Search

The ionic pair self-assembly (IPSAM) composed of poly(ethyleneimine) (PEI) and (phenylthio)acetic acid (PTA) was prepared and the effect of phenolic acids (PAs) (e.g. cinnamic acid (CA), hydroxycinnamic acid (HCA), and dihydroxycinnamic acid (DHCA)) on the upper critical solution temperature (UCST) and the temperature-responsive releasing property of IPSAM were investigated. PEI/PTA ionic pair showed a UCST behavior and the PAs decreased the UCST effective in the order of DHCA > HCA > CA. The PAs were thought to attach to the PEI chain of PEI/PTA ionic pair as pendants. According to the interfacial tensiometry, PEI/PTA(3/7) ionic pair was found to be air/water interface-active due to their amphiphilic property. CA had little effect on the interfacial activity of the ionic pair. HCA and HDCA significantly decreased the interfacial activity possibly because they are more polar than CA thus the hydrophilic and lipophilic balance of PEI/PTA ionic pair could be broken by their attachment to PEI chains. IPSAM was found as nanoparticles whose diameter was tens of nanometer and PAs had little effect on the shape and the size of IPSAM, once the UCST of PEI/PTA/PA ionic pair was above room temperature where the TEM micrographs were taken. If the UCST of PEI/PTA/PA ionic pair was below room temperature, no particulate matters were found on the TEM micrographs. The release degree of cargo loaded in IPSAM increased slowly with time lapse below UCST. Whereas, the release degree increased rapidly with time lapse above UCST, possibly because of the thermally-induced disintegration of IPSAM.

In-situ incorporation of layered double hydroxides (LDH) nanocontainers into plasma electrolytic oxidation (PEO) coatings on AZ91 Mg alloy has been achieved in the present study. Fumarate was selected as Mg corrosion inhibitor for exchange and intercalation into the nanocontainers, which were subsequently incorporated into the coating. It was found that the thickness and compactness of the coatings were increased in the presence of LDH nanocontainers. The corrosion protection performance of the blank PEO, LDH containing PEO and inhibitor loaded coatings was evaluated by means of polarization test and electrochemical impedance spectroscopy (EIS). The degradation process and corrosion resistance of PEO coating were found to be greatly affected by the loaded inhibitor and nanocontainers by means of ion-exchange when corrosion occurs, leading to enhanced and stable corrosion resistance of the substrate.

Hydroxyl-terminated polybutadiene/toluene diisocyanate (HTPB/TDI) system is widely used in composite solid propellants. The migrations of plasticizers and water molecules from solid propellants and surrounding environment to the inhibitor have always been the important issues. This study focuses on the preparation, characterization and anti-migration behavior of graphene oxide (GO)/HTPB nanocomposite liner. The GO/HTPB (GH) composite liners affect the migration of small molecules through a tighter cross-linked structure and weakening function of small molecule adsorption. The anti-migration performance of the liner at different temperatures was analyzed, and the influence of the added amount of GO on the anti-migration performance and adhesion performance was also systematically studied. The overall performance of the liner is optimized when the amount of GO filler is 0.3 wt%. After adding 0.3 wt% GO, the concentration of dioctyl sebacate (DOS) migrated into the liner is decreased by 23.28%, and the concentration of water molecules is decreased by 51.89%, indicating that the introduction of GO can significantly improve the anti-migration performance of the liner. In addition, the bond strength is greatly increased from 0.25 MPa to 0.95 MPa, which meets the application requirements of the current propellant system. This research provides an important way for the preparation of structure-function synergistic anti-migration composite liners.

Gradiently denitrated gun propellant (GDGP) prepared by a “gradient denitration” strategy is obviously superior in progressive burning performance to the traditional deterred gun propellant. Currently, the preparation of GDGP employed a tedious two-step method involving organic solvents, which hinders the large-scale preparation of GDGP. In this paper, GDGP was successfully prepared via a novelty and environmentally friendly one-step method. The obtained samples were characterized by FT-IR, Raman, SEM and XPS. The results showed that the content of nitrate groups gradiently increased from the surface to the core in the surface layer of GDGP and the surface layer of GDGP exhibited a higher compaction than that of raw gun propellant, with a well-preserved nitrocellulose structure. The denitration process enabled the propellant surface with regressive energy density and good progressive burning performance, as confirmed by oxygen bomb and closed bomb test. At the same time, the effects of different solvents on the component loss of propellant were compared. The result showed that water caused the least component loss. Finally, the stability of GDGP was confirmed by methyl-violet test. This work not only provided environmentally friendly, simple and economic preparation of GDGP, but also confirmed the stability of GDGP prepared by this method.

