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Bioprocess and Biosystems Engineering Nov 2023Rape straw was used as the raw material for the biochar in this study, which was then changed using acid, alkali, and magnetic techniques. The laccase was attached using...
Rape straw was used as the raw material for the biochar in this study, which was then changed using acid, alkali, and magnetic techniques. The laccase was attached using the adsorptions-crosslinking process, and the three modified biochars served as the carriers. The ideal circumstances for laccase immobilization were explored, and both biochar and immobilized laccase's characteristics were examined. The removal of 2,4-dichlorophenol (2,4-DCP) by immobilized laccase from modified biochar and its degradation products were researched. The main conclusions are as follows: the optimal concentration of glutaraldehyde (GLU) was 4%, and the pH was four, and the enzyme dosage was 1.75 mg/mL for the immobilized laccase of acid-modified biochar (SBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 2 mg/mL for immobilized laccase from alkali-modified biochar (JBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 1.75 mg/mL for immobilized laccase from magnetically modified biochar (CBC@LAC). SEM images could show the changes in the surface morphology of biochar caused by three modification methods. The BET results demonstrated that acid and magnetic modification increased the specific surface area of biochar, and alkali modification mainly expanded the pore size of biochar. FT-IR and XRD showed that modification and laccase loading had little effect on the structure of biochar. The stability of immobilized laccase was better than that of free laccase in acid-base, heat, and storage. Among the three modified biochar immobilized laccases, JBC@LAC showed the best acid-base stability and thermal stability, and the relative enzyme activity changed the least when pH and temperature conditions changed. The storage stability of SBC@LAC is the best. After 30 days of storage, the relative enzyme activity is still 83%. The removal rates of 2,4-DCP were 57, 99, and 63%, respectively, by SBC@LAC, JBC@LAC, and CBC@LAC. After five reuses, the removal rates of 2,4-DCP by SBC@LAC, JBC@LAC and CBC@LAC were 26, 42, and 27%, respectively. The intermediate products of 2,4-DCP degradation by immobilized laccase were p-phenol, p-benzoquinone and maleic acid.
Topics: Laccase; Enzymes, Immobilized; Spectroscopy, Fourier Transform Infrared; Alkalies
PubMed: 37656258
DOI: 10.1007/s00449-023-02922-0 -
Military Medicine Jan 2024This was an in vivo animal study designed to investigate the interaction between dexamethasone (Dex) and microRNA-204 (miR-204) in a mouse alkali burn-induced corneal...
INTRODUCTION
This was an in vivo animal study designed to investigate the interaction between dexamethasone (Dex) and microRNA-204 (miR-204) in a mouse alkali burn-induced corneal neovascularization (CNV) model. The function of miR-204 was then investigated in human mammary epithelial cells (HMECs) in vitro.
MATERIALS AND METHODS
The CNV model was induced by corneal alkali burn in BLAB/c mice. The mice were randomly divided into five groups: normal control (Ctrl), alkali burn-induced corneal injury (Alkali), alkali burn + Dex (Dex), alkali burn + negative control (NTC), and alkali burn + miR-204 agomir (miR-204). Subconjunctival injection of NTC, Dex, or miR-204 agomir was conducted at 0, 3, and 6 days, respectively, after alkali burn. The corneas were collected at day 7 after injury, and the CNV area was observed using immunofluorescence staining. The expression of miR-204 was analyzed with quantitative real time (qRT)-PCR. In HMECs, exogenous miR-204 agomir or antagomir was used to strengthen or inhibit the expression of miR-204. Migration assays and tube formation studies were conducted to evaluate the function of miR-204 on HMECs.
RESULTS
At 7 days post-alkali burn, CNV grew aggressively into the cornea. MicroRNA-204 expression was reduced in the Alkali group in contrast with the Ctrl group (P = .003). However, miR-204 was upregulated in the Dex group (vs. alkali group, P = .008). The CNV areas in the NTC and miR-204 groups were 59.30 ± 8.32% and 25.60 ± 2.30%, respectively (P = .002). In vitro, miR-204 agomir showed obvious inhibition on HMEC migration in contrast with NTC (P = .033) and miR-204 antagomir (P = .017). Compared with NTC, miR-204 agomir attenuated tube formation, while miR-204 antagomir accelerated HMEC tube formation (P < .05).
