Ex vivo investigation of betaine and boric acid function as preprotective agents on rat synaptosomes to be treated with Aβ (1-42)

Recent evidence suggests that ferroptosis, an iron-dependent cell death process, may be involved in Alzheimer's disease (AD) pathology. The study evaluated the therapeutic potential of betaine and boric acid (BA) pretreatment administered to rats for 21 days in AD. Then, the rats were sacrificed, and morphological and biochemical analyses were performed in brain tissues. Next, an ex vivo AD model was created by applying amyloid-β (Aβ1-42) to synaptosomes isolated from the brain tissues. Synaptosomes were analyzed with micrograph images, and protein and mRNA levels of ferroptotic markers were determined. Betaine and BA pretreatments did not cause any morphological and biochemical differences in the brain tissue. However, Aβ (1-42) administration in synaptosomes increased the levels of acyl-CoA synthetase long chain family member-4 (ACSL4), transferrin receptor-1 protein (TfR1), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) and decreased the levels glutathione peroxidase-4 (GPx4) and glutathione (GSH). Moreover, ACSL4, GPx4, and TfR1 mRNA and protein levels were similar to the ELISA results. In contrast, betaine and BA pretreatments decreased the levels of ACSL4, TfR1, MDA, and 8-OHdG in synaptosomes incubated with Aβ1-42, while promoting increased levels of GPx4 and GSH. In addition, betaine and BA pretreatments completely reversed ACSL4, GPx4, and TfR1 mRNA and protein levels. Therefore, betaine and BA pretreatments may contribute to the prevention of neurodegenerative damage by supporting antiferroptotic activities.

In Situ Formation of a LiBO2 Coating Layer and Spinel Phase for Ni-Rich Cathode Materials from a Boric Acid-Etched Precursor

Ni-rich cathode materials exhibit superior energy densities and have attracted interest among both research and industrial fields; whereas, their practical application is hindered by the intrinsic drawbacks brought by the high nickel content such as structural instability and rapid capacity fading. Herein, in situ formation of a LiBO2 coating layer and spinel phase layer is achieved on the surface of a Ni-rich cathode material via a boric acid etching method at the precursor state. The spinel phase is considered to have a 3D lithium diffusion tunnel and hence faster diffusion kinetics. Moreover, the LiBO2 layer possesses excellent (electro)chemical inertness and can suppress electrolyte decomposition, resulting in a more inorganic and stable cathode-electrolyte interface. The surface reconstructed sample exhibits better cyclic stability (93.3% capacity retention vs 85.3% for the pristine sample at 1 C for 100 cycles) and rate performance. The superiority of this surface reconstruction is demonstrated by a series of electrochemical techniques and characterization methods including high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), post-mortem X-ray photoelectron spectroscopy (XPS) analysis, and density functional theory (DFT) calculations.

Controlling Dielectric Film Defects to Increase the Breakdown Voltage of Conductive Polymer Solid Capacitors

Aluminum solid polymer capacitors are promising devices for the increased demand for power electronics applications. Nonetheless, the low breakdown voltage of commercially available catalysts (∼100 V) limits their applications. In this study, a hydroxide-film-covered high-purity aluminum was anodized at 700 V in boric acid at 85 °C, and the effect of a second hot water immersion (posthydration treatment) after anodizing on the breakdown voltage was studied as a possible future treatment to enhance the withstand voltages of solid electrolytic capacitors. The dielectric breakdown voltage of the anodized aluminum with a PEDOT:PSS coating was ∼500 V, being ∼200 V less than the anodizing voltage; however, the dielectric breakdown voltage was increased above 700 V by introducing the posthydration treatment due to the formation of a nanovoid layer above the dielectric alumina film. Our research suggests that the highly dispersed nanovoids incorporated with PEDOT:PSS avoid the current concentration at some local regions, effectively increasing the dielectric breakdown voltage. The posthydration treatment increased the leakage current by introducing physical defects in the dielectric film. However, the leakage current was reduced by a voltage sweep below the breakdown voltage after the PEDOT:PSS coating or a second anodizing process before the coating, keeping the breakdown voltage above 600 V. A promising processing route to obtain aluminum solid capacitors with high withstand voltage (600 V) found in our research is, first, dipping in hot water; second, anodizing at 700 V; then a second hot water treatment; and a second anodizing at 400 V, which keeps the capacitance invariable with a breakdown voltage enhanced.

High-density polyethylene (HDPE)-incorporated boron carbide and boric acid nanoparticles as a nanoshield of photoneutrons from medical linear accelerators

PURPOSE

The current study aimed to investigate boron carbide and boric acid nanoparticles (NPs) as absorbents for thermal neutrons and high-density polyethylene (HDPE) as a substrate and neutron moderator for fast neutrons. The goal was to assess the performance of boron carbide and boric acid NPs based on HDPE as a nanoshield of photoneutrons from medical linear accelerators.

MATERIALS AND METHODS

This study was conducted in two parts of simulation and practice. The Monte Carlo (MC) simulation involved modeling and verification of the single-layer, double-layer, and combined nanoshields by selecting nanomaterials and substrates and, finally, calculating the macroscopic cross-sections. The practical part involved manufacturing nanoshields based on the simulation results and evaluating the manufactured nanocomposites via experimental measurements.

RESULTS

MC simulation results with an uncertainty of less than 1% showed that for the monolayer samples, the best result belonged to boron carbide at a concentration of 10% and a macroscopic cross-section of 0.933 cm-1. At a concentration of 20%, the highest value among the double-layer samples was 0.936 cm-1 and for the combined samples, this value was 0.928 cm-1. Boron carbide single-layer nanocomposites at a 10% concentration, as well as the bilayer nanoshield of 10% boron carbide and 20% boric acid performed well; however, the best performance belonged to the nanoshield with a macroscopic cross-section of 0.960 and the combination containing 5% boron carbide and 10% boric acid.

CONCLUSIONS

The research suggests that utilizing boron carbide and boric acid nanoshields in combination with HDPE holds promise as a viable approach to protecting from the photoneutrons. Further exploration of these nanocomposite shields and their practical applications is warranted, with the potential to yield significant advancements in radiation therapy safety and efficacy.

11B NMR of the Morphological Evolution of Traditional Chinese Medicine Borax

This article applies nuclear magnetic resonance technology to the study of boron-containing traditional Chinese medicine, in order to explore the morphological evolution of boron elements in traditional Chinese medicine. Borax is a traditional Chinese medicine with anti-corrosion, anti-inflammatory, antibacterial, and anticonvulsant effects. It is made by boiling, removing stones, and drying borax minerals like borate salts. This article introduces an 11B nuclear magnetic resonance method for identifying and characterizing boron-containing compounds in TCM. We applied this technology to borax aqueous solutions in different chemical environments and found that with boron mixed in the form of SP2 hybridization in equilateral triangles and SP3 hybridization in equilateral tetrahedra, the pH changes in alkaline environments significantly affected the ratio of the two. At the same time, it was found that in addition to the raw material peak, boron signals of other boron-containing compounds were also detected in 20 commercially available boron-containing TCM preparations. These new boron-containing compounds may be true pharmaceutical active ingredients, and adding them directly to the formula can improve quality and safety. This article describes the detection of 11B NMR in boron-containing traditional Chinese medicine preparations. It is simple, non-destructive, and can provide chemical fingerprint studies for boron-containing traditional Chinese medicine.

Investigation of the efficacy of epidermal growth factor, boric acid and their combination in cartilage injury in rats: An experimental study

OBJECTIVES

In this study, we aimed to determine the bioefficacy of epidermal growth factor (EGF), boric acid (BA), and their combination on cartilage injury in rats.

MATERIALS AND METHODS

In in vitro setting, the cytotoxic effects of BA, EGF, and their combinations using mouse fibroblast cell (L929), human bone osteosarcoma cell (Saos-2), and human adipose derived mesenchymal stem cells (hAD-MSCs) were determined by applying MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] test. In in vivo setting, 72 rats were randomly divided into four groups. A standard chondral defect was created and microfracture was performed in all groups. Group A was determined as the control group. In addition to the standard procedure, Group B received 100 ng/mL of EGF, Group C received a combination of 100 ng/mL of EGF and 10 µg/mL of BA combination, and Group D 20 µg/mL of BA.

RESULTS

The cytotoxic effect of the combinations of EGF dilutions (1, 5, 10, 25, 50, 100, 200 ng/mL) with BA (100, 300, 500 µg/mL) was observed only in the 72-h application period and in Saos-2. The cytotoxic effect of BA was reduced when combined with EGF. There was no significant difference in the histopathological scores among the groups (p=0.13).

