Effects of 1,3-propanediol associated, or not, with butylene glycol and/or glycerol on skin hydration and skin barrier function

OBJECTIVE

This study aimed to assess the effect of 1,3-propanediol at different concentrations (5%, 10%, or 15%), either applied alone or in combination with butylene glycol (BG) (5%) and/or glycerol (5%), on skin hydration and skin barrier function. The measurements were conducted using capacitance to determine skin hydration and trans epidermal water loss (TEWL) rates to evaluate skin barrier function.

METHODS

A total of 30 healthy female subjects participated in the study. Capacitance and TEWL measurements were conducted at multiple time points, including before application and at 15 min, 2 and 8 h after the humectants were applied to the forearms of the subjects. All the subjects provided written informed consent.

RESULTS

The 1,3-propanediol in all concentrations and in all combinations (with BG and/or glycerol) increased skin hydration and improved skin barrier function 15 min, 2 and 8 h after application. Glycerol increased the hydration performance of 1,3-propanediol. The application of 1,3-propanediol at a concentration of 15%, either alone or in combination with other humectants, reduced the TEWL to a greater extent than lower concentrations of 1,3-propanediol. Furthermore, the addition of glycerol to 1,3-propanediol 15% improved the skin barrier and reduced TEWL when compared with 1,3-propanediol alone and with the combination of 1,3-propanediol + BG.

CONCLUSION

The humectants significantly improved skin hydration and reduced TEWL throughout the 8-h time course. The increase in 1,3-propanediol concentration, as well as its combination with glycerol, provided a greater benefit to the skin, improving both hydration and the skin barrier function.

[Preparation and Performance Study of a Novel Antibacterial Hemostatic Chitosan Sponge]

Objective

To create a novel chitosan antibacterial hemostatic sponge (NCAHS) and to evaluate its material and biological properties.

Methods

Chitosan, a polysaccharide, was used as the sponge substrate and different proportions of sodium tripolyphosphate (STPP), glycerol, and phenol sulfonyl ethylamine were added to prepare the sponges through the freeze-drying method. The whole-blood coagulation index (BCI) was used as the screening criterion to determine the optimal concentrations of chitosan and the other additives and the hemostatic sponges were prepared accordingly. Zein/calcium carbonate (Zein/CaCO3) composite microspheres loaded with ciprofloxacin hydrochloride were prepared and added to the hemostatic sponges to obtain NCAHS. Scanning electron microscope was used to observe the microscopic morphology and porosity of the NCAHS. The water absorption rate, in vitro antibacterial susceptibility rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), in vitro coagulation performance, and hemocompatibility of NCAHS were examined. The coagulation performance of NCAHS was evaluated by using rabbit liver injury and rabbit auricular artery hemorrhageear models and commercial hemostatic sponge (CHS) was used as a control. The in vivo biocompatibility, including such aspects as cytotoxicity, skin irritation in animals, and acute in vivo toxicity, of the NCAHS extracts was examined by using as a reference the national standards for biological evaluation of medical devices.

Results

The NCAHS prepared with 1.5% chitosan (W/V), 0.01% STPP (W/V), 0% glycerol (V/V), 0.15% phenol-sulfonyl-ethylamine (V/V), Zein and CaCO3 at the mixing ratio of 5∶1 (W/W), Zein at the final mass concentration of 2.5 g/L, and ethanol at the final concentration of 17.5% (V/V) were fine and homogeneous, possessing a honeycomb-like porous structure with a pore size of about 200 μm. The NCAHS thus prepared had the lowest BCI value. The water absorption ([2362.16±201.15] % vs. [1102.56±91.79]%) and in vitro coagulation performance (31.338% vs. 1.591%) of NCAHS were significantly better than those of CHS (P<0.01). Tests with the in vivo auricular artery hemorrhage model ([36.00±13.42] s vs. [80.00±17.32] s) and rabbit liver bleeding model ([30.00±0] s vs. [70.00±17.32] s) showed that the hemostasis time of NCAHS was significantly shorter than that of CHS (P<0.01). NCAHS had significant inhibitory ability against S. aureus and E. coli. In addition, NCAHS showed good in vitro and in vivo biocompatibility.

Conclusion

NCAHS is a composite sponge that shows excellent antimicrobial properties, hemostatic effect, and biocompatibility. Therefore, its extensive application in clinical settings is warranted.

