Interaction of carbohydrate modified boron nitride nanotubes with living cells

Growth methodologies of boron nitride nanotubes and their neutron shielding applications: a review

This review provides a comprehensive overview of the growth methodologies and neutron shielding applications of Boron Nitride Nanotubes (BNNTs). BNNTs have garnered significant attention because of their unique combination of high thermal stability, mechanical strength, and exceptional neutron absorption properties. Synthesis methods for BNNTs, including laser ablation, thermal plasma treatment, chemical vapour deposition (CVD), and ball milling have been thoroughly examined, highlighting their mechanisms, advantages, and challenges. Each method contributes uniquely to the quality and applicability of BNNTs in terms of scalability and production efficiency. This study focused on the applications of BNNTs in neutron absorption, particularly in aerospace engineering. BNNTs have shown promising potential in enhancing the safety and longevity of space missions by providing effective radiation protection. Furthermore, their potential in medical applications, particularly in Boron Neutron Capture Therapy (BNCT) for cancer treatment, has been explored. BNCT offers a targeted approach to cancer therapy by utilizing the high boron-10 content of BNNTs for precise and localized treatment. This review also provides an outlook on the future of BNNT research, emphasizing the need for more efficient growth methods to facilitate wider adoption and commercialization. The versatility of BNNTs across various fields, from space exploration to medical science, underscores their potential as materials of significant scientific and technological importance. As research progresses, BNNTs are expected to play a pivotal role in advancing materials science and offer innovative solutions to complex challenges.

Advances in boron nitride-based nanomaterials for environmental remediation and water splitting: a review

Boron nitride has gained wide-spread attention globally owing to its outstanding characteristics, such as a large surface area, high thermal resistivity, great mechanical strength, low density, and corrosion resistance. This review compiles state-of-the-art synthesis techniques, including mechanical exfoliation, chemical exfoliation, chemical vapour deposition (CVD), and green synthesis for the fabrication of hexagonal boron nitride and its composites, their structural and chemical properties, and their applications in hydrogen production and environmental remediation. Additionally, the adsorptive and photocatalytic properties of boron nitride-based nanocomposites for the removal of heavy metals, dyes, and pharmaceuticals from contaminated waters are discussed. Lastly, the scope of future research, including the facile synthesis and large-scale applicability of boron nitride-based nanomaterials for wastewater treatment, is presented. This review is expected to deliver preliminary knowledge of the present state and properties of boron nitride-based nanomaterials, encouraging the future study and development of these materials for their applications in various fields.

Theoretical model study of adsorbed antimalarial-graphene dimers: doping effects, photophysical parameters, intermolecular interactions, edge adsorption, and SERS

Future diagnostics and therapy applications are in part riding on the discovery and implementation of new optical techniques and strategies (which often derive from dyads) for example, prediction of features in surface-enhanced Raman spectroscopy requires the study of chromophore-chromophore interactions involve intermolecular forces, drug delivery, and photo mechanisms which are of great interest. New matches between chromophore systems (i.e. FRET), and π-delocalized surfaces are important to study. We explore low-molecular weight drug molecules and their interaction with the reporter material/surface of graphene. Bonding, charge transfer and orbital interactions for 2-amino-5-(1-methyl-5-nitro-2-imidazolyl)-1,3,4-thiadiazole (megazol or AMIT) on graphene were carried out. The graphene model substrate was monotonically/monatomically substituted (doped) with one neutral heteroatom (N/O/S/B) in place of one carbon center; chemical adsorption of AMIT is due to charge transfer from doped graphene to AMIT (DFT). Our AMIT-nanocluster studies show that the nanoclusters will act as a sensor component for the detection of drugs due to SERS. Our findings identified that the greater the energy of the charge transfer, the stronger the calculated chemical adsorption. Additionally, charge transfer is highest for the N-doped systems and least for pristine graphene, resulting in a stronger adsorption energy for N-doped graphene. Mulliken charge analysis of structures confirms enhancement found in QD-AMIT systems.Communicated by Ramaswamy H. Sarma.