CONCLUSION
The role of Dex in attenuating CNV may be partly attributed to miR-204. MiR-204 may be a potential therapeutic target in alkali burn-induced CNV.
Topics: Animals; Humans; Mice; Alkalies; Antagomirs; Burns, Chemical; Cornea; Corneal Injuries; Corneal Neovascularization; Dexamethasone; Disease Models, Animal; Eye Burns; MicroRNAs
PubMed: 36043264
DOI: 10.1093/milmed/usac260 -
Stem Cell Research & Therapy Feb 2024Corneal alkali burns can lead to ulceration, perforation, and even corneal blindness due to epithelial defects and extensive cell necrosis, resulting in poor healing...
BACKGROUND
Corneal alkali burns can lead to ulceration, perforation, and even corneal blindness due to epithelial defects and extensive cell necrosis, resulting in poor healing outcomes. Previous studies have found that chitosan-based in situ hydrogel loaded with limbal epithelium stem cells (LESCs) has a certain reparative effect on corneal alkali burns. However, the inconsistent pore sizes of the carriers and low cell loading rates have resulted in suboptimal repair outcomes. In this study, 4D bioprinting technology was used to prepare a chitosan-based thermosensitive gel carrier (4D-CTH) with uniform pore size and adjustable shape to improve the transfer capacity of LESCs.
METHODS
Prepare solutions of chitosan acetate, carboxymethyl chitosan, and β-glycerophosphate sodium at specific concentrations, and mix them in certain proportions to create a pore-size uniform scaffold using 4D bioprinting technology. Extract and culture rat LESCs (rLESCs) in vitro, perform immunofluorescence experiments to observe the positivity rate of deltaNp63 cells for cell identification. Conduct a series of experiments to validate the cell compatibility of 4D-CTH, including CCK-8 assay to assess cell toxicity, scratch assay to evaluate the effect of 4D-CTH on rLESCs migration, and Calcein-AM/PI cell staining experiment to examine the impact of 4D-CTH on rLESCs proliferation and morphology. Establish a severe alkali burn model in rat corneas, transplant rLESCs onto the injured cornea using 4D-CTH, periodically observe corneal opacity and neovascularization using a slit lamp, and evaluate epithelial healing by fluorescein sodium staining. Assess the therapeutic effect 4D-CTH-loaded rLESCs on corneal alkali burn through histological evaluation of corneal tissue paraffin sections stained with hematoxylin and eosin, as well as immunofluorescence staining of frozen sections.
RESULTS
Using the 4D-CTH, rLESCs were transferred to the alkali burn wounds of rats. Compared with the traditional treatment group (chitosan in situ hydrogel encapsulating rLESCs), the 4D-CTH-rLESC group had significantly higher repair efficiency of corneal injury, such as lower corneal opacity score (1.2 ± 0.4472 vs 0.4 ± 0.5477, p < 0.05) and neovascularization score (5.5 ± 1.118 vs 2.6 ± 0.9618, p < 0.01), and significantly higher corneal epithelial wound healing rate (72.09 ± 3.568% vs 86.60 ± 5.004%, p < 0.01).
CONCLUSION
In summary, the corneas of the 4D-CTH-rLESC treatment group were similar to the normal corneas and had a complete corneal structure. These findings suggested that LESCs encapsulated by 4D-CTH significantly accelerated corneal wound healing after alkali burn and can be considered as a rapid and effective method for treating epithelial defects.