Various bowel preparation agents have been developed for effective and safe bowel cleansing before colonoscopy. Polyethylene glycol (PEG) is widely used in the elderly. A 2 L PEG solution with ascorbic acid (PEG-Asc) was developed to reduce the volume of standard 4 L PEG. Several cases of

In an effort for further improvement of LSCF hollow fiber membrane properties in oxygen purification application, this work studied the use of polyethylene glycol (PEG) with different molecular weight of 2000, 3400 and 6000 Da as a pore former. A well-prepared hollow fiber membrane was successfully fabricated via extrusion followed by a sintering method. The results showed that the addition of PEG increased the viscosity of the dope suspension and formed a constant asymmetric pore configuration of the membrane after sintering at 1250 °C. The increasing molecular weight of PEG also leads to a decrease in the mechanical strength of the membranes, indicating that finger-like pores were sacrificed by forming irregular pores. The gas tightness was also examined under room temperature which showed that membrane with PEG 3400 achieved the best tightness with the nitrogen permeability of 3.55 × 10−5 mol·m−2·s−1·Pa−1. The oxygen permeation of the membranes was also influenced by the addition of PEG, where the highest oxygen permeation flux of 6.07 × 10−8 mol·cm−2·s−1 was obtained using a hollow fiber membrane with PEG 3400 due to the existence of the lowest dense layer thickness.

Chitosan (CS) is a natural and biopolymer that are suitable biomedical properties such as; biocompatibility, non-toxicity, biodegradability and bioactive polymer that’s reason with a very large application (fabrication of biomedical scaffolds, implants). Some of the biocompatible thermoplastic polymers (PLA, PEEK, PLGA, PE, PP, PMMA, PET and etc.) are most widely used in biomedical field as per their properties from last two decades. Poly-vinyl chloride (PVC) thermoplastic polymer are most widely used in medical field but there are some limitations of their uses. For enhancement of PVC thermoplastic polymers properties sometimes add some bioactive and biocompatible fillers or other bioactive thermoplastic polymers. In this review paper try to link and discussed about the possible reinforcement CS in PVC thermoplastic polymer for biomedical applications.

In this study we report a facile, cost effective one step preparation method for the synthesis of Mn doped cerium oxide (CeO2) nanoparticles (NPs) through co-precipitation technique. The synthesis was performed at relatively low temperature using a green reagent oxalic acid as reducing agent. The structural and optical attributes of the samples were characterized by X-Ray Diffraction spectroscopy (XRD), Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible spectroscopy and SEM (Scanning electron microscopy). The XRD and FTIR results show the formation of Mn doped ceria NPs having a cubic fluorite structure. The morphology and chemical composition of the prepared sample was realized using SEM and EDX spectrum. The synthesized Mn doped ceria NPs shows greater absorption in the visible region and reduced particle size compared to pure ceria NPs.

Statement of problem Adhesive resin cement has been the preferred choice for the placement of prosthetic restorations, but evidence-based studies supporting this selection are sparse. Purpose The purpose of this study was to test the hypothesis that restoration placement with the adhesive 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tributylborane (4-META/MMA-TBB) resin cement is associated with better longevity of teeth than zinc phosphate cement up to 43 years. Materials and methods Study participants were individuals who had been visiting the clinic regularly for more than 20 years from their first visit between November 1970 and April 1985. The vital teeth with prosthetic restorations (N=454), including cast inlays, onlays, crowns, and fixed partial dentures, of 53 patients were assessed from dental charts and radiographs. Most of the bonding surfaces were precious metal alloy, excluding 4 restorations cemented with zinc phosphate and 6 ceramic crowns cemented with 4-META/MMA-TBB resin cement. The Kaplan-Meier method and log-rank test (α=.05) were used to compare longevity between the 2 materials. Chi-squared tests (α=.001) were also used to examine the occurrence rates of events such as secondary caries, endodontic treatment, and the dislodgement of restorations affecting the longevity of the 2 cements. Results Clinical review examination demonstrated that 55.4% of teeth retained with 4-META/MMA-TBB resin cement had been in service for 30 years compared with 43.5% of those retained with zinc phosphate cement, with a significant difference (P=.006). 4-META/MMA-TBB resin cement also demonstrated lower event occurrence rates than zinc phosphate cement for 3 assessed types of events (P Conclusions Within the limitations of this study, 4-META/MMA-TBB resin adhesive cement demonstrated a higher survival rate than conventional zinc phosphate cement in service for 30 years with a lower occurrence of critical events.