CONCLUSION

Our study showed that EGF and low-dose BA application had a positive effect on cartilage healing in rats. Significant decreases in recovery scores were observed in the other groups. The combination of EGF and BA promoted osteoblast growth. Detection of lytic lesions in the group treated with 20 µg/mL of BA indicates that BA may have a cytotoxic effect.

Potential Toxicity of Boric Acid Powder Otic Insufflation

OBJECTIVE

Boric acid (BA) powder is commonly used to treat otologic conditions, such as mastoid bowl inflammation and chronic otitis externa. Exposure to 50 mg per day is thought to cause systemic toxicity in humans. Inflamed skin and mucosal surfaces readily absorb BA. The aim of this study was to measure the doses of BA commonly used in clinical otology and alert the otolaryngology community to BA's underappreciated potential source of systemic toxicity.

STUDY DESIGN

Prospective, controlled.

SETTING

Laboratory.

METHODS

BA dose administration was measured by weighing the BA generated by common insufflators: accordion bellows, House-Sheehy insufflator, DeVilbiss insufflator, and pneumatic powder blower. Manual insufflation was performed with 3 compressions of the bulb. The pneumatic blower was sprayed for 1 second. Measurements were repeated 10 times.

RESULTS

The DeVilbiss insufflator delivered the lowest mean BA dose, 6.1 mg (SD 3.4, range 2.1-13.7), followed by the House-Sheehy 8.9 mg (SD 8.4, range 1.6-27.8), the pneumatic blower 192.8 mg (SD 38.3, range 150.0-261.7), and the accordion, 284.1 mg (SD 215.0, range 37.8-730.8).

CONCLUSION

BA dose delivery is highly variable by insufflator type, and doses thought to cause systemic toxicity are commonly generated. Awareness of and further investigation into the potential toxicity of otic administration of BA seems warranted.

[Determination of boric acid and silicic acid in mineral water by nonsuppressed ion chromatography]

Boron and silicon are widely distributed in nature; in water, these compounds typically present in the forms of boric acid and silicic acid, respectively. The maximum allowable levels of silicic acid and boric acid in water are stipulated in relevant national and industry standards, such as GB 8538-2022. Quality changes in water, which are of great significance in water-quality evaluations, can be understood in terms of its silicic acid and boric acid contents. Boric acid content is usually determined by ion exclusion chromatography, whereas silicic acid content is usually determined by postcolumn derivatization. Therefore, traditional methods cannot achieve the simultaneous determination of silicic acid and boric acid contents in water. Modern ion chromatography has been widely used in the detection of ionic compounds, such as anions, cations, organic acids, organic amines, amino acids, and sugars. Boric (pKa=9.24) and silicic (pKa=9.77) acids are weak acids that dissociate into ionic states under alkaline conditions. Although these compounds cannot be tested using suppressed ion chromatography, they can be retained on ion chromatography columns. In this study, a method based on nonsuppressed conductance detection was established for the simultaneous determination of boric acid and silicic acid in water. The contents of boric acid and silicic acid were detected by nonsuppressed ion chromatography using a Dionex IonPacTM AS20 analytical column. The chromatographic conditions were as follows: flow rate, 1.0 mL/min; column temperature, 30 ℃; eluent, 6 mmol/L sodium hydroxide solution and 60 mmol/L mannitol; and sample injection volume, 50 μL. The effective separation of silicic acid and boric acid was achieved within 8 min. SiO32- and boric acid demonstrated good linear relationships in the concentration ranges of 0.25-100 and 0.5-100 mg/L (correlation coefficients, 0.9999), respectively. The method detection (MDL) and quantification (MQL) limits were 0.078 and 0.26 mg/L for SiO32-, and the MDL and MQL limits were 0.18 and 0.60 mg/L for boric acid. The average recoveries of boric acid and SiO32- (n=6) were 97.3%-105.3%. Moreover, the relative standard deviations were less than 0.9% for boric acid at four spiked levels and less than 0.30% for SiO32- at three spiked levels. Thus, the method meets detection requirements. The pretreatment method is very simple, and the sample can be directly injected through a 0.22 μm water filtration membrane and into the column. The boric acid and silicic acid contents in nine mineral drinking water samples were determined under the optimized analytical conditions. Boric acid was not detected in these nine samples, but silicic acid was detected in six samples. The silicic acid contents detected were between 18.70 and 62.08 mg/L, which was consistent with the concentration ranges marked on the manufacturers' packaging. The proposed method can be used for the determination of boric acid and silicic acid in mineral drinking water and laboratory water, and provides a reference for the simultaneous detection of boric acid and silicic acid in ultrapure water used in the semiconductor industry.

Evaluation of the Antimicrobial Activity of a Formulation Containing Ascorbic Acid and Eudragit FS 30D Microparticles for the Controlled Release of a Curcumin-Boric Acid Solid Dispersion in Turkey Poults Infected with Salmonella enteritidis: A Therapeutic Model

The selection of components within a formulation or for treatment must stop being arbitrary and must be focused on scientific evidence that supports the inclusion of each one. Therefore, the objective of the present study was to obtain a formulation based on ascorbic acid (AA) and Eudragit FS 30D microparticles containing curcumin-boric acid (CUR-BA) considering interaction studies between the active components carried out via Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC) to minimize antagonistic effects, and comprehensively and effectively treat turkey poults infected with Salmonella enteritidis (S. enteritidis). The DSC and FTIR studies clearly demonstrated the interactions between AA, BA, and CUR. Consequently, the combination of AA with CUR and/or BA should be avoided, but not CUR and BA. Furthermore, the Eudragit FS 30D microparticles containing CUR-BA (SD CUR-BA MP) showed a limited release of CUR-BA in an acidic medium, but they were released at a pH 6.8-7.0, which reduced the interactions between CUR-BA and AA. Finally, in the S. enteritidis infection model, turkey poults treated with the combination of AA and SD CUR-BA MP presented lower counts of S. enteritidis in cecal tonsils after 10 days of treatment. These results pointed out that the use of an adequate combination of AA and CUR-BA as an integral treatment of S. enteritidis infections could be a viable option to replace the indiscriminate use of antibiotics.

Boric Acid as A Low-Temperature Graphitization Aid and Its Impact on Structure and Properties of Cellulose-Based Carbon Fibers

In the present paper, a scalable, economically feasible, and continuous process for making cellulose-based carbon fibers (CFs) is described encompassing precursor spinning, precursor additivation, thermal stabilization, and carbonization. By the use of boric acid (BA) as an additive, the main drawback of cellulose-based CFs, i.e., the low carbon yield, is overcome while maintaining a high level of mechanical properties. This is demonstrated by a systematic comparison between CFs obtained from a BA-doped and an un-doped cellulose precursor within a temperature range for carbonization between 1000 and 2000 °C. The changes in chemical composition (via elemental analysis) and physical structure (via X-ray scattering) as well as the mechanical and electrical properties of the resulting CFs were investigated. It turned out that, in contrast to current opinion, the catalytic effect of boron in the formation of graphite-like structures sets in already at 1000 °C. It becomes more and more effective with increasing temperature. The catalytic effect of boron significantly affects crystallite sizes (La, Lc), lattice plane spacings (d002), and orientation of the crystallites. Using BA, the carbon yield increased by 71%, Young's modulus by 27%, and conductivity by 168%, reaching 135,000 S/m. At the same time, a moderate decrease in tensile strength by 25% and an increase in density of 14% are observed.

Success in treating wounds with local boric acid: a case study

Wounds are difficult to treat in patients with diabetes, affecting their quality of life (QoL) and requiring a multidisciplinary approach to their treatment. In addition to systemic treatments such as intravenous antibiotics and debridement, local therapies used in appropriate cases help prevent situations that may result in the need for amputation. Boric acid, an easily accessible agent in local wound care, was considered for use in wounds because of its bactericidal and fungicidal properties, as well as its positive effects on angiogenesis, collagen synthesis and re-epithelialisation. While there are data on the use of boric acid solution in the treatment of hard-to-heal wounds in the literature, its use in wounds is limited. Moreover, although 2-3% boric acid solutions have been used in previous studies, boric acid powder (BAP) was used in this present case study. In this article, BAP was used in the treatment of two patients with diabetic wounds. The application of BAP effectively cleared the necrosis and accelerated wound healing. Boric acid is easily accessible, easy to use and an effective agent that should be considered because of its beneficial effects on wounds patients when used in addition to systemic therapy.

Efficacy of boric acid used to treat experimental vascular graft infection by methicillin-resistant Staphylococcus aureus

INTRODUCTION

We aimed to investigate the efficacy of local boric acid (BA) and teicoplanin in prosthetic vascular graft infection (PVGI) caused by methicillin-resistant Staphylococcus aureus (MRSA) in a rat model.

