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Theoretical MP2 and B3LYPD3 calculations, as well as experimental matrix isolation infrared spectroscopy studies, were used to investigate the 1:1 complexes formed between glycolic acid and water. Out of five computationally predicted forms of GA⋯H 2 O complex the most stable one was detected experimentally in solid argon. This structure is characterized by two intermolecular OH⋯O hydrogen bonds depicting a six-member ring in which water acts both as a proton acceptor and as a proton donor. Two other structures with the alcoholic OH group acting as a proton donor are also tentatively suggested to be present in solid argon., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The conversion of CO 2 into methanol depicts one of the most promising emerging renewable routes for the chemical and biotech industry. Under this regard, native methylotrophs have a large potential for converting methanol into value-added products but require targeted engineering approaches to enhance their performances and to widen their product spectrum. Here we use a systems-based approach to analyze and engineer M. extorquens TK 0001 for production of glycolic acid. Application of constraint-based metabolic modeling reveals the great potential of M. extorquens for that purpose, which is not yet described in literature. In particular, a superior theoretical product yield of 1.0 C-mol Glycolic acid C-mol Methanol is predicted by our model, surpassing theoretical yields of sugar fermentation. Following this approach, we show here that strain engineering is viable and present 1st generation strains producing glycolic acid via a heterologous NADPH-dependent glyoxylate reductase. It was found that lactic acid is a surprising by-product of glycolic acid formation in M. extorquens, most likely due to a surplus of available NADH upon glycolic acid synthesis. Finally, the best performing strain was tested in a fed-batch fermentation producing a mixture of up to total 1.2 g L -1 glycolic acid and lactic acid. Several key performance indicators of our glycolic acid producer strain are superior to state-of-the-art synthetic methylotrophs. The presented results open the door for further strain engineering of the native methylotroph M. extorquens and pave the way to produce two promising biopolymer building blocks from green methanol, i.e., glycolic acid and lactic acid.-1 glycolic acid and lactic acid. Several key performance indicators of our glycolic acid producer strain are superior to state-of-the-art synthetic methylotrophs. The presented results open the door for further strain engineering of the native methylotroph M. extorquens and pave the way to produce two promising biopolymer building blocks from green methanol, i.e., glycolic acid and lactic acid., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: J.T.F., C.S., M.S., and A.R. filed a patent (PCT/EP2023/071399) based on all of the results presented in this paper. The other authors declare no competing interests., (© 2024. The Author(s).)

We recently reported the case of a patient who experienced three consecutive episodes of acute kidney injury, all of them following a "Brazilian" hair-straightening treatment. The cream used for the straightening procedure contained glyoxylic acid. To examine possible underlying mechanisms causing kidney injury, four groups of mice were exposed to topical application of (i) the straightening product, (ii) a cream containing 10% glyoxylic acid, (iii) a cream containing 10% glycolic acid or (iv) a control cream. Application of glycolic acid slightly increased urine oxalate excretion, while glyoxylic acid and the straightening product dramatically increased urine oxalate excretion and caused calcium oxalate nephropathy after transcutaneous absorption. Thus, glyoxylic acid was presumptively absorbed through the skin, metabolized to oxalate and promoted crystallization of calcium oxalate in urine. Hence, cosmetic products containing glyoxylic acid may induce acute kidney injury and should be discontinued. Further studies are needed to investigate the metabolism of glycolic acid and glyoxylic acid following topical application., (Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Amid rising environmental concerns, attempts have been made to produce glycolic acid (GA) using microbial processes with renewable carbon resources instead of using chemicals. The Dahms pathway for GA production uses xylose as a substrate and consists of relatively simple enzymatic steps. However, employing it leads to a decrease in cell growth and GA productivity. Systematically identifying and addressing metabolic bottlenecks in the Dahms pathway are essential for efficient glycolic acid (GA) production have not yet been performed. Through metabolic flux balance analysis, we found that insufficient aldehyde dehydrogenase (AldA) activity lowers GA production and negatively affects cell growth due to reduced energy production. Thus, we discovered a novel AldA isolated from Buttiauxella agrestis (BaAldA) demonstrated a 1.69-fold lower K M and a 1.49-fold higher turnover rate (k cat /K M ) than AldA from Escherichia coli (EcAldA). GA production in E. coli harboring BaAldA was 1.59 times higher than in the original strain. Fed-batch fermentation of E. coli harboring BaAldA produced 22.70 g/L GA with a yield of 0.497 g/g xylose (98.2% of the theoretical maximum yield in the Dahms pathway), showing a higher final yield for GA than previously reported in E. coli. Our novel BaAldA enzyme shows great potential for the production of GA using microorganisms or enzymes. Furthermore, our approach to identifying metabolic bottlenecks using flux balance analysis could be utilized to enhance the microbial production of various desirable products in future studies., Competing Interests: Declarations. Conflict of Interest: The authors declare that there are no competing financial interests. Ethical Approval: Not applicable., (© 2024. The Author(s), under exclusive licence to Microbiological Society of Korea.)

Electrochemical upcycling of nitrate and polyester plastic into valuable products is an ideal solution to realize the resource utilization. Here, the co-production of ammonia (NH 3 ) and glycolic acid (GA) via electrochemical upcycling of nitrate and polyethylene terephthalate (PET) plastics over mesoporous Pd 3 Au film on Ni foam (mPd 3 Au/NF), which is synthesized by micelle-assisted replacement method, is proposed. The mPd 3 Au/NF with well-developed mesoporous structure provides abundant active sites and facilitated transfer channels and strong electronic effect. As such, the mPd 3 Au/NF exhibits high Faraday efficiencies of 97.28% and 95.32% at 0.9 V for the formation of NH 3 and GA, respectively. Theoretical results indicate that the synergistic effect of Pd and Au can optimize adsorption energy of key intermediates *NOH and *OCH 2 -CH 2 OH on active sites and increase bond energy of C─C band, thereby improving the activity and selectivity for the formation of NH 3 and GA. This work proposes a promising strategy for the simultaneous conversation of nitrate and PET plastic into high-value NH 3 and GA., (© 2024 Wiley‐VCH GmbH.)

Background: The hands are one of the areas where skin aging is most noticeable, alongside the face, but limited studies used dermoscopic evaluation on hand aging. The Dermoscopy Photoaging Scale (DPAS) is frequently used to assess face aging but is never used for hand aging. Treating skin aging using chemical peeling is a commonly used method to rejuvenate the skin on the hands, as it is relatively affordable. Using multiple chemical peels may yield more significant results., Aims: To determine the effectiveness of a chemical peeling combination in retarding hand aging and to assess the utility of DPAS in this process., Methods: This study involved 69 Fitzpatrick skin types III-IV volunteers aged 20-69. One hand of each participant was treated with 20% glycolic acid (GA), while the other received a combination of peels consisting of 20% GA and 15% trichloroacetic acid (TCA). The hands were clinically examined before and after the treatments, and dermoscopic examinations were performed using a modified DPAS., Results: Four treatments improved clinical and dermoscopic characteristics in both hands. The combined peeling considerably improved pigmentation intensity on the dorsal hand compared to the GA peel (p < 0.001). Post-chemical peeling patient satisfaction increased significantly., Conclusions: The modified DPAS is a valuable instrument to assess the signs of hand aging. The combination of GA and TCA effectively improves skin aging of the hands and offers an accessible and economical option for addressing skin aging., (© 2024 The Author(s). Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

