Preparation and characterization of high-performance ceramic proppant from recycling utilization of oil-based drilling cuttings pyrolysis residues.

Oil-based drilling cutting pyrolysis residues (ODCPRs), bauxite, and sintering additives were applied to manufacture ceramic proppants with low density and high strength in this work. The effect of ODCPRs ratio, sintering temperature, holding time, and the content of additives on the performance of the proppants was comprehensively investigated, respectively. And the sintering mechanism of proppants was also discussed according to the phase, microstructure, and thermal behavior analyses. The results revealed that at the best sintering condition (1280 °C, holding for 60 min), and a mass ratio (ODCPRs: bauxite: MnO2 at 3:7:0.1), the well-developed granular corundum and acicular mullite formed inside the proppants and interspersed with each other to form a dense structure. The proppants presented low density and high strength as the bulk density of 1.48 g/cm3, the apparent density of 2.94 g/cm3, a breakage ratio of 5.25% under 52 MPa closed pressure, and the acid solubility of 4.80%, which could well meet the requirement of the standards of SY/T 5108-2014. This work provided a new pathway for recycling ODCPRs and the fabrication of high-performance proppants.

Two-dimensional MXene/cobalt nanowire heterojunction for controlled drug delivery and chemo-photothermal therapy.

Two-dimensional (2D) MXene nanomaterials have explored as a great potential candidate for tumor therapy during recent decades, especially for photothermal therapeutic applications. However, MXene-based drug-carriers cannot be elaborately controlled in cancer therapy. To solve the problem, a heterostructured titanium carbide-cobalt nanowires (Ti3C2-CoNWs) nanocarrier is developed for synergetic anticancer with magnetic controlling ability, dual stimuli-responsive drug release, and chemo-photothermal therapy. The structure, drug loading/release behavior, magnetic controlling capacity, photothermal performance, and synergistic therapeutic efficiency of the Ti3C2-CoNWs nanocarrier heterojunction are investigated. The heterostructured Ti3C2-CoNWs nanocarrier exhibits excellent photothermal conversion efficiency under 808 nm laser irradiation and high drug loading ability (225.05%). The doxorubicin (DOX) release behavior can be triggered by acid pH value (4-6) or near-infrared (NIR) irradiation. The Ti3C2-CoNWs nanocarrier heterojunction with synergistic chemo-photothermal therapeutic effect exhibits strong lethality for cancer cells than that of chemotherapy or photothermal therapy (PTT) alone. Therefore, Ti3C2-CoNWs nanocarrier heterojunction will be a promising choice for improving the efficiency of cancer treatment.

The influence of different lactic acid bacteria on sourdough flavor and a deep insight into sourdough fermentation through RNA sequencing.

Ten lactic acid bacteria (LAB) strains of different species isolated from Chinese traditional sourdough were investigated on their volatile compounds in sourdough fermentation. Sourdoughs fermented with different LAB species were analyzed by principal component analysis (PCA) based on their volatiles. Furthermore, the in situ gene expressions of Lactobacillus sanfranciscensis during sourdough fermentation were investigated by using RNA sequencing for the first time. PCA could discriminate between the sourdoughs fermented by homofermentative and heterofermentative LAB, the former containing more aldehydes and ketones with more than 6 carbon atoms, while the latter featuring ethanol and esters. The Lactobacillus plantarum-fermented sourdough was characterized by high C4-C6 volatiles content, while L. sanfranciscensis showed a unique volatile profile without explicit explanatory compounds. The RNA sequencing suggested that, compared to the sourdough fermented for 6 h, L. sanfranciscensis enhanced carbohydrate metabolism and self-protection activities, but decreased cell proliferation in sourdough at 12 h.

Fibroin/peptide co-functionalized calcium titanate nanorods improve osteoinductivity of titanium via mimicking osteogenic niche.