METHODOLOGY

Fourty rats were divided into five groups. Group 1 received no treatments (control group); group 2 was uncontaminated polytetrafluoroethylene (PTFE) graft group; group 3 was untreated and the PTFE graft was contaminated with 2×107 CFU/mL MRSA; group 4 received local BA (8 mg/kg) and was contaminated with with 2×107 CFU/mL MRSA; group 5 received local BA (8 mg/kg) and intraperitoneal teikoplanin (10 mg/kg), and was contaminated with 2×107 CFU/mL MRSA; On the 3rd day, grafts and serums were removed for microbiological, histological and serological tests.

RESULTS

The amounts of culture growth in groups 4 and 5 were significantly lower compared to group 3 (p < 0.001). TNF-α was significantly higher in Group 3 than the other groups (p = 0.001). There was no significant difference between the groups in serum IL-1 levels (p = 0.138). Monocyte chemotactic protein-1 (MCP-1) was not significantly different between groups 3, 4, and 5, but it was significantly higher than groups 1 and 2 (p < 0.001). The severity of inflammation was significantly higher in group 3 than the other groups, and fibroblastic proliferation, granulation tissue and collagen synthesis were significantly lower (p < 0.05).

CONCLUSIONS

Our study showed that local BA and combined teicoplanin treatment is effective in preventing PVGI.

Red algae extract suppresses caspase-3 gene expression and induces catalase antioxidant enzyme in testicles of rats induced by boric acid

Aim To determine the effect of red algae extract on the gene expression of catalase and caspase-3 in testicules of rats induced by boric acid (BA). Methods This is experimental research with post-test control group design. Twenty four healthy male Wistar rats were divided into four treatment groups: a healthy group, negative control group, two treatment groups with red algae extract 400mg/kgBW/day (T1) and red algae extract 800mg/kgBW/day (T2). Each group was treated with BA 500mg/kgBW/day for 14 days, whereas the healthy group did not receive BA. In the treatment groups T1 and T2 were given red algae extract for 14 days. On day 15 all treatment groups were terminated and catalase and caspase-3 gene expression were analysed using qRT-PCR. Results In the healthy group, the expression of the catalase gene was 1.39±0.67 and the expression of the caspase-3 gene was 1.06±0.17. In the negative control group, there was a significant decrease in catalase gene expression, 0.68±0.27 (p<0.05), and a significant increase in caspase-3 gene expression, 5.71±2.47 (p<0.05). Treatment groups T1 and T2 showed a significant increase in catalase gene expression, 2.67±0.69; and 2.85±0.64, respectively (p<0.05) and caspase-3, 3.96±1,16 and 1.89±0.84, respectively, compared to the control group. Conclusion: The administration of red algae extract had a significant effect on increasing the expression of the catalase gene and decreasing the expression of the caspase-3 gene. This suggests that red algae extract has the potential to be developed as a protective agent against exposure to the effects of BA.

Boric Acid Exhibits Anticancer Properties in Human Endometrial Cancer Ishikawa Cells

Objective This study aims to explore the potential anti-cancer properties of boric acid (BA) in human endometrial cancer Ishikawa cells by assessing its influence on cell viability, apoptosis, oxidative stress, and inflammatory responses. Methods The impact of BA at concentrations ranging from 2.5 to 100 mM on cell viability was assessed in Ishikawa cells and normal fibroblast L929 cells (used as the control) through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Spectrophotometric measurements were performed to determine the total oxidant status (TOS) and total antioxidant status (TAS) in BA-treated cells, and the oxidative stress index (OSI) was calculated. The enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of cytochrome c and caspase 3, both of which are constituents of the extrinsic apoptotic pathway. Furthermore, changes in the concentrations of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) in the cells were analyzed using ELISA and immunofluorescence staining. Results The exposure of Ishikawa cells to BA for 24 hours led to a dose-dependent decline in cell viability, with an IC50 value of 40 mM. BA dose-dependently increased cytochrome c and caspase 3 levels in cancer cells. In Ishikawa cells, BA treatment led to a significant elevation in OSI. Moreover, the concentrations of TNF-α and IL-1β exhibited a dose-dependent decrease in BA-treated cells. On the other hand, in L929 cells, BA decreased OSI in a dose-dependent manner but did not change TNF-α and IL-1β levels. Concentrations up to 80 mM had no effect on cell viability and apoptosis, but BA at 80 mM concentration decreased viability and increased cytochrome c and caspase 3 levels in L929 cells. Conclusion BA inhibited cell viability, triggered apoptosis, induced oxidative stress, and suppressed inflammatory responses in endometrial cancer cells. Notably, at its IC50 concentration, BA had no cytotoxic effect on normal fibroblasts. Given its favorable properties, BA may provide a valuable therapeutic option to impede the development and progression of endometrial cancer.

Effect of irrigation acid solutions on cleaning and bond strength to post-space dentin

This study evaluated the effects of irrigating solutions containing 5% boric acid + 1% citric acid or 1% peracetic acid + high concentration hydrogen peroxide on root cleaning and bond strength of cementation systems after 24 h and 6 months of glass fiber post cementation. One hundred and twenty roots were endodontically treated. The specimens were randomized into one of four treatments (n = 10): DW (distilled water); NaOCl2.5% + EDTA17% (2.5% sodium hypochlorite solution + 17% EDTA); PA1% + HP (1% peracetic acid solution + high concentration of hydrogen peroxide); BA5% + CA1% (5% boric acid associated with 1% citric acid). The cleaning efficacy in the cervical, middle, and apical thirds of the post-space, and the push-out bond strength at 24 h and 6 months after post cementation were evaluated by Kruskal-Wallis and two-way ANOVA tests, respectively. BA5% + CA1% showed statistically significantly superior cleaning efficacy compared to the other solutions. This irrigation protocol also resulted in higher bond strength at 24 h and 6 months, regardless of the root third considered, and this was statistically significantly higher than those seen for DW and PA1% + HP. For BA5% + CA1% irrigation protocol, type 1 adhesive failure was the most prevalent. Post-space irrigation with BA5% + CA1% provided both higher cleaning efficacy and better bond strength.

Analysis of the Effectiveness of Technological Lubricants with the Addition of Boric Acid in Sheet Metal Forming

One of the main problems during sheet metal forming is the reduction in coefficient of friction and separation of contact surfaces in order to eliminate buildups of the formed material on the forming tools. For this purpose, technological lubricants based on mineral or synthetic oils are usually used. Unfortunately, their removal from the drawn parts and their subsequent utilization pose many problems and are expensive. Environmentally benign lubricants based on vegetable oils with the addition of boric acid could be an effective alternative to lubricants based on mineral and synthetic oils; however, the solubility of boric acid in oils is limited. Therefore, the paper proposes new, effective, and environmentally friendly methods for applying boric acid to the metal sheet by spraying it on a thin rapeseed oil layer previously applied to the metal sheet or by spraying a 25% solution of boric acid in methyl alcohol onto the sheet. The effectiveness of such lubrication was assessed on the basis of the so-called strip drawing test, Erichsen cupping test, and formation of cylindrical drawn parts in industrial conditions. The tests showed that the addition of boric acid was most effective for forming the DC01 steel sheet, reducing the coefficient of friction by about 60% compared to base oil lubrication. Although its usefulness is lower in the case of other frictional pairs, it eliminates the phenomenon of the formed material sticking to the tool, thus extending the life of the forming tools. The use of the proposed solution reduces production costs and indirectly boosts environmental protection. Moreover, an explanation of the tribological mechanism contributing to the lubrication action of boric acid is given.

Redox Mechanisms Underlying the Cytostatic Effects of Boric Acid on Cancer Cells-An Issue Still Open

Boric acid (BA) is the dominant form of boron in plasma, playing a role in different physiological mechanisms such as cell replication. Toxic effects have been reported, both for high doses of boron and its deficiency. Contrasting results were, however, reported about the cytotoxicity of pharmacological BA concentrations on cancer cells. The aim of this review is to briefly summarize the main findings in the field ranging from the proposed mechanisms of BA uptake and actions to its effects on cancer cells.

