Boric Research Articles

Evaluation of Possible Toxic Effects of Boric Acid in Palourde Clam (Ruditapes decussatus) Through Histological Changes and Oxidative Responses.

The extensive utilization of boric acid, particularly in industrial and agricultural sectors, also engenders concerns regarding the toxicity of boron and its derivatives. Particularly, the behavior of boric acid at increasing concentrations in aquatic ecosystems remains poorly understood. In light of these concerns, this study aimed to investigate the toxicity of boric acid in bivalves, which occupy a critical position in the food chain. Specimens of Ruditapes decussatus, which had not been previously exposed to any pollutants and were cultivated under controlled conditions, were subjected to three different concentrations of boric acid (0.05mg/L, 0.5mg/L, and 5mg/L) in vitro for 96h. Following the exposure period, the specimens were assessed for histological changes (the mantle, gill, and digestive gland) and specific oxidative parameters (the gill and digestive gland), including superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase, and lipid peroxidation (LPO). The research findings indicated that boric acid primarily induced oxidative damage at the applied concentrations and increased antioxidant levels (p < 0.05). Moreover, although no significant histopathological abnormalities were observed in the examined histological sections, subtle changes were noted. This study evaluated the potential adverse effects of boric acid on bivalves, which are crucial components of the aquatic food chain, utilizing histological and specific physiological parameters following its introduction into aquatic environments. It is anticipated that the findings of this study will contribute to the development of new insights and perspectives regarding the extensive use of boric acid.

Carbon Dots-Inked Paper with Single/Two-Photon Excited Dual-Mode Thermochromic Afterglow for Advanced Dynamic Information Encryption.

Achieving thermochromic afterglow (TCAG) in a single material for advanced information encryption remains a significant challenge. Herein, TCAG in carbon dots (CDs)-inked paper (CDs@Paper) was achieved by tuning the temperature-dependent dual-mode afterglow of room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF). The CDs were synthesized through thermal treatment of levofloxacin in melting boric acid with post-purification via dialysis. CDs@Paper exhibited TCAG and excitation-dependent afterglow color properties. The TCAG of CDs@Paper exhibited dynamic color changes from blue at high temperatures to yellow at low temperatures by adjusting the proportion of the temperature-dependent TADF and phosphorescence. Notably, two-photon afterglow in CDs-based afterglow materials and time-dependent two-photon afterglow colors were achieved for the first time. Moreover, leveraging the opposite emission responses of phosphorescence and TADF to temperature, CDs@Paper demonstrated TCAG with temperature-sensing capabilities across a wide temperature range. Furthermore, a CDs@Paper-based 3D code containing color and temperature information was successfully developed for advanced dynamic information encryption. This article is protected by copyright. All rights reserved.

Fully Exploiting Clusterization‐Triggered Room Temperature Phosphorescence of Cellulose by Stepwise Rigidification for Long‐Lived and Excitation Wavelength‐Dependent Afterglows

AbstractAchieving long‐lived room temperature phosphorescence (RTP) in nonconventional luminophores devoid of any conjugated units is fascinating but remains formidably challenging due to their low intersystem crossing efficiency and strong nonradiative decay. Herein, a stepwise rigidification strategy is developed to suppress the nonradiative decay and fully exploit the clusterization‐triggered RTP performance of cellulose. Specifically, the crystallinity is enhanced, and hydrogen bonding is reconstructed by a directed oxidation‐reduction reaction to afford a more rigid environment of cellulose; then, the reconstructed cellulose is further cross‐linked by boric acid to activate double confinement architecture. In return, the phosphorescence lifetime of the target cellulose increases almost one order of magnitude, and the phosphorescence quantum yield increases more than 27 folds. Moreover, the afterglow of the RTP cellulose can be regulated from blue to green by changing excitation wavelength, which is useful for advanced information encryption and anti‐counterfeiting. The stepwise rigidification strategy is also applicable for preparing other nature polysaccharides‐based long‐lived RTP materials, such as chitosan and sodium alginate. Nature polysaccharides are completely biodegradable; thus, this work paves the way for the development of eco‐friendly and practical color‐variable RTP materials.