Epidemiological evidence suggests an association between dioxin and dioxin-like compound (DLC) exposure and human liver disease. The prototypical DLC, 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD), has been shown to induce the progression of reversible hepatic steatosis to steatohepatitis with periportal fibrosis and biliary hyperplasia in mice. Although the effects of TCDD toxicity are mediated by aryl hydrocarbon receptor (AHR) activation, the underlying mechanisms of TCDD-induced hepatotoxicity are unresolved. In the present study, male C57BL/6NCrl mice were gavaged every 4 days for 28 days with 0.03 - 30 μg/kg TCDD and evaluated for liver histopathology and gene expression as well as complementary 1-dimensional proton magnetic resonance (1D- 1 H NMR) urinary metabolic profiling. Urinary trimethylamine (TMA), trimethylamine N -oxide (TMAO), and 1-methylnicotinamide (1MN) levels were altered by TCDD at doses ≤ 3 μg/kg; other urinary metabolites, like glycolate, urocanate, and 3-hydroxyisovalerate, were only altered at doses that induced moderate to severe steatohepatitis. Bulk liver RNA-seq data suggested altered urinary metabolites correlated with hepatic differential gene expression corresponding to specific metabolic pathways. In addition to evaluating whether altered urinary metabolites were liver-dependent, published single-nuclear RNA-seq (snRNA-seq), AHR ChIP-seq, and AHR knockout gene expression datasets provide further support for hepatic cell-type and AHR-regulated dependency, respectively. Overall, TCDD-induced liver effects were preceded by and occurred with changes in urinary metabolite levels due to AHR-mediated changes in hepatic gene expression., Competing Interests: CONFLICT OF INTEREST The authors declare that they have no conflicts of interest with the contents of this article.

Recently, cases of antifreeze poisoning in companion animals, particularly cats, have surged in the Republic of Korea. Ethylene glycol (EG), the toxic primary component of antifreeze, is metabolized into glycolic acid (GA), leading to severe metabolic acidosis, acute kidney injury, and death. Traditional detection methods, although effective, are often time-consuming owing to complex sample preparation. This study involved a novel analytical method utilizing GC-MS for EG and LC-MS/MS for GA detection, which streamlined the detection process by eliminating the need for derivatization. The method was validated for accuracy and reliability, enabling the rapid and precise identification of EG and GA in biological samples. This study also included the successful application of this method in a case where initial exposure to antifreeze was not apparent, which highlighted the effectiveness of this method in diagnosing poisoning even in cases where clinical history is unclear. The development of this rapid diagnostic approach addresses the urgent need for the efficient detection of antifreeze poisoning, improving animal welfare and supporting forensic investigations.

Microbial production of glycolic acid (GA) from ethylene glycol is extensively used in a variety of industries because ethylene glycol is not only an inexpensive raw material but also the main component of industrial wastes. In this study, we produced GA from ethylene glycol using Escherichia coli overexpressing the endogenous 1,2-propanediol oxidoreductase (fucO) and lactaldehyde dehydrogenase (aldA) genes. To increase GA productivity, we screened a random mutant library generated using an error-prone polymerase chain reaction of fucO and obtained FucO mutants MF2-9 and MF6-9 with enhanced GA production in Lysogeny Broth medium containing 800 mM ethylene glycol. MF2-9 contained three amino acid substitutions (D23E, E222K, and G363S) and two synonymous mutations (coding DNA [c.] 93G > A and c.1131T > C) in fucO. MF6-9 contained one amino acid substitution (L377H) in FucO. An amino acid substitution (L377H) and a single synonymous mutation (c.1131T > C) in fucO contributed to the enhancement in GA production. Notably, cell lysates from E. coli harboring a synonymous mutation (c.1131T > C) or amino acid substitution (L377H) in fucO showed that only AldA activity was 1.3-fold higher than that of the cell lysate from E. coli harboring the wild-type fucO. We confirmed that c.1131T > C and L377H mutations increased aldA expression in E. coli. Analysis of mRNA levels and simulation of mRNA stabilization indicated that base substitutions at positions c.1130T, which corresponds to L377H amino acid substitution, and c.1131T increased aldA expression due to partial destabilization of the mRNA. These findings will be useful for the large-scale microbial production of GA from industrial waste., (Copyright © 2024 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

In recent studies we have reported on the near-UV light-induced degradation of iron complexes of various pharmaceutical excipients, such as Fe(III)-citrate and Fe(III)-amino acid complexes. Mechanistic studies revealed a common photo-degradation pattern, i.e. the formation of carbon dioxide radical anion, a potent reducing agent, via an alkoxyl/amino radical intermediate generated by light-induced ligand-to-metal charge transfer (LMCT) involving α-hydroxycarboxylates or amino acids. Herein, we confirm the proposed general photo-degradation pathways through the study of the iron complexes of other α-hydroxycarboxylates that may be present in protein formulations, such as lactate and glycolate. The results indicate that lactate generates even higher yields of • CO 2 - as compared to citrate, suggesting a significant potential of lactate for the promotion of photo-degradation in pharmaceutical formulations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)

Glycolic acid is an important chemical product widely used in various fields, including cosmetics, detergents, textiles, and more. Currently, microbial production of glycolic acid has disadvantages such as poor genetic stability, low yield, and high cost. Additionally, whole-cell catalytic production of glycolic acid typically requires the addition of relatively expensive sorbitol as a carbon source, which limits its industrial production. To develop an industrially applicable method for glycolic acid production, this study used ethylene glycol as a substrate to screen the glycolic acid-producing strains through whole-cell catalysis, obtaining a Rhodotorula sp. capable of producing glycolic acid. The strain was then subjected to UV mutagenesis and high throughput screening, and the positive mutant strain RMGly-20 was obtained. After optimization in shake flasks, the glycolic acid titer of RMGly-20 reached 17.8 g/L, a 10.1-fold increase compared to the original strain. Using glucose as the carbon source and employing a fed-batch culture in a 5 L fermenter, strain RMGly-20 produced 61.1 g/L of the glycolic acid. This achievement marks the preliminary breeding of a genetically stable glycolic acid-producing strain using a cheap carbon source, providing a new host for the biosynthesis of glycolic acid and promoting further progress toward industrial production.

This study evaluated bond strength of glass fiber posts to root dentin using push-out (PO) and diametral compression (DC), testing glycolic acid as a conditioner and varying dentin moisture. An additional aim was to test whether DC can be an alternative test to PO for bond strength assessment. Eighty bovine teeth were divided into eight groups (n = 10) defined by the use of either 37% glycolic acid or 37% phosphoric acid (PA) on moist or wet dentin before bonding with either Adapter SingleBond/RelyX ARC or One Step Plus/Duo-Link Bisco. Each tooth provided discs with an internal diameter of 2 mm, external diameter of 5 mm, and height of 2 mm, which underwent PO and DC. Finite element analysis (FEA) was carried out on 3D models. When analyzing PO results through linear regression, the highest values of bond strength were observed using glycolic acid on wet dentin in the cervical and middle thirds of the teeth. Analyzing DC results, the only statistical influence on values was the dental thirds. The scatterplot of the DC results and the PO bond strength values indicated no relationship between the results of the two tests (r = 0.03; p = 0.64). PO test detected more sensitive changes in bond strength values than DC., (© 2024 Scandinavian Division of the International Association for Dental Research. Published by John Wiley & Sons Ltd.)

