Porous calcium silicate bioactive material-alginate composite for bone regeneration.

Bone tissue engineering aims to address bone-related problems that arise from trauma, infection, tumors, and surgery. Polymer and calcium silicate bioactive material (BM) based composites are commonly preferred as potential materials for bone treatment. However, the polymer has low bioactivity, thus, the current work aims to prepare a composite scaffold based on BM-sodium alginate (Alg) by varying the Alg percentage to optimize the porous nature of the composite. Primarily, the BM was synthesized by a simple precipitation method using rice husk and eggshell as the precursors of silica and calcium, while the BM-Alg composite was prepared by a facile cross-linking approach. The BM-Alg composite was studied using XRD, FTIR, SEM, and BET techniques. Further, an in vitro bioactivity study was performed in simulated body fluid (SBF) which shows hydroxyapatite formation. The in vitro haemolysis study displayed less than 5% haemolysis. Subsequently, the angiogenesis study was carried out using the ex ovo CAM model which reveals enhanced neovascularization. The MG-63 cells were used to study the biocompatibility, and they displayed a non-toxic nature at a concentration of 10 mg mL-1. Further, the in vivo biocompatibility results also reveal its non-toxic nature. Thus, the BM-Alg composite acts as a potential biocompatible material for bone tissue engineering applications.

Bioactive material­sodium alginate-polyvinyl alcohol composite film scaffold for bone tissue engineering application.

Road accidents and infection-causing diseases during bone surgery are serious problems in orthopedics, and thus, addressing these pressing challenges is crucial. In the present study, the 70S30C calcium silicate bioactive material (BM) is synthesized by a sustainable approach employing a precipitation method using recycled rice husk and eggshells as a precursor of silica and calcium. Further, 70S30C BM is composited with sodium alginate (SA) and polyvinyl alcohol (PVA), and the films were prepared by solvent casting method. The composite films were prepared without the addition of acid, binder, and crosslinking agents. Further, the films were characterized by BET, XRD, ATR-FTIR, SEM, and EDS mapping. The in vitro bioactivity and biodegradation study is performed in the simulated body fluid (SBF). The in vitro haemolysis study is executed using human blood and the results demonstrate haemocompatibility of the composite films. The ex ovo CAM assay also exhibits good neovascularization. The in vitro and in vivo biocompatibility assay proves its non-toxic nature. Further, the in vivo study reveals that the engineered composite film demonstrates accelerated osteogenesis. This work broadens the orthopedic potential of the composite film and offers bioactivity, haemocompatibility, angiogenesis, non-toxicity, and in vivo osteogenesis which would serve as a potential candidate for bone tissue engineering application.

Engineering H2O2 Self-Supplying Platform for Xdynamic Therapies via Ru-Cu Peroxide Nanocarrier: Tumor Microenvironment-Mediated Synergistic Therapy.

Of the most common, hypoxia, overexpressed glutathione (GSH), and insufficient H2O2 concentration in the tumor microenvironment (TME) are the main barriers to the advancment of reactive oxygen species (ROS) mediated Xdynamic therapies (X = photo, chemodynamic, chemo). Maximizing Fenton catalytic efficiency is crucial in chemodynamic therapy (CDT), yet endogenous H2O2 levels are not sufficient to attain better anticancer efficacy. Specifically, there is a need to amplify Fenton reactivity within tumors, leveraging the unique attributes of the TME. Herein, for the first time, we design RuxCu1-xO2-Ce6/CPT (RCpCCPT) anticancer nanoagent for TME-mediated synergistic therapy based on heterogeneous Ru-Cu peroxide nanodots (RuxCu1-xO2 NDs) and chlorine e6 (Ce6), loaded with ROS-responsive thioketal (TK) linked-camptothecin (CPT). The Ru-Cu peroxide NDs (RCp NDs, x = 0.50) possess the highest oxygen vacancy (OV) density, which grants them the potential to form massive Lewis's acid sites for peroxide adsorption, while the dispersibility and targetability of the NDs were improved via surface modification using hyaluronic acid (HA). In TME, RCpCCPT degrades, releasing H2O2, Ru2+/3+, and Cu+/2+ ions, which cooperatively facilitate hydroxyl radical (•OH) formation and deactivate antioxidant GSH enzymes through a cocatalytic loop, resulting in excellent tumor therapeutic efficacy. Furthermore, when combined with laser treatment, RCpCCPT produces singlet oxygen (1O2) for PDT, which induces cell apoptosis at tumor sites. Following ROS generation, the TK linkage is disrupted, releasing up to 92% of the CPT within 48 h. In vitro investigations showed that laser-treated RCpCCPT caused 81.5% cell death from PDT/CDT and chemotherapy (CT). RCpCCPT in cancer cells produces red-blue emission in images of cells taking them in, which allows for fluorescence image-guided Xdynamic treatment. The overall results show that RCp NDs and RCpCCPT are more biocompatible and have excellent Xdynamic therapeutic effectiveness in vitro and in vivo.

