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Nature-derived exosomes have been noted as emerging carriers for anticancer drugs. In this study, as a proof-of-concept, the anticancer drug doxorubicin (Dox) was loaded onto i-motif-modified exosomes (Exo-i-motif) to deliver Dox to cancer cells efficiently. The double-stranded biotin-i-motif/flare (ds-i-motif-bio)s efficiently released Dox in an acidic pH-responsive manner within 1 h. Based on gel electrophoresis, it was clearly confirmed that ds-i-motif-bio successfully interacts with biotin-conjugated exosomes and streptavidin (strep) via the biotin–streptavidin interaction. The particle sizes were below 150 nm without aggregation after strep-mediated modification of ds-i-motif-bio on the surfaces of the exosomes. In addition, released Dox had intact bioactivity for anti-proliferation after immobilization onto the exosomes. This study could serve as a new concept of pH-responsive delivery systems of anticancer drug using nature-derived exosomes with i-motifs.

Over the last few centuries, aging-related diseases have become a part of the global health care problem. The skin is essentially more sensitive to aging because it is influenced by environmental exposure and genetic (genetically determined) processes. The use of a suitable cosmetic anti-aging material using a biomolecule with conventionally important medicine can help to protect damaged skin tissue. A new topical cosmetic anti-aging material should simulate the function of an extracellular matrix with its enhanced physiochemical, biological oxidative stress, and antioxidant properties. This study examined the significant features of CA–APPPKK (caffeic acid conjugated with peptide (APPPKK)) to determine if it meets the requirements for a cosmetic anti-aging biomolecule. Non-toxic CA–APPPKK was synthesized using a simple approach and CA stabilized with a peptide to form the new biomaterials. The cytotoxicity of the CA–APPPKK was examined with a CCK-8 assay and a reactive oxygen species (ROS) assay to evaluate the biological applications. CA–APPPKK caused a decrease in cell viability and membrane damage, and the degree of induction was dose dependent. The longevity-extending role of CA–APPPKK was attributed to its anti-oxidative activity and increased oxidative stress resistance. The anti-inflammatory capacity of CA–APPPKK was measured using a NO assay. This new approach indicates that CA–APPPKK is a potentially cosmetic anti-aging biomaterial for the prevention of oxidative stress-induced premature skin ageing and can be used to study aging-related diseases.

Blue-green microalgal blooms have been caused concerns about environmental problems and human-health dangers. For removal of such cyanobacteria, many mechanical and chemical treatments have been trialled. Among various technologies, the flocculation-based harvesting (precipitation) method can be an alternative if the problem of the low yield of recovered biomass at low concentrations of cyanobacteria is solved. In the present study, it was utilized mixtures of magnesium aminoclay [MgAC] and cerium aminoclay [CeAC] with different particle sizes to harvest cyanobacteria feedstocks with ∼100% efficiency within 1h by ten-fold lower loading of ACs compared with single treatments of [MgAC] or [CeAC]. This success was owed to the compact networks of the different-sized-ACs mixture for efficient bridging between microalgal cells. In order to determine the usage potential of biomass harvested with AC, the mass was heat treated under the reduction condition. This system is expected to be profitably utilizable in adsorbents and catalysts.

We describe the preparation of a nanohybrid consisting of nitrogen doped reduced graphene oxide and CuS nanoparticles (N-rGO/CuS) by in-situ microwave irradiation at weight ratios of 25/75, 50/50, and 75/25. The resulting nanohybrids were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, FTIR, spectroscopy, scanning electron and transmission electron microscopy, electrochemically by cyclic voltammetry and electrochemical impedance analysis. It is shown that the CuS nanoparticles are evenly decorated onto the N-rGO surface. The nanohybrids was placed on glassy carbon electrode (GCE) where they showed electro-reductive activity towards picric acid, typically at working voltages between −0.2 and −0.8 V (vs. SCE). Effects of pH value and scan rate were evaluated, and it is shown that two electrons are involved in electro-reduction. The detection limits of the GCE modified with various N-rGO/CuS hybrids (with 25/75, 50/50, and 75/25 wt%) are 6.2, 3.2, and 0.069 μM respectively. The method demonstrates its applicability in sensing of picric acid with good reproducibility.

Cobalt oxide (Co 3 O 4 ) nanospindles-decorated reduced graphene oxide (RGO) composite is prepared via thermal decomposition of a three-dimensional coordination complex precursor, cobalt benzoate dihydrazinate, at 200 °C. Transmission electron microscopy reveals that Co 3 O 4 nanospindles with an average particle size of I (μA) = 2.0660 C + 6.7869 ( R 2 = 0.9992). The sensor exhibits a high sensitivity of 29.5 μA μM −1 cm −2 , a rapid response time of 5 s, and a low detection of limit of 0.14 μM. The proposed electrode shows good reproducibility and long-term stability. The sensor is used to determine the nitrite level in tap water with acceptable recovery, implying its feasibility for practical application.

Since materials used in or exposed to high-temperature environments can undergo variation or degradation of mechanical properties, it is important to evaluate mechanical properties at high temperature, in particular for structural applications and aerospace materials. Instrumented indentation testing (IIT) is widely used to evaluate such mechanical properties of materials as tensile properties, residual stress, fracture toughness, etc., exploiting theoretical approaches to indentation mechanics. In this study, we used IIT to evaluate variations in tensile properties with temperature of the Ti alloy Ti-6Al-4V, a candidate material for aerospace applications, using a high-temperature chamber and a modified representation method. Comparison of our results with conventional uniaxial tensile test results showed good agreement (within a 10% error range) in yield strength and ultimate tensile strength. This confirms the potential of IIT for evaluating to evaluate high-temperature tensile properties of metallic materials and for research on material behavior in various temperature conditions.

The recoveries of Sr2+ and La3+ as rare earth metals (REMs) were studied using Mg-aminoclay–humic acid [MgAC–HA] complexes prepared by self-assembled precipitation due to electrostatic attraction between water-solubilized [MgAC] and water-soluble [HA], and were compared with the recoveries using [MgAC] and [HA]. The influences of pH and Sr2+ and La3+ concentrations in single and binary systems were evaluated. The adsorbents before/after adsorption of Sr2+ and La3+ were characterized by (1) scanning electron microscopy (SEM) micrographs, (2) Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), and extended X-ray absorption fine structure (EXAFS) spectra, and by (3) powder X-ray diffraction (XRD) pattern analysis. After fitting Langmuir and Freundlich isotherms, the Langmuir model was found to present better matches than the Freundlich one: the maximum adsorption capacities of Sr2+ and La3+ were 0.12 mg g−1 and 4.76 mg g−1 in the binary system at room temperature, and the optimal recovery pH was ∼8.0. In practical seawater meanwhile, the recoveries of Sr2+ and La3+ by [MgAC–HA] complexes were the highest in the binary system. However, with further recycling runs, the recoveries of Sr2+ and La3+ were critically diminished due to disassembly in [MgAC–HA] complexes under acidic conditions. Thus, for the purposes of industrial application, we are currently pursuing the enhancement of recyclability for [MgAC–HA] complexes by their encapsulation or direct hydrogel formation.