Chitosan and α-cellulose-based mupirocin topical film-forming spray: Optimization, in vitro characterization, antimicrobial studies and wound healing activity

The study aimed to develop a biopolymer-based mupirocin film-forming spray (MUP-FFS) for wound healing using chitosan and α-cellulose. MUP-FFS formulation was optimized by box-Behnken design, wherein the amount of chitosan, glycerol, and microfluidizer cycles showed a significant effect on the drying time and sprayability, but drug release remained unaffected. The optimized MUP-FFS formulation prepared by 13 microfluidizer cycles containing chitosan (0.125 %), glycerol (2.76 %) was quickly sprayable with 235 s drying time. The viscosity, spray uniformity and occlusive potential were found optimum for MUP-FFS. MUP-FFS released 98.066 % of MUP, 2-fold and 4-fold greater than the marketed ointment and MUP-API. The transmission electron microscopy displayed a homogeneous fibrous network, and scanning electron microphotographs showed uniform drug distribution on the MUP-film surface. The antimicrobial study revealed the efficacy of MUP-FFS against S.aureus and E.coli, wherein the former was more susceptible to formulation than the later. MUP-FFS indicated better wound contraction and healing than other groups on 7th and 14th day in rats. On Day-21, MUP-FFS could regress TGF-β1 to a normal level similar to the marketed formulation, which was also reflected in histopathological observations. Therefore, MUP-FFS can be a treatment option for chronic wounds, applied without touch and with minimal mechanical pressure.

Tailored chitosan/glycerol micropatterned composite dressings by 3D printing for improved wound healing

Wound infection control is a primary clinical concern nowadays. Various innovative solutions have been developed to fabricate adaptable wound dressings with better control of infected wound healing. This work presents a facile approach by leveraging 3D printing to fabricate chitosan/glycerol into composite dressings with tailored micropatterns to improve wound healing. The bioinks of chitosan/glycerol were investigated as suitable for 3D printing. Then, three tailored micropatterns (i.e., sheet, strip, and mesh) with precise geometry control were 3D printed onto a commercial dressing to fabricate the micropatterned composite dressings. In vitro and in vivo studies indicate that these micropatterned dressings could speed up wound healing due to their increased water uptake capacity (up to ca. 16-fold@2 min), benign cytotoxicity (76.7 % to 90.4 % of cell viability), minor hemolytic activity (<1 %), faster blood coagulation effects (within 76.3 s), low blood coagulation index (14.5 % to 18.7 % @ 6 min), enhanced antibacterial properties (81.0 % to 86.1 % against S. aureus, 83.7 % to 96.5 % against E. coli), and effective inhibition of wound inflammation factors of IL-1β and TNF-α. Such tailored micropatterned composite dressing is facile to obtain, highly reproducible, and cost-efficient, making it a promising implication for improved and personalized contaminated wound healing.

Insights into alternative cryoprotectants to freeze sperm of domestic cats

Globalization and habitat destruction pose a significant threat to wildlife felids. Even though conservation banks for genetic materials have been created, the sperm cryopreservation with minimal cell damage is still a great challenge. Thus, this study aimed to compare the effects of two commercial extenders with different concentrations of alternative cryoprotectants on thawed sperm quality of domestic cats. Five adult cats were anaesthetized (using a combination of 40 μg/kg medetomidine associated to 5 mg/kg ketamine), and the semen was collected by electroejaculation (electrical stimulation of 2-3 V). Semen samples were evaluated for sperm characteristics (kinetics, morphology, membrane integrity and morphometry). Subsequently, they were sorted into two aliquots and centrifuged. The aliquots were added to a commercial extender containing 3% glycerol and 2% methylformamide (extender I) or 2% glycerol and 3% methylformamide (extender II), frozen, thawed (37°C/30 s) and reevaluated. Comparatively, the sperm kinetics and membrane integrity of fresh semen were higher (p < .002) than frozen samples in extender I and II. Total and progressive motility were lowest in the thawed samples. However, the subjective analysis indicated high sperm motility, since the kinetics evaluation was impaired by the low cell number in the thawed samples. There were no differences in sperm morphology between the groups. In the sperm morphometric analysis, a significant difference (p = .04) was identified in the length of the intermediate piece in extender II samples compared with fresh and extender I. Thus, it can be concluded that although the concentrations tested did not maintain the kinetic parameters and membrane integrity of spermatozoa after thawing, the extender with a lower concentration of glycerol was less toxic for maintaining the midpiece length.

Beauveria bassiana submerged spores for control of two-spotted spider mite (Tetranychus urticae Koch (Acari: Tetranychidae)): production, stability, and virulence

In this study, IBCB 66, IBCB 868, and CBMAI 1306 isolates of Beauveria bassiana were grown in liquid culture for 4 days, leading to elevated submerged spores (SS) levels. The influence of the addition of different glycerol concentrations (0, 3, and 6%) (v/v) in the liquid culture was investigated regarding the stability (at 4 and 27 °C) of dried formulations. The virulence of SS was compared with aerial spores (AS) against Tetranychus urticae (Koch) (Acari: Tetranychidae). The results demonstrate the potential of using SS to control T. urticae. CBMAI 1306 and IBCB 868 isolates caused T. urticae mortality rates of 91.11% and 88.89% 5 days after treatment, respectively, when applied at concentrations of 1 × 108 SS mL-1. The median Lethal Time (LT50) values for these strains were 2.64 and 2.61 days, respectively. The dried formulations showed potential acaricidal activity. Higher glycerol concentrations in the liquid culture medium reduced formulation stability at 27 °C.

