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American Journal of Physiology. Lung... Dec 2020Electronic nicotine delivery systems, or e-cigarettes, utilize a liquid solution that normally contains propylene glycol (PG) and vegetable glycerin (VG) to generate...
Electronic nicotine delivery systems, or e-cigarettes, utilize a liquid solution that normally contains propylene glycol (PG) and vegetable glycerin (VG) to generate vapor and act as a carrier for nicotine and flavorings. Evidence indicated these "carriers" reduced growth and survival of epithelial cells including those of the airway. We hypothesized that 3% PG or PG mixed with VG (3% PG/VG, 55:45) inhibited glucose uptake in human airway epithelial cells as a first step to reducing airway cell survival. Exposure of H441 or human bronchiolar epithelial cells (HBECs) to PG and PG/VG (30-60 min) inhibited glucose uptake and mitochondrial ATP synthesis. PG/VG inhibited glycolysis. PG/VG and mannitol reduced cell volume and height of air-liquid interface cultures. Mannitol, but not PG/VG, increased phosphorylation of p38 MAPK. PG/VG reduced transepithelial electrical resistance, which was associated with increased transepithelial solute permeability. PG/VG decreased fluorescence recovery after photobleaching of green fluorescent protein-linked glucose transporters GLUT1 and GLUT10, indicating that glucose transport function was compromised. Puffing PG/VG vapor onto the apical surface of primary HBECs for 10 min to mimic the effect of e-cigarette smoking also reduced glucose transport. In conclusion, short-term exposure to PG/VG, key components of e-cigarettes, decreased glucose transport and metabolism in airway cells. We propose that this was a result of PG/VG reduced cell volume and membrane fluidity, with further consequences on epithelial barrier function. Taking these results together, we suggest these factors contribute to reduced defensive properties of the epithelium. We propose that repeated/chronic exposure to these agents are likely to contribute to airway damage in e-cigarette users.
Topics: Biological Transport; Electronic Nicotine Delivery Systems; Epithelial Cells; Glucose; Glycerol; Humans; Propylene Glycol; Respiratory System
PubMed: 32996783
DOI: 10.1152/ajplung.00123.2020 -
Journal of Dairy Science Mar 2020This experiment aimed to evaluate the suitability of glycerol and propylene glycol to reduce microbial count and preserve immune properties in heat-treated goat...
This experiment aimed to evaluate the suitability of glycerol and propylene glycol to reduce microbial count and preserve immune properties in heat-treated goat colostrum. Colostrum samples from 11 goats were each divided into 9 aliquots. Different concentrations (2, 6, 10, and 14%; vol/vol) of either glycerol or propylene glycol were added to the aliquots. Phosphate buffer solution was added to one aliquot, which was set as the control (CG). After the respective additions, all colostrum samples were heat treated at 56°C for 1 h. After cooling, aerobic mesophilic bacteria were cultured. The samples were frozen until free fatty acid, IgG, IgA, and IgM concentrations and chitotriosidase activity were measured. No differences were found in aerobic mesophilic bacteria counts between either 10 or 14% glycerol and propylene glycol additives. These additions reduced bacterial count to a greater extent than CG, and 2 or 6% additions. Colostrum IgG concentration was not affected by either of the additives or their concentrations. The propylene glycol additive reduced IgA and IgM concentrations and chitotriosidase activity, compared with CG. Conversely, glycerol did not affect any of the studied immune variables. In conclusion, glycerol addition to goat colostrum before heat treatment is suitable to enhance bacterial reduction, whereas colostrum immune properties were not affected.
Topics: Animals; Bacteria; Bacterial Load; Colostrum; Female; Glycerol; Goats; Hexosaminidases; Hot Temperature; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Pasteurization; Pregnancy; Propylene Glycol
PubMed: 31882214
DOI: 10.3168/jds.2019-17535 -
International Journal of Pharmaceutics Jul 2020Tofacitinib citrate (TC) has recently gained interest in treating skin disorders such as psoriasis, atopic dermatitis and baldness. Unfortunately, the oral...
Tofacitinib citrate (TC) has recently gained interest in treating skin disorders such as psoriasis, atopic dermatitis and baldness. Unfortunately, the oral administration shows side effects, such as decreased neutrophil counts. To this end, the topical delivery of TC can be used to reduce the risk associated with systemic exposure. However, TC shows minimal absorption via skin. Hence, the objective of this study is to enhance the skin delivery of TC using a non-invasive approach. The liposomes based on propylene glycol, named as proposomes, carrying TC, were studied. The vesicle characteristics and in vitro skin permeation were assessed. The proposomes enhanced the skin permeability of TC by 4-11 folds. The composition of proposomes was found to affect the skin permeation and deposition of TC. The proposomes were stable for at least 6 months. Overall, proposomes were effective for targeted topical drug delivery.