Effect of Boric Acid on the Ionization Equilibrium of α-Hydroxy Carboxylic Acids and the Study of Its Applications

To investigate the synergistic catalytic effects of boric acid and α-hydroxycarboxylic acids (HCAs), we analyzed and measured the effects of the complexation reactions between boric acid and HCAs on the ionization equilibrium of the HCAs. Eight HCAs, glycolic acid, D-(-)-lactic acid, (R)-(-)-mandelic acid, D-gluconic acid, L-(-)-malic acid, L-(+)-tartaric acid, D-(-)-tartaric acid, and citric acid, were selected to measure the pH changes in aqueous HCA solutions after adding boric acid. The results showed that the pH values of the aqueous HCA solutions gradually decreased with an increase in the boric acid molar ratio, and the acidity coefficients when boric acid formed double-ligand complexes with HCAs were smaller than those of the single-ligand complexes. The more hydroxyl groups the HCA contained, the more types of complexes could be formed, and the greater the rate of change in the pH. The total rates of change in the pH of the HCA solutions were in the following order: citric acid > L-(-)-tartaric acid = D-(-)-tartaric acid > D-gluconic acid > (R)-(-)-mandelic acid > L-(-)-malic acid > D-(-)-lactic acid > glycolic acid. The composite catalyst of boric acid and tartaric acid had a high catalytic activity-the yield of methyl palmitate was 98%. After the reaction, the catalyst and methanol could be separated by standing stratification.

Therapeutic Efficacy of Boric Acid Treatment on Brain Tissue and Cognitive Functions in Rats with Experimental Alzheimer's Disease

Introduction

Oxidative stress has an important role in the pathophysiology of Alzheimer's disease (AD), the most common type of dementia. Boric acid (BA) contributes significantly to the protection of the brain by reducing lipid peroxidation and supporting antioxidant defense. We aimed to evaluate the therapeutic potential of BA treatment in AD rats.

Materials and Methods

Four groups were formed as Control (C), Alzheimer's (A), Alzheimer's + Boric acid (ABA), Boric acid (BA). Intracerebroventricular injection of Streptozotocin (STZ) was preferred to create an AD. After 4 weeks, BA was applied 3 times every other day. The Radial Arm Maze Test (RAMT) was used to evaluate memory and learning abilities. Biochemical and histopathological evaluations were made in the hippocampus.

Results

Initial RAMT inlet/outlet (I/O) numbers were similar. Two weeks after STZ injection, I/O numbers decreased in group A and ABA compared to group C and BA (p<0.05). After the second BA application, I/O numbers increased in the ABA group compared to the A group (p<0.05). In group A, PON-1, TOS and OSI levels were higher and TAS levels were lower than in groups BA and C. After BA treatment, PON-1 and OSI levels were lower in the ABA group than in the A group (p<0.05). Although there was an increase in TAS value and a decrease in TOS, this did not make a statistical difference. The thickness of the pyramidal cell in CA1 and the granular cell layers in the dentate gyrus, and the number of intact and degenerated neurons in the pyramidal cell layer were similar between the groups.

Discussion

Significant improvement in learning and memory abilities after BA application is promising for AD.

Conclusion

These results show that BA application positively affects learning and memory abilities, and reduces oxidative stress. More extensive studies are required to evaluate histopathological efficacy.

Phosphate and Borate-Based Composite Interface of Single-Crystal LiNi0.8Co0.1Mn0.1O2 Enables Excellent Electrochemical Stability at High Operation Voltage

The application of nickel-rich cathodes in lithium-ion batteries has been hampered by its rapid capacity/voltage fading and limited performance of rate. In this work, a passivation technique is used to create a stable composite interface on single-crystal LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) surface, which greatly improves the cycle life-span and high-voltage constancy of cathode with 4.5 and 4.6 V cut-off voltage. The improved Li⁺ conductivity of the interface enables a firm cathode-electrolyte interphase (CEI), which reduces interfacial side reactions, lowers the risk of safety hazards, and improves irreversible phase transitions. As a result, the electrochemical performance of single-crystal Ni-rich cathode are remarkably enhanced. The specific capacity of 152 mAh g^-1 can be delivered at a charging/discharging rate of 5 C under 4.5 V cut-off voltage, much higher than 115 mAh g^-1 of the pristine NCM811. After 200 cycles at 1 C, the composite interface modified NCM811 demonstrates outstanding capacity retention of 85.4% and 83.8% at 4.5 V and 4.6 V cut-off voltage, respectively.

Exploring the mechanisms underlying the toxicity of boric acid against the land snail, Theba pisana

BACKGROUND

The land snail, Theba pisana, is one of the most important threats facing agriculture around the globe. Boric acid (BOA) is currently used as a safe alternative molluscicide to control land snails in sustainable agriculture, but the mechanisms of toxicity have not yet been investigated. The present study characterizes the lethal and sub-lethal (0.5 and 1 mg g^-1 ) toxic effects of BOA-contaminated food for 14 days by examining physiological, biochemical and histopathological indicators in T. pisana to understand the mechanisms underlying its toxic action.

RESULTS

BOA was found to be lethal against T. pisana with LC₅₀ values of 24.7 and 8.05 mg g^-1 after 3 and 7 days of exposure, respectively. BOA sublethal concentrations led to a significant reduction in food consumption and growth of snails after 14 days of exposure. BOA also caused a significant increase in testosterone levels, whereas an opposite effect was observed in estradiol levels. An increase in progesterone levels in snails in the 0.5 mg g^-1 BOA group and a decrease in the 1 mg g^-1 BOA group were observed after all exposure times. Moreover, the lipid peroxidation level and catalase activity were elevated, whereas acetylcholinesterase activity was inhibited in the treated snails. Alteration in glutathione-S-transferase activity was noticed after exposure to both sublethal concentrations. In addition, BOA induced histopathological alterations in the digestive gland of T. pisana.

CONCLUSION

Our findings provide novel insights into how physiological, biochemical and histopathological alterations can be used to explore the mechanisms underlying BOA toxicity against snails. © 2022 Society of Chemical Industry.

Modulating Emission of Boric Acid into Highly Efficient and Color-Tunable Afterglow via Dehydration-Induced Through-Space Conjugation

Inorganic boric acid (BA) is generally not considered an efficient afterglow material, and several groups have reported its extremely weak room-temperature phosphorescence (RTP) in the blue spectral region. It is discovered that heat treatment of BA results in increased afterglow intensity (27-fold increase) and prolonged emission lifetime (from 0.83 to 1.59 s), attributed to enhanced through-space conjugation (TSC) of BA. The afterglow intensity of BA can be increased further (≈415 folds) by introducing p-hydroxybenzoic acid (PHA), which contains a conjugated molecular motif, to further promote the TSC of the BA system. This combination results in the production of afterglow materials with a photoluminescence quantum yield of 83.8% and an emission lifetime of 2.01 s. In addition, a tunable multicolor afterglow in the 420-490 nm range is achieved owing to the enhancement of the RTP and thermally activated delayed fluorescence of PHA, where BA exerts a confinement effect on the guest molecules. Thus, this study demonstrates promising afterglow materials produced from extremely abundant and simple precursor materials for various applications.

Laboratory evaluations of biodegradable boric acid hydrogel baits for the control of Argentine ant (Hymenoptera: Formicidae)

Due to their mutualistic relationship with plant pests, the Argentine ant is considered a major pest in subtropical fruit orchards and vineyards. Besides insecticide sprays, liquid baiting has been demonstrated as an effective method to suppress the Argentine ant populations. To improve the economic feasibility of liquid baiting, hydrogel materials have been recently tested as a carrier for liquid baits containing various insecticidal active ingredients. Here, we tested boric acid as a toxicant in the aqueous sugar bait delivered in a biodegradable calcium alginate hydrogel. Laboratory tests demonstrated that boric acid (1%) liquid bait incorporated in the calcium alginate hydrogel effectively killed Argentine ant workers. Potassium sorbate (0.25%) added to the liquid bait as a preservative did not impact the efficacy of boric acid even though it significantly reduced the degree of swelling of the hydrogel beads in the bait solution. Testing with 2-month-old bait suggested that long-term storage might impact bait efficacy even with potassium sorbate preservative.

Engineering a potent boron-10-enriched polymeric nanoparticle for boron neutron capture therapy

Background: Boron neutron capture therapy (BNCT) is a promising cancer treatment that eliminates tumor cells by triggering high-energy radiation within cancer cells. Aim: In vivo evaluation of poly(vinyl alcohol)/boric acid crosslinked nanoparticles (PVA/BA NPs) for BNCT. Materials & methods: PVA/BA NPs were synthesized and intravenously injected into tumor-bearing mice for BNCT. Results: The in vitro boron uptake of PVA/BA NPs in tumor cells was 70-fold higher than the required boron uptake for successful BNCT. In an in vivo study, PVA/BA NPs showed a 44.29% reduction in tumor size compared with clinically used boronophenylalanine for oral cancer in a murine model. Conclusion: PVA/BA NPs exhibited effective therapeutic results for oral cancer treatments in BNCT.

