Stimulatory Effect of Hexagonal Boron Nitrides in Wound Healing

Hazard assessment of hexagonal boron nitride and hexagonal boron nitride reinforced thermoplastic polyurethane composites using human skin and lung cells

Hexagonal boron nitride (hBN) is an emerging two-dimensional material attracting considerable attention in the industrial sector given its innovative physicochemical properties. Potential risks are associated mainly with occupational exposure where inhalation and skin contact are the most relevant exposure routes for workers. Here we aimed at characterizing the effects induced by composites of thermoplastic polyurethane (TPU) and hBN, using immortalized HaCaT skin keratinocytes and BEAS-2B bronchial epithelial cells. The composite was abraded using a Taber® rotary abraser and abraded TPU and TPU-hBN were also subjected to photo-Fenton-mediated degradation mimicking potential weathering across the product life cycle. Cells were exposed to the materials for 24 h (acute exposure) or twice per week for 4 weeks (chronic exposure) and evaluated with respect to material internalization, cytotoxicity, and proinflammatory cytokine secretion. Additionally, comprehensive mass spectrometry-based proteomics and metabolomics (secretomics) analyses were performed. Overall, despite evidence of cellular uptake of the material, no significant cellular and/or protein expression profiles alterations were observed after acute or chronic exposure of HaCaT or BEAS-2B cells, identifying only few pro-inflammatory proteins. Similar results were obtained for the degraded materials. These results support the determination of hazard profiles associated with cutaneous and pulmonary hBN-reinforced polymer composites exposure.

Polymer-clay nanofibrous wound dressing materials containing different boron compounds

BACKGROUND

Montmorillonite (MMT) is a biocompatible nanoclay and its incorporation into polymeric matrix not only improves the polymer's wettability/biodegradability, but also enhances cellular proliferation, and differentiation. On the other hand, the positive effect of boron (B) on the healing cascade and its antibacterial properties have drawn the attention of researchers.

MATERIALS & METHODS

In this regard, B compounds in different chemical structures, boron nitride (BN), zinc borate (ZB), and phenylboronic acid (PBA), were adsorbed onto MMT and then, poly (lactic acid) (PLA) based MMT/B including micron/submicron fibers were fabricated by electrospinning.

RESULTS

The incorporation of MMT nanoparticles into the PLA demonstrated a porous fiber topography with enhanced thermal properties, water uptake capacity, and antibacterial effect. Furthermore, the composites including BN, ZB, and PBA showed bacteriostatic effects against Gram-negative and Gram-positive pathogenic bacteria (Escherichia coli and Staphylococcus aureus). In-vitro cell culture studies performed with human dermal fibroblasts (HDF) indicated the non-toxic effect of B compounds. The results showed that incorporation of MMT supported cell adhesion and proliferation, and further addition of B compounds especially PBA increased cell viability for 14 days.

CONCLUSION

The results illustrated the acceptable characteristics of the B-containing composites and their favorable effect on the cells, demonstrating their potential as a skin tissue engineering product.

Environmental and Health Impacts of Graphene and Other Two-Dimensional Materials: A Graphene Flagship Perspective

Two-dimensional (2D) materials have attracted tremendous interest ever since the isolation of atomically thin sheets of graphene in 2004 due to the specific and versatile properties of these materials. However, the increasing production and use of 2D materials necessitate a thorough evaluation of the potential impact on human health and the environment. Furthermore, harmonized test protocols are needed with which to assess the safety of 2D materials. The Graphene Flagship project (2013-2023), funded by the European Commission, addressed the identification of the possible hazard of graphene-based materials as well as emerging 2D materials including transition metal dichalcogenides, hexagonal boron nitride, and others. Additionally, so-called green chemistry approaches were explored to achieve the goal of a safe and sustainable production and use of this fascinating family of nanomaterials. The present review provides a compact survey of the findings and the lessons learned in the Graphene Flagship.