Reuse of coal fly ash (CFA) as construction materials is one of the sustainable methods for mitigating its environmental impacts. However, the potential leaching of heavy metals and the limited effect on mechanical improvement impede the reuse of CFA. The objective of this research was to investigate the effects of environmental impact and mechanical improvement of the microbially induced calcium carbonate (CaCO3) precipitation (MICP) process on the CFA–soil mixture. Two resources of CFA, named CFA1 and CFA2, were used. CFA1 is classified as off-specification fly ash, and CFA2 is classified as class F-type fly ash. Experimental results showed that the unconfined compressive stress (UCS) of MICP-treated soil increased significantly with the addition of CFA. The MICP-treated 3% CFA1–soil mixture obtained the highest UCS of 2200 kPa, which was much higher than that of the MICP-treated soil (798 kPa). The maximum UCS of the MICP-treated 3% CFA2–soil mixture was 1398 kPa. X-ray diffraction analysis indicated that the main mineral crystal pattern present in the MICP-treated samples was calcite. Scanning electron microscopy images revealed that the formed calcium carbonate worked as a bridge to connect soil particles together, attached to the surface of soil or located in the pore side of soil particles. In addition, the batch leaching test indicated that cadmium (Cd), copper (Cu), magnesium (Mg), nickel (Ni) and zinc (Zn) were detected in the MICP-treated soil. With the addition of CFA, there was no metal exceeding the maximum contaminant level from the MICP-treated CFA1–soil mixture.

An E. coli reduction-powered supramolecular polymerization is reported, leading to the fabrication of an NIR photothermal antibacterial agent in situ. To this end, a bifunctional monomer containing...

Lycorine-nanoparticles (LYC-NPs) were successfully synthesized using anti-solvent precipitation-freeze drying method, and characterized using transmission electron microscopy (TEM), particle size analysis and Fourier transform infrared spectroscopy (FTIR). Then, the antitumor effects of LYC-NPs against HepG2 cells were investigated, and the underlying molecular mechanisms were explored. Our results showed that LYC-NPs displayed potent antiproliferative against HepG2 cells concentration dependently. Flow cytometry analysis exhibited that LYC-NPs triggered apoptosis and impeded cell cycle in G0/G1 phase. Moreover, the up-regulated expression of cleaved caspases-3 and Bax, and decrease of mitochondrial membrane potential and the Bcl-2 expression were involved in LYC-NPs apoptosis, implying that LYC-NPs induced apoptosis via the mitochondrial-mediated apoptosis pathway. Furthermore, LYC-NPs distinctly impaired HepG2 cells migration and invasion with down-regulation of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. These results indicated that LYC-NPs could be an favorable agent for restraining the growth and metastasis of HepG2 cells.

Highly durable and stretchable ionic conductors are indispensable components for flexible electronics. However, fabricating such ionic conductors that are also non-toxic and biodegradable remains a...

Effective bond of cement sheath to casing or formation depends on higher tensile strength and lower young's modulus which are a measure of its ability to withstand deformation under load without parting. This work utilized Ethylene Vinyl Acetate (EVA) redispersible polymer powder as additive in the class G cement to characterize bonding ability. Tensile strength was measured for samples cured at 90 °C for 3 days, whereas compressive strength was measured for samples cured at 120 °C for 1 day and 3 days under atmospheric pressure. The results showed that, with the addition of beyond 10% by weight of cement (BWOC) of polymer, not only tensile strength was improved, but also reduced young's modulus. Addition of EVA additive beyond 10% BWOC showed significant benefit of flexibility in the cement system. FTIR (Fourier Transform Infrared Spectroscopy) indicated that presence of high VA (Vinyl Acetate) has no effect on polymerization of Silicates, which shows it does not hider in the formation of C–S–H phase. Intensity of chemical bond augmented with longer curing time and increased polymer content, as seen in O–H stretching vibration at 3434 cm−1 and from Carboxylate anion at 1571 cm−1 to confirm on hydrolysis. Mercury Intrusion porosimeter (MIP) showed significant reduction in fraction of mesopore sizes within the cement matrix, with the polymer addition.

Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys. However, poor wear resistance and microcracks formed during the solidification have limited it extensive application. There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys. Herein, the epoxy resin powder coating with polydopamine modified molybdenum disulfide (MoS2@PDA-EP powder coating with 0, 0.1, 0.2, 0.5, 1.0 wt.% loading) was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance. The results revealed that the addition of MoS2@PDA enhanced the adhesion strength between coatings and alloys, wear resistance and corrosion protection of the powder coatings. Among them, the optimum was obtained by 0.2 wt.% MoS2@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix. To conclude, MoS2@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.