Effect of Temperature and Concentration on the Corrosion Behavior of 42CrMoE Low Alloy Steel in Boric Acid Solution

Effect of Temperature and Concentration on the Corrosion Behavior of 42CrMoE Low Alloy Steel in Boric Acid Solution

Protective Effect of Boric Acid Against Ochratoxin A-Induced Toxic Effects in Human Embryonal Kidney Cells (HEK293): A Study on Cytotoxic, Genotoxic, Oxidative, and Apoptotic Effects.

The present study evaluates the protective properties of boric acid (BA) against the toxic effects induced by ochratoxin A (OTA) in human embryonic kidney cells (HEK293). The focus is on various parameters such as cytotoxicity, genotoxicity, oxidative stress, and apoptosis. OTA is a known mycotoxin that has harmful effects on the liver, kidneys, brain, and nervous system. BA, on the other hand, a boron-based compound, is known for its potential as a vital micronutrient with important cellular functions. The results show that BA administration not only increases cell viability but also mitigates the cytotoxic effects of OTA. This is evidenced by a reduction in the release of lactate dehydrogenase (LDH), indicating less damage to cell membranes. In addition, BA shows efficacy in reducing genotoxic effects, as the frequency of micronucleus (MN) and chromosomal aberrations (CA) decreases significantly, suggesting a protective role against DNA damage. In addition, the study shows that treatment with BA leads to a decrease in oxidative stress markers, highlighting its potential as a therapeutic intervention against the deleterious effects of OTA. These results emphasize the need for further research into the protective mechanisms of boron, particularly BA, in combating cell damage caused by OTA.

Synergistic effect of seaweed extract and boric acid and/or calcium chloride on productivity and physico-chemical properties of Valencia orange.

Many citrus species and cultivars are grown successfully in tropical and subtropical countries, as well as in arid and semi-arid regions with low levels of organic matter and low cation exchange, resulting in lower nutrient uptake by the plant. The essential nutrients needed for citrus flowering and fruit set are limited in winter due to a reduction in transpiration rate, negatively effecting vegetative growth, flowering, yield, and fruit quality. The present investigation was carried out to assess the nutritional status, fruit yield parameters, and fruit quality of Valencia orange trees after foliar spraying of seaweed extract (SW) combined with calcium chloride and boric acid and their combinations in the 2020/2021 and 2021/2022 seasons. The treatments were arranged in a split-plot design (three levels spraying seaweed extract × four levels spraying calcium chloride and boric acid and their combinations × four replicates × one tree/replicate). The results indicated that all of the characteristics measured, including leaf chlorophyll, leaf mineral contents, fruit yield parameters, fruit physical properties, and fruit chemical properties, were significantly affected by the foliar spraying of seaweed extract (SW) combined with calcium chloride and boric acid and their combinations. Although all treatments increased the productivity and the physical and chemical properties of Valencia orange fruits compared to the control, a treatment of 10 g/L SW combined with 0.5 g/L boric acid and 1 g/L calcium chloride produced superior results. This ratio of SW, boric acid, and calcium chloride is therefore recommended to enhance productivity and improve the physico-chemical properties of Valencia orange for greater fruit yield.

Concentration-Dependent Effects of Boric Acid on Osteogenic Differentiation of Vascular Smooth Muscle Cells.

Vascular calcification can be triggered by oxidative stress and inflammation. Although boron possesses antioxidant and anti-inflammatory properties, its effect on osteogenic differentiation of vascular smooth muscle cells (VSMCs) has yet to be examined. Therefore, we aimed to investigate the effect of boric acid (BA), the main form of boron in body fluids, on the osteogenic differentiation of VSMCs. Following the isolation of VSMCs, the effects of BA on cell proliferation were determined by MTT. The impact of various BA concentrations on the osteogenic differentiation of VSMCs was evaluated by Alizarin red S and alkaline phosphatase (ALP) stainings and the o-cresolphthalein complexone method. In addition, mRNA expressions of osteogenic-related (Runx2 and ALP) and antioxidant system-related genes (Nrf2 and Nqo1) were detected using qRT-PCR analysis. BA treatments did not alter the proliferation of VSMCs. Osteogenic differentiation of VSMCs treated with 100 and 500μM BA (moderate and high plasma concentrations) was no different from untreated cells. However, increased osteogenic differentiation was observed with the lowest blood level (2μM) and extremely high BA concentration (1000μM). Consistent with these results, mRNA expression of Runx2 increased with 2 and 1000μM BA treatments, while Nrf2 and Nqo1 expressions increased significantly with 100 and 500μM BA. BA has different effects on VSMCs at various concentrations. The low blood level and too high BA concentration appear detrimental as they increase the osteogenic differentiation of VSMCs in vitro. We propose to investigate BA's effects and mechanism of action on vascular calcification in vivo.