Reverse pharmacology approach to validate the diabetic wound-healing activity of Jatyadi thailam formulations in vitro on diabetic mimic environment

Objective: Jatyadi thailam, an Ayurvedic preparation, is renowned for its efficacy in diabetic wound healing and inflammation. This study aimed to validate and compare the diabetic wound-healing potential of two Jatyadi thailam formulations - Ayurvedic formulary of India Jatyadi thailam (JT-AFI) and Yogagrantha formulation of Jatyadi thailam (JT-YG), in a diabetic environment using L929 fibroblast cells in vitro. Methodology: The effects on cell survival, proliferation, migration, angiogenesis, cell cycle progression, apoptosis, ROS generation, and mitochondrial function were evaluated.Results: The formulations promoted cell proliferation, migration, angiogenesis, while also regulating cell cycle and apoptosis. They effectively suppressed ROS generation and modulated mitochondrial function. JT-AFI exhibited superior efficacy in accelerating diabetic wound healing compared to JT-YG.Conclusion: These findings provide substantial support for the mechanistic role of Jatyadi thailam in diabetic wound healing.

TiB2-Derived Nanosheets Enhance the Tensile Strength and Controlled Drug Release of Biopolymeric Films Used in Wound Healing

Wound healing using an alginate-based biopolymeric film is one of the most preferred treatments. However, these films lack mechanical strength (elasticity and tensile strength), show higher initial burst release, and exhibit high vapor permeability. The present study reports the development of nanosheets derived from titanium diboride (10 nm) (NTB)-incorporated biopolymeric films (0.025, 0.05, and 0.1% w/v) using sodium alginate (SA) and carboxymethyl cellulose (CMC) to overcome the shortfalls. The surface properties of the film, nanosheet distribution within the film, and possible interactions with the film are explored by using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). These analyses confirm that nanosheets are uniformly distributed in the film and introduce unevenness on the film's surface. The tensile strength of the nanosheet-incorporated film (0.1% NTB film) using UTM is found to be 24.30 MPa (six times higher compared to the blank film), equivalent to human skin. The water vapor transmission rate of the film is also found to be in the desired range (i.e., 2000-2500 g/m2 day). The biocompatibility of the NTB film is confirmed by the MTT assay test using NIH/3T3 cells and HEK 293 cells. Furthermore, the scratch assay shows that the developed films promote cell migration and proliferation. The antibacterial activity of the film is also demonstrated using a model drug, tetracycline hydrochloride (TCl). Besides, the film exhibits the sustained release of TCl and follows the Korsmeyer-Peppas model for drug release. Overall, the 0.1% w/v NTB film is easy to fabricate, biocompatible and shows superior mechanical properties.

Recent Progress in Fabrication and Application of BN Nanostructures and BN-Based Nanohybrids

Due to its unique physical, chemical, and mechanical properties, such as a low specific density, large specific surface area, excellent thermal stability, oxidation resistance, low friction, good dispersion stability, enhanced adsorbing capacity, large interlayer shear force, and wide bandgap, hexagonal boron nitride (h-BN) nanostructures are of great interest in many fields. These include, but are not limited to, (i) heterogeneous catalysts, (ii) promising nanocarriers for targeted drug delivery to tumor cells and nanoparticles containing therapeutic agents to fight bacterial and fungal infections, (iii) reinforcing phases in metal, ceramics, and polymer matrix composites, (iv) additives to liquid lubricants, (v) substrates for surface enhanced Raman spectroscopy, (vi) agents for boron neutron capture therapy, (vii) water purifiers, (viii) gas and biological sensors, and (ix) quantum dots, single photon emitters, and heterostructures for electronic, plasmonic, optical, optoelectronic, semiconductor, and magnetic devices. All of these areas are developing rapidly. Thus, the goal of this review is to analyze the critical mass of knowledge and the current state-of-the-art in the field of BN-based nanomaterial fabrication and application based on their amazing properties.

Cytotoxicity of 2D engineered nanomaterials in pulmonary and corneal epithelium

Two-dimensional (2D) engineered nanomaterials are widely used in consumer and industrial goods due to their unique chemical and physical characteristics. Engineered nanomaterials are incredibly small and capable of being aerosolized during manufacturing, with the potential for biological interaction at first-contact sites such as the eye and lung. The unique properties of 2D nanomaterials that make them of interest to many industries may also cause toxicity towards epithelial cells. Using murine and human respiratory epithelial cell culture models, we tested the cytotoxicity of eight 2D engineered nanomaterials: graphene (110 nm), graphene oxide (2 um), graphene oxide (400 nm), reduced graphene oxide (2 um), reduced graphene oxide (400 nm), partially reduced graphene oxide (400 nm), molybdenum disulfide (400 nm), and hexagonal boron nitride (150 nm). Non-graphene nanomaterials were also tested in human corneal epithelial cells for ocular epithelial cytotoxicity. Hexagonal boron nitride was found to be cytotoxic in mouse tracheal, human alveolar, and human corneal epithelial cells. Hexagonal boron nitride was also tested for inhibition of wound healing in alveolar epithelial cells; no inhibition was seen at sub-cytotoxic doses. Nanomaterials should be considered with care before use, due to specific regional cytotoxicity that also varies by cell type. Supported by U01ES027288 and T32HL007013 and T32ES007059.