Objective: We conducted the present study to investigate the anticancer effects of curcumin and chrysin loaded in the alginate-chitosan hydrogel on breast cancer (T47D) and lung cancer (A549). Background: Cancer, which is defined as abnormal cell growth, is one of the biggest public health problems in the world. Natural compounds, such as polyphenols, are used as chemo-preventive and chemotherapeutic agents in different types of cancer owing to their antioxidant, antineoplastic, and cytotoxic properties. To improve their bioavailability and releasing behavior, hydrogel systems with high drug loadingg, stability and hydrophilic nature have been designed. Methods: The curcumin-chrysin-loaded alginate-chitosan hydrogels were prepared through the ionic gelation mechanism utilizing CaCl2. The prepared hydrogels were studied by using the Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The MTT and DAPI staining assays were employed for cytotoxicity and apoptosis studies of curcumin-chrysin- loaded alginate-chitosan hydrogels. The effects of the curcumin-chrysin-loaded alginate-chitosan hydrogels on the cell cycle of cell lines T47D and A549 were also evaluated using the propidium iodide staining. Results: The curcumin-chrysin-loaded alginate-chitosan hydrogels could significantly (p Conclusion: The alginate-chitosan hydrogels could work best as an enhanced anticancer drug delivery system.

Sulfation of wheat straw soda lignin by the sulfamic acid–urea mixture in different solvents has been investigated for the first time. The effect of a catalyst used in the lignin sulfation process on the yield of the lignin sulfates and sulfur content in them has been explored. It has been found that the optimal medium for the lignin sulfation with sulfamic acid is dioxane and, in the presence of a catalyst, urea. Although the sulfated lignins obtained using the reaction in dimethyl sulfoxide and diglyme have the maximum sulfur contents (11.2% and 9.9%, respectively), these products are difficult to isolate and purify, which complicates the use of these solvents. Sulfated lignin obtained in the dioxane medium has a high (10.1%) sulfur content and is easy to isolate and purify. The incorporation of sulfate groups into the lignin structure has been confirmed by the infrared and nuclear magnetic resonance spectroscopy investigations. In the infrared spectra of sulfated lignin, characteristic absorption bands at 800–860 and 1260–1200 cm−1 appear. The dominant substitution of aliphatic hydroxyl groups has been confirmed by the nuclear magnetic resonance spectroscopy study. It has been found that, during the modification and purification of lignin, the latter is fractionated, which results in the redistribution of molecular weights toward the high molecular-weight region, as well as the removal of some low-molecular-weight components, which is reflected in a decrease in the number of signals in the nuclear magnetic resonance spectra.

Rare earth elements (lanthanide and yttrium, abbreviated as REY) provide important support for national security, energy production, environmental protection and economic growth. In recent years, many studies have shown that the content of REY in some coal or coal by-products is close to or even higher than that in traditional REY ore, which makes coal a potential source of REY. This study took the No. 17 coal of Panzhou mining area in Liupanshui coal field as the research object, and the content and occurrence modes of REY in raw coal and 7 density fraction samples were studied. The results show that the content of REY in the raw coal reaches 220.67 μg/g, which is significantly higher than the average REY in the World coal and Chinese coal as reported in the literature. Gravity separation has a certain pre-enrichment effect on REY and the fraction sample ＞1.8 g/cm3 has the highest REY of 426.27 μg/g (equal to rare earth oxide 0.1%). Study on correlation between REY and ash yields reveals that the organic affinity of the light rare earth is higher than the medium rare earth and the heavy rare earth. As shown by XRD and XRF, the major minerals in coal are kaolinite, quartz and calcite, and the content of REY in coal is significantly related to Al and Si and kaolinite, which implies that REY occur mainly in kaolinite. LA-ICP-MS was adopted to determine chemical composition of micro-zone in kaolinite in coal and the results show that there is no obvious correlation between REY and the content of Al and Si. This indicates that the REY occurred probably in the form of adsorption. The research results provide a scientific reference for the potential extraction of the associated REY in the coal.