Tribological Aspects of Sheet Titanium Forming

Friction, wear, and lubrication are inherent to all metal-forming processes. Unfortunately, they are particularly troublesome when forming titanium materials, which tend to form titanium buildup on the working surfaces of the forming tools. Lubrication is one of the most effective ways to separate contacting surfaces and eliminate galling, thus reducing tool wear. The paper presents the tribological aspects of titanium sheets forming using environmentally friendly lubricants with the addition of boric acid. The lubricant's effectiveness was assessed on the basis of technological tests, such as the strip drawing test, the Erichsen cupping test, and the formation of spherical drawn parts in industrial conditions. Moreover, the results of the numerical simulation of forming a titanium hat-shaped part are presented. Numerical calculations of forming processes were performed using the PamStamp 2G system based on the finite element method. Both experiments and numerical analyses showed the positive effect of lubricants with boric acid on sheet titanium forming.

Boric acid transport activity of marine teleost aquaporins expressed in Xenopus oocytes

Marine teleosts ingest large amounts of seawater containing various ions, including 0.4 mM boric acid, which can accumulate at toxic levels in the body. However, the molecular mechanisms by which marine teleosts absorb and excrete boric acid are not well understood. Aquaporins (Aqps) are homologous to the nodulin-like intrinsic protein (NIP) family of plant boric acid channels. To investigate the potential roles of Aqps on boric acid transport across the plasma membrane in marine teleosts, we analyzed the function of Aqps of Japanese pufferfish (Takifugu rubripes) expressed in Xenopus laevis oocytes. Takifugu genome database contains 16 genes encoding the aquaporin family members (aqp0a, aqp0b, aqp1aa, aqp1ab, aqp3a, aqp4a, aqp7, aqp8bb, aqp9a, aqp9b, aqp10aa, aqp10bb, aqp11a, aqp11b, aqp12, and aqp14). When T. rubripes Aqps (TrAqps) were expressed in X. laevis oocytes, a swelling assay showed that boric acid permeability was significantly increased in oocytes expressing TrAqp3a, 7, 8bb, 9a, and 9b. The influx of boric acid into these oocytes was also confirmed by elemental quantification. Electrophysiological analysis using a pH microelectrode showed that these TrAqps increase B(OH)₃ permeability. These results indicate that TrAqp3a, 7, 8bb, 9a, and 9b act as boric acid transport systems, likely as channels, in marine teleosts.

Morphological changes in striated muscle fibres caused by components of the Thiel embalming method

BACKGROUND

Thiel-fixed body donors are highly valued for surgical training courses. The pronounced flexibility of Thiel-fixed tissue has been postulated to be caused by histologically visible fragmentation of striated muscle. The aim of this study was to analyse whether a specific ingredient, pH, decay, or autolysis could cause this fragmentation in order to modulate the Thiel solution to adapt specimen flexibility specifically to the needs of different courses.

MATERIALS AND METHODS

Striated muscle of the mouse was fixed for different time periods in formalin, Thiel solution, and its individual ingredients, and analysed by light microscopy. Further, pH-values of Thiel solution and its ingredients were measured. In addition, unfixed muscle tissue was histologically analysed including Gram staining to investigate a relationship between autolysis, decomposition, and fragmentation.

RESULTS

Muscle fixed with Thiel solution for 3 months was slightly more fragmentated than muscle fixed for 1 day. Fragmentation was more pronounced after 1 year of immersion. Three individual salt ingredients showed slight fragmentation. Decay and autolysis had no effect on fragmentation, which occurred regardless of the pH of all solutions.

CONCLUSIONS

Fragmentation of Thiel-fixed muscle is dependent on fixation time and most likely occurs due to salts present in the Thiel solution. Adjustment of the salt composition in the Thiel solution with verification of the influence on the fixation effect, fragmentation and flexibility of the cadavers could be performed in further studies.

New Method for Preparing ZnO Layer for Efficient and Stable Organic Solar Cells

Owing to outstanding optoelectronic properties and simple preparation, zinc oxide (ZnO) has widely been used in organic solar cells (OSCs). Although versatile cathode interface materials have been designed in past, ZnO remains indispensable owing to its excellent overall performance. Therefore, solving the persistent problem of residual amine reacting with non-fullerene acceptors will make ZnO superior over other materials, and thus improve the performance and energy budget of OSCs. Herein, a simple, effective, and economical method for removing residual amine in ZnO without distorting ZnO is reported. By accurately comparing the alkalinities of ZnO and residual amine, boric acid (BA) is selected as the amine-removing agent because of its suitable acidic dissociation constant. Moreover, the high water solubility of BA ensures that the post-cleaning process can be easily performed. The work function, electron extraction, and stability of cathode interface layer are optimized through rinsing them with BA. Consequently, the power conversion efficiency (PCE) and stability of OSCs under long-term illumination are significantly improved. The optimal 0.04 and 1.00 cm²  single-junction OSCs are based on PBDB-TF:HDO-4Cl:BTP-eC9 bulk heterojunction output 18.40% and 17.42% efficiencies, respectively. Furthermore, tandem OSCs based on the BA-treated ZnO exhibit a 19.56% PCE, demonstrating the reliability of this method.

Solid-State Luminescent Materials with Multiple Emission Colors and Near-Unity Quantum Yield

Developing solid luminescent materials with a unity quantum yield and tunable emission color is promising, although it is still a difficult task. A straightforward heat-treatment method has been developed to load 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) into the matrix of boric acid (BA) to produce powders with a near-unity quantum yield and tunable emission color from yellow to green. Our results suggest that the emission of the powders originates from PTCDA, and the tunability of the emission color is caused by the hydrolysis of PTCDA in the alkaline environment. The near-unity quantum yield is attributed to the BA matrix, which confines PTCDA. In addition, the powder also shows excellent thermal stability that allows its application in light-emitting diodes. The above results are important for the development of solid-state luminescent materials for various applications, and also provide a clue for studying the emission properties of luminescent materials.

The dual role of boron in vitro neurotoxication of glioblastoma cells via SEMA3F/NRP2 and ferroptosis signaling pathways

Glioblastoma multiform (GBM) is a malignant tumor cancer that originates from the star-shaped glial support tissues, namely astrocytes, and it is associated with a poor prognosis in the brain. The GBM has no cure, and chemotherapy, radiation therapy, and immunotherapy are all ineffective. A certain dose of Boric acid (BA) has many biochemical effects, conspicuously over antioxidant/oxidant rates. This article sought to investigate the modifies of various doses of BA on the glioblastoma concerning cytotoxicity, ferroptosis, apoptosis, and semaphorin-neuropilin signaling pathway. The Cytotoxic activity and cell viability of BA (0.39-25 mM) in C6 cells were tested at 24, 48, and 72 h using 3-(4,5-dimethylthiazol, 2-yl)-2,5-diphenyl tetrazolium bromide (MTT). The IC₅₀ concentration of BA at 1.56 mM was found and cell lysate used for biochemical analysis. Glutathione peroxidase 4 (GPx4) and ACLS4 levels of ferroptosis, levels of total antioxidant (TAS) and oxidant (TAS) parameters, malondialdehyde (MDA), apoptotic proteins as caspase 3 (CASP3) and caspase 7 (CASP7) were measured. The ferroptosis, semaphoring-neuropilin, apoptotic pathway markers and cell counts were analyzed with flow cytometry, Q-PCR, Western and Elisa technique in the C6 cell lysate. BA triggered ferroptosis in the C6 cells dose-dependently, affecting the semaphorin pathway, so reducing proliferation with apoptotic compared with untreated cell as control group (p < .05). This study revealed that BA, defined as trace element and natural compound, incubated ferroptosis, total oxidant molecules, and caspase protein in a dose-dependently by disrupting SEMA3F in tumor cells.

Trichomoniasis refractory to 5-nitroimidazole therapy in Trinidad

Trichomoniasis is the most common non-viral sexually transmitted infection (STI) occurring worldwide and the majority of infected persons (70-85%) have mild or no genital symptoms. Symptoms in women may include a vaginal discharge which may be associated with vulval irritation and most infections can be effectively treated with metronidazole 500mg bd for seven days. Trichomoniasis unresponsive to 5-nitroimidazole therapy is uncommon but results in substantial therapeutic challenges, especially in resource limited countries. We present such a case which was eventually treated with a low-cost intravaginal combination of boric acid and clotrimazole cream.

