Boron nitride nanotubes (BNNT) are produced by many different methods leading to variances in physicochemical characteristics and impurities in the final product. These differences can alter the toxicity profile. The importance of understanding the potential pathological implications of this high aspect ratio nanomaterial is increasing as new approaches to synthesize and purify in large scale are being developed. In this review, we discuss the various factors of BNNT production that can influence its toxicity followed by summarizing the toxicity findings from in vitro and in vivo studies conducted to date, including a review of particle clearance observed with various exposure routes. To understand the risk to workers and interpret relevance of toxicological findings, exposure assessment at manufacturing facilities was discussed. Workplace exposure assessment of BNNT from two manufacturing facilities measured boron concentrations in personal breathing zones from non-detectable to 0.95 μg/m and TEM structure counts of 0.0123 ± 0.0094 structures/cm, concentrations well below what was found with other engineered high aspect ratio nanomaterials like carbon nanotubes and nanofibers. Finally, using a purified BNNT, a "read-across" toxicity assessment was performed to demonstrate how known hazard data and physicochemical characteristics can be utilized to evaluate potential inhalation toxicity concerns.

Since antiquity, curcumin, from turmeric is utilized in traditional Indian medicine () to treat bone disorders. However, the hydrophobic nature and poor absorption of curcumin limit its clinical applications. There is a need to develop a novel strategy that can significantly enhance curcumin's biological properties. The current work reports the utilization of Zn-curcumin complex from a fluoride doped hydroxyapatite matrix for osteosarcoma inhibition, osteoblast growth, and anti-bacterial properties. The interaction between Zn and curcumin increases curcumin release by ~ 2.5 folds. The fabricated drug delivery system shows up to ~ 1.6 times enhancement in osteoblast cell viability. The presence of curcumin results in ~ 4 times more osteosarcoma inhibition compared to control. The antibacterial efficacy of this system is confirmed against , due to the presence of antibacterial fluoride, zinc, and curcumin. This multifunctional drug delivery system can be utilized for various bone-tissue engineering and dental applications.

The possibilities of utilizing nacre as a reinforcing material to manufacture 3D printed bone grafts are yet to be explored. This work reports the feasibility of fabricating 3D printed nacre-hydroxyapatitestarch composite bone graft substitutes, emphasizing the effects of nacre addition on biological and mechanical properties. Pressure-less extrusion-based 3D printing of ceramic-polymer viscous slurry is challenging due to the composition and process-parameter variations. To overcome these challenges, a dual extrusion solid freeform fabricator (SFF) has been designed. An increase in nacre loading improves the compressive strength from 9.5 ± 0.1 MPa to 11.7 ± 0.2 MPa, without any post-processing or sintering. Nacre's in vitro osteogenic properties lead to a slight increase in hFOB cellular attachment on the graft surface by day 11. The fabricated structures show good mechanical integrity during the dissolution study in simulated body fluid (SBF). These bone graft substitutes may be utilized to repair low load bearing skeletal defects.

Regenerative engineering is a field that seeks to regenerate complex tissues and biological systems, rather than simply restore and repair individual tissues or organs. Since the first introduction of regenerative engineering in 2012, numerous research has been devoted to the development of this field. Biodegradable polymers such as polyphosphazenes in particular have drawn significant interest as regenerative engineering materials for their synthetic flexibility in designing into materials with a wide range of mechanical properties, degradation rates, and chemical functionality. These polyphosphazenes can go through complete hydrolytic degradation and provide harmlessly and pH neutral buffering degradation products such as phosphates and ammonia, which is crucial for reducing inflammation . Here, we discuss the current accomplishments of polyphosphazene, different methods for synthesizing them, and their applications in tissue regeneration such as bones, nerves, and elastic tissues.

Hepatocyte growth factor (HGF) is a novel potential therapy for improving bone health in patients with type II diabetes and hypertension, but its effect on the bone molecular structure is not revealed yet. Here, X-ray absorption near edge structure (XANES) spectroscopy was used to explore the effects elicited by HGF on the bone chemical structure. This study assessed local calcium (Ca) and phosphorus (P) coordination of diabetic hypertensive rat bones, each with and without HGF treatment. Results revealed that HGF has significant effects on Ca and P coordination chemistry as confirmed by presence of more soluble phosphates in the HGT-treated groups. Data indicated that treated bones have a poorly developed phosphate structure as evidenced by drastic drop in post-edge shoulder in P L-edge compared to diabetic hypertensive and diabetic control bone. Presence of soluble Ca and P, products of bone resorption, with HGF treatment suggests unbalanced bone resorption and formation.