Boron nitride nanotubes reinforced gelatin hydrogel-based ink for bioprinting and tissue engineering applications

The rapid evolution of 3D bioprinting technique, very few biomaterials have been studied and utilised as ink solutions to produce structures. In this work, a polymeric nanocomposite hydrogel-based ink solution was developed using boron nitride nanotubes (BNNTs) reinforced gelatin for 3D bioprinting of scaffolds. The ink solutions and printed scaffolds were characterised for their printability, mechanical, thermal, water uptake, and biological properties (cell viability and inflammation). The viscoelastic behaviour of the scaffolds indicated the increase in storage modulus with an increase in BNNTs composition. Additionally, the compressive strength of the scaffolds increased from 9.43 ± 1.3 kPa to 30.09 ± 1.5 kPa with the addition of BNNTs. Similarly, the thermal stability of the scaffolds enhanced with an increase in BNNTs composition. Furthermore, the scaffolds with a higher concentration of BNNTs displayed resilience in cell culture media at 37 °C for up to 14 days compared with pure gelatin scaffolds. The cell viability results showed a decreased viability rate with an increased concentration of BNNTs scaffolds. However, BNNTs incubated with cells did not display cytokine inflammation. Therefore, this work provides a potential hydrogel-based ink solution for 3D bioprinting of biomimetic tissue constructs with adequate structural stability for a wide range of tissue engineering and regenerative medicine applications.

Exposure to boron trioxide nanoparticles and ions cause oxidative stress, DNA damage, and phenotypic alterations in Drosophila melanogaster as an in vivo model

Boron trioxide nanoparticles (B₂ O₃ NPs) have recently been widely used in a range of applications including electronic device technologies, acousto-optic apparatus fields and as nanopowder for the production of special glasses. We propose Drosophila melanogaster as a useful in vivo model system to study the genotoxic risks associated with NP exposure. In this study we have conducted a genotoxic evaluation of B₂ O₃ NPs (size average 55.52 ± 1.41 nm) and its ionic form in D. melanogaster. B₂ O₃ NPs were supplied to third instar larvae at concentrations ranging from 0.1-10 mM. Toxicity, intracellular oxidative stress (reactive oxygen species, ROS), phenotypic alterations, genotoxic effect (via the wing somatic mutation and recombination test (SMART), and DNA damage (via Comet assay) were the end-points evaluated. B₂ O₃ NPs did not cause any mutagenic/recombinogenic effects in all tested non-toxic concentrations in Drosophila SMART. Negative data were also obtained with the ionic form. Exposure to B₂ O₃ NPs and its ionic form (at two highest concentrations, 2.5 and 5 mM) was found to induce DNA damage in Comet assay. Additionally, ROS induction in hemocytes and phenotypic alterations were determined in the mouths and legs of Drosophila. This study is the first study reporting genotoxicity data in the somatic cells of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects in a concentration dependent manner caused by B₂ O₃ NPs and its ionic form. The obtained in vivo results contribute to improvement the genotoxicity database on the B₂ O₃ NPs.

Prospects of Biosensors Based on Functionalized and Nanostructured Solitary Materials: Detection of Viral Infections and Other Risks

Advances in nanotechnology over the past decade have emerged as a substitute for conventional therapies and have facilitated the development of economically viable biosensors. Next-generation biosensors can play a significant role in curbing the spread of various viruses, including HCoV-2, and controlling morbidity and mortality. Pertaining to the impact of the current pandemic, there is a need for point-of-care biosensor-based testing as a detection method to accelerate the detection process. Integrating biosensors with nanostructures could be a substitute for ultrasensitive label-free biosensors to amplify sensing and miniaturization. Notably, next-generation biosensors could expedite the detection process. An elaborate description of various types of functionalized nanomaterials and their synthetic aspects is presented. The utility of the functionalized nanostructured materials for fabricating nanobiosensors to detect several types of viral infections is described in this review. This review also discusses the choice of appropriate nanomaterials, as well as challenges and opportunities in the field of nanobiosensors.