Structural Determination of the Nanocomplex of Borate with Styrene-Maleic Acid Copolymer-Conjugated Glucosamine Used as a Multifunctional Anticancer Drug

The development of effective anticancer drugs is essential for chemotherapy that specifically targets cancer tissues. We recently synthesized a multifunctional water-soluble anticancer polymer drug consisting of styrene-maleic acid copolymer (SMA) conjugated with glucosamine and boric acid (BA) (SGB complex). It demonstrated about 10 times higher tumor-selective accumulation compared with accumulation in normal tissues because of the enhanced permeability and retention effect, and it inhibited tumor growth via glycolysis inhibition, mitochondrial damage, and thermal neutron irradiation. Gaining insight into the anticancer effects of this SGB complex requires a determination of its structure. We therefore investigated the chemical structure of the SGB complex by means of nuclear magnetic resonance, infrared (IR) spectroscopy, and liquid chromatography-mass spectrometry. To establish the chemical structure of the SGB complex, we synthesized a simple model compound─maleic acid-glucosamine (MAG) conjugate─by using a maleic anhydride (MA) monomer unit instead of the SMA polymer. We obtained two MAG-BA complexes (MAGB) with molecular weights of 325 and 343 after the MAG reaction with BA. We confirmed, by using IR spectroscopy, that MAGB formed a stable complex via an amide bond between MA and glucosamine and that BA bound to glucosamine via a diol bond. As a result of this chemical design, identified via analysis of MAGB, the SGB complex can release BA and demonstrate toxicity to cancer cells through inhibition of lactate secretion in mild hypoxia that mimics the tumor microenvironment. For clinical application of the SGB complex, we confirmed that this complex is stable in the presence of serum. These findings confirm that our design of the SGB complex has various advantages in targeting solid cancers and exerting therapeutic effects when combined with neutron irradiation.

Enhancement of ferroptosis by boric acid and its potential use as chemosensitizer in anticancer chemotherapy

Ferroptosis is a form of regulated cell death (RCD) characterized by intracellular iron ion accumulation and reactive oxygen species (ROS)-induced lipid peroxidation. Ferroptosis in cancer and ferroptosis-related anticancer drugs have recently gained interest in the field of cancer treatment. Boron is an essential trace element playing an important role in several biological processes. Recent studies have described contrasting effects of boric acid (BA) in cancer cells, ranging from protective/mitogenic to damaging/antiproliferative. Interestingly, boron has been shown to interfere with critical factors involved in ferroptosis-intracellular glutathione and lipid peroxidation in the first place. Thus, the present study was aimed to verify the ability of boron to modulate the ferroptotic process in HepG2 cells, a model of hepatocellular carcinoma. Our results indicate that-when used at high, pharmacological concentrations-BA can increase intracellular ROS, glutathione, and TBARS levels, and enhance ferroptosis induced by RSL3 and erastin. Also, high BA concentrations can directly induce ferroptosis, and such BA-induced ferroptosis can add to the cytotoxic effects of anticancer drugs sorafenib, doxorubicin and cisplatin. These observations suggest that BA could be exploited as a chemo-sensitizer agent in order to overcome cancer drug resistance in selected conditions. However, the possibility of reaching suitably high concentrations of BA in the tumor microenvironment will need to be further investigated.

Silicon and boron on cauliflower induce attractiveness and mortality in Plutella xylostella

BACKGROUND

Boron (B) and silicon (Si) are fundamental for brassica nutrition, and in some cases, they have potential as an insecticide. Plutella xylostella (L.) (Lepidoptera: Plutellidae), one of the most economically important agricultural pests, is difficult to control due to the resistance to insecticides and the absence of alternative control methods.

RESULTS

Cauliflower leaves sprayed with Si and B showed a higher concentration of the beneficial element and micronutrient, respectively. When evaluating the firmness of the cauliflower leaves, it was found that the plants with leaf sprayings of Si and B did not differ statistically from each other. However, they showed an increase in firmness, in relation to the plants of the control treatment. Leaf spraying of Si and B on cauliflower did not influence the number of eggs/female. The attractiveness index showed that both Si and B applications stimulated the presence of second instar larvae, being more stimulating in relation to the control treatment. However, the use of Si and B in isolation showed a positive result, since it caused high mortality in diamondback moth larvae compared to the control treatment.

CONCLUSION

The application of both foliar fertilizers positively affects the attractiveness index of the larvae, being attractive; however, both Si and B caused high mortality (~80%). The results showed that Si and B have the potential to control P. xylostella and serve as a basis for alternative pest management in brassica crops. © 2022 Society of Chemical Industry.

Boron- and Boric Acid-Treated Titanium Implant Surfaces in Sheep Tibia: A Histologic, Histomorphometric and Mechanical Study

The aim of this study was to compare the topographical, chemical and osseointegration characteristics of sandblasting and acid-etching (SLA) surfaces and dental implants treated by boron compounds. Titanium (Ti) disks (n = 20) were modified using boron (B) and boric acid (H3BO3) and then compared with the conventional SLA surface via surface topographic characterizations. Dental implants (3.5 mm in diameter and 8 mm in length) with the experimental surfaces (n = 96) were inserted into the tibias of six sheep, which were left to heal for 3 and 7 weeks. Histologic, histomorphometric (bone−implant contact (BIC%)) and mechanical tests (removal torque value (RTV)) were performed. The boron-coated surface (BC group) was smoother (Rz: 4.51 μm ± 0.13) than the SLA (5.86 μm ± 0.80) and the SLA-B (5.75 μm ± 0.64) groups (p = 0.033). After 3 weeks, the highest mean RTV was found in the SLA group (37 N/cm ± 2.87), and the difference compared with the BC group (30 N/cm ± 2.60) was statistically significant (p = 0.004). After 7 weeks, the mean RTV was >80 N/cm in all groups; the highest was measured in the H3BO3-treated (BS) group (89 N/cm ± 1.53) (p < 0.0001). No statistically significant differences were found in the BIC%s during both healing periods between the groups. H3BO3 seems to be a promising medium for dental implant osseointegration.

Chitosan-Boric Acid Scaffolds for Doxorubicin Delivery in the Osteosarcoma Treatment

Biologically compatible chitosan-based scaffolds have been considered a promising platform for tissue regeneration, tumor treatment, and targeted drug delivery. Chitosan-based scaffolds can be utilized as pH-sensitive drug carriers with targeted drug delivery resulting in less invasive tumor treatments. Further improvement with bioactive ions, such as borate ions, can result in the dual functionality of chitosan carriers provided by simultaneous antitumor efficacy and tissue regeneration. Here, boric acid-containing crosslinked chitosan scaffolds were prepared as delivery systems of doxorubicin, a chemotherapy drug used in the treatment of osteosarcoma. The encapsulation of boric acid was indicated by FTIR spectroscopy, while the ICP-MS analysis indicated the rapid release of boron in phosphate buffer (pH 6.0) and phosphate-buffered saline solution (pH 7.4). The obtained chitosan-boric acid scaffolds exhibit a highly porous and interconnected structure responsible for high swelling capacity, while enzymatic degradation indicated good scaffolds stability during four weeks of incubation at pH 6.0 and 7.4. Furthermore, the release of doxorubicin investigated in phosphate buffers indicated lower doxorubicin concentrations at pH 7.4 with respect to pH 6.0. Finally, the cytotoxicity of prepared doxorubicin-encapsulated scaffolds was evaluated on human sarcoma cells indicating the scaffolds' potential as cytostatic agents.

Effects of Boric Acid and Storage Temperature on the Analysis of Microalbumin Using Aptasensor-Based Fluorescent Detection

The instability of human serum albumin (HSA) in urine samples makes fresh urine a requirement for microalbumin analyses using immunoturbidimetry. Here, we determined the ability of an aptasensor-based fluorescent platform to detect microalbumin in old, boric acid-preserved urine samples. Our results show that the cleavage site of protease enzymes on urine albumin protein differed from the binding position of the aptamer on HSA protein, suggesting the aptasensor may be effective for albumin detection in non-fresh urine. Furthermore, the addition of boric acid in urine samples over a short term (at ambient temperature (T_a) and 4 °C), long term (-20 and -80 °C), and following freeze-thawing (1-3 cycles) did not significantly affect albumin stability, as analyzed using the aptasensor. Therefore, boric acid stabilized has in urine stored over a short- and long-term. Thus, the aptasensor developed by us is applicable for HSA detection in boric acid-preserved urine that has been stored for 7-d at T_a and 4 °C, and in the long-term at -80 °C.