Cryopreservation of human cerebral microvascular endothelial cells with glycerol

The cryopreservation of human cerebral microvascular endothelial cells (hCMEC) has facilitated their commercial availability for research studying the blood-brain barrier. The currently employed cryopreservation protocol uses 10% dimethyl sulfoxide (Me2SO) in cell medium, or 5% Me2SO in 95% fetal bovine serum (FBS) as cryoprotective agents (CPAs). However, Me2SO is toxic to cells and FBS is animal-derived and not chemically defined, so reducing the concentrations of these components is desirable. Recently, we showed that cryopreserving hCMEC in cell medium with 5% Me2SO and 6% hydroxyethyl starch (HES) results in over 90% post-thaw cell viability. This previous work was performed using an interrupted slow cooling (graded freezing) approach followed by SYTO13/GelRed staining to assay for membrane integrity. In this paper, we repeated graded freezing of hCMEC in cell medium containing 5% Me2SO and 6% HES, but this time using Calcein AM/propidium iodide staining to ensure that the stain is an equivalent alternative to SYTO13/GelRed for assessment of cell viability, and that results are comparable to those previously published. Next, using graded freezing experiments and Calcein AM/propidium iodide staining, we examined the effectiveness of non-toxic glycerol as a CPA at different concentrations, loading times, and cooling rates. The cryobiological response of hCMEC was used to develop a protocol that optimizes both the permeating and non-permeating capabilities of glycerol. HCMEC in cell medium loaded with 10% glycerol for 1 h at room temperature, ice nucleated at -5 °C and held for 3 min, and then cooled at -1 °C/min to -30 °C before plunging into liquid nitrogen had post-thaw viability of 87.7% ± 1.8%. Matrigel tube formation assay and immunocytochemical staining of junction protein ZO-1 were carried out on post-thaw hCMEC to ensure that the cryopreserved cells were viable and functional, in addition to being membrane-intact.

Effect of cryoprotectant-induced intracellular ice formation and crystallinity on bactria during cryopreservation

Cryopreservation is widely used for the long-term storage of bacteria. Glycerol is one of the traditional cryoprotectants used widely to prevent cryoinjury during the cryopreservation of bacteria,although it may be toxic to the cells. To overcome these issues, synthetic antifreeze polymers are also used as cryoprotectants to inhibit ice formation. In the study, we compared the performance of various antifreeze synthetic polymers including poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone), poly(ethylene glycol), and dextran with glycerol, among which PVA performed best on decreasing the ice growth rate.The impacts of glycerol, trehalose, combined with PVA on the survival of S. thermophilus were also explored. Notably,. S. thermophilus stored in 100 mg/mL trehalose and 1 mg/mL PVA +50 mg/mL trehalose combo showed significantly enhanced survival when compared with those in traditional cryoprotectant (20% [v/v] glycerol), which achieved the survival percentage of only 41.03 ± 0.09%. The effects of the freezing temperature and crystallinity on the survival of S. thermophilus were elucidated.

The cryoprotective effect of Guar gum co-supplemented with ethylene glycol and glycerol in Simmental bull semen

Sperm cryopreservation often reduces sperm quality by forming of intra- and extracellular ice crystals. Various compounds widely used to counteract this effect. The guar gum was considered as an extracellular cryoprotective substance. The present study evaluated the impact of the co-supplementation of guar gum with ethylene glycol or glycerol in the cryopreservation of bull sperm. Four ejaculates from 4 bulls were pooled and divided into ten groups consisting of 4 controls (glycerol 6%, ethylene glycol 6%, glycerol 3.5%, and ethylene glycol 3.5%, and six treatment groups including guar gum in 0.001% and 0.002% alone and or co-supplemented either with 3.5% glycerol or 3.5% ethylene glycol and frozen in liquid nitrogen. The sperm motility, viability, plasma membrane and DNA integrity, apoptotic-like changes, antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities evaluated. The groups contained 3.5% glycerol + 0.001% guar gum, 3.5% ethylene glycol + 0.001% guar gum, and 0.001% guar gum alone showed higher values for live sperm, antioxidant enzymes, membrane integrity, mitochondrial membrane potential (MMP), fertilization, cleavage, and blastocyst rates; and lower values for apoptotic-like changes, H2O2 level, and DNA damage than the control groups. In conclusion, adding guar gum to the bull sperm diluent either alone or combined with glycerol or ethylene glycol ameliorated sperm viability and kinematic parameters and antioxidant capacity while reducing DNA damage and apoptotic-like changes. Guar gum also has improved embryo development. Due to its cost-effectiveness and physicochemical properties, guar gum is a promising supplement for bull sperm cryopreservation.