The global market for alpha-hydroxy acids (AHAs) is undergoing significant expansion, propelled by increasing demand for skincare products that address aging and environmental damage. This review focuses on the dermatological applications of AHAs, particularly in cosmetic formulations like chemical peels. We have identified that AHAs, such as glycolic and lactic acids, enhance skin rejuvenation by promoting apoptosis in skin cells, boosting collagen and elastin synthesis, and improving skin texture and luminosity. Our comprehensive analysis reveals a nuanced understanding of AHAs' effectiveness across various skin types and conditions, demonstrating their broad utility in treating conditions like acne, hyperpigmentation, and photoaging. However, the optimal concentrations for therapeutic efficacy with minimal side effects are yet to be precisely defined, necessitating further research. Regulatory compliance is underscored as essential for the safe application of AHAs in cosmetics, with international guidelines recommending specific concentrations and pH levels to minimize potential skin irritation. In Conclusion, the review highlights the effectiveness of AHAs in cosmetic dermatology, emphasizing the necessity for continued research and rigorous regulatory adherence to maximize their safe and beneficial application worldwide., Competing Interests: The author declares no competing interests in this work., (© 2024 Almeman.)

Objectives: Acne scars often become challenging to treat with satisfactory results. The chemical reconstruction of skin scars (CROSS) technique has been used with high concentrations of trichloroacetic acid (TCA) which often produces unacceptable side effects. There is a dearth of data, with 50% glycolic acid (GA) for the same indication in the management of acne scars in the Indian population. This study aimed to assess the clinical response of acne scars after the application of 50% GA with that after the use of 65% TCA in a similar manner., Material and Methods: An institution-based prospective comparative study was performed with patients aged 16-45 years of either sex with acne scars and not been treated within the past 1 year. Subjects were assigned to receive one of the formulations (50% GA [Group A] and 65% TCA [Group B]). Grading of scars was done on day 1 and day 35 based on patients' assessment on a four-point visual scale and physicians' assessment by the Goodman-Baron qualitative global acne scar grading scale. The procedure was repeated every fortnightly for three such. Data were analyzed by Statistica version 6 (Tulsa, Oklahoma: StatSoft Inc. 2001)., Results: The visual improvement scale of patients showed 41.38% ( n = 12) fair improvement in group A, whereas 58.06% ( n = 18) showed good improvement in group B. Grading by the Goodman-Baron scale showed 9.68% ( n = 3) showed four grade changes in group B., Conclusion: Improvement is best observed with 65% TCA. Adverse effects were noted more with 65% TCA, especially acneiform eruption which was lacking in the previous studies. GA can be a safer alternative to TCA with acceptable results. Our study opens the scientific window for future research on different concentrations of GA as a CROSS agent., Competing Interests: There are no conflicts of interest., (© 2024 Published by Scientific Scholar on behalf of Journal of Cutaneous and Aesthetic Surgery.)

Objectives: Medium-depth peels are dynamic tools when used as part of office procedures for the treatment of acne scars. Most of the available literature on chemical peels focuses on their role in skin rejuvenation and hyperpigmentation. There is a paucity of well-conducted studies that have compared peels in the treatment of acne scars in Asian patients., Material and Methods: The study aimed to compare the efficacy of 70% glycolic acid (GA) and 30% trichloroacetic acid (TCA) chemical peels in the treatment of facial atrophic acne scars. A longitudinal, right-left study was conducted to assess the effectiveness and side effects of 70% GA and 30% TCA in 30 patients with acne scars. A total of four peeling sessions were performed every 4 weeks. Evaluation of the response was done using Goodman and Baron's quantitative global acne scarring grading system (GBASG), physician visual analog scale (VAS), and patient VAS at baseline and 4, 8, 12, and 16 weeks. Relevant statistical tests were employed to study the effectiveness of both TCA and GA peels., Results: Significant reduction was noted in mean GBASG scores on both sides at 8, 12, and 16 compared to baseline score ( P = 0.000). Mean GBASG scores decreased from 12.67 ± 3.19 to 8.97 ± 2.73 on the 70% GA side while that on the 30% TCA side reduced from 13.20 ± 3.56 to 6.83 ± 2.60 ( P = 0.003). The results were much better on the TCA peel side as compared to GA peel as per physician VAS ( P = 0.000) and patient VAS ( P = 0.000). Side effects such as post-inflammatory hyperpigmentation and acne were seen on both sides while dryness and crusting were more common on the TCA peel side., Conclusion: A 30% TCA peel is efficacious and well-tolerated for mild-to-moderate acne scars. About 70% GA peel is an effective alternative to TCA peel, especially for patients not tolerating TCA or requiring lesser downtime., Competing Interests: There are no conflicts of interest., (© 2024 Published by Scientific Scholar on behalf of Journal of Cutaneous and Aesthetic Surgery.)

This study aims to investigate glycolic acid (GA) as a final irrigant on push-out bond strength of fiber post and smear removal. Ninety mandibular premolars were stabilized with a silicone key and photographed, and canal cross-section was calculated by image processing software. Round canal morphology was selected. The specimens were divided into five groups (n = 18); 10%GA, 17%EDTA, NaOCl + 10%GA, NaOCl + 17%EDTA, and the control. Fifteen specimens were used for the push-out. Three specimens were evaluated using a scanning electron microscope after post space preparation. Two-way ANOVA and Chi-square were used for statistics. GA presented higher strength than EDTA (p < 0.05). The NaOCl + GA showed higher strength than the NaOCl + EDTA (p < 0.05). The highest values were observed in cervical and lowest in apical thirds (p < 0.05). The most failure type was between dentin and resin (p < 0.05). GA removed the smear in the post space including the apical third. The NaOCl + GA has superiority to NaOCl + EDTA on push-out strength. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA. Glycolic acid improved the bond strength of fiber post when used as a final post space irrigant. The combination of NaOCl and glycolic acid did not negatively affect the bond strength and was more effective compared to the combination with EDTA., (© 2024. The Author(s), under exclusive licence to The Society of The Nippon Dental University.)

Background: Acanthosis nigricans is a non-inflammatory skin pigmentary disorder characterized by a dark, velvety appearance, primarily observed in the neck and axillary areas. It is commonly associated with obesity, diabetes, and insulin resistance. Although the primary treatment is correcting the underlying disorders, many aesthetic modalities have been established to improve appearance owing to cosmetic concerns., Aims: We aimed to compare and investigate the effectiveness and side effects of tretinoin 0.05% and glycolic acid 70% in treating acanthosis nigricans lesions of the axillary and neck area., Methods: This single-blinded, randomized trial recruited patients with neck or axillary involvement. Each patient was randomized to use cream tretinoin 0.05% every other night on one side, while the other side was treated with glycolic acid 70%, which was applied every 2 weeks at the clinic for four consecutive sessions. The study duration was 8 weeks, and patients were evaluated every 2 weeks based on their response to treatment, satisfaction, and side effects., Results: Thirty patients, including 14 with neck lesions and 16 with axillary lesions, were included. Tretinoin was significantly more effective for axillary lesions in terms of treatment response and patient satisfaction (p = 0.02 and p = 0.008, respectively). It was also shown that as the severity of the lesions increased, the response to treatment and patient satisfaction decreased, specifically when treating axillary lesions with glycolic acid (p = 0.02 and p = 0.03, respectively)., Conclusion: Neither method was significantly effective for neck lesions. However, tretinoin 0.05% was shown to be more efficacious in treating axillary lesions of acanthosis nigricans, despite causing minimal side effects., (© 2024 The Authors. Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.)