Effects of boric acid and potassium metaborate on cytokine levels and redox stress parameters in a wound model infected with methicillin‑resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) infections are usually found in hospital settings and, frequently, in patients with open wounds. One of the most critical virulence factors affecting the severity and recurrence of infections is the biofilm; increasing antibiotic resistance due to biofilm formation has led to the search for alternative compounds to antibiotics. The present study aimed to use boric acid and potassium metaborate against MRSA infection in a fibroblast wound model. For this purpose, a two-part experiment was designed: First, MRSA strains were used for the test, and both boric acid and potassium metaborate were prepared in microdilution. In the second step, an MRSA wound model was prepared using a fibroblast culture, and treatments with boric acid and potassium metaborate were applied for 24 h. For the evaluation of the effects of treatment, cell viability assay (MTT assay), analysis of redox stress parameters, including total oxidant status and total antioxidant capacity analyses, lactate dehydrogenase analysis and immunohistochemical staining were performed. In addition, IL-1β and IL-10 gene expression levels were assayed. According to the results, potassium metaborate was more effective and exhibited a lower toxicity to fibroblast cells compared to boric acid; moreover, potassium metaborate decreased the level of prooxidant species and increased the antioxidant status more effectively than boric acid. The IL-1β level in the bacteria group was high; however, boric acid and potassium metaborate significantly decreased the expression levels of inflammatory markers, exhibiting the potential to improve the resolution of the lesion. On the whole, the findings of the present study suggest that boric acid and potassium metaborate may be effective on the tested microorganisms.

Plasma Electrolytic Oxidation of Zr-1%Nb Alloy: Effect of Sodium Silicate and Boric Acid Addition to Calcium Acetate-Based Electrolyte

This work aimed at the development of wear and corrosion resistant oxide coatings for medical implants made of zirconium alloy, by plasma electrolytic oxidation (PEO). The effect of sodium silicate and boric acid addition to calcium acetate electrolyte on the coating properties was studied. Different aspects of the PEO coating were investigated: microstructure, electrochemical and wear behavior, wettability and apatite-forming ability. The resultant coatings consist of a dense inner layer 1.4–2.2 µm thick and a porous outer layer. The total thickness of the coating is 12–20 µm. It was found that the coating contains the tetragonal zirconia (70–95%). The obtained coatings show high corrosion resistance and reduce the surface corrosion current by 1–3 orders of magnitude, depending on the electrolyte additive, compared to the uncoated surface. The addition of boric acid to the electrolyte significantly increases the wear resistance of the coating and reduces the coefficient of friction. In terms of the combination of the coating characteristics, the electrolyte with the addition of the alkali and boric acid is recommended as the most effective.

Boric acid and Schiff base-based fluorescent sensor for detection of L-tryptophan in milk and BSA samples

In the present paper, the fluorescence sensor based on Schiff base and boric acid was developed for easy and rapid detection of L-tryptophan in different samples such as milk and bovine serum albumin. The photoluminescence intensity was measured by using fluorescent measurements and the results indicated that the developed fluorescent sensor was exhibited selective, sensitive, reliable determination against L-tryptophan, and a series of various analytes such as cations, amino acids, and organic compounds were used to investigate the selectivity of the fluorescent chemosensor. The limit of detection and linear range of the chemosensor were calculated as 0.82 μM, and 0.1-500 μM, respectively. The performance of the chemosensor was evaluated in terms of selectivity, reversible usage, stability, and interference/anti-interference. The developed chemosensor was exhibited excellent photostability, and it was a great potential application of L-tryptophan in bovine serum albumin and milk samples.

Nanoinhibitory Impacts of Salicylic Acid, Glycyrrhizic Acid Ammonium Salt, and Boric Acid Nanoparticles against Phytoplasma Associated with Faba Bean

Phytoplasmas are economically important plant pathogenic bacterial diseases, causing severe yield losses worldwide. In this study, we tested nanoformulations such as glycyrrhizic acid ammonium salt (GAS), salicylic acid (SA), and boric acid (BA) as novel antimicrobial agents inducing the resistance against the phytoplasma disease in faba bean. The nanoparticles (NP) were foliar-applied to naturally phytoplasma-infected faba bean with three concentrations from each of SA, GAS, and BA, under field conditions. Nested PCR (using universal primer pairs P1/P7 and R16F2n/R16R2) were reacted positively with all symptomatic samples and gave a product size of approximately 1200 bp, while the healthy plant gave no results. Transmission electron microscopy examinations of phytoplasma-infected faba bean plants treated with different nanoparticles revealed that severe damage occurred in phytoplasma particle’s structure, degradation, malformation, lysis in the cell membrane, and the cytoplasmic leakage followed by complete lysis of phytoplasma cells. Exogenous application of GAS-NP (1.68 µM), SA-NP (0.28 µM), and BA-NP (0.124 µM) suppressed the infection percentage of phytoplasma by 75%, 50%, and 20%, and the disease severity by 84%, 64%, and 54%, respectively. Foliar application of nanoparticles improved Fv/Fm (maximum quantum efficiency of PSII Photochemistry), PI (the performance index), SPAD chlorophyll (the relative chlorophyll content), shoots height, and leaves number, thus inducing recovery of the plant biomass and green pods yield. The most effective treatment was GAS-NP at 1.68 µM that mediated substantial increases in the shoots’ fresh weight, shoots’ dry weight, number of pods per plant, and green pods yield by 230%, 244%, 202% and 178%, respectively, compared to those of infected plants not sprayed with nanoparticles. This study demonstrated the utility of using nanoparticles, particularly GAS-NP at 1.68 µM to suppress the phytoplasma infection.

Flower Mimics Roll Out Multicolored Carpets to Lure and Kill the House Fly

Flowers and their spatial clustering are important parameters that mediate the foraging behavior and visitation rate of pollinating insects. Visual stimuli are crucial for triggering behavioral changes in the house fly, Musca domestica, which regularly visits plants for feeding and reproduction. The success of bait technology, which is the principal means of combatting flies, is adversely affected by reduced attractiveness and ineffective application techniques. Despite evidence that house flies have color vision capacity, respond to flowers, and exhibit color and pattern preference, the potential of artificial flowers as attractive factors has not been explored. The present study was performed to investigate whether artificial floral designs can lure and kill house flies. Starved wild house flies were presented with equal opportunities to acquire sugar meals, to which boric acid had been added as a toxin, from one flower arrangement (blue-dominated design, BDD; yellow-dominated design, YDD; or pink-dominated design, PDD), and a non-toxic white design (WDD). We also allowed house flies to forage within an enclosure containing two non-toxic floral designs (WDDs). The differences in mortality between the two environments with and without toxicant were examined. The survival rate of Musca domestica was extremely high when WDDs containing non-toxic sugar sources were the only feeding sites available. When given an option to forage in an environment containing a BDD and a WDD, house flies showed a high mortality rate (76%) compared to their counterparts maintained in the WDD environment (2%). When kept in an enclosure containing one YDD and a WDD, flies showed a mortality rate of 88%; however, no mortality occurred among flies confined to a compound with a WDD pair. When provided an even chance of foraging in an enclosure containing a mixed pair of floral arrangements (PDD and WDD) and another with two WDDs, flies showed a higher mortality rate (78%) in the first environment. However, the maximum survival rate (100%) was seen in the WDD environment. Exposure to YDD tended to result in a greater mortality rate than with the two other floral designs. Mortality gradually increased with time among flies exposed to tested artificial floral designs. The results presented here clearly indicated that artificial flower arrangements with a toxic sugar reward were strikingly attractive for house flies when their preferred color (white) was present. These observations offer novel possibilities for future development of flower mimic-based house fly control.

Three regions of the NIP5;1 promoter are required for expression in different cell types in Arabidopsis thaliana root

Arabidopsis thaliana NIP5;1, a boric acid diffusion facilitator, is involved in the acquisition of boron (B) from soil for growth under B limitation. AtNIP5;1 is expressed mainly in roots, where its expression is highest in the root cap and elongation zone. Here, we studied the role of the AtNIP5;1 promoter in the expression of this gene in roots. We fused a series of AtNIP5;1 promoter variants with deleted 5'-fragments to the GUS reporter gene and investigated the expression patterns by histochemical staining. We found that three regions of the AtNIP5;1 promoter are required for specific expression in the root cap and elongation zone (-880 to -863 bp from the translation start site), distal side of the differentiation zone (-747 to -722 bp), and basal side of the differentiation zone (-661 and -621 bp). The results suggest that at least three regions of the AtNIP5;1 promoter each confer different cell-type-specific expression.

Utility of Ethylene-Diamine-Tetraacetic Acid Buffer Solution With Boric Acid for Immunostaining of Specimens Stored for an Extended Period

Antigen modification and denaturation are recognized causes of false negatives in immunostaining. Specimens that have been stored for an extended period at room temperature show decreased immunoreactivity and may mislead the diagnosis. Studies of the molecular targeting of drugs often involve immunostaining of previous samples and, in some situations, only unstained specimens can be used. The present study aimed to develop an effective staining method to recover antigen activation in unstained specimens stored for an extended period by using ethylene-diamine-tetraacetic acid (EDTA) buffer solution with boric acid. We compared several commonly used antigen retrieval solutions and found that Tris-borate-EDTA (TBE) buffer solution with a pH ≥8.3 provided sufficient antigen retrieval. However, pH values higher than 8.3 (9.0, 10.0, and 11.0) frequently caused severe tissue damage. Thus, TBE with pH 8.3 was the most suitable antigen retrieval solution for recovering the antigenicity of specimens stored for an extended period. This procedure may allow useful immunohistochemical information, even from sections that have been stored for an extended period.