Glycerol tributylate (Triacylglycerol tributanoate) promoted the liver lipid metabolism by cultivating the intestinal flora of grass carp (Ctenopharyngodon idellus)

To investigate the effects of glycerol tributyrin (TB) (Triacylglycerol tributanoate) on the regulation of liver lipid metabolism by intestinal flora of grass carp (Ctenopharyngodon idellus). The compound feed with soybean oil 2.8% + fish oil 1.8%, soybean oil 6.3% + fish oil 1.8%, and soybean oil 6.2% + fish oil 1.8% + TB 0.1% was added to the basal diet as a fat source and fed to the basal (control) group, high lipid (HL) group, and tributyrin (TB) group for 12 weeks. We tested the growth performance, fat content, diversity, and abundance of gut flora and other related indexes of grass carp by Soxhlet extraction, liver tissue enzyme activity, oil red O staining, and 16S rRNA high-throughput sequencing. The results showed that the liver fat number and liver fat content of grass carp in the TB group were lower than those in the HL group, while the fattening degree was significantly higher than those in the other two groups; according to the indices such as Shannon, Ace, and Coverage, it was found that the grass carp in the TB group had the highest abundance and diversity of intestinal microflora; at the portal level, Proteobacteria and Fusobacteria were the main dominant flora in the TB group, with the number of unique OUTs accounting for about 59. 9% of the total number measured; at the genus level, the relative abundance of lipase-producing, short-chain fatty acid-associated bacteria, such as Bacillus-Lactobacillus and Bifidobacterium, was significantly lower (p < 0.05). Thus, we conclude that the addition of TB to high-fat diets can alter the structure of the intestinal microbial community and promote hepatic lipid metabolism in grass carp. TB can alleviate fatty liver in grass carp by increasing the relative abundance of short-chain fatty acids in the intestine. Meanwhile, TB inhibits the conversion of primary bile acids to secondary bile acids in the host, which can block intestinal FXR signaling and the hepatic FXR-SHP pathway, thus slowing down fat synthesis and alleviating the accumulation of liver lipids in grass carp.

Long-Term Impact of Daily E-cigarette Exposure on the Lungs of Asthmatic Mice

INTRODUCTION

Although the greater popularity of electronic cigarettes (EC) among asthmatics is alarming, there is limited knowledge of the long-term consequences of EC exposure in asthmatics.

AIMS AND METHODS

Mild asthmatic C57/BL6J adult male and female mice were established by intranasal insufflation with three combined allergens. The asthmatic and age and sex-matched' naïve mice were exposed to air, nicotine-free (propylene glycol [PG]/vegetable glycerin [VG]-only), or PG/VG+Nicotine, 4 hours daily for 3 months. The effects of EC exposure were accessed by measuring cytokines in bronchoalveolar lavage, periodic acid-schiff (PAS) staining, mitochondrial DNA copy numbers (mtCN), and the transcriptome in the lung. Significance was false discovery rate <0.2 for transcriptome and 0.05 for the others.

RESULTS

In asthmatic mice, PG/VG+Nicotine increased PAS-positive cells and IL-13 compared to mice exposed to air and PG/VG-only. In naïve mice exposed to PG/VG+Nicotine and PG/VG-only, higher INF-γ was observed compared to mice exposed only to air. PG/VG-only and PG/VG+Nicotine had significantly higher mtCN compared to air exposure in asthmatic mice, while the opposite pattern was observed in non-asthmatic naïve mice. Different gene expression patterns were profoundly found for asthmatic mice exposed to PG/VG+Nicotine compared to PG/VG-only, including genes involved in mitochondrial dysfunction, oxidative phosphorylation, and p21-activated kinase (PAK) signaling.

CONCLUSIONS

This study provides experimental evidence of the potential impact of nicotine enhancement on the long-term effects of EC in asthmatics compared to non-asthmatics.

IMPLICATIONS

The findings from this study indicate the potential impact of EC in asthmatics by addressing multiple biological markers. The long-term health outcomes of EC in the susceptible group can be instrumental in supporting policymaking and educational campaigns and informing the public, healthcare providers, and EC users about the underlying risks of EC use.

Cryopreservation effect on DNA methylation profile in rainbow trout spermatozoa

Spermatozoa are the cells that are most commonly used for cryopreservation of valuable genetic resources in aquaculture. It is known that fish spermatozoa transmit to the embryo not only their genetic but also their epigenetic profile, especially DNA methylation. Therefore, any alteration of the DNA methylation profile in spermatozoa induces the risk of transmitting epigenetic alterations to the offspring. The aim of this study was to assess the effect of cryopreservation on DNA methylation in rainbow trout spermatozoa. To trigger variable cellular response after freezing-thawing, spermatozoa from mature males were cryopreserved with dimethyl sulfoxide, methanol or glycerol as cryoprotectant. We observed that dimethyl sulfoxide was the best to preserve thawed spermatozoa functions. Methanol only slightly preserved all the cellular parameters, while glycerol failed to protect motility and fertilization ability. The consequences on DNA methylation were assessed using Reduced Representation Bisulfite Sequencing (RRBS). Sperm cryopreservation did not thoroughly impact DNA methylation, although 335-564 differentially methylated cytosines were characterized depending on the cryoprotectant. Very few of them were shared between cryoprotectants, and no correlation with the extent of cellular damage was found. Our study showed that DNA methylation was only slightly altered after sperm cryopreservation, and this may render further analysis of the risk for the progeny very challenging.