In Vitro and In Vivo Cytotoxicity of Boron Nitride Nanotubes: A Systematic Review

Boron nitride nanotubes (BNNTs) are an exciting class of nanomaterials due to their unique chemical and physical characteristics. In recent decades, BNNTs have gained huge attention in research and development for various applications, including as nano-fillers for composites, semiconductor devices, hydrogen storage, and as an emerging material in biomedical and tissue engineering applications. However, the toxicity of BNNTs is not clear, and the biocompatibility is not proven yet. In this review, the role of BNNTs in biocompatibility studies is assessed in terms of their characteristics: cell viability, proliferation, therapeutic outcomes, and genotoxicity, which are vital elements for their prospective use in biomedical applications. A systematic review was conducted utilising the databases Scopus and Web of Science (WOS) (2008-2022). Additional findings were discovered manually by snowballing the reference lists of appropriate reviews. Only English-language articles were included. Finally, the significant analysis and discussion of the chosen articles are presented.

Extrusion-Based Bioprinted Boron Nitride Nanotubes Reinforced Alginate Scaffolds: Mechanical, Printability and Cell Viability Evaluation

Alginate (Alg) hydrogels are commonly used as bioinks in 3D bioprinting. However, one of the significant drawbacks of using Alg hydrogels is their unstable mechanical properties. In this study, a novel hydrogel-based ink composed of Alg reinforced with functionalised boron nitride nanotubes (f-BNNTs) was developed and systematic quantitative characterisation was conducted to validate its printability, physiochemical properties and biocompatibility. The printability, contact angle and mechanical test results indicated good structural stability of the scaffolds. The thermal stability of the scaffolds increased with the incorporation of f-BNNTs into Alg. Human embryonic kidney cells (HEK 293T) were seeded on the scaffolds and the cell viability was recorded for 24, 48 and 72 h. Quantitative studies showed a slight effect on toxicity with a higher concentration of BNNTs in scaffolds. The results suggest that the 3D printable f-BNNTs reinforced Alg could be used as bioink for tissue engineering applications with further studies on biocompatibility.

Boron nitride nanotube scaffolds: emergence of a new era in regenerative medicine

Tissue engineering scaffolds have transformed from passive geometrical supports for cell adhesion, extension and proliferation to active, dynamic systems that can in addition, trigger functional maturation of the cells in response to external stimuli. Such 'smart' scaffolds require the incorporation of active response elements that can respond to internal or external stimuli. One of the key elements that direct the cell fate processes is mechanical stress. Different cells respond to various types and magnitudes of mechanical stresses. The incorporation of a pressure-sensitive element in the tissue engineering scaffold therefore, will aid in tuning the cell response to the desired levels. Boron nitride nanotubes (BNNTs) are analogous to carbon nanotubes and have attracted considerable attention due to their unique amalgamation of chemical inertness, piezoelectric property, biocompatibility and, thermal and mechanical stability. Incorporation of BNNTs in scaffolds confers them with piezoelectric property that can be used to stimulate the cells seeded on them. Biorecognition and solubilization of BNNTs can be engineered through surface functionalization with different biomolecules. Over the years, the importance of BNNT has grown in the realm of healthcare nanotechnology. This review discusses the salient properties of BNNTs, the influence of functionalization on theirin vitroandin vivobiocompatibility, and the uniqueness of BNNT-incorporated tissue engineering scaffolds.

Toxicity of boric acid, borax and other boron containing compounds: A review

Boron, often in the form of boric acid, is widely used as a flame retardant in insulation products, and although humans ingest boron through food, high exposure may lead to unwanted health effects. We assessed the toxicity of boric acid, borax and other forms of boron, after inhalation, dermal and oral exposure. After oral exposure, boron is absorbed over the gastrointestinal tract. Intact skin seems to pose a more effective barrier to boron than compromised skin. Boron excretion seems to mainly occur via the urine, although after skin exposure boron has been demonstrated in bile and gastrointestinal contents. Inhalation toxicity data are sparse, but one animal study showed reduced foetal weight after inhalation of cellulose that had a boric acid content of 20%. Skin exposure to boric acid has proven fatal in some cases, and the range of toxicity effects include abdominal as well as local effects on the skin. Fatalities from boric acid also have occurred after oral ingestion, and the endpoints in animals are weight loss and reproductive toxicity. Concerning genotoxicity studies, the overall picture indicates that boron-containing compounds are not genotoxic. There was no evidence of the carcinogenicity of boric acid in a 2-year study in mice.