Development of HDPE/natural fiberboard nanocomposite reinforced Bi2O3/BaO and H3BO3: A sustainable approach for gamma and neutron shielding application

AbstractRadiation shielding materials significantly contribute to various fields. In this research, a new eco‐friendly nanocomposite shielding material based on high‐density polyethylene (HDPE) and natural fiberboard (NF) with different concentrations of barium oxide nanowires (BaO), bismuth oxide nanorods (Bi2O3), and boric acid (H3BO3) is constructed and investigated for 137Cs, 60Co gamma ray, and 142Am–Be neutron sources. Mechanical and physical testing and thermal analysis were conducted to assess the impact of nanostructure incorporation on the structural integrity and thermal stability of the nanocomposite. The 60Co gamma and neutron attenuation properties were evaluated using the appropriate radiation sources. The transmission and absorption coefficients of the nanocomposites were measured. The results demonstrated that HDPE/NF filled with BaO, Bi2O3 nanostructure, and boric acid has higher tensile strength and thermal stability than unfilled HDPE/NF. The results displayed that the HDPE/NF filled with 1.5% Bi2O3 and 1.5% BaO improved gamma attenuation and also HDPE/NF/10% boric acid had a high value. The outcomes of this research provide valuable insights into the design and fabrication of radiation shielding materials by understanding the relationship between nanoparticle concentration, radiation attenuation properties, and the mechanical and thermal characteristics of the nanocomposite. This study aims to optimize the performance and applicability of HDPE/NF nanocomposites for radiation protection applications.Highlights Synthesis of BaO nanowires and bismuth oxide (Bi2O3) nanorods by hydrothermal simple method. Fabrication and characterization of a new HDPE/natural fiberboard (NF) nanocomposite containing BaO/Bi2O3/H3BO3 as an eco‐friendly additive. The HDPE/NF/1.5% BaO/1.5% Bi2O3 nanocomposite has better tensile strength and more thermal stability. Usage of HDPE/NF/1.5% BaO/1.5% Bi2O3 nanocomposite that should be utilized for radiation shielding. Usage of HDPE/NF/1.5% BaO/1.5% Bi2O3/10% H3BO3 nanocomposite that should be utilized for neutron attenuation performance.

Mitigating Fruit Cracking and Premature Dropping in Bael (Aegle marmelos) cv. NB-9 under Subtropical Conditions: Evaluating the Effects of Bio-formulations and Boric Acid

The present investigation entitled “Mitigating Fruit Cracking and Premature Dropping in Bael (Aegle marmelos) cv. NB-9 under Subtropical Conditions: Evaluating the Effects of Bio-formulations and Boric Acid” was carried out during the year 2022-2023 at Main Experimental Station, Department of Fruit Science, College of Horticulture &amp; Forestry, A.N.D.U.A.&amp;T., Narendra Nagar (Kumarganj), Ayodhya, Uttar Pradesh, India (Lat 26.540849° Long 81.830421°). Application of various bio-formulations and boric acid with eco-friendly materials to study the various vegetative properties, cracking, fruit drop and effect on the vegetative growth of fruit. The experiment was laid down in randomized block design (RBD) with (12) treatments and (03) replications. The experiment consists of 12 treatments including control, T1 (Control), T2 (FYM 50 Kg), T3 (FYM 100 Kg), T4 (Boric acid 200g), T5 (Boric acid 400g), T6 (Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]), T7 (FYM 50Kg + Boric acid 200g), T8 (FYM 50Kg + Boric acid 400g), T9 (FYM 50Kg +Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]), T10 (FYM 100Kg + Boric acid 200g), T11 (FYM 100 Kg + Boric acid 400g) and T12 (FYM 100Kg +Biofertilizer 250g/plant [100g Azotobacter + 100g Biovita + 50g PSB]) was used for this study. The results revealed that treatment T7 outperformed the rest with minimum fruit cracking (1.53%), fruit drop (76.20%), the maximum number of flowers per plant (171.19), day-to-flowering (31.38) and yield (181.69 q/ha) was most effective in a vegetative quality and yield point of view. Thus, the treatment combination T7 is therefore recommended for application to Bael trees in subtropical conditions to obtain high yields with better quality fruits.