Is glycerol a good cryoprotectant for sperm cells? New exploration of its toxicity using avian model

Glycerol is a cryoprotectant used widely for the cryopreservation of animal sperm, but it is linked to a decrease in fertility. The mechanism underlying the negative effects of glycerol remains unclear. Therefore, in this study, we aimed to gain a better understanding by using the chicken model. First, we investigated the impact of increasing the concentration of glycerol during insemination on hen fertility. Our findings revealed that 2% glycerol resulted in partial infertility, while 6% glycerol led to complete infertility. Subsequently, we examined the ability of sperm to colonize sperm storage tubules (SST) during in vivo insemination and in vitro incubation. The sperm used in the experiment were stained with Hoechst and contained 0, 2, or 6% glycerol. Furthermore, we conducted perivitelline membrane lysis tests and investigated sperm motility, mitochondrial function, ATP concentration, membrane integrity, and apoptosis after 60 min of incubation with different glycerol concentrations (0%, 1%, 2%, 6%, and 11%) at two temperatures to simulate pre-freezing (4 °C) and post-insemination (41 °C) conditions. Whereas 2% glycerol significantly reduced 50% of sperm containing SST, 6% glycerol completely inhibited SST colonization in vivo. On the other hand, in vitro incubation of sperm with SST revealed no effect of 2% glycerol, and 6% glycerol showed only a 17% reduction in sperm-filled SST. Moreover, glycerol reduced sperm-egg penetration rates and also affected sperm motility, bioenergetic metabolism, and cell death at 4 °C. These effects were observed when the concentration of glycerol exceeded 6%. Furthermore, at 41 °C, glycerol caused even greater damage, particularly in terms of reducing sperm motility. These data altogether reveal important effects of glycerol on sperm biology, sperm migration, SST colonization, and oocyte penetration. This suggests that glycerol plays a role in reducing fertility and presents opportunities for improving sperm cryopreservation.

Sunflower cake associated with crude glycerin in white laying hens diets: Performance and quality, antioxidant activity and lipid oxidation of eggs

The objective of this study was to evaluate the effects of sunflower cake inclusion and its association with crude glycerin in the diet of laying hens. A total of 320 laying hens with 39 weeks of age were distributed in a completely randomized design in a 4 × 2 factorial scheme with 5 replications of 8 birds. The studied factors were 4 inclusion levels of sunflower cake and 2 levels of crude glycerin. The inclusion of 210 g/kg of sunflower cake reduced egg mass and worsened feed conversion, and after the level 70 g/kg there was reduction in yolk coloration and specific density of eggs with or without the addition of glycerin in the diet. The addition of 70 g/kg of crude glycerin reduced the specific density of eggs in all levels of sunflower cake. There was increase in phenolic compounds, antioxidant capacity and antioxidant activity in eggs and reduction in lipid oxidation of yolks from fresh and stored eggs, with the inclusion of sunflower cake. The addition of crude glycerin increased the lipid oxidation of egg yolks. Therefore, it is possible to include up to 140 g/kg sunflower cake in the diet of laying hens, with or without crude glycerin, without impairing performance and egg quality, obtaining higher antioxidant capacity of eggs and lower lipid oxidation in yolks from fresh and stored eggs. The inclusion of 70 g/kg crude glycerin does not affect laying hens performance, however, it worsens shell quality and increases lipid oxidation in the liver and egg yolks.

Enhanced Cryopreservation Efficacies of Ice Recrystallization Inhibiting Nanogels

Development of new cryopreservation technologies holds significant potential to revolutionize the fields of cell culture, tissue engineering, assisted reproduction, and transfusion medicine. The current gold standard small-cell permeating cryopreservation agents (CPAs) demonstrate promising cryopreservation efficacies but are cytotoxic and immunogenic at the concentrations required for cryopreservation applications. In comparison, new cell impermeable CPAs of nanodimensions demonstrate outstanding potential to overcome the drawbacks of existing CPAs. In this study, we report the synthesis of vitamin B5 analogous methacrylamide (B5AMA)-incorporated nanogels as a potential solution to address the commonly observed limitations of existing CPAs. The stimuli-responsive poly(B5AMA) nanogels prepared by radical polymerization demonstrated significant ice recrystallization inhibition efficacies and showed either superior or comparable cryopreservation efficacies compared to the traditional cryoprotectant DMSO/glycerol in both eukaryotic and prokaryotic cells.

A simple and fast alternative method to remove glycerol from chicken semen after cryopreservation

A concentration of 11% of glycerol is the standard one for sperm cryopreservation in chickens, however, the presence of just 2% glycerol already causes severe fertility reduction, suggesting the necessity of removing glycerol before artificial insemination (AI). The major approach developed for this purpose is serial dilution followed by centrifugation (SDC), which demands special equipment (such as a refrigerate room) to maintain post-thaw semen at 4 °C, besides being time consuming. Therefore, we attempted to develop a simple method to remove glycerol from chicken frozen-thawed semen based on a colloidal gel, Percoll, which is ordinarily used to select motile and viable sperm in mammals as well as in fresh chicken semen. In this study, we used a Percoll based glycerol removal solution (GRS) containing sucrose to avoid frozen-thawed sperm suffering from osmotic stress. Subsequently, several conditions including GRS compositions (GRS A, B, C and D) and centrifugation temperatures (4 and 20 °C) were compared by their influence on sperm in vitro parameters. Afterwards, GRS A and D were selected for fertility evaluation, compared to conventional SDC method. Our results showed that the fertility with GRS A at both 4 and 20 °C were higher than GRS D (p < 0.05) and similar or even superior to the fertility obtained with SDC method. Altogether, our novel GRS protocol is a valuable method for chicken sperm cryobanking policy, supported by its notable results of fertility as well as saving 44% of time, with a simple equipment at flexible operation temperatures of 4 or 20 °C.