Topics: Administration, Cutaneous; Cadaver; Chemistry, Pharmaceutical; Drug Delivery Systems; Drug Stability; Humans; Liposomes; Male; Middle Aged; Particle Size; Piperidines; Propylene Glycol; Protein Kinase Inhibitors; Pyrimidines; Skin Absorption
PubMed: 32565283
DOI: 10.1016/j.ijpharm.2020.119558 -
Use of Propylene-Glycol as a Cosolvent for GnRH in Synchronization of Estrus and Ovulation in Sheep.Animals : An Open Access Journal From... May 2020The foreseen shortage of eCG for estrus synchronization in sheep makes necessary the development of alternative protocols. The aim of the present work was to evaluate...
The foreseen shortage of eCG for estrus synchronization in sheep makes necessary the development of alternative protocols. The aim of the present work was to evaluate the reproductive response of sheep in breeding season to the administration of GnRH using propylene-glycol as a cosolvent and the subcutaneous route for slowing and extending the release of GnRH, as well as the most adequate timing for such administration. In the present study, protocols based on a short-term CIDR treatment and a single subcutaneous dose of GnRH in propylene-glycol at 36 h after CIDR removal induced a similar ovarian response to protocols based on administration of eCG at CIDR removal or intramuscular GnRH in distilled water at 56 h after. In such protocol, 80% of the animals developed estrus in a narrow timing (75% between 36 and 48 h after CIDR removal), and all of them also ovulated in a narrow window (87.5% between 72 and 76 h after CIDR removal, with 62.5% between 72 and 76 h) and showed a similar ovulation rate and plasma progesterone concentrations at the induced estrous cycle. Hence, administration of GnRH in propylene-glycol may constitute an alternative to traditional protocols based on the administration of eCG.
PubMed: 32455785
DOI: 10.3390/ani10050897 -
Materials (Basel, Switzerland) Jan 2023A series of calcium oxide-magnesium oxide (CaO-MgO) catalysts were prepared under the effects of different precipitating agents and using varied Mg/Ca ratios. The...
A series of calcium oxide-magnesium oxide (CaO-MgO) catalysts were prepared under the effects of different precipitating agents and using varied Mg/Ca ratios. The physiochemical characteristics of the prepared catalysts were analyzed using XRD, FE-SEM, BET, FTIR, and TG/DTA techniques. Quantification of basic active sites present on the surface of the CaO-MgO catalysts was carried out using the Hammett indicator method. The as-prepared mixed oxide samples were tested for propylene carbonate (PC) synthesis through the alcoholysis of urea with propylene glycol (PG). The effects of the catalyst composition, catalyst dose, reaction temperature, and contact time on the PC yield and selectivity were investigated. The maximum PC yield of 96%, with high PC selectivity of 99% and a urea conversion rate of 96%, was attained at 160 °C using CaO-MgO catalysts prepared using a Mg/Ca ratio of 1 and NaCO as a precipitating agent. The best-performing catalysts also exhibited good reusability without any significant loss in PC selectivity. It is expected that the present study will provide useful information on the suitability of different precipitating agents with respect to the catalytic properties of the oxides of Ca and Mg and their application in the synthesis of organic carbonates.
PubMed: 36676471
DOI: 10.3390/ma16020735 -
ACS Nano Aug 2023An important goal of systems and synthetic biology is to produce high value chemical species in large quantities. Microcompartments, which are protein nanoshells...
An important goal of systems and synthetic biology is to produce high value chemical species in large quantities. Microcompartments, which are protein nanoshells encapsulating catalytic enzyme cargo, could potentially function as tunable nanobioreactors inside and outside cells to generate these high value species. Modifying the morphology of microcompartments through genetic engineering of shell proteins is one viable strategy to tune cofactor and metabolite access to encapsulated enzymes. However, this is a difficult task without understanding how changing interactions between the many different types of shell proteins and enzymes affect microcompartment assembly and shape. Here, we use multiscale molecular dynamics and experimental data to describe assembly pathways available to microcompartments composed of multiple types of shell proteins with varied interactions. As the average interaction between the enzyme cargo and the multiple types of shell proteins is weakened, the shell assembly pathway transitions from (i) nucleating on the enzyme cargo to (ii) nucleating in the bulk and then binding the cargo as it grows to (iii) an empty shell. Atomistic simulations and experiments using the 1,2-propanediol utilization microcompartment system demonstrate that shell protein interactions are highly varied and consistent with our multicomponent, coarse-grained model. Furthermore, our results suggest that intrinsic bending angles control the size of these microcompartments. Overall, our simulations and experiments provide guidance to control microcomparmtent size and assembly by modulating the interactions between shell proteins.
Topics: Bacterial Proteins; Molecular Dynamics Simulation; Propylene Glycol; Organelles
PubMed: 37552700
DOI: 10.1021/acsnano.3c03353 -
Nicotine & Tobacco Research : Official... Nov 2023Although the greater popularity of electronic cigarettes (EC) among asthmatics is alarming, there is limited knowledge of the long-term consequences of EC exposure in...
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.