Influence of binder and solvents on the electrochemical performance of screen-printed MXene electrodes.

The present study is concerned with the use of binders and solvents in fabricating MXene electrodes, which play a vital role in influencing supercapacitive performance. The electrodes were prepared by screen printing MXene on flexible stainless steel mesh (FSSM) substrate, which is a straightforward, efficient, and cost-effective approach. The influence of binder and solvent on the electrochemical performance was investigated by fabricating them with and without using a binder i.e. only organic solvents ethanol and n-methyl-2-pyrrolidone (NMP). The electrode with the binder is abbreviated as MX-B@FSSM and was prepared with the composition of acetylene black conducting material, polyvinylidene fluoride (PVDF) polymer binder, and MXene (MX) as active material. While electrodes without binder were prepared by a slurry of MXene using organic solvent ethanol and NMP and are abbreviated as MX-E@FSSM and MX-N@FSSM, respectively. The electrochemical performance of these MX-B@FSSM, MX-E@FSSM and MX-N@FSSM electrodes was examined by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy. The influence of the binder altered the electrochemical performance. The samples MX-B@FSSM, MX-E@FSSM, and MX-N@FSSM show the specific capacitance of 35.60, 490.80, and 339.6 F g-1, respectively at 2 mA cm-2current density. The MX-E@FSSM electrode exhibited marginally the best electrochemical performance. Furthermore, MnO2/MXene//MX-E asymmetric supercapacitor device exhibits 252 F g-1specific capacitance at 35.2 Wh kg-1energy density demonstrating a promising electrode for the supercapacitor.

Depositing silver nanoparticles on/in a glass slide by the sonochemical method.

A glass substrate was coated with silver by ultrasound irradiation. The structure and morphology of the nanoparticles in the deposited film were characterized using methods such as XRD, TEM, HR TEM, HRSEM, AFM, TOF-SIMS and optical spectroscopy. It was demonstrated that nucleation and the ensuing growth of the nanoparticles occurs in solution and is influenced by the concentration of the precursor, temperature and time of sonication. TOF-SIMS measurements revealed that silver nanoparticles passed through the glass interface and diffused within the glass substrate up to ∼60 nm. An analysis of the thermal effects accompanying the sonochemical cavitation of micro-bubbles in the solution near the solid surfaces shows that the collision of nanoparticles can lead to their melting and coalescence. Sonochemical deposition takes place layer by layer, so that the completion of the deposition of each layer of nanoparticles is followed by the sintering of adjacent particles and the formation of a close-packed layer. Using PVP as a stabilizing agent, a monolayer coating of silver nanoparticles on the glass surface was obtained. The coated glass demonstrated antibacterial activity.

Microscale size triangular gold prisms synthesized using Bengal gram beans (Cicer arietinum L.) extract and HAuCl4x3H20: a green biogenic approach.

Single step and completely green room temperature biosynthesis of microscale size triangular gold prisms (approximately 25 nm thick) using remnant water collected from soaked Bengal gram beans (Cicer arietinum L.) is reported for the first time. Extracellular transport of protein and biomolecules from protein rich gram beans mediate the reduction of aqueous Au3+ ions and direct the growth of triangular prisms. The growth of triangular gold prisms is monitored by UV-vis spectrometer and supported by complementary characterizations using UV-vis/NIR, TEM, EDS, light microscope, XRD, XPS, ATR-FTIR, and ESI-MS. Plausible mechanism for the formation of microscale size triangular gold prisms is discussed. Effect of varying compositions of gram bean extract and aqueous Au3+ solution governing the morphology of the resultant gold particles is also investigated. Procuring the reducing, growth directing, and stabilizing molecules from the remnant water (extract), which normally would have been a kitchen waste, and water as a universal solvent makes it a completely green process displaying both environmental and economic advantages. Furthermore, this biosynthesis approach is simple, green, and an eco-friendly alternative to chemical synthesis of triangular gold prisms with rates comparable to chemical methods.