Biomaterials with antibacterial activity are widely developed for the treatment of bone infection. In the present study, hydroxyapatite (HAp) nanorods were prepared by green synthesis using Azadirachta indica and Coccinia grandis leaf extract. The prepared samples were characterized by various characterization techniques and the results indicate that the prepared samples are constituted of phase pure polycrystalline HAp having hexagonal crystal structure. Moreover, antibacterial activity test confirm that the HAp prepared using leaf extract as a solvent having significant antibacterial activity against Escherichia coli and Staphylococcus aureus. Hence, green synthesis can be a prospective way to develop orthopedic biomaterials with antibacterial properties.

Understanding peripheral nerve repair requires the evaluation of three-dimensional (3D) structures that serve as platforms for 3D cell culture. Multiple platforms for 3D cell culture have been developed, mimicking peripheral nerve growth and function, in order to study tissue repair or diseases. To recreate an appropriate 3D environment for peripheral nerve cells, key factors are to be considered, including selection of cells, polymeric biomaterials to be used, and fabrication techniques to shape and form the 3D scaffolds for cellular culture. This review focuses on polymeric 3D platforms used for the development of 3D peripheral nerve cell cultures.

Graphene nanopores are utilized in various notable applications such as water desalination, molecular separation, and DNA sequencing. However, the creation of stable nanopores is still challenging due to the self-healing nature of graphene. In this study, using molecular dynamics simulations we explore the drilling of nanopores through graphene by bombardment with Si-nanoparticles. This enables the Si-passivation along the nanopore rim, which is known as an efficient way to stabilize graphene nanopores. The interplay between graphene and projectile causes the anomalous behaviors such as local maxima depending on particle size. The observations are thoroughly analyzed with interaction energy and shape changes.

Gelatin-based hydrogels derived from hydrolysis of collagen have been extensively used in pharmaceutical and medical applications because of their biocompatibility and biodegradability. For example, gelatin-based hydrogels are finding use in drug delivery and tissue engineering because they are able to promote cell adhesion and proliferation. In addition, these hydrogels can be used as wound dressings due to their attractive fluid absorbance properties. Manufacturing technologies such as ultraviolet stereolithography and two-photon polymerization can be used to prepare structures containing photosensitive gelatin-based hydrogels. This review describes the preparation of gelatin-based hydrogels and use of these materials for biomedical applications.

The hydrobaric effect on photoactivity of titanium dioxide (TiO2) fabricated by cathodic deposition in an aqueous solution was evaluated in this study. When the applied pressure was increased to 35 MPa, the water-splitting performance was improved by almost fourfold of the performance of the TiO2 prepared at atmospheric pressure. The surface states effect was significant in the deposited TiO2, which was exploited to affect the charges recombination of TiO2, and thereby enhance the resultant photoelectrochemical water-splitting performance. The hydrobaric cathodic deposition could be extended to fabrication of other metal oxides to eliminate the negative influence from the high-temperature process.

Cobalt oxide thin films with different thicknesses were synthesized by atomic layer deposition. After a thermal reduction process, under a controlled atmosphere of hydrogen, it was possible to convert cobalt oxide to metallic cobalt. The different thicknesses were obtained considering from 500 to 2000 cycles of CoCp2/O3. The thin films were characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray microanalysis, and by magneto-optical Kerr effect measurements. The indirect synthesis process allows us to obtain cobalt oxide and cobalt thin films with controlled thicknesses and extraordinary magnetic properties, with coercivities above 500 Oe.

Core–shell silicon–silicon oxide nanowires are synthesized at low temperatures using inorganic and organic compounds of a tin as a catalyst. In situ simultaneous one-dimensional growth of pristine silicon nanowires (SiNWs) using alloy catalyst is reported here. Such a development process generates a high-quality SiNW that is not determined by other atomic species in the plasma. A possible growth model is discussed to understand the synchronized precipitation of a SiNW core and an oxide shell. Nanowires grown here eliminate the additional fabrication steps to deposit anticipated oxide shell that is achieved by precipitation from the same catalyst that precipitates core nanowires.

Tissue engineering holds great promise for advancing cancer research and achieving the goals of the Cancer Moonshot by providing better models for basic research and testing novel therapeutics. This paper focuses on the use of hydrogel biomaterials due to their unique ability to entrap cells in three-dimensional (3D) matrix that mimics tissues and can be programmed with physical and chemical cues to recreate key aspects of tumor microenvironments. The chemistry of some commonly used hydrogel platforms is discussed, and important examples of their use in tissue engineering 3D cancer models are highlighted. Challenges and opportunities for future research are also discussed.

The effect of tellurium (Te) doping on the electrocatalytic activity of La1−x Te x MnO3 toward the oxygen reduction reaction is investigated for the first time. La1−x Te x MnO3 with x-values up 23% were synthesized from a single ionic liquid-based precursor, yielding nanoparticles with mean diameter in the range of 40–68 nm and rhombohedral unit cell. Electrochemical studies were performed on carbon-supported particles in alkaline environment. The composition dependence activity is discussed in terms of surface density of Mn sites and changes in the effective Mn oxidation state.