Applying Boron by Fertigation or as a Foliar Fertilizer Is More Effective than Soil Applications in Northern Highbush Blueberry

Boron (B) is often deficient in many fruit crops, including blueberry (Vaccinium sp.). The objective of the present study was to evaluate different methods for applying B fertilizers to two commercial cultivars of northern highbush blueberry (V. corymbosum Earliblue and Aurora) in western Oregon, USA. Treatments included soil application of sodium tetraborate in early April (before bloom), foliar application of boric acid in late April (during bloom or petal fall), weekly fertigation with boric acid from April through July, and a control with no B. The plants were irrigated by drip, and the fertilizers were applied for two consecutive seasons at a total rate of 1.5 kg·ha−1 B per year. Each method of fertilizer application increased the concentration of B in the soil solution relative to the control, but fertigation was the only treatment that increased extractable soil B to the recommended level of 0.5 to 1.0 mg·kg−1 B. In terms of plant nutrition, foliar application of B was the most effective method for increasing the concentration of B in the leaves, roots, and fruit, followed by fertigation. Soil application of B, on the other hand, was relatively ineffective and, after 2 years, only increased the concentration of B in the leaves of ‘Earliblue’. Although leaf B levels were initially deficient at the site (&lt;30 ppm B), none of the B application methods had any effect on yield, berry weight, fruit firmness, or titratable acidity of the fruit in either cultivar. However, foliar applied B resulted in higher concentrations of soluble solids in the fruit than no B or soil applied B in ‘Earliblue’, whereas B fertigation resulted in higher concentrations of soluble solids than soil applied B in ‘Aurora’. On the basis of these results, applying B by fertigation or as a foliar spray is recommended over the use of soil applications of B fertilizer in northern highbush blueberry.

Poly(vinyl alcohol) gels cross-linked by boric acid for radiation protection of astronauts

Gels are soft materials composed of hydrophilic polymers cross-linked in water by physical or chemical bonds. Due to their lightweight and water-rich nature, these materials find application in various fields, including the space environment, for radiation protection purposes. In fact, thanks to their high hydrogen content, gels exhibit significant radiation stopping power, resulting in reduced fragmentation of incident particles. This suggests their potential utility in shielding electronic devices and safeguarding astronauts’ health. In this work, cross-linked gels based on poly(vinyl alcohol) (PVA) and boric acid (BA) were fabricated and their properties were investigated using different experimental and modeling techniques. The effect of parameters, such as time and temperature, used for fabricating the PVA/BA gels is assessed. Fourier transform infrared spectroscopy (FTIR) was employed to evaluate the ability of BA to form hybrid interpolymeric bonds with PVA macromolecules. To understand the thermo-mechanical properties and viscoelastic behavior of these gels, dynamic mechanical analysis (DMA) in compression mode was performed. The shielding properties were evaluated in different space radiation environments considering galactic cosmic rays, solar particle events, and low earth orbit radiation using deterministic transport codes. The High charge (Z) and Energy TRaNsport (HZETRN) code was employed to create different cross sections as first output for the selected materials, and then, propagate and transport the ionizing radiation inside the materials. The results highlight several advantages of PVA/BA gels fabricated at room temperature without heat treatments. Firstly, the incorporation of BA allows for a slight increase in water content compared to gels produced without the crosslinker. Additionally, an examination of elastic moduli reveals improved mechanical properties exhibiting approximately twice the elastic modulus of PVA gels. Moreover, the analysis of dosimetry quantities suggests that the radiation protection effectiveness of these gels is comparable to that of pure water, while heat-treated PVA/BA gels exhibit a reduced water content resulting in decreased shielding properties and decreased flexibility. Consequently, PVA/BA gels realized at room temperature appear to be the optimal material between PVA gels and the heat-treated counterparts, making them well-suited for integration into astronaut personal protective equipment.