Recently, there has been a notable surge in interest regarding reclaiming valuable chemicals from waste plastics. However, the energy-intensive conventional thermal catalysis does not align with the concept of sustainable development. Herein, we report a sustainable electrocatalytic approach allowing the selective synthesis of glycolic acid (GA) from waste polyethylene terephthalate (PET) over a Pd 67 Ag 33 alloy catalyst under ambient conditions. Notably, Pd 67 Ag 33 delivers a high mass activity of 9.7 A mg Pd -1 for ethylene glycol oxidation reaction (EGOR) and GA Faradaic efficiency of 92.7 %, representing the most active catalyst for selective GA synthesis. In situ experiments and computational simulations uncover that ligand effect induced by Ag incorporation enhances the GA selectivity by facilitating carbonyl intermediates desorption, while the lattice mismatch-triggered tensile strain optimizes the adsorption of *OH species to boost reaction kinetics. This work unveils the synergistic of strain and ligand effect in alloy catalyst and provides guidance for the design of future catalysts for PET upcycling. We further investigate the versatility of Pd 67 Ag 33 catalyst on CO 2 reduction reaction (CO 2 RR) and assemble EGOR//CO 2 RR integrated electrolyzer, presenting a pioneering demonstration for reforming waste carbon resource (i.e., PET and CO 2 ) into high-value chemicals., Competing Interests: Competing interests statement:The authors declare no competing interest.

In order to evaluate the role of the placenta in the etiology of ethylene glycol (EG) developmental toxicity, the distribution of EG and its main metabolites, glycolic acid (GA) and oxalic acid (OX), into the conceptus was determined at the beginning and completion of placentation in the rat and rabbit. Two groups (n = 28) of timed-pregnant Wistar rats were administered EG (1000 mg/kg bw/day, oral gavage) from gestation day (GD) 6 to either GD 11 or GD 16; similarly, two groups (n = 28) of timed-pregnant New Zealand White rabbits were administered EG from GD 6 to either GD 10 or GD 19. Four animals from each group were sacrificed at 1, 3, 6, 9, 12, 18, or 24 h after the final administration, and maternal blood, extraembryonic fluid, and embryonic tissue were removed for analysis of EG, GA, and OX. The three analytes were predominantly cleared from all compartments in both species within 24 h. Neither EG nor OX preferentially accumulated into the conceptus compartments, compared with the maternal blood, in either species. Critically, GA was preferentially accumulated from the maternal blood only into the rat embryo at GD 11, but not at GD 16 and not into the rabbit embryo at either GD 10 or GD 19. The accumulation of GA into the rat embryo, and its decline over the course of placentation, is discussed in relation to the expression of monocarboxylate transporter isoforms across the syncytiotrophoblast., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The physiology of different Escherichia coli stains was analyzed for growth with glycolate as a potentially promising sustainable sole source of carbon and energy. Different E. coli strains showed large differences regarding lag phases after provision of glycolate. Whereas E. coli W showed fast adaptation, E. coli BW25113, JM101, and BL21 (DE3) needed extensive time for adaption (up to 30 generations) until the attainable µ max was reached, which, at 30 °C, amounted to 0.20-0.25 h -1 for all strains. The overexpression of genes encoding glycolate degradation did neither overcome the need for adaptation of E. coli BL21 (DE3) nor improve growth of E. coli W. Rather, high level expression of proteins involved in uptake and initial degradation steps had an adverse effect on growth. Overall, the results show a promising capacity of E. coli strains for growth on glycolate., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Plastics have become an indispensable material in many fields of human activities, with production increasing every year; however, most of the plastic waste is still incinerated or landfilled, and only 10% of the new plastic is recycled even once. Among all plastics, polyethylene terephthalate (PET) is the most produced polyester worldwide; ethylene glycol (EG) is one of the two monomers released by the biorecycling of PET. While most research focuses on bacterial EG metabolism, this work reports the ability of Saccharomyces cerevisiae and nine other common laboratory yeast species not only to consume EG, but also to produce glycolic acid (GA) as the main by-product. A two-step bioconversion of EG to GA by S. cerevisiae was optimized by a design of experiment approach, obtaining 4.51 ± 0.12 g l-1 of GA with a conversion of 94.25 ± 1.74% from 6.21 ± 0.04 g l-1 EG. To improve the titer, screening of yeast biodiversity identified Scheffersomyces stipitis as the best GA producer, obtaining 23.79 ± 1.19 g l-1 of GA (yield 76.68%) in bioreactor fermentation, with a single-step bioprocess. Our findings contribute in laying the ground for EG upcycling strategies with yeasts., (© The Author(s) 2024. Published by Oxford University Press on behalf of FEMS.)

Superficial chemical peels are one of the most popular skin resurfacing procedures in a dermatologists' clinic today due to quick application process, fast recovery, good patient acceptance, and excellent cosmetic results. The role of various peeling agents like glycolic acid, salicylic acid, trichloroacetic acid, Jessner's solution, retinoic acid, and lactic acid in the management of melasma has been established as that of an additional or maintenance therapy. This article details the current evidence and recommendations for the use of chemical peels in the treatment of melasma, a chronic and recurrent hyperpigmentary disorder., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Nonsurgical periodontal therapy results in the formation of a smear layer which inhibits tissue regeneration. Root biomodification (RB) using various agents has been tried for the enhancement of new attachment formation. However, no substantial therapeutic advantages of currently available root conditioning agents have been reported emphasizing the need for additional biologically acceptable agents. Glycolic acid (GA) due to its antimicrobial nature and ability of initiation and proliferation of fibroblasts may potentially modify root surface enabling regeneration., Materials and Methods: Eighty specimens from 40 single-rooted teeth were treated with 17% ethylenediaminetetraacetic acid (EDTA) and 5% GA and scanning electron microscopy analysis was done. The micrographs were examined for the evaluation of smear layer removal, total number of dentinal tubules, total number of patent dentinal tubules, mean diameter and surface area of dentinal tubules, and dentin erosion. Statistical analysis was done using unpaired t -test for intergroup comparison., Results: The efficacy of smear layer removal ( P = 0.01) and dentin erosion ( P = 0.042) was significantly better in the GA group. Both the groups showed no difference in dentinal tubule-related parameters., Conclusion: GA showed improved RB with greater smear layer removal and lesser dentin erosion, indicating its use as a potent alternative to the conventional EDTA root conditioning., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Indian Society of Periodontology.)

Upgrading overall water splitting (OWS) system and developing high-performance electrocatalysts is an attractive way to the improve efficiency and reduce the consumption of hydrogen (H 2 ) production from electrolyzed water. Here, a Pt cluster/Ir metallene heterojunction structure (Pt/Ir hetero-metallene) with a unique Pt/Ir interface is reported for the conversion of ethylene glycol (EG) to glycolic acid (GA) coupled with H 2 production. With the assistance of ethylene glycol oxidation (EGOR), the Pt/Ir||Pt/Ir hetero-metallene two-electrode water electrolysis system exhibits a lower cell voltage of 0.36 V at 10 mA cm -2 . Furthermore, the Faradaic efficiency of EG to GA is as high as 87%. The excellent performance of this new heterostructure arise from the charge redistribution and strain effects induced by Pt-Ir interactions between the heterogeneous interfaces, as well as the larger specific surface area and more active sites due to the metallene structure., (© 2023 Wiley-VCH GmbH.)