Laser-based 3D Printing was utilized to deposit a silica (SiO) coating on the surface of Ti6Al4V (Ti64) alloy for implementation onto articulating surfaces of load-bearing implants. The surface laser melting (SLM) technique was implemented in 1, and 2 laser passes (1LP and 2LP) after SiO deposition to understand the influence of remelting on the coating's hardness and tribological performance. It was observed that compositional and microstructural features increased the cross-sectional hardness. Wear rate was observed to decrease from 2.9×10 in the Ti64 to 5.2 ×10, 3.8×10, and 2.1×10 mm/Nm for the as-processed or zero laser-pass (0LP), 1LP, and 2LP, respectively. Coated samples displayed a positive shift in open-circuit potential (OCP) during linear wear by displaying a 368, 85, and 613 mV increase compared to Ti64 for 0LP, 1LP, and 2LP, respectively. Our results showed promising tribological performance of SiO coated Ti6Al4V for articulating surfaces of load-bearing implants.

In this study, magnesium and strontium-doped β-tricalcium phosphates were synthesized to understand dopant impact on substrate chemistry and morphology, and proliferation and osteogenic differentiation of mesenchymal stem cells. Under solid-state synthesis, magnesium doping stabilized the β-phase in tricalcium phosphate, with 22% less α-phase content than control. Strontium doping increased α-phase formation by 17%, and also resulted in greater surface porosity, leading to greater crystal precipitation . Magnesium also significantly enhanced the proliferation of stem cells (P < 0.05) and differentiation into osteoblasts with increased alkaline phosphatase production (P < 0.05) at all time points. These results indicated that magnesium stabilizes β-tricalcium phosphate and enhanced early and late-time-point osteoconduction and osteoinduction of mesenchymal stem cells.

Pure and doped iron oxide and hydroxide nanoparticles are highly potential materials for biological, environment, energy and other technological applications. On demand of the applications, single phase as well as multiple phase of different polymorphs or composites of iron oxides with compatible materials for example, zeolite, SiO, or Au are prepared. The properties of the as-synthesized nanoparticles are predominantly dictated by the local structure and the distribution of the cations. Mössbauer spectroscopy is a perfect and efficient characterization technique to investigate the local structure of the Mössbauer-active element such as Fe, Au, and Sn. In the present review, the local structure transformation on the optimization of the magnetite coexisted with iron hydroxides, spin dynamics of the bare, caped, core-shell and the composites of iron oxide nanoparticles (IONPs), dipole-dipole interactions and the diffusion of IONPs were discussed, based on the findings using Mössbauer spectroscopy.

The ever increasing proportion of an energy consuming society and the boost in industrialization accelerated the depletion of fossil fuel based energy sources at an alarming rate. This emphasizes the necessity of sustainable energy generation and storage to meet the daily energy demands. But, these alternative renewable energy sources like solar and wind power are intermittent and highly depend on weather, place and individuals. This creates the inevitability of suitable energy storage devices like batteries and supercapacitors. The interfacing of energy storing devices is required to maintain the supply chain equilibrium, power efficiency, regulate power fluctuations and reduce pollution. Besides, the boom in electric mobility and consumer electronics also require uninterrupted power supply. Hence, in the upcoming years the energy storing devices play a vital role in addressing the energy crisis. Innovations in new materials and technologies will be the core area of research and development in the coming future. 2D materials like graphene,transition metal carbides and nitrides (MXenes), transition metal borides (MBenes) and so on are the new class of materials among them MXenes are getting more attention in energy storage owing to its exceptional properties.

3D CsPbX inorganic perovskite materials have attracted much attention in optoelectronic devices because of their strong absorbance, high photoluminescent quantum yield, tunable band gap, and narrow emission bandwidth. However, their practical usefulness is limited due to their poor stability in ambient conditions. Here, we created photoluminescent 0D CsPbX (X = Br, Br/I) suspensions in toluene by adding a small amount of water. The photoluminescent 0D CsPbX perovskite was mixed with polymethylmethacrylate (PMMA) forming 0D CsPbX/PMMA composite films with higher PL, stability, transparency, and transmittance than that of the 3D CsPbX/PMMA composite films prepared separately. Moreover, the PL intensity maintains 90% of the initial value after 30 days in water, showing excellent water stability. The flexible white-light LED device prepared by the composite films illustrated good luminescence performance with color rendering index 74.77, chromaticity coordinates (0.32, 0.33), and color temperature 6997 K.