Boron- and calcium-interspersed cathode-electrolyte interphases on Ni-rich layered oxide cathodes for advanced performance lithium-ion batteries

Although Ni-rich layered oxides (Ni-rich NCM) have become the preferred cathode materials in the electric vehicle market, their unsustainable cycling behavior arising from the extremely high reactivity at the interface has become a formidable challenge. To alleviate this problem, we propose modifying the cathode-electrolyte interphase (CEI) of Ni-rich L-NCM cathodes by incorporating B/Ca functional groups. Dual-functionalized CEI layers are prepared by heating boric acid (H3BO3) and calcium oxide (CaO) in a one-step process. Islands of B- and Ca-functionalized CEI layer are observed at the Ni-rich L-NCM cathode, and the thickness is controlled to approximately 2.4 nm. The B-functional group not only lowers the concentration of residual lithium but also compensates for the longer Li+ migration distance by providing a desirable pathway based on ion-hopping sites. The Ca functional groups increase the mechanical rigidity of the Ni-rich L-NCM cathode, which inhibits the appearance of microcracks. In terms of its cycling behavior, the capacity retention of the cell with the B/Ca-incorporated Ni-rich L-NCM cathode improves markedly (72.4%), whereas the bare Ni-rich L-NCM material only retains 44.3% of its capacity after 100 cycles.

Design of new boron-doped carbon dots for nano-level assay of nebivolol in human plasma and commercial products; Application to greenness assessments

Recently, nanomaterials have attracted a lot of attention due to their potential as effective fluorescent nano-sensor probes. They were distinguishing substitutes for other luminescent techniques, such as fluorescent dyes and luminous derivatization, because of their affordability, environmental friendliness, and special photocatalytic properties. In the suggested work, a straightforward method was used to create boron and nitrogen carbon dots (B@CDs) with a good quantum yield value of 31.15% utilizing boric acid and di-sodium EDTA. For the purpose of characterizing QDs, a variety of instruments were employed, such as transmission electron microscopy, fluorescence spectroscopy, X-ray FTIR, and UV–VIS spectroscopy. Nebivolol (NEB) is a cardiovascular medication used globally to treat congestive heart failure and hypertension, is in the meantime. For this reason, a brand-new, environmentally friendly analytical technique was created to determine the amount of human plasma, uniformity test, and commercial nebivolol (NEB) tablets. After gradually adding NEB, the response of B@CQDs was enhanced at 438 nm (excitation at 371 nm). The calibration graph ranged between 20 and 500 ng mL−1 with a quantification limit (LOQ) of 2.50 ng mL−1 and a detection limit (LOD) of 0.82ng mL−1.

Synthesis of fluorescein-containing polymeric heterogeneous photocatalyst and its applications

A novel fluorescein-containing polymeric photosensitizer (FS-PHEMA) was successfully synthesized and used as an excellent heterogeneous photocatalyst for aerobic photooxidation of thioethers, hydroxylation of aryl boric acids, and oxidative self-coupling of amines. All the reactions could run smoothly upon irradiation of blue LED under aerobic conditions at room temperature. This heterogeneous photosensitizer can be easily separated, recovered, and reused at least 5 times without significant loss of catalytic activity, showing a good potential in practical applications.