To solve the low thermal stability of polyolefin membranes, our group developed porous polymers using cellulose acetate (CA) material. The formation of pores in CA involved creating plasticized regions within the CA membrane using additives. By applying gas pressure to these regions, a CA/glycolic acid membrane could be prepared with a small average pore size and high porosity. According to the porosimeter measurement, the average pore size of the membrane was 150 nm, and the porosity was 77%. SEM observations of the surface and cross-section of the CA/glycolic acid membrane confirmed the abundant distribution of fine pores. Furthermore, IR analysis revealed the removal of glycolic acid from the membrane after pore formation, indicating its interaction with CA during the process of gas permeation. Additionally, TGA analysis demonstrated a decrease in thermal stability due to the formation of numerous pores after gas permeation., Competing Interests: Declaration of competing interest There are no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Mesenchymal stem cells (MSCs) have a high tropism for the hypoxic microenvironment of tumors. The combination of nanoparticles in MSCs decreases tumor growth in vitro as well as in rodent models of cancers in vivo. Covalent conjugation of nanoparticles with the surface of MSCs can significantly increase the drug load delivery in tumor sites. Nanoparticle-based anti-angiogenic systems (gold, silica and silicates, diamond, silver, and copper) prevented tumor growth in vitro. For example, glycolic acid polyconjugates enhance nanoparticle drug delivery and have been reported in human MSCs. Labeling with fluorescent particles (coumarin-6 dye) identified tumor cells using fluorescence emission in tissues; the conjugation of different types of nanoparticles in MSCs ensured success and feasibility by tracking the migration and its intratumor detection using non-invasive imaging techniques. However, the biosafety and efficacy; long-term stability of nanoparticles, and the capacity for drug release must be improved for clinical implementation. In fact, MSCs are vehicles for drug delivery with nanoparticles and also show low toxicity but inefficient accumulation in tumor sites by clearance of reticuloendothelial organs. To solve these problems, the internalization or conjugation of drug-loaded nanoparticles should be improved in MSCs. Finally, CXCR4 may prove to be a promising target for immunotherapy and cancer treatment since the delivery of siRNA to knock down this alpha chemokine receptor or CXCR4 antagonism has been shown to disrupt tumor-stromal interactions.

For the first time, anisotropic hydrogel material with a highly oriented structure was obtained by the chemical reaction of polymer-analogous transformation of chitosan glycolate-chitosan base using triethanolamine (TEA) as a neutralizing reagent. Tangential bands or concentric rings, depending on the reaction conditions, represent the structural anisotropy of the hydrogel. The formation kinetics and the ratio of the positions of these periodic structures are described by the Liesegang regularities. Detailed information about the bands is given (formation time, coordinate, width, height, and formation rate). The supramolecular ordering anisotropy of the resulting material was evaluated both by the number of Liesegang bands (up to 16) and by the average values of the TEA diffusion coefficient ((15-153) × 10 -10 and (4-33) × 10 -10 m 2 /s), corresponding to the initial and final phase of the experiment, respectively. The minimum chitosan concentration required to form a spatial gel network and, accordingly, a layered anisotropic structure was estimated as 1.5 g/dL. Morphological features of the structural anisotropic ordering of chitosan Liesegang structures are visualized by scanning electron microscopy. The hemocompatibility of the material obtained was tested, and its high sorption-desorption properties were evaluated using the example of loading-release of cholecalciferol (loading degree ~35-45%, 100% desorption within 25-28 h), which was observed for a hydrophobic substance inside a chitosan-based material for the first time.

Objectives: To develop dual-functional etchants that could demineralize and stabilize dentin collagen simultaneously, and to assess the effects of these etchants on collagen crosslinking, biostability and resin bonding properties under clinically relevant conditions., Methods: Dual-functional etchants were prepared by mixing 56% glycolic acid and 17% phosphoric acid and adding 1% of theaflavins (TF) or proanthocyanidins from grape seed extract (GSE). The etchant without crosslinker was used as control. The prepared human dentin specimens were treated with the 3 etchants for 30 s and analyzed for chemical interaction using Fourier transform infrared spectroscopy and resistance of the demineralized layer to collagenase degradation using electron microscopy (EM). Resin-dentin interfacial bonding properties were evaluated after 24 h and after 10,000 thermocycling through microtensile bond strength (μTBS), nanoleakage and matrix metalloproteinases (MMPs) activity via in situ zymography. Statistical analysis was done using ANOVA and post- hoc Tuckey's test., Results: Compared to control, TF and GSE dual-functional etchants were able to demineralize dentin, induce collagen crosslinking and protect the demineralized layer from collagenase degradation within 30 s. High resolution EM images showed better protection with TF etchant compared to GSE. There was a significant reduction in μTBS and an increase in nanoleakage and MMPs activity in control after thermocycling (p < 0.05) while these changes weren't seen in dual-functional etchants., Significance: Dual-functional etchants, especially TF containing, provide collagen protection against degradation and result in stable μTBS and less nanoleakage and MMPs activity under clinically relevant conditions., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Melasma is a complex skin disorder characterized by brown or dark patches, primarily affecting facial areas. Despite numerous treatment options, the effective management of melasma remains challenging. This study aims to fill a gap in the literature by rigorously comparing the effectiveness of three prevalent chemical peeling agents, 15% trichloroacetic acid (TCA), 15% phenol, and 2% glycolic acid, in treating melasma., Materials and Methods: A randomized controlled trial was conducted involving patients who were clinically diagnosed with melasma. Participants were divided into three groups, each receiving one of the chemical peeling treatments. The primary measure of efficacy was the Melasma Area and Severity Index (MASI) score, recorded before and after the treatment series. Side effects were also documented and analyzed., Results: Preliminary findings suggest a significant reduction in MASI scores in the group treated with 15% TCA peel. The average MASI score reduction was 8.5 points for the TCA group, 6.0 points for the phenol group, and 5.2 points for the glycolic acid group. Side effects such as redness and mild irritation were noted but were least prevalent in the TCA group., Conclusion: Our study indicates that 15% TCA peel is not only effective but also comparatively safer in treating melasma. It shows a more rapid and significant improvement in reducing melasma symptoms than 15% phenol and 2% glycolic acid peels. However, further research is warranted to validate these findings over a larger population., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Prasad et al.)

Introduction: Bone defects are often observed after surgery for fractures and bone tumors. Their treatment is technically difficult and sometimes results in negative clinical and economic outcomes. To repair bone defects, a bone graft is implanted by selecting a transplant material from an autologous or artificial bone. Each method has its advantages and disadvantages. Compared to the gold standard of autologous bone graft, bone graft substitutes are not limited by the amount of harvested graft and avoid complications at the donor site. ORB-03 is a new cotton-like bone graft substitute composed of beta-tricalcium phosphate (β-TCP) and a bioabsorbable polymer, polylactic-co-glycolic acid (PLGA). ORB-03 is easy to mold and can fill various bone defect shapes, and its three-dimensional microfiber scaffold can enhance the differentiation of osteoblasts and promote osteogenesis. We investigated the efficacy, ease of handling, and safety of ORB-03 as a bone graft substitute. A multicenter, open-label, single-group study was conducted at six institutions., Methods: Between July 2018 and August 2019, 60 patients with bone defects caused by fracture, benign tumors, or an iliac donor site from bone harvesting were enrolled in this study; 54 patients were finally included for the safety analysis and 48 patients for the image analysis. During surgery, ORB-03 was mixed with the patient's blood and molded into a bone defect. To evaluate the efficacy of ORB-03, radiography and computed tomography (CT) were performed at intervals until 24 weeks after surgery., Results: The effective rate and its accurate bilateral 95% confidence interval (CI) were calculated based on the efficacy criteria at 24 weeks postoperatively. The ease with which ORB-03 could be handled in surgery was evaluated. Adverse events that occurred after surgery were evaluated, and those associated with ORB-03 were examined. Bone fusion was good in all cases, and the radiography and CT effective rates were 100.0% and 91.5%, respectively. Handling was easy in all cases. There were four adverse events, none of which were clinically problematic., Conclusions: ORB-03 was found to be easy to handle, safe, and effective as a bone graft substitute for bone defects., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Tokeshi et al.)