Multifunctional Photoactive Hydrogels for Wound Healing Acceleration

Light is an attractive tool that has a profound impact on modern medicine. Particularly, light-based photothermal therapy (PTT) and photodynamic therapy (PDT) show great application prospects in the prevention of wound infection and promoting wound healing. In addition, hydrogels have shown attractive advantages in the field of wound dressings due to their excellent biochemical effects. Therefore, multifunctional photoresponsive hydrogels (MPRHs) that integrate the advantages of light and hydrogels are increasingly used in biomedicine, especially in the field of wound repair. However, a comprehensive review of MPRHs for wound regeneration is still lacking. This review first focuses on various types of MPRHs prepared by diverse photosensitizers, photothermal agents (PHTAs) including transition metal sulfide/oxides nanomaterials, metal nanostructure-based PHTAs, carbon-based PHTAs, conjugated polymer or complex-based PHTAs, and/or photodynamic agents (PHDAs) such as ZnO-based, black-phosphorus-based, TiO₂-based, and small organic molecule-based PHDAs. We also then discuss how PTT, PDT, and photothermal/photodynamic synergistic therapy can modulate the microenvironments of bacteria to inhibit infection. Overall, multifunctional hydrogels with both therapeutic and tissue regeneration capabilities have been discussed and existing challenges, as well as future research directions in the field of MPRHs and their application in wound management are argued.

Local anesthetic lidocaine-encapsulated polymyxin-chitosan nanoparticles delivery for wound healing: in vitro and in vivo tissue regeneration

In relieving local pains, lidocaine, one of ester-type local anesthetics, has been used. To develop the lidocaine membranes of enhanced local anesthetic effects, we have designed to establish the composition of wound dressings based on lidocaine chloride (LCH) (anesthetic drug)-loaded chitosan (CS)/polymyxin B sulfate (PMB). The LCH membranes (LCH-CS/PMB) was fabricated by the LCH oxide solutions within the CS/PMB matrix. The influences of different experimental limitations on CS/PMB membrane formations were examined. The double membrane particle sizes were evaluated by scanning electron microscopy (HR-SEM). Additionally, antibacterial efficacy was developed for gram-positive and negative microorganisms. Moreover, we examined in vivo healing of skin wounds formed in mouse models over 16 days. In contrast to the untreated wounds, rapid healing was perceived in the LCH-CS/PMB-treated wound with less damaging. These findings indicate that LCH-CS/PMB-based bandaging materials could be a potential innovative biomaterial for tissue repair and regeneration for wound healing applications in an animal model.

Synthesis and characterization of silver nanoparticles decorated polydopamine coated hexagonal boron nitride and its effect on wound healing

BACKGROUND

Wound healing is an essential physiological process involving many cell types and their products acting in a marvellous harmony to repair damaged tissues. During the healing process, cellular proliferation and extracellular matrix remodelling stages could be interrupted by undesired factors including microorganisms and altered metabolic activities. In such a case, the process requires some external stimulants to accelerate or remediate the healing stages.

METHODS

In this study, we report a multifunctional wound healing stimulating agent. In this context, hexagonal boron nitride (hBN) nanoparticles, silver nanoparticles (AgNPs) and polydopamine(pdopa) were used through mussel-inspired chemistry of dopamine to obtain pdopa coated hBN (hBN@pdopa) and AgNPs decorated hBN@pdopa (hBN@pdopa-AgNPs). These two nanostructures were investigated to observe stages of healing.

RESULTS

AgNPs were chosen for inflammation reduction and hBN for induced cell proliferation and migration. In in vitro experiments, firstly, high cellular uptake capacity and biocompatibility of hBN@pdopa and hBN@pdopa-AgNPs were evaluated. They were also tested for their reaction against increased concentration of reactive oxygen species (ROS) in injured cells. Finally, their effect on cellular migration, intracellular tube formation and F-actin organization were monitored by light and confocal microscopy, respectively.