Ecotoxicological assessment of commercial boron nitride nanotubes toward Xenopus laevis tadpoles and host-associated gut microbiota

Despite the growing interest for boron nitride nanotubes (BNNT) due to their unique properties, data on the evaluation of the environmental risk potential of this emerging engineered nanomaterial are currently lacking. Therefore, the ecotoxicity of a commercial form of BNNT (containing tubes, hexagonal-boron nitride, and boron) was assessed in vivo toward larvae of the amphibian Xenopus laevis. Following the exposure, multiple endpoints were measured in the tadpoles as well as in bacterial communities associated to the host gut. Exposure to BNNT led to boron accumulation in host tissues and was not associated to genotoxic effects. However, the growth of the tadpoles increased due to BNNT exposure. This parameter was associated to remodeling of gut microbiome, benefiting to taxa from the phylum Bacteroidetes. Changes in relative abundance of this phylum were positively correlated to larval growth. The obtained results support the finding that BNNT are biocompatible as indicated by the absence of toxic effect from the tested nanomaterials. In addition, byproducts, especially free boron present in the tested product, were overall beneficial for the metabolism of the tadpoles.

In vitro investigation of the effects of boron nitride nanotubes and curcumin on DNA damage

BACKROUND

Stem cells provide an opportunity to analyse the effects of xenobiotic on cell viability, differentiation and cell functions. Evaluation of the possible cytotoxic and DNA damaging effects on bone marrow CD34+ stem cells is important for their ability to differentiate into blood cells, and also for bone marrow diseases therapy. Boron nitride nanotubes and curcumin are potential nanoformulation agents that can be used together in the treatment of cancer or bone marrow diseases. Therefore, it is important to evaluate their possible effects on different cell lines.

OBJECTIVES

In this study, it was aimed to evaluate the cytotoxic and DNA damaging effects of boron nitride nanotubes which are commonly used in pyroelectric, piezoelectric and optical applications, but there is not enough information about its biocompatibility. Also, it was intended to research the effects of curcumin being used frequently in treatment processes for antioxidant properties.

METHODS

The possible cytotoxic and DNA damaging effects of boron nitride nanotubes and curcumin on CD34+ cells, HeLa and V79 cells were evaluated by MTT assay and Comet assay, respectively.

RESULTS AND CONCLUSION

Boron nitride nanotubes and curcumin had cytotoxic effects and cause DNA damage on CD34+ cells, HeLa and V79 cells at several concentrations, probably because of increased ROS level. However, there were not concentration - dependent effect and there were controversial toxicity results of the studied cell lines. Its mechanism needs to be enlightened by further analysis for potential targeted drug development. Graphical abstract.

One-Step Synthesis of Hexagonal Boron Nitrides, Their Crystallinity and Biodegradation

Hexagonal boron nitrides (hBNs) have recently been investigated for several novel applications due to their unique properties such as biocompatibility, superhydrophobicity, electrical insulation, and thermal and chemical stability. In addition, their biodegradation products have recently reported to have therapeutic effect on certain cancer types. hBNs are easily synthesized from boron and nitrogen precursors at moderately low temperatures. However, crystallinity and yield vary depending on the type of precursor, reaction temperature, and duration. In this study, a simple one-step hBNs synthesis method is reported without a catalyst, which might be an undesired contaminant for biomedical applications. The influence of boron precursors (boric acid, colemanite, or boron trioxide) on hBNs crystallinity, stability, and biodegradation in suspensions containing oxidative and hydrolytic degradation agents is investigated with the aim of their possible application in biomedicine. We found that the choice of boron precursor is a critically important parameter controlling the hBNs crystallinity and dependently influencing the biodegradation rate.