Breast cancer patients are characterized by the oncobiotic transformation of multiple microbiome communities, including the gut microbiome. Oncobiotic transformation of the gut microbiome impairs the production of antineoplastic bacterial metabolites. The goal of this study was to identify bacterial metabolites with antineoplastic properties. We constructed a 30-member bacterial metabolite library and screened the library compounds for effects on cell proliferation and epithelial-mesenchymal transition. The metabolites were applied to 4T1 murine breast cancer cells in concentrations corresponding to the reference serum concentrations. However, yric acid, glycolic acid, d-mannitol, 2,3-butanediol, and trans-ferulic acid exerted cytostatic effects, and 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, and vanillic acid exerted hyperproliferative effects. Furthermore, 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 2,3-butanediol, and hydrocinnamic acid inhibited epithelial-to-mesenchymal (EMT) transition. We identified redox sets among the metabolites (d-mannitol-d-mannose, 1-butanol-butyric acid, ethylene glycol-glycolic acid-oxalic acid), wherein only one partner within the set (d-mannitol, butyric acid, glycolic acid) possessed bioactivity in our system, suggesting that changes to the local redox potential may affect the bacterial secretome. Of the nine bioactive metabolites, 2,3-butanediol was the only compound with both cytostatic and anti-EMT properties.

Introduction: Superficial nail plate abnormalities are a potential consequence of harsh cosmetic manicures and also manifest as a symptom of nail diseases such as nail lichen planus, nail psoriasis, and onychomycosis. Chemical peels for the nails may provide a solution to improve nail appearance. We reviewed articles that assessed the efficacy of using chemical peels for the nails., Methods: Searches on PubMed were performed to identify studies that discussed the use of chemical peels on the nail published up to July 2022., Results: A total of 4 studies with a total of 96 patients were found involving the use of chemical peels for the nail. It was found that there was marked improvement in aesthetic appearance for nail surface abnormalities induced by cosmetics., Discussion/conclusion: Studies with larger sample sizes that compare the efficacy of doses, treatment length, and a standardized method to assess results are needed to determine best treatment protocol. Chemical peels for the nails may provide fast improvement of the appearance of the nail and be utilized as a supportive treatment in association with specific treatment., Competing Interests: Wilhelmina Lam has nothing to disclose. Dr. Antonella Tosti’s disclosures: consultant – DS Laboratories, MONAT Global, Almirall, Thirty Madison, Eli Lilly, P&G, Pfizer, Myovant, Bristol Myers Squibb, Ortho Dermatologics, and Curallux, LLC; PI – Eli Lilly, Concert, and Erchonia., (© 2023 S. Karger AG, Basel.)

The objectives of this study were to compare the effects of various acid solutions combined with ultrasonics as an aid to remove mineral trioxide aggregate (MTA)-based root canal filling and to assess their effect on the surface topography and microhardness of root canal dentin., Materials and Method: Fifty human permanent single rooted and single canaled freshly extracted teeth were decoronated and sectioned apically to prepare the middle third of root sections of 5 mm length. The canals were prepared in a step-back manner. OrthoMTA was packed throughout the prepared canals. These root sections were incubated for one week and subsequently randomly allocated to five groups (n = 10) according to the OrthoMTA removal method: No treatment (NT); 5% glycolic acid + ultrasonics (5% GA+U); 10% glycolic acid + ultrasonics (10% GA+U); 10% citric acid + ultrasonics (10% CA+U); Distilled water + ultrasonics (DW+U). A 1 mm deep well was created within the coronal end of the set OrthoMTA. Wells were filled with each respective test solution and left for 5 min. Thereafter, further removal of OrthoMTA used a specific ultrasonic tip. Finally, the canals were flushed using 1 mL of the respective test solutions and activated with a Controlled Memory ultrasonic tip for two cycles of 20 s each followed by flushing with 1 mL of distilled water and paper point drying of the canals. Then, specimens were longitudinally split into two halves and examined under a scanning electron microscope (1000×) to assess the residual OrthoMTA and surface topography of root canal dentin. The Vickers surface microhardness of treated radicular dentin was measured using the HMV-2 microhardness tester., Result: Data were analysed using one-way ANOVA followed by Tukey's post hoc test. Significant differences for residual OrthoMTA were observed between (10% GA+U) with (5% GA+U), (10% CA+U), (DW+U) and (NT) ( p value < 0.01). In the context of microhardness, (5% GA+U) and (10% GA+U) showed statistically significant difference compared to (NT), (10% CA+U) and (DW+U) ( p value < 0.01)., Conclusion: 10% GA+U was superior to other tested groups in removing OrthoMTA, but it substantially reduced dentin microhardness.

Biological recycling of PET waste has been extensively investigated recently to tackle plastic waste pollution, and ethylene glycol (EG) is one of the main building blocks recovered from this process. Wild-type Yarrowia lipolytica IMUFRJ 50682 can be a biocatalyst to biodepolymerize PET. Herein, we report its ability to perform oxidative biotransformation of EG into glycolic acid (GA): a higher value-added chemical with varied industrial applications. We found that this yeast tolerates high EG concentrations (up to 2 M) based on maximum non-inhibitory concentration (MNIC) tests. Whole-cell biotransformation assays using resting yeast cells showed GA production uncoupled to cell growth metabolism, and 13 C nuclear magnetic resonance (NMR) analysis confirmed GA production. Moreover, higher agitation speed (450 vs. 350 rpm) resulted in a 1.12-fold GA production improvement (from 352 to 429.5 mM) during Y. lipolytica cultivation in bioreactors after 72 h. GA was constantly accumulated in the medium, suggesting that this yeast may also share an incomplete oxidation pathway (i.e., it is not metabolized to carbon dioxide) as seen in acetic acid bacterial group. Additional assays using higher chain-length diols (1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol) revealed that C4 and C6 diols were more cytotoxic, suggesting that they underwent different pathways in the cells. We found that this yeast consumed extensively all these diols, however, 13 C NMR analysis from supernatant identified solely the presence of 4-hydroxybutanoic acid from 1,4-butanediol, along with GA from EG oxidation. Findings reported herein reveal a potential route for PET upcycling to a higher value-added product., (© 2023 Wiley-VCH GmbH.)

The failure of current sanitation practices requires the development of effective solutions for microbial control. Although combinations using antibiotics have been extensively studied to look for additive/synergistic effects, biocide combinations are still underexplored. This study aims to evaluate the antimicrobial effectiveness of dual biocide and triple biocide/phytochemical combinations, where phytochemicals are used as quorum sensing (QS) inhibitors. The biocides selected were benzalkonium chloride (BAC) and peracetic acid (PAA) - as commonly used biocides, and glycolic acid (GA) and glyoxal (GO) - as alternative and sustainable biocides. Curcumin (CUR) and 10-undecenoic acid (UA) were the phytochemicals selected, based on their QS inhibition properties. A checkerboard assay was used for the screening of chemical interactions based on the cell growth inhibitory effects against Bacilluscereus and Pseudomonasfluorescens. It was observed that dual biocide combinations resulted in indifference, except the PAA + GA combination, which had a potential additive effect. PAA + GA + CUR and PAA + GA + UA combinations also triggered additive effects. The antimicrobial effects of the combinations were further evaluated on the inactivation of planktonic and biofilm cells after 30 min of exposure. These experiments corroborated the checkerboard results, in which PAA + GA was the most effective combination against planktonic cells (additive/synergistic effects). The antimicrobial effects of triple combinations were species- and biocide-specific. While CUR only potentiate the antimicrobial activity of GA against B.cereus, GA + UA and PAA + GA + UA combinations promoted additional antimicrobial effects against both bacteria. Biofilms were found to be highly tolerant, with modest antimicrobial effects being observed for all the combinations tested. However, this study demonstrated that low doses of biocides can be effective in bacterial control when combining biocides with a QS inhibitor, in particular, the combination of the phytochemical UA (as a QS inhibitor) with GA and PAA., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Engineered microbial cells can produce sustainable chemistry, but the production competes for resources with growth. Inducible synthetic control over the resource use would enable fast accumulation of sufficient biomass and then divert the resources to production. We developed inducible synthetic resource-use control over Saccharomyces cerevisiae by expressing a bacterial ClpXP proteasome from an inducible promoter. By individually targeting growth-essential metabolic enzymes Aro1, Hom3, and Acc1 to the ClpXP proteasome, cell growth could be efficiently repressed during cultivation. The ClpXP proteasome was specific to the target proteins, and there was no reduction in the targets when ClpXP was not induced. The inducible growth repression improved product yields from glucose (cis,cis-muconic acid) and per biomass (cis,cis-muconic acid and glycolic acid). The inducible ClpXP proteasome tackles uncertainties in strain optimization by enabling model-guided repression of competing, growth-essential, and metabolic enzymes. Most importantly, it allows improving production without compromising biomass accumulation when uninduced; therefore, it is expected to mitigate strain stability and low productivity challenges.