We report on the intermediate-temperature synthesis (973 K) and operation (<750 K) of Ce4.67(SiO4)3O-based thin-film oxy-apatites. The apatite thin films show the high conductivity of ~0.05–0.5 S/cm and excellent stability in reducing atmosphere (<10−17 atm), which makes promising these materials as anodes for intermediate-temperature solid oxide fuel cell (SOFC) application. The proto-type SOFCs implementing single-layer apatite and apatite/Pt bilayer anodes were fabricated and the resulting performance (e.g., peak power density of ~5 mW/cm2 at 748 K) presents notable feasibility of ZCS-based oxy-apatite anodes for thin-film SOFC devices.

Tin oxide (SnO2) nanoparticles in gram scale quantity were synthesized from inexpensive Sn feedstock by flame oxidation. Selection of optimal feedstock size based on computational fluid dynamics ensures complete conversion of Sn into SnO2 nanoparticles. The rapid melting and oxidation of feedstock in high-temperature oxidative flame endow the crystalline and phase-pure SnO2 nanoparticles, as evident from x-ray diffraction and transmission electron microscopy analysis. Dye-sensitized solar cells fabricated using flame-SnO2 nanoparticles show higher efficiency (ɳ = 2.72%) than that of commercial SnO2 nanoparticles (ɳ = 1.53%). The increased efficiency is attributed to suppression of electron recombination caused by passivation of sub-band-edge surface states.

While preclinical models such as orthotopic tumors generated in mice from patient-derived specimens are widely used to predict sensitivity or therapeutic interventions for cancer, such xenografts can be slow, require extensive infrastructure, and can make in situ assessment difficult. Such concerns are heightened in highly aggressive cancers, such as glioblastoma (GBM), that display genetic diversity and short mean survival. Biomimetic biomaterial technologies offer an approach to create ex vivo models that reflect biophysical features of the tumor microenvironment (TME). We describe a microfluidic templating approach to generate spatially graded hydrogels containing patient-derived GBM cells to explore drug efficacy and resistance mechanisms.

Nickel oxide-based materials have attracted significant interest for a variety of energy conversion applications although many of their structures remain unresolved. In this study, Density Functional Theory+U (DFT+U) and hybrid DFT calculations are used to analyze the properties of crystalline nickel oxyhydroxide (β-NiOOH) with hydrogen (H) vacancies. Hydrogen vacancies are found to lower the band gap without creating states inside the band gap. Inter-layer crossing is a possible transport pathway, while intra-layer transport is inhibited. Bulk modulus is not influenced by H vacancies in the crystal. β-NiOOH with H vacancies exhibits good electronic properties, essential for solid electrolytes and anodes in solid oxide fuel cells.

Nuclear translocation of Yes-associated-protein (YAP) in single cells serves as a key sensor of matrix stiffness. On two-dimensional (2D) polyacrylamide (PA) hydrogels, we found that nuclear YAP localization in epithelial clusters increases with gel stiffness and reduces with cell density. To measure YAP activity in 3D-like confinement of tunable stiffness, we fabricated PA-based microchannels. Here, narrower channels enhanced nuclear YAP localization even in softer extracellular matrix and denser epithelial clusters, both of which reduced YAP activation in 2D. Thus, the presented hydrogel microchannel-based platform may reveal new mechanosensitive cellular signatures in 3D-like settings, which cannot be captured on standard 2D hydrogels.

Carbon-coated silicon nanowires (C-Si NWs) were prepared as anodes for lithium-ion batteries (LIBs). The C-Si NWs were synthesized using a simple and effective fabrication strategy via magnesiothermic reduction. The synthesis sequence of carbon coating before the chemical etching of the reduced Si NWs/MgO composite was found to be critical for improved battery performance. In addition, carbon coating was found to help to stabilize the solid electrolyte interphase layer during battery cycling, which is important to realize the benefits of Si-based LIBs. This synthesis method provides an efficient route to synthesizing high-performance Si electrodes via magnesiothermic reduction.

Starting from polydisperse diatomaceous earth (DE), we proposed an efficient separation method for obtaining different morphologies of biosilica from diatoms. DE is a very low-cost source of silica containing all the differently nanostructured elements. By a glucose gradient/dialysis, three types of biosilica morphologies were achieved: rods, valves, and clusters. We fully characterized the diatom fractions and we used them to produce fluorescent biosilica platforms (“tabs”). These supports exhibited good resistance in water, ethanol, and soft scraping. A preliminary biologic application by testing Saos-2 proliferation was also performed to check osteoblasts-like cells biologic attitude for this scaffolds with tunable nanostructure.

Two-step, solar-driven thermochemical fuel production offers the potential of efficient conversion of solar energy into dispatchable chemical fuel. Success relies on the availability of materials that readily undergo redox reactions in response to changes in environmental conditions. Those with a low enthalpy of reduction can typically be reduced at moderate temperatures, important for practical operation. However, easy reducibility has often been accompanied by surprisingly poor fuel production kinetics. Using the La1−x Sr x MnO3 series of perovskites as an example, we show that poor fuel production rates are a direct consequence of the diminished enthalpy. Thus, material development efforts will need to balance the countering thermodynamic influences of reduction enthalpy on fuel production capacity and fuel production rate.

Human mesenchymal stem cells (MSCs) are the most intensely studied and clinically used adult stem cell type. Conventional long-term cultivation of MSCs as a monolayer is known to result in a reduction of their functionality and viability. In addition, large volumes of cell culture medium are required to obtain cell quantities needed for their clinical use. In this proof of concept study, we cultivated human MSCs within a three-dimensional nanofibrillar cellulose (NFC) hydrogel. We show that NFC is biocompatible with human MSCs, and represents a feasible approach to upscaling of their culture.