral vein without recanalization and displacement in rabbit models. Furthermore, the hydrogel can embolize the ruptured femoral artery to arrest active bleeding. Owing to the advantages of the hydrogel, including adjustable gelation time, mechanical properties, viscosities, injection forces, and embolic pressure, as well as good biocompatibility and biodegradability, radiopacity, excellent embolization performance and intravascular diffusivity, easy usage, low cost, allowing it to be a potential embolic agent to treat multiple vascular diseases in clinic.

Investigation of the Mitigation of DMSO-Induced Cytotoxicity by Hyaluronic Acid following Cryopreservation of Human Nucleus Pulposus Cells.

To develop an off-the-shelf therapeutic product for intervertebral disc (IVD) repair using nucleus pulposus cells (NPCs), it is beneficial to mitigate dimethyl sulfoxide (DMSO)-induced cytotoxicity caused by intracellular reactive oxygen species (ROS). Hyaluronic acid (HA) has been shown to protect chondrocytes against ROS. Therefore, we examined the potential of HA on mitigating DMSO-induced cytotoxicity for the enhancement of NPC therapy. Human NPC cryopreserved in DMSO solutions were thawed, mixed with equal amounts of EDTA-PBS (Group E) or HA (Group H), and incubated for 3-5 h. After incubation, DMSO was removed, and the cells were cultured for 5 days. Thereafter, we examined cell viability, cell proliferation rates, Tie2 positivity (a marker of NP progenitor cells), and the estimated numbers of Tie2 positive cells. Fluorescence intensity of DHE and MitoSOX staining, as indicators for oxidative stress, were evaluated by flow cytometry. Group H showed higher rates of cell proliferation and Tie2 expressing cells with a trend toward suppression of oxidative stress compared to Group E. Thus, HA treatment appears to suppress ROS induced by DMSO. These results highlight the ability of HA to maintain NPC functionalities, suggesting that mixing HA at the time of transplantation may be useful in the development of off-the-shelf NPC products.

Energetics of dehydroepiandrosterone polymorphs I and II from solution and drop-sublimation Calvet microcalorimetry measurements

The lattice enthalpies and monotropic relationship of two dehydroepiandrosterone (DEHA) polymorphs (forms I and II) were evaluated through a combination of differential scanning calorimetry (DSC), isothermal solution microcalorimetry, and drop-sublimation Calvet microcalorimetry experiments. The standard molar enthalpy of transition between both forms was determined as ΔtrsHmo(II→I, 298.15 K) = −0.90 ± 0.07 kJ mol−1 and ΔtrsHmo(II→I, 417.8 K) = −1.7 ± 1.0 kJ mol−1, from measurements of standard molar enthalpies of solution in dimethyl sulfoxide and enthalpies of fusion, respectively. Drop-sublimation Calvet microcalorimetry experiments on form I led to ΔsubHmo(cr I, 298.15 K) = 132.0±3.3 kJ mol−1. This result, when combined with the more precise ΔtrsHmo(II→I) value obtained by solution calorimetry, afforded ΔsubHmo(cr II, 298.15 K) = 131.1±3.3 kJ mol−1. The overall data indicate that on enthalpic grounds form I is more stable than form II from 298.15 K up to fusion. This conclusion, and the fact that DSC experiments indicated that form I has also a considerably higher temperature fusion, namely, Tfus(cr I)= 422.5±0.2 K and Tfus(cr II) = 413.1±0.2 K, suggest that the two polymorphs are monotropically related.