Topics: Rats; Animals; Burns, Chemical; Chitosan; Alkalies; Wound Healing; Cornea; Corneal Injuries; Corneal Opacity; Stem Cells; Hydrogels
PubMed: 38355568
DOI: 10.1186/s13287-024-03653-z -
Environmental Research Jul 2023Hydrogen (H) is a possible energy transporter and feedstock for energy decarbonization, transportation, and chemical sectors while reducing global warming's... (Review)
Review
Hydrogen (H) is a possible energy transporter and feedstock for energy decarbonization, transportation, and chemical sectors while reducing global warming's consequences. The predominant commercial method for producing H today is steam methane reforming (SMR). However, there is still room for development in process intensification, energy optimization, and environmental concerns related to CO emissions. Reactors using metallic membranes (MRs) can handle both problems. Compared to traditional reactors, MRs operates at substantially lower pressures and temperatures. As a result, capital and operational costs may be significantly cheaper than traditional reactors. Furthermore, metallic membranes (MMs), particularly Pd and its alloys, naturally permit only H permeability, enabling the production of a stream with a purity of up to 99.999%. This review describes several methods for H production based on the energy sources utilized. SRM with CO capture and storage (CCUS), pyrolysis of methane, and water electrolysis are all investigated as process technologies. A debate based on a color code was also created to classify the purity of H generation. Although producing H using fossil fuels is presently the least expensive method, green H generation has the potential to become an affordable alternative in the future. From 2030 onward, green H is anticipated to be less costly than blue hydrogen. Green H is more expensive than fossil-based H since it uses more energy. Blue H has several tempting qualities, but the CCUS technology is pricey, and blue H contains carbon. At this time, almost 80-95% of CO can be stored and captured by the CCUS technology. Nanomaterials are becoming more significant in solving problems with H generation and storage. Sustainable nanoparticles, such as photocatalysts and bio-derived particles, have been emphasized for H synthesis. New directions in H synthesis and nanomaterials for H storage have also been discussed. Further, an overview of the H value chain is provided at the end, emphasizing the financial implications and outlook for 2050, i.e., carbon-free H and zero-emission H.
Topics: Carbon Dioxide; Hydrogen; Water; Steam; Methane
PubMed: 37105287
DOI: 10.1016/j.envres.2023.115963 -
Advanced Materials (Deerfield Beach,... Feb 2024Lysosomes are critical in modulating the progression and metastasis for various cancers. There is currently an unmet need for lysosomal alkalizers that can selectively...
Lysosomes are critical in modulating the progression and metastasis for various cancers. There is currently an unmet need for lysosomal alkalizers that can selectively and safely alter the pH and inhibit the function of cancer lysosomes. Here an effective, selective, and safe lysosomal alkalizer is reported that can inhibit autophagy and suppress tumors in mice. The lysosomal alkalizer consists of an iron oxide core that generates hydroxyl radicals (•OH) in the presence of excessive H and hydrogen peroxide inside cancer lysosomes and cerium oxide satellites that capture and convert •OH into hydroxide ions. Alkalized lysosomes, which display impaired enzyme activity and autophagy, lead to cancer cell apoptosis. It is shown that the alkalizer effectively inhibits both local and systemic tumor growth and metastasis in mice. This work demonstrates that the intrinsic properties of nanoparticles can be harnessed to build effective lysosomal alkalizers that are both selective and safe.
Topics: Mice; Animals; Neoplasms; Lysosomes; Nanoparticles; Apoptosis; Autophagy
PubMed: 37643367
DOI: 10.1002/adma.202305394 -
International Journal of Molecular... Nov 2023Ensuring food security for the global population is a ceaseless and critical issue. However, high-salinity and high-alkalinity levels can harm agricultural yields... (Review)
Review
Ensuring food security for the global population is a ceaseless and critical issue. However, high-salinity and high-alkalinity levels can harm agricultural yields throughout large areas, even in largely agricultural countries, such as China. Various physical and chemical treatments have been employed in different locations to mitigate high salinity and alkalinity but their effects have been minimal. Numerous researchers have recently focused on developing effective and environmentally friendly biological treatments. Endophytes, which are naturally occurring and abundant in plants, retain many of the same characteristics of plants owing to their simultaneous evolution. Therefore, extraction of endophytes from salt-tolerant plants for managing plant growth in saline-alkali soils has become an important research topic. This extraction indicates that the soil environment can be fundamentally improved, and the signaling pathways of plants can be altered to increase their defense capacity, and can even be inherited to ensure lasting efficacy. This study discusses the direct and indirect means by which plant endophytes mitigate the effects of plant salinity stress that have been observed in recent years.
Topics: Endophytes; Salinity; Alkalies; Salt Tolerance; Salt-Tolerant Plants
PubMed: 38069239
DOI: 10.3390/ijms242316917 -
Journal of Visualized Experiments : JoVE Aug 2023The cornea is critical for vision, and corneal healing after trauma is fundamental in maintaining its transparency and function. Through the study of corneal injury...