2D-BN nanoparticles as a spectroscopic marker and drug delivery system with protection properties

An application of 2D-BN nanoparticles as a spectroscopic marker, weak luminescent marker and anticancer drug (doxorubicin, DOX) delivery system with protection properties was studied for the LNCaP strains of cancer cells using FTIR and Raman spectroscopy for analysing the cancer cells, cells with BN, the cancer cells with DOX, and the cancer cells with BN nanoparticles loaded by DOX. Study of IR absorption and Raman spectra of the LNCaP strains of cancer cells incubated with 2D-BN nanoparticles for 1 hour showed that the 2D-BN nanoparticles could pass through the cell membrane and localize inside the membrane or close to the membrane in the cytoplasm of the cells. We registered the spectra of the disturbed lipids during the DOX-2D-BN passing through the membrane. After incubation for 2 hours and more, spectral changes in other structural components of the cell (nuclei, cytoplasm, mitochondria) can be registered. Confocal microscopy showed that a gold nanostructured support enhances the fluorescence of the cancer cells with 2D-BN as well as that with DOX, however the double action of 2D-BN and DOX on the cancer cells aggravates the emission property of the studied system. An MTT test showed that the toxicity of DOX on the 2D-BN nanoparticles is less than that on the reference cells, and at the same time the efficiency of the DOX action on the cancer cells does not change.

An application of 2D-BN nanoparticles as spectroscopic marker, weak luminescent marker and anticancer drug (doxorubicin, DOX) delivery system with protection property was studied for the LNCaP strains of cancer cells.

Boron nitride nanotubes for gene silencing

BACKGROUND

Non-viral gene delivery is increasingly investigated as an alternative to viral vectors due to low toxicity and immunogenicity, easy preparation, tissue specificity, and ability to transfer larger sizes of genes.

METHODS

In this study, boron nitride nanotubes (BNNTs) are functionalized with oligonucleotides (oligo-BNNTs). The morpholinos complementary to the oligonucleotides attached to the BNNTs (morpholino/oligo-BNNTs) are hybridized to silence the luciferase gene. The morpholino/oligo-BNNTs conjugates are administered to luciferase-expressing cells (MDA-MB-231-luc2) and the luciferase activity is monitored.

RESULTS

The luciferase activity is decreased when MDA-MB-231-luc2 cells were treated with morpholino/oligo-BNNTs.

CONCLUSIONS

The study suggests that BNNTs can be used as a potential vector to transfect cells.

GENERAL SIGNIFICANCE

BNNTs are potential new nanocarriers for gene delivery applications.

Evaluation of boron nitride nanotubes and hexagonal boron nitrides as nanocarriers for cancer drugs

AIM

Boron nitride nanotubes (BNNTs) and hexagonal boron nitrides (hBNs) are novel nanostructures with high mechanical strengths, large surface areas and excellent biocompatibilities. Here, the potential use of BNNTs and hBNs as nanocarriers was comparatively investigated for use with cancer drugs.

MATERIALS & METHODS

Doxorubicin (Dox) and folate are used as model drugs and targeting agents, respectively.

RESULTS & DISCUSSION

The obtained results indicate that BNNTs have about a threefold higher Dox loading capacity than hBNs. It was also found that cellular uptake of folate-Dox-BNNTs was much higher when compared with Dox-BNNTs for HeLa cells, due to the presence of folate receptors on the cell surface, leading to increased cancer cell death. In summary, folate and Dox conjugated BNNTs are promising agents in nanomedicine and may have potential drug delivery applications.