The surface-inspirable biomaterials have captured extensive attention in simulating microenvironments by mimicking nanoscale architectures and signal molecules in the extracellular matrix (ECM). To activate osteogenic differentiation through biomimetic nanostructures, osteoid-like calcium titanate nanorods (CT) were fabricated via anodization and hydrothermal treatment. SEM, EDS, and XPS were employed to confirm the morphology and chemical composition. The functional fibroin and peptide layers on CT (PFCT) were subsequently applied to provide binding sites and bioactive molecules for osteoblast growth and differentiation. The hydrophilicity obviously increased with the protein layers. PFCT presented enhanced cell viability with pronounced pseudopod extension and continuous proliferation. The osteogenic differentiation analysis revealed that the alkaline phosphatase expression improved in the early stage. The calcium nodes and the collagen secretion were also enhanced. Quantitative polymerase chain reaction assessment indicated that osteogenesis-related markers including ALP, Col1, and Runx2, were up-regulated. The in vitro results demonstrated that fibroin/peptide co-functionalized calcium titanate nanorods were efficient to stimulate osteoblasts and improve cell adhesion, proliferation, and differentiation. Therefore, the nanorods can create an osteogenic niche on titanium implants, which can be a promising modification strategy in bone tissue engineering application.

HAp@GO drug delivery vehicle with dual-stimuli-triggered drug release property and efficient synergistic therapy function against cancer.

Nanoscale hydroxyapatite (HAp) is an optimal candidate material in biomedical area for its good biocompatibility and bioactivity. In this study, HAp nanorods are prepared via hydrothermal method and combined with monolayered graphene oxide (GO). The obtained HAp@GO with excellent biocompatibility is revealed to have high drug loading capacity (698.7 µg/mg) for anticancer drug doxorubicin (DOX) and efficient photothermal conversion property. And the drug release property of DOX loaded HAp@GO (HAp@GO-DOX) is demonstrated to be controlled by pH and near-infrared light, which is favorable for cancer therapy. in vitro studies on cancer therapy demonstrate that the combined treatment, compared with either chemotherapy or photothermal therapy alone, has better synergistic therapeutic effect. These findings prove the great potential application of the nanocomposites for cancer therapy.

Cobalt nanowire-based multifunctional platform for targeted chemo-photothermal synergistic cancer therapy.

Cobalt nanowires (CoNWs) simultaneously possessing advantages in photothermal effect, targeting drug delivery and photoacoustic imaging property are hopefully promising strategies to further improve the treatment efficiency and reduce the side effects of cancer chemotherapy. Herein, a unique cobalt-based structure decorated with graphene oxide (GO) and polyethylene glycol (PEG) is fabricated through a facile approach. The resultant nanohybrids show relatively low cytotoxicity, favorable biocompatibility as well as inherit the outstanding properties of cobalt. Moreover, CoNWs decorated with GO and PEG (CoNWs-GO-PEG) can load therapeutic drug molecules (e.g., doxorubicin, DOX) with a high drug loading capacity (992.91 mg/g), and simultaneously they are responsive to pH, NIR (near-infrared) irradiation and magnetism stimulation. Accordingly, CoNWs-GO-PEG-DOX shows the satisfactory effect of eliminating cancer cells with synergistic chemo-photothermal therapy in vitro. Current work provides a solid demonstration of the potential of CoNWs-GO-PEG for serving as a targeted antitumor agent in synergistic chemo-photothermal therapy.

Dual therapeutic cobalt-incorporated bioceramics accelerate bone tissue regeneration.

Bone grafting on defects caused by trauma or tumor stimulates bone regeneration, a complex process requiring highly orchestrated cell-signal interactions. Bone vascular growth is coupled with osteogenesis, but less is known about the interplay between angiogenesis and osteogenesis. Understanding this relationship is relevant to improved bone regeneration. Here, tricalcium phosphate (TCP) scaffolds doped with varying concentration of cobalt (Co-TCP) were designed to investigate the dosage effect of vascularization on bone formation. The surface structure, phase composition, mechanical features, and chemical composition were investigated. Co doping improved the mechanical properties of TCP. Co-TCP, particularly 2% and 5% Co-TCP, boosted cell viability of bone marrow stromal cells (BMSCs). The 2% Co-TCP promoted alkaline phosphatase activity, matrix mineralization, and expression of osteogenic genes in BMSCs in vitro. However, excessive Co doping decreased TCP-induced osteogenesis. Meanwhile, Co-TCP dose-dependently favored the growth and migration of human umbilical vein endothelial cells (HUVECs), and the expression of vascular endothelial growth factor (VEGF). The 2% Co-TCP significantly shrank the defect area in rat alveolar bone compared with TCP. Smaller bone volume and more abundant blood vessels were observed for 5% Co-TCP compared with 2% Co-TCP. The CD31 immunostaining in the 5% Co-TCP group was more intense than the other two groups, indicating of the increment of endothelium cells. Besides, 5% Co-TCP led to mild inflammatory response in bone defect area. Overall, TCP doped appropriately with Co has positive effect on osteogenesis, while excessive Co suppressed osteoblast differentiation and bone formation. These data indicate that vascularization within a proper range promotes osteogenesis, which may be a design consideration for bone grafts.