Objectives: The aim of this study was to evaluate the effectiveness of ultrasonic activation (US) over glycolic acid on microhardness, cohesive strength, flexural strength, and fracture resistance of root dentin, comparing with conventional final irrigation protocols., Methods: Samples were obtained from 140 extracted bovine teeth and distributed into four test groups: microhardness (50 teeth), cohesive strength (15 teeth), flexural strength (15 teeth), and fracture resistance (60 teeth). In all four tests, specimens were subdivided into five groups, according to final irrigation protocols: G1: distilled water (DW); G2: 17% ethylenediaminetetraacetic acid (EDTA); G3: 17% glycolic acid (GA); G4: 17% EDTA + US; and G5: 17% GA + US. The duration time of each protocol was set in 1 min. After irrigation protocols, the Vickers tester was used to evaluate microhardness and the universal testing machine was used to evaluate the cohesive strength, flexural strength, and fracture resistance of the root dentin. One-way ANOVA test and the Tukey HSD were used for multiple comparison tests in all evaluations (α = 5%)., Results: In general, groups 2 (EDTA), 4 (EDTA + US), and 5 (GA + US) promoted the highest reduction of microhardness, being statistically different from other groups (p < 0.05). Cohesive strength, flexural strength, and fracture resistance data revealed that no differences between groups were observed (p > 0.05)., Conclusions: The association of GA and US results in microhardness reduction, with no influence on cohesive strength, flexural strength, and fracture resistance of the root dentin., Clinical Relevance: The use of US over GA has no influence on some mechanical properties of root dentin., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Glyoxylic acid (GA) is widely used as a straight perming agent for hair care products, however, advanced GA penetration-enhancing agents are desired due to the peculiar odour and hair colour fading caused by the continuous use of GA products. Hence, it is important to develop a penetration-enhancing agent that helps minimize the GA concentration. We have found that the combined use of GA and glycolic acid (GCA) has a strong hair straightening effect., Methods: Straightening hair test was carried out to the evaluation of the effect of additives. Liquid chromatography-mass spectrometry (LC/MS) was performed to quantify the GA penetration amount into human hair. Attenuated total reflection (ATR) Fourier transform-infrared spectroscopy (FT-IR) and FT-IR microscope were implemented to estimate the localization of GA in the hair., Results: Straightening hair tests indicated that the hair straightening effect by GA was enhanced by the presence of GCA. LC/MS results showed that the addition of GCA enhanced the amount of GA that penetrated human hair by about four times. ATR FT-IR and FT-IR microscope measurements indicated that GA was localized more in the innermost region of hair (medulla) than the cortex and cuticle. The GA accumulated in the medulla disappeared after a hair straightener treatment at 180°C due to the chemical reaction., Conclusions: The GA penetration-enhancing effect of GCA is worth investigating to reduce the GA concentration in products for more comfortable use., (© 2023 Society of Cosmetic Scientists and Societe Francaise de Cosmetologie.)

At present, the development and usage of degradable plastics instead of traditional plastics is an effective way to solve the pollution of marine microplastics. Poly (butylene adipate-co-terephthalate) (PBAT) is known as one of the most promising biodegradable materials. Nevertheless, the degradation rate of PBAT in water environment is slow. In this work, we successfully prepared four kinds of high molecular weight polyester copolyesters (PBATGA) via quaternary copolymerization. The results showed that the intrinsic viscosity of PBATGA copolymers ranged from 0.74 to 1.01 dL/g with a glycolic acid content of 0-40%. PBATGA copolymers had excellent flexibility and thermal stability. The tensile strength was 5~40 MPa, the elongation at break was greater than 460%, especially the elongation at break of PBATGA10 at 1235%, and the thermal decomposition temperature of PBATGA copolyesters was higher than 375 °C. It was found that PBATGA copolyester had a faster hydrolysis rate than PBAT, and the weight loss of PBATGA copolymers showed a tendency of pH = 12 > Lipase ≈ pH = 7 > pH = 2. The quaternary polymerization of PBAT will have the advantage of achieving industrialization, unlike the previous polymerization process. In addition, the polymerization of PBATGA copolyesters not only utilizes the by-products of the coal chemical industry, but also it can be promising in the production of biodegradable packaging to reduce marine plastic pollution.

Electrocatalytic hydrogenation (ECH) of oxalic acid (OX) to produce glycolic acid (GA), an important building block of biodegradable polymers as well as application in various branches of chemistry, has attracted extensive attention in the industry, while it still encounters challenges of low reaction rate and selectivity. Herein, we reported a cation adsorption strategy to realize the efficient ECH of OX to GA by adsorbing Al 3+ ions on an anatase titanium dioxide (TiO 2 ) nanosheet array, achieving 2-fold enhanced GA productivity (1.3 vs 0.65 mmol cm -2 h -1 ) with higher Faradaic efficiency (FE) (85 vs 69%) at -0.74 V vs RHE. We reveal that the Al 3+ adatoms on TiO 2 both act as electrophilic adsorption sites to enhance the carbonyl (C═O) adsorption of OX and glyoxylic acid (intermediate) and also promote the generation of reactive hydrogen (H*) on TiO 2 , thus promoting the reaction rate. This strategy is demonstrated effective for different carboxylic acids. Furthermore, we realized the coproduction of GA at the bipolar of a H-type cell by pairing ECH of OX (at cathode) and electrooxidation of ethylene glycol (at anode), demonstrating an economical manner with maximum electron economy.

We have previously reported that sequence-controlled copolyesters such as poly((ethylene diglycolate) terephthalate) (poly(GEGT)) showed higher melting temperatures than those of the corresponding random copolymers and high biodegradability in seawater. In this study, to elucidate the effect of the diol component on their properties, a series of new sequence-controlled copolyesters composed of glycolic acid, 1,4-butanediol or 1,3-propanediol, and dicarboxylic acid units was studied. 1,4-Butylene diglycolate (GBG) and 1,3-trimethylene diglycolate (GPG) were prepared by the reactions of 1,4-dibromobutane or 1,3-dibromopropane with potassium glycolate, respectively. Polycondensation of GBG or GPG with various dicarboxylic acid chlorides produced a series of copolyesters. Terephthalic acid, 2,5-furandicarboxylic acid, and adipic acid were used as the dicarboxylic acid units. Among the copolyesters bearing terephthalate or 2,5-furandicarboxylate units, the melting temperatures ( T m at 90 °C, while the corresponding random copolymer was reported to be amorphous. The glass-transition temperatures of the copolyesters decreased as the carbon number of the diol component increased. Poly(GBGF) was found to show higher biodegradability in seawater than that of poly(butylene 2,5-furandicarboxylate) (PBF). On the other hand, the hydrolysis of poly(GBGF) was suppressed in comparison with that of poly(glycolic acid). Thus, these sequence-controlled copolyesters have both improved biodegradability compared to PBF and lower hydrolyzability than PGA.T m at 90 °C, while the corresponding random copolymer was reported to be amorphous. The glass-transition temperatures of the copolyesters decreased as the carbon number of the diol component increased. Poly(GBGF) was found to show higher biodegradability in seawater than that of poly(butylene 2,5-furandicarboxylate) (PBF). On the other hand, the hydrolysis of poly(GBGF) was suppressed in comparison with that of poly(glycolic acid). Thus, these sequence-controlled copolyesters have both improved biodegradability compared to PBF and lower hydrolyzability than PGA.