Cellular uptake, genotoxicity and cytotoxicity of cobalt ferrite magnetic nanoparticles in human breast cells

Magnetic nanoparticles (MNPs) have been increasingly used for many years as MRI agents and for gene delivery and hyperthermia therapy, although there have been conflicting results on their safety. In this study, cobalt ferrite magnetic nanoparticles (CoFe-MNPs) were prepared by the co-precipitation method and their surfaces were modified with silica by the sol-gel method. The particle and hydrodynamic sizes, morphology and crystal structure of the bare and silica-coated CoFe-MNPs were evaluated by transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FTIR). The size of the bare CoFe-MNPs was in the range 8-20 nm and they were homogeneously coated with 3-4 nm silica shells. The bare and silica-coated CoFe-MNPs were agglomerated at physiological pH. However, the sizes of the agglomerates were below 200 nm both in water and complete medium. The cytotoxic and genotoxic potentials of the bare and silica-coated CoFe-MNPs were evaluated in a metastatic breast cancer cell line, MDA-MB-231, as well as a noncancerous mammary epithelial cell line, MCF-10A, by using XTT cytotoxicity, single-cell gel electrophoresis (comet), and cytokinesis-blocked (CB) micronucleus (CBMN) assays. Characterization studies with TEM, inductively coupled plasma optical emission spectroscopy (ICP-OES) and Prussian blue staining indicated that the CoFe-MNPs were internalized into the cells by energy-dependent endocytosis. The highest amount of uptake was observed in the cancer cells and the uptake of the silica-coated CoFe-MNPs was higher than that of the bare ones in both cell lines. The bare CoFe-MNPs showed higher levels of both cytotoxicity and genotoxicity than the silica-coated CoFe-MNPs. Moreover, the cancer cells seemed to be more susceptible to the CoFe-MNPs' toxicity compared to the noncancerous cells. There was a concentration and time-dependent increase in DNA damage and the micronucleus (MN) frequency, which was statistically significant starting with the lowest concentration of bare CoFe-MNPs (p < 0.05), while no significance was observed below the concentration of 250 μg mL-1 for the silica-coated MNPs. Also, the extent of both DNA damage and MN frequency was much higher in the cancer cells compared to the noncancerous cells. According to our results, the silica coating ameliorated both the cytotoxicity and genotoxicity as well the internalization of the CoFe-MNPs.

Boron nitride nanotubes as vehicles for intracellular delivery of fluorescent drugs and probes

AIM

To evaluate the response of cells to boron nitride nanotubes (BNNTs) carrying fluorescent probes or drugs in their inner channel by assessment of the cellular localization of the fluorescent cargo, evaluation of the in vitro release and biological activity of a drug (curcumin) loaded in BNNTs.

METHODS

Cells treated with curcumin-loaded BNNTs and stimulated with lipopolysaccharide were assessed for nitric oxide release and stimulation of IL-6 and TNF-α. The cellular trafficking of two cell-permeant dyes and a non-cell-permeant dye loaded within BNNTs was imaged.

RESULTS

BNNTs loaded with up to 13 wt% fluorophores were internalized by cells and controlled release of curcumin triggered cellular pathways associated with the known anti-inflammatory effects of the drug.

CONCLUSION

The overall findings indicate that BNNTs can function as nanocarriers of biologically relevant probes/drugs allowing one to examine/control their local intracellular localization and biochemical effects, leading the way to applications as intracellular nanosensors.

Water-dispersed thermo-responsive boron nitride nanotubes: synthesis and properties

In this study, water-dispersed thermo-responsive boron nitride nanotubes (BNNTs) were prepared in a simple two-step process, where on the first step oligoperoxide was grafted via the interaction of amino groups (defects) of BNNTs with pyromellitic chloroanhydride fragments in oligoperoxide molecules. The second step involves N-isopropylacrylamide (NIPAM) graft polymerization 'from the surface' of oligoperoxide-functionalized BNNTs resulting in poly(N-isopropylacrylamide) (PNIPAM) coating. The pristine and functionalized BNNTs were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, dynamic light scattering, scanning electron microscopy and atomic force microscopy. PNIPAM-functionalized BNNTs exhibit excellent dispersibility in water and possess thermo-responsive properties. The water-dispersion of thermo-responsive PNIPAM-functionalized BNNTs can help their potential use in biomedical applications as 'smart' surfaces, nanotransducers and nanocarriers.

Theoretical study of adsorption of amino acids on graphene and BN sheet in gas and aqueous phase with empirical DFT dispersion correction

Suitability of BN nanosheet/graphene towards the adsorption of amino acids established by dispersion corrected DFT calculations.