Fe/Zn-modified tricalcium phosphate (TCP) biomaterials: preparation and biological properties.

Bone repairing materials play an essential role in the repair treatment of bone defects. The presence of calcium phosphate invertebrates is of significance for bone repairing processes. However, the mechanical properties and osteogenic activities of many current calcium phosphate materials are not ideal, which limit their biological applications. Therefore, it is an effective alternative strategy to study the modification of calcium phosphate biomaterials to address these limitations. In this research, in order to enhance the biological performance of tricalcium phosphate (ß-TCP), metal species (Fe and Zn) modified ß-TCP materials through the co-precipitation method were successfully developed. The physical, chemical and biological properties of the binary composites were carefully studied for the first time. The bioactivities of the Fe-TCP and Zn-TCP were evaluated by simulating body fluid (SBF) immersion experiments, blood compatibility, and cytotoxicity tests. The findings demonstrated that the metal-TCP with excellent cytocompatibility and osteogenic properties shows good potential in medical applications.

Strontium/adiponectin co-decoration modulates the osteogenic activity of nano-morphologic polyetheretherketone implant.

Polyetheretherketone (PEEK)-based implants have become popular in hard tissue orthopedic and dental field. However, its inherent bio-inertness limited its applications for bone repair/substitution of osteoporosis patients, with poor osteogenesis capability. In order to ameliorate their bioactivity, the 3D porous PEEK substrate was created by sulfonate processing, and the substrate was subsequently incorporated with strontium (Sr) through a hydrothermal reaction in Sr(OH)2 solutions. The adiponectin (APN) protein membrane was deposited on the substrate via polydopamine-assisted deposition. Surface characterization results disclosed that the nanostructures had been formed on sPEEK-Sr-APN surafces, and APN coatings on the substrates could adjust Sr release rate and further mediate cell-material interactions. in vitro experiments indicated that the cellular effects (proliferation and differentiation) of MC3T3-E1 were significantly increased with Sr/APN coordinated regulation. This study provides bioactive Sr and APN as promising active components for bio-functional bone regeneration/substitution, and optimizes the osteointegration of PEEK implants in clinic.

Bioinspired, biocompatible and peptide-decorated silk fibroin coatings for enhanced osteogenesis of bioinert implant.

In this study, we develop an osteopromotive polyetheretherketone (PEEK) implant decorated with silk fibroin and bone forming peptide, in which the surface of bioinert PEEK implant is firstly sulfonated to form a three-dimensional, porous topography and then is functionalized with silk fibroin via spin-coating process and peptide decoration. The bio-test results show that cells on the functional bioinert implants exhibit better cell adhesion, proliferation and spreading, when compared with the uncoated ones. Moreover, the peptide-decorated silk fibroin coatings have ability to hasten the osteogenic differentiation and maturation of osteoblast-like cells. Our findings show the potential of the functional PEEK implants with superior bioactivity and osteoinductive property in orthopedics and dentistry. Besides, the facile, bioinspired, osteopromotive modification strategy can be used in other orthopedic and dental implants, such as titanium, zirconium dioxide.

Environmental-Friendly and Facile Synthesis of Co3O4 Nanowires and Their Promising Application with Graphene in Lithium-Ion Batteries.

In this work, we developed an eco-friendly strategy for preparing Co3O4 nanowires. The process consisted of two steps: controllable synthesis of metal cobalt nanowires followed by a facile air-oxidization step. The 1D nanowire structure with a high aspect ratio was easily achieved via a magnetic-field-assisted self-assembly of cobalt ion complexes during reduction. After air-calcinations, the Co3O4 nanowires were prepared in large scale and ready to be used as the anode material for lithium-ion batteries. The Co3O4 nanowires, which possessed a length ranging from 3 to 8 µm with the aspect ratio more than 15, exhibited a reversible lithium storage capacity up to ~ 790 mAh/g when using a small amount of defect-free graphene flakes as conductive additives. The superior electrochemical performances were ascribable to the synergistic "flat-on" effect between the 1D nanowires and the 2D graphene. Therefore, the Co3O4 nanowire/graphene composite holds promising application for lithium-ion batteries.