The cornea is critical for vision, and corneal healing after trauma is fundamental in maintaining its transparency and function. Through the study of corneal injury models, researchers aim to enhance their understanding of how the cornea heals and develop strategies to prevent and manage corneal opacities. Chemical injury is one of the most popular injury models that has extensively been studied on mice. Most previous investigators have used a flat paper soaked in sodium hydroxide to induce corneal injury. However, inducing corneal and limbal injury using flat filter paper is unreliable, since the mouse cornea is highly curved. Here, we present a new instrument, a modified biopsy punch, that enables the researchers to create a well-circumscribed, localized, and evenly distributed alkali injury to the murine cornea and limbus. This punch-trephine method enables researchers to induce an accurate and reproducible chemical burn to the entire murine cornea and limbus while leaving other structures, such as the eyelids, unaffected by the chemical. Moreover, this study introduces an enucleation technique that preserves the medial caruncle as a landmark for identifying the nasal side of the globe. The bulbar and palpebral conjunctiva, and lacrimal gland are also kept intact using this technique. Ophthalmologic examinations were performed via slit lamp biomicroscope and fluorescein staining on days 0, 1, 2, 6, 8, and 14 post-injury. Clinical, histological, and immunohistochemical findings confirmed limbal stem cell deficiency and ocular surface regeneration failure in all experimental mice. The presented alkali corneal injury model is ideal for studying limbal stem cell deficiency, corneal inflammation, and fibrosis. This method is also suitable for investigating pre-clinical and clinical efficacies of topical ophthalmologic medications on the murine corneal surface.
Topics: Animals; Mice; Cornea; Corneal Injuries; Disease Models, Animal; Alkalies; Biopsy; Limbal Stem Cell Deficiency
PubMed: 37590514
DOI: 10.3791/65609 -
Journal of Ocular Pharmacology and... Dec 2023The eye is a highly protected organ from ocularly administered drugs; drug- and formulation-related factors contribute significantly to ocular bioavailability. There...
The eye is a highly protected organ from ocularly administered drugs; drug- and formulation-related factors contribute significantly to ocular bioavailability. There has been a growing interest in using nonsteroidal anti-inflammatory drugs in ophthalmology for treating postoperative pain, inflammation, and seasonal allergic conjunctivitis. A preformulation-assisted design boosts efficacy and reduces dose requirements. This work aims to study the preformulation characteristics of ketorolac tromethamine to improve ocular performance and future formulation development through developing an high-performance liquid chromatography (HPLC) stability-indicating assay, forced degradation under stress conditions, solubility, as well as partition and distribution coefficient measurements. An isocratic HPLC with diode array detector method was developed and validated. Accelerated degradation under different stressors (acid, alkali, heat, and oxidative) was studied. In addition, solubility, partition, and distribution were investigated at different pHs of 3.5-7.4. The results indicated that the developed HPLC method was simple, rapid (retention time ≃3 min), sensitive, selective, robust, and stability indicating. The drug seems more chemically sensitive to acid degradation (∼30% and 40% of the drug was degraded under 0.1 M and 1 M HCl at 60°C for 24 h, respectively). Another significant degradation was recorded in the following order: Oxidative > alkali > heat (phosphate-buffered saline) > heat (distilled water). Being a weak ionizable drug, both water and lipid solubility, as measured through partition coefficients, it demonstrated pH-dependency. For the optimum balance of water and lipid solubility required for penetration through the lipophilic corneal epithelial barrier, ketorolac eye drops would be better formulated between pH 5.5 and 6.6 than being formulated at the physiological fluid pH 7.4, where the drug is extremely hydrophilic and less permeable.
