Development of techniques to isolate, culture, and transplant human spermatogonial stem cells (SSCs) has the future potential to treat male infertility. To maximize the efficiency of these techniques, methods for SSC cryopreservation need to be developed to bank SSCs for extended periods of time. Although, it has been demonstrated that SSCs can reinitiate spermatogenesis after freezing, optimal cryopreservation protocols that maximize SSC proliferative capacity post-thaw have not been identified. The objective of this study was to develop an efficient cryopreservation technique for preservation of SSCs. To identify efficient cryopreservation methods for long-term preservation of SSCs, isolated testis cells enriched for SSCs were placed in medium containing dimethyl sulfoxide (DMSO) or DMSO and trehalose (50 mM, 100 mM, or 200 mM), and frozen in liquid nitrogen for 1 week, 1 month, or 3 months. Freezing in 50 mM trehalose resulted in significantly higher cell viability compared to DMSO at all thawing times and a higher proliferation rate compared to DMSO for the 1 week freezing period. Freezing in 200 mM trehalose did not result in increased cell viability; however, proliferation activity was significantly higher and percentage of apoptotic cells was significantly lower compared to DMSO after freezing for 1 and 3 months. To confirm the functionality of SSCs frozen in 200 mM trehalose, SSC transplantation was performed. Donor SSCs formed spermatogenic colonies and sperm capable of generating normal progeny. Collectively, these results indicate that freezing in DMSO with 200 mM trehalose serves as an efficient method for the cryopreservation of SSCs.
Polyelectrolyte complexation is critical to the formation and properties of many biological and polymeric materials, and is typically initiated by aqueous mixing followed by fluid-fluid phase separation, such as coacervation. Yet little to nothing is known about how coacervates evolve into intricate solid microarchitectures. Inspired by the chemical features of the cement proteins of the sandcastle worm, here we report a versatile and strong wet-contact microporous adhesive resulting from polyelectrolyte complexation triggered by solvent exchange. After premixing a catechol-functionalized weak polyanion with a polycation in dimethyl sulphoxide (DMSO), the solution was applied underwater to various substrates whereupon electrostatic complexation, phase inversion, and rapid setting were simultaneously actuated by water-DMSO solvent exchange. Spatial and temporal coordination of complexation, inversion and setting fostered rapid (∼25 s) and robust underwater contact adhesion (Wad ≥ 2 J m(-2)) of complexed catecholic polyelectrolytes to all tested surfaces including plastics, glasses, metals and biological materials.
Technology for preserving sperm is useful for disseminating valuable male genetic traits. Cold storage is suitable for easily transporting sperm as an alternative to the shipment of live animals. However, there is a technical limitation in that the fertility of cold-stored sperm declines within 3 days. To overcome this problem, we examined the protective effects of quercetin and dimethyl sulfoxide (DMSO). DMSO and quercetin maintained the fertility and motility of cold-stored sperm for 10 days. In addition, quercetin attenuated the reduction of mitochondrial membrane potential of cold-stored sperm during sperm preincubation, allowing the induction of capacitation, and it localized to the midpiece of sperm. Furthermore, DMSO and quercetin enhanced the level of tyrosine phosphorylation of cold-stored sperm. DMSO and quercetin have life-prolonging effects on sperm during cold storage. Cold storage using DMSO and quercetin will provide a robust system for internationally transporting valuable sperm samples.
We have developed metal-free regiocontrolled dehydrogenative C-H/C-H cross-coupling of aryl sulfoxides with phenols by means of trifluoroacetic anhydride. Since the reaction would proceed through an interrupted Pummerer reaction followed by sulfonium-tethered [3,3]-sigmatropic rear-rangement, the C-H/C-H coupling takes place exclusively between the ortho positions of both substrates. Various functional groups including carbonyl, halo, siloxy, and even boryl moieties are compatible. The biaryl products naturally possess hydroxy and sulfanyl groups, which allows the products to be useful synthetic intermediates, as evidenced by the syntheses of pi-expanded heteroarenes such as unprecedented 7,12-dioxahelicene.