Post-synthetic modification of covalent organic framework for efficient adsorption of organochlorine pesticides from cattle's milk

Analysis of organochlorine pesticides (OCPs) residues in milk faces a significant challenge. Herein, a sea urchin structured covalent organic framework bearing boric acid groups named COF-B(OH)2 was synthesized and applied as a coating material for solid-phase microextraction (SPME) of the OCPs in cattle’s milk. Its performance was superior to that of three commonly used commercial SPME fibers, which could be due to the coexistence of hydrogen bonding, halogen bonding, π-stacking and electrostatic interactions. Besides, the fiber coating displayed good stability and reusability. After optimization, a COF-B(OH)2 based SPME coupled with gas chromatography-electron capture detection was established for the sensitive detection of the OCPs from milk samples. The limits of detection (S/N = 3) were between 0.04 and 1.0 μg kg−1. Satisfactory accuracy was achieved with the method recoveries in the range of 87.5 % to 112.5 %. These results manifest the feasibility of the COF-B(OH)2 coated fiber for the enrichment of the trace OCPs from milk samples.

The effect of doping different amounts of boron on the corrosion resistance and biocompatibility of TiO2 nanotubes synthesized on SLM Ti6Al4V samples

This comprehensive study investigates the corrosion and biocompatibility performances of boron-doped TiO2 nanotubes (TNT) synthesized on Ti6Al4V alloy produced by the selective laser melting (SLM) process. Structural analysis reveals a consistent reduction in nanotube diameter across varying boron doping levels (0.05 - 2 M boric acid doping), with B4-TNT exhibiting the smallest diameter at 190 nm. Boron incorporation induces phase transformation and decreases in diameter of nanotubes, influencing the material's structural properties. Corrosion resistance assessments indicate a significant enhancement, with B4-TNT demonstrating the highest polarization resistance (Rt = 2849.03 kΩ.cm2). The observed improvements are attributed to the combination of reduced nanotube diameter, altered phase structure, and increased polarization resistance, collectively contributing to enhanced corrosion resistance. Biocompatibility experiments conducted with human fibroblast cells (HDFa) reveal that B-doped TNTs foster increased cell viability compared to undoped TNT and uncoated alloy surfaces. These findings underscore the potential of boron doping as a strategic approach to improve corrosion resistance and enhance the biocompatibility of Ti6Al4V implants. This study provides valuable insights for advancing materials in biomedical applications with improved structural, corrosion-resistant, and biocompatible properties.

In Vitro Effects of Boric Acid on Cell Cycle, Apoptosis, and miRNAs in Medullary Thyroid Cancer Cells.

Medullary thyroid cancer (MTC) is a highly aggressive and chemotherapy-resistant cancer originating from the thyroid's parafollicular C cells. Due to its resistance to conventional treatments, alternative therapies such as boric acid have been explored. Boric acid, a boron-based compound, has shown anticarcinogenic effects, positioning it as a potential treatment option for MTC. TT medullary thyroid carcinoma cell line (TT cells) and human thyroid fibroblast (HThF cells) were utilized for the cell culture experiments. Cell viability was assessed using the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. Total RNA was extracted using Trizol reagent for gene expression and microRNA (miRNA) analysis via reverse transcription-polymerase chain reaction (RT-PCR). The extent of apoptosis induced by boric acid was determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Colony formation assays were conducted to evaluate the impact of boric acid on the colony-forming ability of MTC cells. At 48h, 50% inhibitory concentration (IC50) of boric acid was found to be 35μM. Treatment with boric acid resulted in significant modulation of apoptosis-related genes and miRNAs, including increased expression of phorbol-12-myristate-13-acetate-induced protein 1(NOXA), apoptotic protease activating factor 1 (APAF-1), Bcl-2-associated X protein (Bax), caspase-3, and caspase-9. In contrast, the expression of B cell lymphoma 2 (Bcl2), B cell lymphoma- extra-large (Bcl-xl), and microRNA-21 (miR-21), which are linked to the aggressiveness of MTC, was significantly reduced. The TUNEL assay indicated a 14% apoptosis rate, and there was a 67.9% reduction in colony formation, as shown by the colony formation assay. Our study suggests that boric acid may have anticancer activity in MTC by modulating apoptotic pathways. These findings suggest that boric acid could be a potential therapeutic agent for MTC and possibly for other malignancies with similar pathogenic mechanisms.