Topics: Male; Mice; Female; Animals; Nicotine; Electronic Nicotine Delivery Systems; Asthma; Lung; Propylene Glycol; Glycerol; Vegetables
PubMed: 37349133
DOI: 10.1093/ntr/ntad100 -
Pharmaceutics Aug 2023Ischemic stroke is the second-leading cause of death. Hyperglycemia, which is characteristic of diabetes mellitus, contributes to the development of endothelial...
Ischemic stroke is the second-leading cause of death. Hyperglycemia, which is characteristic of diabetes mellitus, contributes to the development of endothelial dysfunction and increases the risk of stroke. Isoxsuprine is an efficient beta-adrenergic agonist that improves blood flow to the ischemic aria and stops the infarct core from growing. However, low bioavailability, a short biological half-life, and first-pass hepatic metabolism reduce the therapeutic efficacy of oral isoxsuprine. Therefore, the authors focused on developing isoxsuprine-loaded liposomes containing ethanol and propylene glycol (ILEP) formulation as nasal drops for the treatment of ischemic stroke in diabetic patients. Different ILEP formulations were optimized using Design Expert software, and the selected formulation was examined in vivo for its anti-stroke effect using a rat model of diabetes and stroke. The optimized ILEP, composed of 15% propylene glycol, 0.16% cholesterol, 10% ethanol, and 3.29% phospholipid, improved the sustainability, permeation, and targeting of isoxsuprine. Furthermore, the in vivo studies verified the improved neurological behavior and decreased dead shrunken neurons and vascular congestion of the rats treated with the optimized ILEP formulation, demonstrating its anti-stroke activity. In conclusion, our study found that treatment with an optimized ILEP formulation prevented the initiation and severity of stroke, especially in diabetic patients.
PubMed: 37765211
DOI: 10.3390/pharmaceutics15092242 -
Materials (Basel, Switzerland) Mar 2022Currently, catalytic processing of biorenewable raw materials into valuable products attracts more and more attention. In the present work, silica-supported FePO and...
Currently, catalytic processing of biorenewable raw materials into valuable products attracts more and more attention. In the present work, silica-supported FePO and Fe-Mo-O catalysts are prepared, their phase composition, and catalytic properties are studied in the process of selective oxidation of propylene glycol into valuable mono- and bicarbonyl compounds, namely, hydroxyacetone and methylglyoxal. A comparative analysis of the main routes of propylene glycol adsorption with its subsequent oxidative conversion into carbonyl products is carried out. The DFT calculations show that in the presence of adsorbed oxygen atom, the introduction of the phosphate moiety to the Fe-containing site strengthens the alcohol adsorption on the catalyst surface with the formation of the 1,2-propanedioxy (-OCH(CH)CHO-) intermediate at the active site. The introduction of the molybdenum moiety to the Fe-containing site in the presence of the adsorbed oxygen atom is also energetically favorable, however, the interaction energy is found by 100 kJ/mol higher compared to the case with phosphate moiety that leads to an increase in the propylene glycol conversion while maintaining high selectivity towards C products. The catalytic properties of the synthesized iron-containing catalysts are experimentally compared with those of Ag/SiO sample. The synthesized FePO/SiO and Fe-Mo-O/SiO catalysts are not inferior to the silver-containing catalyst and provide ~70% selectivity towards C products, while the main part of propylene glycol is converted into methylglyoxal in contrast to the Ag/SiO catalyst featuring the selective transformation of only the secondary C-OH group in the substrate molecule under the studied conditions with the formation of hydroxyacetone. Thus, supported Fe-Mo-O/SiO catalysts are promising for the selective oxidation of polyatomic alcohols under low-temperature conditions.
PubMed: 35269137
DOI: 10.3390/ma15051906 -
Journal of Hazardous Materials Mar 2023No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of...
No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of E-cigarette products containing nicotine or tetrahydrocannabinol was investigated. Mice were intratracheally administered propylene glycol (PG), vegetable glycerin (VG), vitamin E acetate (VEA), or nicotine individually for two weeks. Cytological and histological changes were noticed in PG- and VEA-treated mice that exhibited pathophysiological changes which were associated with symptoms seen in patients with symptoms of E-cigarette or Vaping Use-Associated Lung Injuries (EVALI) or E-cigarette users. Compared to potential human exposure situations, while the VEA exposure condition was similar to the dose equivalent of VEA content in E-cigarettes, the PG condition was about 47-137 times higher than the dose equivalent of the daily PG intake of E-cigarette users. These results reveal that VEA exposure is much more likely to cause problems related to EVALI in humans than PG. Transcriptomic analysis revealed that PG exposure was associated with fibrotic lung injury via the AKT signaling pathway and M2 macrophage polarization, and VEA exposure was associated with asthmatic airway inflammation via the mitogen-activated protein kinase signaling pathway. This study provides novel insights into the pathophysiological effects of individual ingredients of E-cigarettes.
Topics: Humans; Mice; Animals; Lung Injury; Vaping; Electronic Nicotine Delivery Systems; Nicotine; Vitamin E; Propylene Glycol; Lung
PubMed: 37055947
DOI: 10.1016/j.jhazmat.2022.130454