Newly Designed Mesoporous Silica and Organosilica Nanostructures Based on Pentablock Copolymer Templates in Weakly Acidic Media

We developed a new category of porous silica and organosilicas nanostructures in a facile method based on weakly acidic aqueous-ethanol media by utilizing two different pentablock copolymer templates of type PLGA-PEO-PPO-PEO-PLGA. Pluronic block templates were used mainly to prepare these pentablock copolymers with different molecular weights and volume ratios. Silica precursor tetraethyl orthosilicate and organosilicas precursor 1,4-bis(triethoxysilyl)benzene have been used as main source for synthesizing the silica and organosilicas samples. Weak Lewis acids iron(III) chloride hexahydrate, aluminum(III) chloride hexahydrate, and boric acid were utilized as catalyst instead of any strong inorganic acids and the molar ratio of catalyst/precursor has been optimized to 1–2 for preparation of ordered mesostructures. Reaction temperatures have been optimized to 25 °C for pure silica and both 25 °C as well as 40 °C for organosilicas to get the best result for mesostructures. A detailed analysis by using various analytical techniques like synchrotron small angle X-ray scattering, nitrogen sorption, transmission electron microscopy, scanning electron microscope, solid-state ²⁹Si CP-MAS nuclear magnetic resonance (NMR), and so on has revealed well developed mesostructures with surface area of 388–836 m²/g for silica and 210–691 m²/g for organosilica samples, respectively. Furthermore, bimodal typepores have been observed from pore size distribution plot of the samples. Thermal stability of the materials was up to 400 °C as analyzed by thermogravimetric analysis.

Effects of 3% Boric Acid Solution on Cutaneous Candida albicans Infection and Microecological Flora Mice

To determine the effect of 3% boric acid solution on cutaneous infections with Candida albicans (CA) in mice and its effect on skin microflora. Female mice were divided into three groups, with 18 mice in each group. Two injection sites were randomly selected, and 0.1 mL of CA mycelium suspension was injected into the epidermis and dermis of the back of mice. Group N was treated with sterile water for injection (SWFI). We observed the clinical manifestations, fungal fluorescence microscopic examination and colony count. Group B were hydropathically compressed with 3% boric acid solution for 30 min every 12 h. Group M was treated with SWFI, and group N was not treated. One week later, each group was observed with naked eyes, and skin samples were collected. The effect of boric acid on skin microflora was measured using Internal Transcribed Spacer Identification (ITS) and 16S rRNA genes. There were no significant changes in group M. In group B, the degree of skin injury was alleviated, the wounds healed markedly, and the exudate amount decreased. The effective rate of group B (83%) was significantly higher than that of group M (25%) (P < 0.05). The relative average abundance of Candida (P < 0.0001) and CA (P < 0.05) in group B was significantly lower than that in group M. Compared with group M, the microbial richness of group B changed little, but the diversity decreased. The flora structure of group B was significantly different from that of group M, but like that of group N. In group B, the abundance of Proteobacteria (P < 0.001), Enterobacteriaceae (P < 0.001), and Escherichia-Shigella (P < 0.001) was significantly greater, and the abundance of Firmicutes (P < 0.001), Staphylococcaceae (P < 0.001), and Staphylococcus (P < 0.001) were significantly lower. The 3% boric acid solution significantly reduced the symptoms of skin infection with Candida albicans. It inhibited the growth of Candida albicans and CA, reduced the diversity of skin microorganisms, increased the abundance of Proteobacteria, Enterobacteriaceae, Escherichia-Shigella, and reduced the abundance of Firmicutes, Staphylococcaceae, Staphylococcus.

Antifungal activity of boric acid, triclosan and zinc oxide against different clinically relevant Candida species

BACKGROUND

The genus Candida includes about 200 different species, but only a few are able to produce disease in humans. The species responsible for the highest proportion of human infections is Candida albicans. However, in the last two decades there has been an increase in the proportion of infections caused by other Candida species, including C. glabrata (Nakaseomyces glabrata), C. parapsilosis, C. tropicalis, C. krusei (Pichia kudriavzevi) and more recently C. auris. Decolonisation of patients has been used as an infection control strategy for bacterial infections, but information about decolonisation products used in clinical practice for Candida and other fungal pathogens is limited. Compounds with antimicrobial activity, such as triclosan (TR), boric acid (BA) and zinc oxide (ZO), are mainly used in personal care products. These products can be used for long periods of time without an abrasive skin effect and are a possible alternative for patient decolonisation in healthcare settings.

OBJECTIVE

The aim of this study was to evaluate the antifungal activity of boric acid (BA), triclosan (TR) and zinc oxide (ZO), individually and combined, against clinically relevant Candida species.

MATERIALS AND METHODS

Compounds to be screened for antifungal activity were evaluated at different concentrations, alone, and combined, using a well diffusion assay. The statistical evaluation was performed using analysis of variance (ANOVA) and a post hoc analysis using the multiple comparisons method.

RESULTS

Individually, BA and TR showed antifungal activity against all Candida species evaluated but ZO did not show any antifungal activity. Mixtures of BA [5%]-TR [0.2%]; BA [5%]-TR [0.3%]; BA [5%]-TR [0.2%]-ZO [8.6%]; and BA [5%]-TR [0.2%]-ZO [25%] yielded the highest antifungal activity. An increased antifungal effect was observed in some mixtures when compared with individual compounds.

CONCLUSIONS

We demonstrated antifungal activity of BA and TR against multiple Candida species, including against a clade of the emerging healthcare-associated pathogen C. auris. Additionally, this study shows enhancement of the antifungal effect and no antagonism among the mixtures of these compounds. Further research is needed to determine whether these compounds can reduce the burden of Candida on skin.

Towards Advances in Molecular Understanding of Boric Acid Biocatalyzed Ring-Opening (Co)Polymerization of δ-Valerolactone in the Presence of Ethylene Glycol as an Initiator

Following our previous studies on the molecular level structure of (co)oligoesters obtained via anionic homo- and co-polymerization of novel β-substituted β-lactones, prepared by the atmospheric pressure carbonylation reaction of respective epoxides, the boric acid biocatalyzed ring-opening (co)polymerization of δ-valerolactone has been studied. As a co-monomer the 6-methy-ε-caprolactone, prepared by the one-pot oxidation of respective alcohol, and ethylene glycol as polymerization initiator were used. The obtained copolymers were characterized by 1H-NMR, GPC and ESI-MS, respectively in order to confirm their chemical structures and identity. Subsequently, tandem mass spectrometry (MS-MS studies) via collision-induced dissociation were utilized to characterize the fragmentation pattern. ESI-MS and NMR analyses confirmed the formation of random linear copolymer chains composed of different polyester repeat units. MS-MS experiments showed that fragmentation proceeds via ester bound cleavage along the (co)polyester chains. The innovative aspect of this contribution is related to the elaboration of the telechelic (co)polymers end-capped with hydroxyl end groups and well-defined molecular architectures, which could facilitate the development of new flexible macromolecular systems for potential biomedical applications.

Development and Demonstration of Low-Impact IPM Strategy to Control Argentine Ants (Hymenoptera: Formicidae) in Urban Residential Settings

Argentine ants are one of the most common nuisance pest ants treated by pest management professionals (PMPs) in southern and western urban residential areas of the United States. Two new technologies (spraying with a pheromone adjuvant and using a biodegradable hydrogel bait delivery method) were used to develop a unique low-impact integrated pest management (IPM) protocol for Argentine ants in urban residential settings. The IPM protocol included a one-time perimeter spray treatment with 0.03% fipronil (mixed with a pheromone adjuvant) at the beginning of the ant season to achieve a quick knockdown. The initial spray application was followed by a biodegradable hydrogel baiting with 1% boric acid as a maintenance treatment. This low-impact IPM protocol was compared with two other conventional methods: (1) one initial fipronil application and one pyrethroid spray application for maintenance, or (2) one initial fipronil application and one essential oil insecticide spray application for maintenance. Based on Argentine ant foraging activity, the protocols were compared for their control efficacy. Insecticide use information and treatment time were also recorded and compared among different treatment protocols. Our results provided empirical data to support the effectiveness and economic feasibility of the low-impact IPM protocol for managing Argentine ants in urban residential settings.