Boron-Containing Mesoporous Silica Nanoparticles with Effective Delivery and Targeting of Liver Cancer Cells for Boron Neutron Capture Therapy.

Nanocarriers have been researched comprehensively for the development of novel boron-containing agents in boron neutron capture therapy (BNCT). We designed and synthesized a multifunctional mesoporous silica nanoparticle (MSN)-based boron-containing agent. The latter was coated with a lipid bilayer (LB) and decorated with SP94 peptide (SFSIIHTPILPL) on the surface as SP94-LB@BA-MSN. The latter incorporated boric acid (BA) into hydrophobic mesopores, coated with an LB, and modified with SP94 peptide on the LB. SP94-LB@BA-MSN enhanced nano interface tumor-targeting ability but also prevented the premature release of drugs, which is crucial for BNCT because adequate boron content in tumor sites is required. SP94-LB@BA-MSN showed excellent efficacy in the BNCT treatment of HepG-2 cells. In animal studies with tumor-bearing mice, SP94-LB@BA-MSN exhibited a satisfactory accumulation at the tumor site. The boron content reached 40.18 ± 5.41 ppm in the tumor site 4 h after injection, which was 8.12 and 15.51 times higher than those in mice treated with boronated phenylalanine and those treated with BA. For boron, the tumor-to-normal tissue ratio was 4.41 ± 1.13 and the tumor-to-blood ratio was 5.92 ± 0.45. These results indicated that nanoparticles delivered boron to the tumor site effectively while minimizing accumulation in normal tissues. In conclusion, this composite (SP94-LB@BA-MSN) shows great promise as a boron-containing delivery agent for the treatment of hepatocellular carcinoma using BNCT. These findings highlight the potential of MSNs in the field of BNCT.

Properties and Performance of Epoxy Resin/Boron Acid Composites.

This research study focused on the effect of adding boric acid to epoxy resin in order to obtain a composite material with improved properties and performance. To this end, a fine powder of boric acid (H3BO3) was introduced into epoxy resin in different amounts, i.e., 0.5 g, 1.0 g, and 1.5 g. As the matrix of the epoxy composites, styrene-modified epoxy resin based on bisphenol A (BPA) (Epidian 53) was used. It was cross-linked with two types of curing agents, i.e., an amine (ET) and a polyamide (PAC). The mechanical properties of the obtained epoxy composites (in terms of compressive strength, compressive modulus, and compressive strain) were determined at room temperature in order to assess the effect of the addition of boron acid and of the type of curing agent employed to cure the epoxy on these characteristics. Calorimetric measurements were made to highlight any changes in the glass transition temperature (Tg) as a result of the addition of boric acid to epoxy resin. Finally, flammability tests were performed on both Epidian 53/PAC and Epidian 53/ET epoxy composites to analyze their fire behavior and consequently establish the effectiveness of the selected additive as a flame retardant.

Preparation and properties of phenolic foam modified with boric acid and organosiloxane by supercritical CO2 technology

AbstractIn this study, a silica boron modified phenolic resin foam (SiBPF) is prepared in a reactor under specific pressure and temperature and using supercritical CO2 (scCO2) as a physical foaming agent, to improve phenolic foam (PF) brittle and friable properties and avoid environmental pollution caused by conventional physical foaming. To determine the partially curing degree for foaming, the influence of partially curing time at partially curing degrees between 39.88% and 53.17% was studied. Further, through an orthogonal experimental method, the optimized foaming process parameters—partially curing time of 6 h, adsorption time of 9 h, foaming pressure of 1 MPa, and foaming temperature of 130°C—were determined. The SiBPF, thus prepared under the optimized conditions, exhibited a density of 0.2356 g/cm3, an average cell size of 86.66 μm, and a cell density of 7.10 × 106 cells/cm3. Its compressive strength was found to be 7.28 MPa, with a specific compressive strength of 30.90 MPa/g·cm−3. At 800°C, the carbon residue rate, thermal decomposition temperature T5%, and Tmax reached 77.61%, 355.21, and 702.70°C, respectively. The thermal conductivity of SiBPF was measured to be 0.0644 W/mK, with the rear temperature stabilizing at 60°C on a hot platform of 100°C.