CONCLUSION

The results clearly indicate that the hBN@pdopa-AgNPs significantly decrease ROS production, promote wound closure, and reorganize tube formation in cells.

In Vivo Tissue Implantation Model of In Vivo Tissue Implantation Model of Lidocaine (LCH)-Encapsulated Dextran (DEX)/Glycol (GLY) Nanoparticles Delivery for Pain Management

Lidocaine-loaded nanoparticles are versatile nanomaterials that may be used in pain treatment due to their wound healing properties. The current study describes a wound dressing formulation focused on lidocaine-loaded dextran/ethylene glycol nanoparticles (an anesthetic drug). The lidocaine-loaded dextran/ethylene glycol membranes were fabricated using lidocaine solutions inside the dextran/ethylene glycol medium. The influence of various experimental conditions on dextran/ethylene glycol nanoparticle formations were examined. The sizes of dextran/ethylene glycol and lidocaine-loaded dextran/glycol nanoparticles were examined through the HR-SEM. Moreover, the efficacy antibacterial activity of dextran/glycol and lidocaine-loaded dextran/ethylene glycol nanoparticles was evaluated against the microorganisms grampositive and negative. Furthermore, we observed the In Vivo wound healing of wounds in skin using a mice model over a 16 days period. In this difference to the wounds of untreated mouse, quick healing was observed in the lidocaine-loaded dextran/glycol nanoparticles-treated wounds with fewer injury. These results specify that lidocaine-loaded dextran/ethylene glycol nanoparticles-based dressing material could be a ground-breaking nanomaterial having wound repair and implantations potential required for wound injury in pain management, which was proven using an animal model.

Modulation of Cellular Response to Different Parameters of the Rotating Magnetic Field (RMF)-An In Vitro Wound Healing Study

Since the effect of MFs (magnetic fields) on various biological systems has been studied, different results have been obtained from an insignificant effect of weak MFs on the disruption of the circadian clock system. On the other hand, magnetic fields, electromagnetic fields, or electric fields are used in medicine. The presented study was conducted to determine whether a low-frequency RMF (rotating magnetic field) with different field parameters could evoke the cellular response in vitro and is possible to modulate the cellular response. The cellular metabolic activity, ROS and Ca2+ concentration levels, wound healing assay, and gene expression analyses were conducted to evaluate the effect of RMF. It was shown that different values of magnetic induction (B) and frequency (f) of RMF evoke a different response of cells, e.g., increase in the general metabolic activity may be associated with the increasing of ROS levels. The lower intracellular Ca2+ concentration (for 50 Hz) evoked the inability of cells to wound closure. It can be stated that the subtle balance in the ROS level is crucial in the wound for the effective healing process, and it is possible to modulate the cellular response to the RMF in the context of an in vitro wound healing.

Interactions Between 2D Materials and Living Matter: A Review on Graphene and Hexagonal Boron Nitride Coatings

Two-dimensional material (2DM) coatings exhibit complex and controversial interactions with biological matter, having shown in different contexts to induce bacterial cell death and contribute to mammalian cell growth and proliferation in vitro and tissue differentiation in vivo. Although several reports indicate that the morphologic and electronic properties of the coating, as well as its surface features (e.g., crystallinity, wettability, and chemistry), play a key role in the biological interaction, these kinds of interactions have not been fully understood yet. In this review, we report and classify the cellular interaction mechanisms observed in graphene and hexagonal boron nitride (hBN) coatings. Graphene and hBN were chosen as study materials to gauge the effect of two atomic-thick coatings with analogous lattice structure yet dissimilar electrical properties upon contact with living matter, allowing to discern among the observed effects and link them to specific material properties. In our analysis, we also considered the influence of crystallinity and surface roughness, detailing the mechanisms of interaction that make specific coatings of these 2DMs either hostile toward bacterial cells or innocuous for mammalian cells. In doing this, we discriminate among the material and surface properties, which are often strictly connected to the 2DM production technique, coating deposition and post-processing method. Building on this knowledge, the selection of 2DM coatings based on their specific characteristics will allow to engineer desired functionalities and devices. Antibacterial coatings to prevent biofouling, biocompatible platforms suitable for biomedical applications (e.g., wound healing, tissue repairing and regeneration, and novel biosensing devices) could be realized in the next future. Overall, a clear understanding on how the 2DM coating's properties may modulate a specific bacterial or cellular response is crucial for any future innovation in the field.