Macrophages are innate immune cells that play important roles in wound healing. Particularly, M1 macrophages are considered pro-inflammatory and promote initial phases of inflammation. Long-term exposure to inflammatory stimuli causes an increase in M1 macrophages, which contributes to chronic inflammation. Activated M1 macrophages have been shown to upregulate integrin α2β1 expression. To interfere with α2β1 binding, we designed a biofunctional hydrogel utilizing a collagen I-derived peptide, DGEA (Asp-Gly-Glu-Ala). We hypothesize that M1 macrophage activation can be reduced in the presence of DGEA. Effects of DGEA on M1 macrophages were studied via soluble delivery and immobilization within poly(ethylene glycol) (PEG) hydrogels. We demonstrate that M1 macrophage activation is reduced both via soluble delivery of DGEA in 2D and via immobilized DGEA in a 3D PEG-DGEA hydrogel. This novel biomaterial can manipulate inflammatory macrophage activation and can be applied to prevent chronic inflammatory conditions via macrophage manipulation.

Selenium nanocrystals (SeNPs) were developed using fruit (CGF) extract by green microwave approach. The morphological characters revealed that the quasi SeNPs with dimensions ranging from 12 to 24 nm have been arranged in encapsulated spherical geometries with dimensions ranging from 0.47 to 0.71 m. The DPPH assay revealed that SeNPs at a concentration of 70 µl of 99.2% had the greatest possible scavenging capacity. The nanoparticle concentrations were around 500 g/mL and the cellular uptake of SeNPs through living thing extracellular matrix cell lines in vitro was limited to 75.1 ± 3.8%. The biocidal activity was tested against , , and strains. Since it had the greatest MIC against with 32 mm compared with the reference antibiotics. These incredible qualities of SeNPs suggest that attempting to manipulate multi-purpose nanoparticles for powerful and flexible wound and skin therapeutic innovations is very impressive.

Extracting mechanical data of thin films on rigid substrates using nanoindentation is compromised by the mechanical properties of underlying substrates, which may falsify the obtained results. With ongoing miniaturization, the substrate influence becomes more pronounced. In this study we present an experimental approach to extract the true Young's modulus of crystalline-amorphous multilayers by means of nanoindentation. We used 1 µm thick multilayers comprised of amorphous CuZr and nanocrystalline Cu. All films were deposited onto two rigid substrate types with Young's moduli below and above the ones expected for the deposits (film-to-substrate hardness and elastic moduli ratios between 0.3 to 1.1 and 0.6 to 1.5, respectively). Linear extrapolation of indentation data to zero indentation depth allows to precisely determine the real film's Young's modulus. Same investigations were performed on monolithic Cu and CuZr films of same thickness. While the hardness values change with the variation of the bilayer thickness of the multilayer structures, the Young's modulus is not affected by the interfaces.

Conductive biohybrid cell-material systems have applications in bioelectronics and biorobotics. To date, conductive scaffolds are limited to those with low electrical conductivity or 2D sheets. Here, 3D biohybrid conductive systems are developed using fibroblasts or cardiomyocytes integrated with carbon nanotube (CNT) forests that are densified due to interactions with a gelatin coating. CNT forest scaffolds with a height range of 120-240 µm and an average electrical conductivity of 0.6 S/cm are developed and shown to be cytocompatible as evidenced from greater than 89% viability measured by live-dead assay on both cells on day 1. The cells spread on top and along the height of the CNT forest scaffolds. Finally, the scaffolds have no adverse effects on the expression of genes related to cardiomyocyte maturation and functionality, or fibroblast migration, adhesion, and spreading. The results show that the scaffold could be used in applications ranging from organ-on-a-chip systems to muscle actuators.

A new integrated deposition system taking advantage of magnetron sputtering and electron cyclotron-plasma enhanced chemical vapour deposition (IMS ECR-PECVD) is presented that mitigates the drawbacks of each fabrication system. This tailor-made system provides users with highly homogeneous and pure thin films with less undesired hydrogen and well-controlled rare-earth concentration compared to existing methods of rare-earth doping, such as metalorganic powders, sputtering, and ion implantation. We established the first comprehensive report on the deposition parameters of argon flow and sputtering power to achieve desired rare-earth concentrations in a wide composition range of terbium (Tb) doped-silicon oxide (Tb:SiO) matrices including silicon-rich ( < 2), oxygen-rich ( > 2), and stoichiometric silicon oxide ( = 2). The deposition parameters to fabricate crystalline structure (TbSiO) in oxygen-rich samples are reported where Tb ions are optically active. IMS ECR-PECVD pushes the solubility limit of the rare-earth dopant in silicon films to 17 at.% for the desired future nanophotonic devices.

Two-dimensional (2D) layered materials as a new class of nanomaterial are characterized by a list of exotic properties. These layered materials are investigated widely in several biomedical applications. A comprehensive understanding of the state-of-the-art developments of 2D materials designed for multiple nanoplatforms will aid researchers in various fields to broaden the scope of biomedical applications. Here, we review the advances in 2D material-based biomedical applications. First, we introduce the classification and properties of 2D materials. Next, we summarize surface and structural engineering methods of 2D materials where we discuss surface functionalization, defect, and strain engineering, and creating heterostructures based on layered materials for biomedical applications. After that, we discuss different biomedical applications. Then, we briefly introduced the emerging role of machine learning (ML) as a technological advancement to boost biomedical platforms. Finally, the current challenges, opportunities, and prospects on 2D materials in biomedical applications are discussed.