The Effect of Cryopreservation on the Survival of Nocardia farcinica and Yersinia pestis vaccine strains

Pathogenic microorganisms are valuable biological resources, closely related to biosecurity, human health, environmental protection, and renewable energy. It is very important to properly preserve the microbial resources by methods to maintain the purity, viability, and integrity, and to avoid prolonged degradation. The present work aims to explore the cryopreservation technology of Nocardia farcinica (Gram-positive bacteria) and Yersinia pestis vaccine strains (Gram-negative bacteria). The effects of cryoprotectants (CPAs), freezing temperature, and freeze-thaw cycles on the two bacteria in the cryopreservation process were studied. The results showed that the addition of CPAs (glycerol, propylene glycol, sucrose, glucose, l-carnitine, l-proline, and skim milk) significantly enhanced the survival rates of the N. farcinica and Y. pestis vaccine strains. However, high concentrations of CPAs can produce biochemical toxicity in the two pathogens. The utilization of composite CPAs not only reduced the toxicity but also improved the survival rates of samples during cryopreservation. The optimal composite CPA for N. farcinica is 0.292 M sucrose, 0.62 M l-carnitine, and 2.82 M glycerol. The optimal composite CPA for Y. pestis is 0.62 M l-carnitine, 8.46 M glycerin, and 0.292 M sucrose. The results showed that the quality of the strains stored at -80°C and -196°C was better. For the case of freeze-thaw cycles, the two pathogens have different degrees of reduction, and the survival rate of Y. pestis decreased more than that of N. farcinica. The uniform distribution of bacteria in CPAs can form uniform nucleation sites in the solution system, which is beneficial to the cryopreservation of strains, as can be seen from the experimental results from a differential scanning calorimeter. This study may provide a reference for better preservation of precious natural biological resources of pathogenic microorganisms.

Sir2 and Glycerol Underlie the Pro-Longevity Effect of Quercetin during Yeast Chronological Aging

Quercetin (QUER) is a natural polyphenolic compound endowed with beneficial properties for human health, with anti-aging effects. However, although this flavonoid is commercially available as a nutraceutical, target molecules/pathways underlying its pro-longevity potential have yet to be fully clarified. Here, we investigated QUER activity in yeast chronological aging, the established model for simulating the aging of postmitotic quiescent mammalian cells. We found that QUER supplementation at the onset of chronological aging, namely at the diauxic shift, significantly increases chronological lifespan (CLS). Consistent with the antioxidant properties of QUER, this extension takes place in concert with a decrease in oxidative stress. In addition, QUER triggers substantial changes in carbon metabolism. Specifically, it promotes an enhancement of a pro-longevity anabolic metabolism toward gluconeogenesis due to improved catabolism of C2 by-products of yeast fermentation and glycerol. The former is attributable to the Sir2-dependent activity of phosphoenolpyruvate carboxykinase and the latter to the L-glycerol 3-phosphate pathway. Such a combined increased supply of gluconeogenesis leads to an increase in the reserve carbohydrate trehalose, ensuring CLS extension. Moreover, QUER supplementation to chronologically aging cells in water alone amplifies their long-lived phenotype. This is associated with intracellular glycerol catabolism and trehalose increase, further indicating a QUER-specific influence on carbon metabolism that results in CLS extension.

Freezing of equine semen is influenced by exposure time and concentration of the cryoprotectant glycerol

BACKGROUND

Glycerol is a cryoprotectant widely used in the freezing of mammalian semen, but no study has demonstrated its optimum concentration and the appropriate exposure time for equine species.

OBJECTIVE

To demonstrate that the exposure time (15, 30, 45, 60, 75 and 90 min) versus concentration (2, 3, 4 and 5%) of the cryoprotectant glycerol influences the freezing success of equine semen.

MATERIALS AND METHODS

The ejaculate of 12 stallions were frozen in different glycerol concentrations following different exposure times. The thawed sperm was evaluated for kinetic parameters using a Computer Assisted Semen Analysis (CASA) system and cell feature parameters were assessed by flow cytometry.

RESULTS

Considering the total and progressive motility of the spermatozoa, we concluded that protocols using 5% glycerol for 15 and 30 min exposure, 4% glycerol for 45 min exposure and 3% glycerol for 90 min exposure generated the best results.

CONCLUSION

We suggest the use of any of these protocols for a better cryopreservation of equine semen. Doi: 10.54680/fr23410110412.