Topics: Ketorolac Tromethamine; Anti-Inflammatory Agents, Non-Steroidal; Ketorolac; Alkalies; Water; Lipids; Ophthalmic Solutions
PubMed: 37676986
DOI: 10.1089/jop.2023.0066 -
Methods in Molecular Biology (Clifton,... 2024Antifreeze proteins (AFPs) are biomolecules that can bind to ice and hinder its growth, thus holding significant potential for biotechnological and biomedical... (Review)
Review
Antifreeze proteins (AFPs) are biomolecules that can bind to ice and hinder its growth, thus holding significant potential for biotechnological and biomedical applications. AFPs are a subset of ice-binding proteins (IBPs) and are found in various organisms across different life kingdoms. This mini-review investigates the underlying mechanisms by which AFPs impede ice growth, emphasizing the disparities between hyperactive and moderate AFPs. Hyperactive AFPs exhibit heightened thermal hysteresis (TH) activity and can bind to both the basal and prism planes of ice crystals, enabling them to endure extremely cold temperatures. In contrast, moderate AFPs predominantly bind to the prism/pyramidal planes and demonstrate lower TH activity. The structural diversity of AFPs and the presence of ordered water molecules on their ice-binding sites (IBS) have been subjects of debate among researchers. Multiple hypotheses have been proposed concerning the significance of ordered water molecules in ice binding. Gaining insights into the binding dynamics and the factors influencing TH activity in AFPs is crucial for the development of efficient synthetic compounds and the establishment of comprehensive models to elucidate ice growth inhibition. Here we emphasize the necessity for further research to unravel the mechanisms of AFPs and presents a pathway for constructing models capable of comprehensively explaining their inhibitory effects on ice growth.
Topics: Humans; Ice; Antifreeze Proteins; Binding Sites; Biotechnology; Water
PubMed: 37943458
DOI: 10.1007/978-1-0716-3503-2_12 -
Journal of the American Society of... Jan 2024In CKD, metabolic acidosis is commonly treated with alkali in the hope that it will improve bone health. In a post hoc analysis of the Bicarbonate Administration to... (Randomized Controlled Trial)
Randomized Controlled Trial
SIGNIFICANCE STATEMENT
In CKD, metabolic acidosis is commonly treated with alkali in the hope that it will improve bone health. In a post hoc analysis of the Bicarbonate Administration to Stabilize eGFR Pilot Trial, we investigated whether sodium bicarbonate affects serum levels of bone turnover markers and other hormones related to bone health in individuals with CKD who have normal to slightly reduced total CO2 (20-28 mEq/L). Sodium bicarbonate increased serum levels of α-klotho but had no significant effect on other bone health markers, including intact fibroblast growth factor-23 (iFGF-23), intact parathyroid hormone (iPTH), and bone-specific alkaline phosphatase (B-SAP). Further study is needed to determine the effect of bicarbonate administration on clinical aspects of bone health.
BACKGROUND
Treatment with alkali has been hypothesized to improve bone health in CKD by mitigating adverse effects of acid on bone mineral. We investigated the effect of treatment with sodium bicarbonate on bone turnover markers and other factors related to bone metabolism in CKD.
METHODS
This is a post hoc analysis of the Bicarbonate Administration to Stabilize eGFR Pilot Trial in which 194 individuals with CKD and serum total CO2 20-28 mEq/L were randomly assigned to placebo or one of two doses of sodium bicarbonate (0.5 or 0.8 mEq/kg lean body weight per day) for 28 weeks. The following serum measurements were performed at baseline, week 12, and week 28: B-SAP, c-telopeptide, procollagen type I intact N-terminal propeptide, iPTH, iFGF-23, soluble klotho, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and tartrate-resistant acid phosphatase 5b. The difference (sodium bicarbonate versus placebo) in mean change of each bone biomarker from baseline was determined using linear mixed models.
RESULTS
One hundred sixty-eight participants submitted samples for post hoc investigations. Mean eGFR was 37±10 ml/min per 1.73 m2 and mean total CO2 was 24±3 mEq/L at baseline. Sodium bicarbonate induced a dose-dependent increase in soluble klotho levels compared with placebo. There was no significant effect of treatment with either dose of sodium bicarbonate on any of the other bone biomarkers, including iFGF-23, iPTH, and B-SAP. Effects on bone biomarkers were similar in those with baseline serum total CO2 <24 mEq/L compared with those with total CO2 ≥24 mEq/L.
CONCLUSIONS
In this pilot trial of individuals with CKD and total CO2 20-28 mEq/L, sodium bicarbonate treatment increased serum klotho levels but did not affect other bone health markers over 28 weeks.
CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER
ClinicalTrials.gov, NCT02521181.
Topics: Humans; Sodium Bicarbonate; Bicarbonates; Renal Insufficiency, Chronic; Pilot Projects; Carbon Dioxide; Bone Remodeling; Biomarkers; Alkalies
PubMed: 38170601
DOI: 10.1681/ASN.0000000000000264