We address the effect of elastic inhomogeneity on elastic modulus and hardness determinations made by depth-sensing indentations performed on individual particles embedded within a matrix of different elastic modulus. Finite element simulations and nanoindentation experiments are used to quantify the consequences of particle/matrix elastic inhomogeneity and we propose an adaptation of the Oliver-Pharr method that gives access to particle properties knowing those of the matrix. The method is suitable for any combination of matrix and particle elastic modulus and for any type of indenter, provided that the area of the tested particles along the surface of the sample is measured and that a large number of particles are probed. Further conditions for the implementation of the method are that testing conditions be such (i) that permanent deformation of the matrix is avoided, and (ii) that permanent deformation in each probed particle under the indenter is not affected by the matrix.

An effective technique for improving electrochemical efficiency is to rationally design hierarchical nanostructures that completely optimize the advantages of single components and establish an interfacial effect between structures. In this study, core-shell NiMoO@NiS/MoS hetero-structured nanorods are prepared via a facile hydrothermal process followed by a direct sulfurization. The resulting hierarchical architecture with outer NiS/MoS nanoflakes shell on the inner NiMoO core offers plentiful active sites and ample charge transfer pathways in continuous heterointerfaces. Ascribing to the porous core-shell configuration and synergistic effect of bimetal sulfides, the obtained NiMoO@NiS/MoS as electrode material presents an unsurpassed specific capacity of 373.4 F g at 10 A g and remarkable cycling performance in the 6 M KOH electrolyte. This work delivers a rational method for designing highly efficient electrodes for supercapacitors, enlightening the road of exploring low-cost materials in the energy storage domain.

Cold spray (CS) processing is a layer-by-layer solid-state deposition process in which particles at a temperature below their melting point are launched to sufficiently high velocities to adhere to a substrate (and previously deposited particles), forming coatings/parts. Despite being in existence for over four decades, particle bonding mechanisms in the CS process are unclear due to the complex particle-particle/carrier gas interactions that obscure assessment. This review evaluates recent findings from single-particle impact approaches that circumvent these complexities and further provide new insights on bonding mechanisms. Theories on the evolution of oxide layer breakup and delamination, adiabatic shear instability, jetting, melting, and interface solid-state amorphization that contributes to bonding are assessed and carefully reviewed. Although there is a unified condition in which bonding sets on, this study shows that no singular theory explains bonding mechanism. Rather, dominant mechanism is a function of the prevailing barriers unique to each impact scenario.

Realizing breathable shape memory fiber-based material with antibacterial and waterproof performances is important for multitiered wearable protection to address the increasing concerns of air pollution. Herein, using an alternating electrospinning-electrospraying technology, we develop a fiber-based membrane with Janus wettability based on a silk fibroin nanofibers-substrate (SFNFs), a polyurethane nanospheres-top layer (PUNSs), and a middle layer of PU nanofibers-mat with in-situ grown silver nanoparticles (PUNFs-AgNPs), which serves separately for skin contact, a self-cleaning physical barrier to resist external aerosol/bacteria (PM2.5 filtration efficiency ~ 98.1%), and a bio-barrier that can sterilize harmful particles and inhibit bacteria proliferation (> 95%). This breathable Janus film (SFNFs/PUNFs-AgNPs/PUNSs, SPAP) with an antibacterial filter shows shape memory stretchability enabled by the thermoplastic PU component, which is mechanically adaptive to human body for wearable protection. This work presents a breathable wearable material for air-filtration and anti-bacteria, promising for applications such as wound dressings, medical masks, protection suits, and multifunctional filters.

Recent advances in fabricating scalable two-dimensional or freestanding functional materials have shown promise for their use in modern silicon-based electronics and future technologies. A growing interest is in creating freestanding complex oxide membranes using new methods like epitaxial lift-off and mechanical exfoliation to enhance their quality and integrity. Despite these advances, it remains challenging to consistently produce high-quality freestanding oxide membranes on a large scale for practical use. This perspective paper provides an overview of release-and-transfer techniques for fabricating freestanding single-crystalline complex oxide layers, which are initially grown epitaxially. Specifically, we systematically explore the advantages and disadvantages of water-assisted exfoliation of freestanding oxide layers, which have been widely adopted using a water-soluble sacrificial layer in recent years. Furthermore, we compare this approach with other methods to navigate future directions in oxide layer transfer technology, considering material selections, fabrication processes, and functionalization strategies.