Effect of Crude Glycerin in the Feed of Lactating Goats on Concentrations of Essential and Toxic Metals in Serum, Urine, Milk, and Artisanal "Coalho" Cheese

Goat farming is concentrated in semi-arid and tropical regions in Brazil. From 2006 to 2017, the number of goats sold in the country increased by 65.7%. The dairy products from these animals present higher digestibility, high vitamin A and B content, hypoallergenicity, and less lactose compared to dairy products from cows, in addition to having a higher sales value. Since corn and soybean meal generate an expense for feed management, crude glycerin, originating from the manufacture of biodiesel, has been studied as an energy substitute. However, this product contains heavy metals, posing risks to animal and human health. Few data are available on trace elements in biological samples and products derived from goats' milk with the dietary introduction of glycerin. The objective was to quantify aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and zinc (Zn) in the serum, urine, milk, and artisanal "coalho" cheese of dairy goats fed different levels of crude glycerin in feed management. In total, 16 Saanen goats were selected, lactating females, that were distributed in four Latin squares and randomly treated with different levels of crude glycerin (0, 5, 10, and 15%). After the end of each experiment cycle, serum, urine, milk, and artisanal "coalho" cheese samples were collected at the four moments. The samples were submitted to digestion assisted by microwave radiation. The multi-element analysis was carried out using inductively coupled plasma optical emission spectrometry (ICP OES). There was no influence of crude glycerin levels replacing corn in serum, milk, urine, and artisanal "coalho" cheese. The serum concentration of the metals Cu, Fe, Zn, and Mn; urine concentrations of Cu, Zn, Mn, Mo, and Cr; and milk and artisanal "coalho" cheese concentrations of Cu, Zn, and Mn remained within the standards found in the literature. The inclusion of 5 to 15% of crude glycerin, derived from cotton oil, in the diets of dairy goats in partial replacement of corn, does not alter the concentration of essential and toxic metals in serum, urine, milk, and artisanal "coalho" cheese and does not, therefore, present a risk factor for intoxication.

Rat bronchoalveolar lavage proteome changes following e-cigarette aerosol exposures

E-cigarette liquids are complex mixtures of chemicals consisting of humectants, such as propylene glycol (PG) and vegetable glycerin (VG), with nicotine or flavorings added. Published literature emphasizes the toxicity of e-cigarette aerosols with flavorings whereas much less attention has been given to the biologic effects of humectants. The purpose of the current study was to provide a comprehensive view of the acute biologic effects of e-cigarette aerosols on rat bronchoalveolar lavage (BAL) using mass spectrometry-based global proteomics. Sprague-Dawley rats were exposed to e-cigarette aerosol for 3 h/day for three consecutive days. Groups included: PG/VG alone, PG/VG + 2.5% nicotine (N), or PG/VG + N + 3.3% vanillin (V). Right lung lobes were lavaged for BAL and supernatants prepared for proteomics. Extracellular BAL S100A9 concentrations and BAL cell staining for citrullinated histone H3 (citH3) were also performed. From global proteomics, ∼2,100 proteins were identified from rat BAL. The greatest change in number of BAL proteins occurred with PG/VG exposures alone compared with controls with biological pathways enriched for acute phase responses, extracellular trap formation, and coagulation. Extracellular BAL S100A9 concentrations and the number of citH3 + BAL cells also increased significantly in PG/VG and PG/VG + 2.5% N. In contrast to PG/VG or PG/VG + N, the addition of vanillin to PG/VG + N increased BAL neutrophilia and downregulated lipid transport proteins. In summary, global proteomics support e-cigarette aerosol exposures to PG/VG alone as having a significant biologic effect on the lung independent of nicotine or flavoring with increased markers of extracellular trap formation.

Effect of isolation protocols and cryoprotectants on freezing of stallion epididymal spermatozoa

BACKGROUND

The recovery of spermatozoa from the cauda epididymis may be the only option to obtain genetic material from elite stallions that had undergone castration or sudden death due to colic or severe injury.

OBJECTIVE

To evaluate two different protocols for retrieval of stallion epididymal spermatozoa and to evaluate different cryoprotectants on the freezability of the epididymal spermatozoa.

MATERIALS AND METHODS

Six epididymides from three stallions were collected immediately after routine castration under general anesthesia. In the first experiment, each epididymis (of two testes) of the same stallion were processed using different methods for retrieval of the epididymal spermatozoa and were pooled and cryopreserved either using 5% glycerol or 5% dimethyl formamide (DMF) as cryoprotectant. The semen quality parameters viz., progressive motility, HOST, viability and acrosome integrity were evaluated at the fresh, pre-freeze and post-thaw stages.

RESULTS

Retrograde method of flushing of epididymis yielded significantly (p < 0.05) higher concentration of the stallion sperm than that of the floating method. The qualitative semen parameters i.e., viability, plasma membrane integrity and acrosome integrity were found to be significantly restored using 5% DMF as cryoprotectant in comparison to when 5% glycerol was used.