Catalytic conversion of cellulose to liquid fuel and highly valuable platform chemicals remains a critical and challenging process. Here, bismuth-decorated β zeolite catalysts (Bi/β) were exploited for highly efficient hydrolysis and selective oxidation of cellulose to biomass-derived glycolic acid in an O 2 atmosphere, which exhibited an exceptionally catalytic activity and high selectivity as well as excellent reusability. It was interestingly found that as high as 75.6% yield of glycolic acid over 2.3 wt% Bi/β was achieved from cellulose at 180 °C for 16 h, which was superior to previously reported catalysts. Experimental results combined with characterization revealed that the synergetic effect between oxidation active sites from Bi species and surface acidity on H-β together with appropriate total surface acidity significantly facilitated the chemoselectivity towards the production of glycolic acid in the direct, one-pot conversion of cellulose. This study will shed light on rationally designing Bi-based heterogeneous catalysts for sustainably generating glycolic acid from renewable biomass resources in the future.

Objective: To evaluate the influence of photodynamic therapy (PDT), different final irrigants, and ultrasonic activation (US) on the bond strength of glass fiber posts (GFP) to root dentin., Methods: One hundred twenty bovine roots were divided into 12 groups according to PDT application, the type of final endodontic irrigant, and US. The samples were divided into 12 groups (n = 10): G1-DW(distilled water); G2-DW+US; G3-17% EDTA; G4-17% EDTA+US; G5-17% GA (glycolic acid); G6-17% GA+US; G7-PDT+DW; G8-PDT+DW+US; G9-PDT+17% EDTA; G10-PDT+17% EDTA+US; G11-PDT+17% GA; G12-PDT+17% GA+US. After cementing the glass fiber posts with resin cement, roots were sectioned into 2-mm-thick slices. One slice from the cervical third and another from the middle third were used for the push out test (PO), and the other two for the diametral compression test (DC). Thus, 10 samples were obtained per third for each mechanical test (n = 10). Kruskal-Wallis and Student-Newman-Keuls tests were used to analyze PO and DC data, and Pearson's correlation test was used to verify the relationship between the variables. Failure patterns were analyzed with chi-square test., Results: Significant differences were found in the PO test among the experimental groups (p < 0.001; power=1.00). PDT improved bond strength when using EDTA. PDT and US increased bond strength when using GA. Favorable failure patterns occurred more frequently in Group GA+US. There was no correlation between data obtained with PO and DC tests (r = 0.112; p = 0.729)., Conclusion: PDT provided the highest bond strength values of GFP to root dentin when associated with GA and US or when associated only with EDTA., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The main problem of manufacturing with traditional biodegradable plastics is that it is more expensive than manufacturing with polymers derived from petroleum, and the application scope is currently limited due to poor comprehensive performance. In this study, a novel biodegradable poly(butylene adipic acid/terephthalate-co-glycolic acid) (PBATGA) copolyester with 25-60% glycolic acid units was successfully synthesized by esterification and polycondensation using cheap coal chemical byproduct methyl glycolate instead of expensive glycolic acid. The structure of the copolyester was characterized by ATR-FTIR, 1 H NMR, DSC, and XRD; and its barrier property, water contact angle, heat resistance, and mechanical properties were tested. According to the experiment result, the PBATGA copolyesters showed improved oxygen (O 2 ) and water vapor barrier character, and better hydrophilicity when compared with PBAT. The crystallization peaks of PBATGAs were elevated from 64 °C to 77 °C when the content of the GA unit was 25 mol %, meanwhile, the elongation at the break of PBATGA25 was more than 1300%. These results indicate that PBATGA copolyesters have good potentiality in high O 2 and water vapor barrier and degradable packaging material.

Disseminated facial verruca plana is a chronic disorder that causes significant psychological distress. However, safe and effective treatment is lacking. This study aimed to explore the efficacy and safety of 35% glycolic acid (GA) for the treatment of disseminated facial verruca plana. A split-face clinical trial was conducted to explore the efficacy and safety of using chemical peeling with 35% GA for the treatment of disseminated facial verruca plana. One side of the face was applied with 35% GA once every fortnight for a total of three times. Adapalene gel was applied every night to the other side of the face as the control. The clearance rate of lesions was evaluated at different time points. Between June 2020 and December 2020, 30 patients with disseminated verruca plana who visited the Dermatology Hospital of Southern Medical University were enrolled. After three chemical peelings with 35% GA that was applied at 2-week intervals, 15 (50%) patients achieved >70% lesion reduction. The same effective rate in the adapalene gel-treated side of the face was documented in eight patients. Subgroup analysis showed a higher clearance rate in patients with a shorter disease duration. Moreover, concurrent improvements in facial roughness were observed in the 35% GA-treated group. Adverse effects including mild erythema and desquamation were observed during chemical peeling with 35% GA. In conclusion, chemical peeling with 35% GA could be a safe and effective option for treating disseminated facial verruca plana, especially for those who desire skin improvement., (© 2022 Wiley Periodicals LLC.)

Catalytic valorization of raw glycerol derived from biodiesel into high-value chemicals has attracted great attention. Here, we report chemoenzymatic cascade reactions that convert glycerol to lactic acid and glycolic acid. In the enzymatic step, a coenzyme recycling system was developed to convert glycerol into 1,3-dihydroxyacetone (DHA) with a yield of 92.3% in potassium phosphate buffer (300 mM, pH 7.1) containing 100 mM glycerol, 2 mM NAD + , 242 U/mL glycerol dehydrogenase-GldA and NADH oxidase-SpNox K184R at 30 °C. Subsequently, NaOH or NaClO 2 catalyzes the formation of lactic acid and glycolic acid from DHA. The high yield of lactic acid (72.3%) and glycolic acid (78.2%) verify the benefit of the chemoenzymatic approaches., (© 2022. The Author(s).)

Background/aim: Inhalation toxicity tests of glycolic acid, which is used in many household products, have been reported, but the pulmonary toxicity of glycolic-acid has not been confirmed. Here, the lung damage caused by glycolic acid was investigated in rats., Materials and Methods: An intratracheal instillation test was performed with glycolic acid in male rats. Bronchoalveolar lavage fluid (BALF) and histopathological analysis were conducted to identify the pulmonary toxicities., Results: Intratracheal instillation of glycolic acid caused weight loss in animals and increased the content of lactate dehydrogenase, total protein, polymorphonuclear neutrophils, and inflammatory cytokines in BALF. In addition, pulmonary edema, alveolar/interstitial inflammation, and necrosis and desquamation of bronchial/bronchiolar epithelia were confirmed via histopathological examination., Conclusion: Exposure to glycolic acid can be harmful and toxic to the lungs., (Copyright © 2022, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)