Solidification and Biotoxicity Assessment of Thermally Treated Municipal Solid Waste Incineration (MSWI) Fly Ash.

In the present work, thermal treatment was used to stabilize municipal solid waste incineration (MSWI) fly ash, which was considered hazardous waste. Toxicity characteristic leaching procedure (TCLP) results indicated that, after the thermal process, the leaching concentrations of Pb, Cu, and Zn decreased from 8.08 to 0.16 mg/L, 0.12 to 0.017 mg/L and 0.39 to 0.1 mg/L, respectively, which well met the limits in GB5085.3-2007 and GB16689-2008. Thermal treatment showed a negative effect on the leachability of Cr with concentrations increasing from 0.1 to 1.28 mg/L; nevertheless, it was still under the limitations. XRD analysis suggested that, after thermal treatments, CaO was newly generated. CaO was a main contribution to higher Cr leaching concentrations owing to the formation of Cr (VI)-compounds such as CaCrO4. SEM/EDS tests revealed that particle adhesion, agglomeration, and grain growth happened during the thermal process and thus diminished the leachability of Pb, Cu, and Zn, but these processes had no significant influence on the leaching of Cr. A microbial assay demonstrated that all thermally treated samples yet possessed strong bactericidal activity according to optical density (OD) test results. Among all samples, the OD value of raw fly ash (RFA) was lowest followed by FA700-10, FA900-10, and FA1100-10 in an increasing order, which indicated that the sequence of the biotoxicity for these samples was RFA > FA700-10 > FA900-10 > FA1100-10. This preliminary study indicated that, apart from TCLP criteria, the biotoxicity assessment was indispensable for evaluating the effect of thermal treatment for MSWI fly ash.

Stabilization of lead in incineration fly ash by moderate thermal treatment with sodium hydroxide addition.

Municipal solid waste (MSW) incineration fly ash (IFA) can be potentially reused as a substitute for some raw materials, but treatment for detoxification is indispensable owing to high contents of heavy metals in fly ash. In the present work, due to excessive leaching concentration of lead (Pb), a moderate thermal treatment with sodium hydroxide (NaOH) addition was employed to stabilize Pb in IFA. The moderate thermal treatment was performed under relatively low temperature ranging from 300 to 500°C and at retention time from 1 to 3 h with NaOH addition in a range of 1 to 9%. Leaching results showed that leaching concentrations of Pb in IFA leachates decreased below the standard for hazardous waste identification (5 mg/L) in China under all treatment scenarios. With the increase of temperature, retention time and the amount of NaOH, the concentration of Pb were further suppressed in IFA leachates. Especially, at 500°C for 3 h with 9% NaOH addition, the concentration of Pb dropped to 0.18 mg/L, which was below the standard for sanitary landfill (0.25 mg/L) in China. In thermal process, needle-like crystallites melted to form granules and clumps with compacter structure and less pores. After the thermal treatment, water-soluble and exchangeable fractions of Pb significantly decreased. Therefore, the thermal treatment coupled with NaOH could be applied to realize the environmentally sound management of MSW IFA.

Peptide-Decorated Nanofibrous Niche Augments In Vitro Directed Osteogenic Conversion of Human Pluripotent Stem Cells.

Realization of clinical potential of human pluripotent stem cells (hPSCs) in bone regenerative medicine requires development of simple and safe biomaterials for expansion of hPSCs followed by directing their lineage commitment to osteoblasts. In the present study, a chemically defined peptide-decorated polycaprolactone (PCL) nanofibrous microenvironment was prepared through electrospinning technology and subsequent conjugation with vitronectin peptide to promote the culture and osteogenic potential of hPSCs in vitro. The results indicated that hPSCs successfully proliferated and maintained their pluripotency on the biointerface of peptide-conjugated nanofibers without Matrigel under defined conditions. Moreover, the prepared niche exhibited an appealing ability in promoting directed differentiation of hPSCs to osteoblastic phenotype without embryoid body formation step, determined from the cell morphological alteration, alkaline phosphate activity, and osteogenesis-related gene expression, as well as protein production. Such well-defined, xeno-free, and safe nanofiber scaffolds that allow the survival and facilitate osteo-differentiation of hPSCs provide a novel platform for hPSCs differentiation via cell-nanofiber interplay, and possess great value in accelerating the translational perspectives of hPSCs in bone tissue engineering.