CONCLUSION

Retrograde flushing method of epididymis yielded significantly higher sperm concentration to that of the floating method, and 5% DMF as cryoprotectant provided acceptable freezability of stallion epididymal spermatozoa. DOI: 10.54680/fr23310110312.

Assessing the benefits of antioxidant and antibiotics treatments for cryopreservation of the model alga Ectocarpus siliculosus and the endemic alga Acinetospora asiatica

BACKGROUND

Cryopreservation in liquid nitrogen is a suitable technique for preserving seaweeds, a group of photosynthetic organisms with many applications. Although there are some standard protocols for seaweed cryopreservation, most rely on expensive controlled-rate coolers. Moreover, several factors, such as the use of antioxidants or antibiotics, remain unexplored.

OBJECTIVE

To test the effect of 2-mercapthoethanol (antioxidant) and antibiotic mixtures on the cryopreservation of the model alga Ectocarpus siliculosus and the endemic brown seaweed Acinetospora asiatica using a low-tech passive rate cooler.

MATERIALS AND METHODS

2-mercaptoethanol was added to the cryoprotectant (CPA) solution, while antibiotic mixtures were included in the culture medium during the recovery process. In addition, two CPA solutions were tested on E. siliculosus.

RESULTS

After two weeks of recovery, the treatment comprising PSC antibiotic mixture (Penicillin G, streptomycin, and chloramphenicol) showed a significant increase in post-thaw viability. Antioxidant treatment did not improve viability. The highest viabilities for E. siliculosus and A. asiatica were 64-83%, and 83-87%, respectively, using 10% glycerol + 10% proline as CPA solution.

CONCLUSION

E. siliculosus and A. asiatica were successfully cryopreserved using a low-tech passive rate cooler, 10% glycerol + 10% proline solution, and antibiotic treatment. The highest post-thaw viabilities (64-87%) reported for PSC antibiotic mixture suggest the potential benefits of using antibiotics during post-thaw recovery of marine macroalgae. This study is the first report on the cryopreservation of A. asiatica. DOI: 10.54680/fr23310110212.

Effect of type and concentration of cryoprotectant on the motility, viability, and fertility of climbing perch Anabas testudineus Bloch, 1792 (Pisces: Anabantidae) sperm

The climbing perch, Anabas testudineus is a freshwater fish that has economic value in Indonesia. It is cultured in the country, but the breeding technology, specifically sperm storage, is not well developed. Sperm cryopreservation is one of the preservation methods that need to be developed to support fish breeding technology. The type of cryoprotectants and its concentration are species-dependent and determines the success of this approach. Therefore, this study is aimed at determining the optimal type and concentration of cryoprotectant for sperm cryopreservation of A. testudineus. Four separate study series were performed, each of which evaluated one type of cryoprotectant at five concentration levels. The cryoprotectants used were DMSO, methanol, glycerol, and ethanol, and the tested concentrations were 0%, 5%, 10%, 15%, and 20%, which were combined with 5% egg yolks. Each treatment was conducted with three replications. The results showed that the type of cryoprotectant and its concentration significantly affected sperm motility, viability, and fertility of climbing perch (P < 0.05). The best outcome was obtained in DMSO, and methanol at a concentration of 10%, glycerol at 5%, and ethanol at 15%. However, the highest motility, viability, and fertility values were observed at 10% DMSO, indicating it is the best type and concentration for sperm cryopreservation of climbing perch A. testudineus.

Reduction of wrinkles: From a computational hypothesis to a clinical, instrumental, and biological proof

BACKGROUND

Facial wrinkles are clear markers of the aging process, being chronological, photo-induced, or reflecting repetitive facial expressions. The aim of this study is to provide new insights into the biophysical and biological mechanisms involved in the formation, prevention, or elimination of the expression wrinkles.

MATERIALS AND METHODS

We use a computational model to get a better understanding of the wrinkle mechanical behavior and evolution after skin softening and suggesting a possible antiaging mechanism. Then, we provide a clinical demonstration of the anti-wrinkle effect of a long-term application of a 20% glycerol in a moisturizer formula (GBM) versus its vehicle on crow's feet. Skin hydration, elasticity, and wrinkles visibility were evaluated by a combination of clinical and instrumental in vivo data, inverse finite element analysis, and proteomic data.

RESULTS

The computational model shows a predominantly compressive stress beneath the wrinkle and its significant decrease by the softening of stratum corneum. The associated clinical study confirmed a significant increase of skin hydration and elasticity as well as a decrease of wrinkle visibility after 2 and 4 months as application for both formulas; this effect being stronger for GBM. A softening effect on stratum corneum and dermis was also observed for the GBM. Furthermore, proteomic data revealed an effect of upregulation of four proteins associated with desquamation, cell-glycan extracellular interactions, and protein glycation/oxidation, functions related to the tissue mechanics and adhesion.

CONCLUSIONS

We provide an in vivo demonstration of the anti-ageing benefit of glycerol at high dose (20%) reflected by a cumulative skin surface softening effect. The use of high moisturizing potent formulations should bring additional performance to other conventional moisturizing formulations.