Optimization of the etch-and-rinse technique: New perspectives to improve resin-dentin bonding and hybrid layer integrity by reducing residual water using dimethyl sulfoxide pretreatments
- Dental materials : official publication of the Academy of Dental Materials
- Published 7 days ago
To determine whether bonding effectiveness and hybrid layer integrity on acid-etched dehydrated dentin would be comparable to the conventional wet-bonding technique through new dentin biomodification approaches using dimethyl sulfoxide (DMSO).
The storage media is directly related to the prognosis of avulsed teeth, with resveratrol drawing attention due to its antioxidant and anti-inflammatory proprieties. The aim of this study was to evaluate the repair process in rat teeth following delayed replantation after storage in resveratrol ® dissolved in dimethyl sulfoxide (DMSO).
The objective was to evaluate effect of dimethyl sulfoxide (DMSO) on microtensile bond strength (µTBS) and nanoleakage (NL). Superficial dentin was acid-etched and pretreated with DMSO. Etch-and-rinse adhesive was applied and restored with resin composite incrementally. After 24 h, teeth were sectioned, stored in artificial saliva for 24-h or 6-months before µTBS evaluation. Failure modes were examined. Six beams per group were submitted to nanoleakage evaluation using SEM. Data were analyzed using ANOVA and Tukey’s test (α=0.05). Pretreatment had no significant effect on µTBS after 24 h (p>0.05). After 6 months storage, µTBS of control decreased significantly, more than with the groups treated with 0.01% or higher (p<0.05). DMSO-pretreated groups preserved µTBS in all groups. After 6-months, all groups except 0.001% showed significantly lower nanoleakege compared to control (p<0.05). DMSO (0.01-20%) may improve the hybrid layer integrity and bonding durability. The best results were seen with low (1-5%) of DMSO concentrations.
The oxidative coupling of photogenerated alkyl radicals with readily available styrenes is disclosed. This visible-light-mediated method allows rapid access to a wide range of α-alkyl-acetophenones in good yields and with high functional group tolerance. In addition, the developed protocol features room temperature conditions, low photocatalyst loadings, and the use of dimethyl sulfoxide as nontoxic and mild terminal oxidant.
In this study we systematically explored the mixed cation perovskite Csx(MA0.4FA0.6)1-xPbI3 fabricated via sequential introduction of cations. The effects of Cs+ on the fabrication and performance of inorganic-organic mixed cation perovskite solar cells were examined in detail which is beyond the normal understanding of adjusting band gap. It is found that a combined intercalation of Cs+ and dimethyl sulfoxide (DMSO) in PbI2-DMSO precursor film formed a strong and steady coordinated intermediate phase to retard PbI2 crystallization, suppress yellow non-perovskite δ-phase and obtain a highly reproducible perovskite film with less defects and larger grains. The Cs-contained triple cation mixed perovskite Cs0.1(MA0.4FA0.6)0.9PbI3 devices yield over 20% reproducible efficiencies, superior stabilities and fill factors of around 0.8 with very narrow distribution.
Metal halide perovskite solar cells (PSCs) have advanced to the forefront of solution-processed photovoltaic techniques and made stunning progress in power conversion efficiency (PCE). Further improvements in device performances rely on perfecting the structure and morphology of perovskite films. However, undesirable defects such as pinholes and grain boundaries are often created in film preparations due to lack of knowledge of the precise reaction mechanism. Here, in situ grazing-incidence X-ray diffraction (GI-XRD) investigations are performed, facilitated by other techniques, on the formation of the widely adopted MAPbI3 (MA = methylammonium) perovskite films from their intermediate adduct (IA) phases. The influences of solvent vapor atmospheres on MAPbI3 films are also systematically investigated, where the dynamic conversion processes between different phases are visualized in real time. Further in situ GI-XRD and infrared spectroscopy measurements reveal that the IA phases contain both N,N-dimethylformamide and dimethyl sulfoxide (DMSO) as coordinating molecules. By tuning the DMSO concentration in perovskite precursors, the ideal perovskite film is formed and the best PCE is achieved for the planar MAPbI3 -based PSCs. These findings highlight the role of IA phases and the effect of solvent atmospheres on the quality of perovskite films, providing direct insights into their growth mechanism.