Biodegradable magnesium alloys have excellent properties with respect to biodegradability, biocompatibility, and biomechanics, which may indicate a possibility of its application in intestinal stents. Investigation of Mg-Zn-Y-Nd alloy's application in intestinal stents has been performed. This study aims to investigate the degradation behavior of Mg-Zn-Y-Nd alloy intestinal stents coated with poly(L-lactide)/paclitaxel in the intestinal environment and its biocompatibility with intestinal tissue. In this paper, Mg-Zn-Y-Nd alloy's corrosion properties were evaluated by the immersion test in human feces, SEM and XRD, and animal tests. In vitro results showed that when the Mg-Zn-Y-Nd alloy was immersed in human feces for two weeks, its corrosion resistance could be improved by micro arc oxidation (MAO) and poly-l-lactide (PLLA) dual coating. Additionally, this result was also confirmed in vivo experiments by rabbit model. And animal tests also demonstrated that the Mg-Zn-Y-Nd alloy with MAO/PLLA/paclitaxel dual coating drug-eluting stents could inhibit the proliferation of local intestinal tissue around the stents. However, in vivo studies illustrated that the intestinal stents gradually degraded in rabbit model within 12 days. Considering the degradation rate of the stent was faster than expected in rabbits, the support performance of the scaffold requires further improvement.

Abstrct Polycaprolactone/hydroxyapatite (PCL/HA) composite coating was fabricated by a combination of hydrothermal and dipping methods to delay the degradation of Mg alloy AZ31 as bioresorbable materials. The PCL/HA coating was composed of nano rod-shape HA crystals and PCL filled in the space of HA crystals. Compared with the single HA coating, the binding strength between the PCL/HA composite coating and Mg alloy was obviously improved and the PCL/HA coating still adhered to the surface of AZ31 substrate even after 38 days of immersion. The electrochemical corrosion rate of HA coated sample was reduced by ten times after being filled by PCL. The electrochemical impedance spectroscopy (EIS) and immersion test results showed that the PCL/HA composite coating could provide a more effective barrier for Mg substrate than the HA coating alone. The cytocompatibility and the antibacterial property of HA coating and PCL/HA coating were evaluated by culturing with bone marrow-derived mesenchymal stem cells (BMSCs) and methicillin-resistant staphylococcus aureus (MRSA) for 24 h under direct culture conditions, respectively. The PCL/HA composite coating showed better BMSC cell compatibility, more suitable for BMSC adhesion than HA coating alone and showed a potential application prospect as a biological materials. However, from the perspective of clinical applications, the antibacterial property of PCL/HA composite coating needs to be further improved.

An innovative application of the solvent evaporation technique was suggested. Solvent evaporation technique is a technique for drug encapsulation and nanosphere preparation. Th widely used technique is also facing the problem of low actual drug entrapment percent, which is not economic from the industrial view. The goal of this work is trying to use the advantage of this technique concerning the product sphericity and the ability to control particle size, to prepare a drug as pure crystals spheres. Ibuprofen is selected as a model drug. The spheres are formed by using Polyvinyl pyrrolidone (PVP) or Polyethylene glycol (PEG) as an antiaggregating agent but not formed on using tween or span. Particle size and actual drug content depend on the concentrations the antiaggregating agent used. Surfaces of the drug crystal spheres are porous with empty sphere internal structure on using PVP but spongy and rough on using PEG. The drug has its identity chemical form in the drug crystal spheres. IR scan of spheres prepared on using PEG showed a characteristic ether peak. DSC showed melting endothermic peak of PEG, but X-ray showed minor change in the drug crystal patterns. Drug release profiles from crystal spheres prepared with the same antiaggregating agent are close to each other. The drug release profiles from drug crystal spheres prepared by using PEG are more controlled than that prepared by using PVP. The drug release mechanism is diffusion. It was concluded that, the same technique could be suggested for preparation of other biomedical material in pure crystals spheres with controlled particle size. These properties may encourage to prepare very small particles with spherical shape for inhalation or injection as an innovative particle technology application for the widely used technique.

Chitosan-coated Fe3O4 nanoparticles were prepared by coprecipitation followed by reaction with chitosan and different volumes of glutaraldehyde. Coating was modified by varying the volume of glutaraldehyde and reaction time. XRD pattern shows maxima compatible Fe3O4 structure. FTIR spectroscopia confirms the presence of chitosan, more evident in samples with higher chitosan content, as denoted by TGA. TEM images of samples with low glutaraldehyde content reveal particles coated with a homogeneous chitosan shell. Meanwhile, those prepared with high glutaraldehyde volume show nanoparticles dispersed in an organic matrix. Samples present almost superparamagnetic behavior with magnetization saturation values that are reduced as the content of organic matter increases. Regarding the stability of these samples in solution, the presence of a homogeneous coating improves the initial suspension, although it does not prevent its subsequent aggregation over time. However, this aggregation process is reduced for sample synthesized with 1 mL of glutaraldehyde after 6 h of reaction.

A nitrogen-sulfur dual-doped citric-acid porous carbon/sulfur (NS-CAPC/S) materials was prepared by an easy hydrothermal method applying glutathione as nitrogen-sulfur origin and citric-acid carbon as carbon origin. The detailed structure of the materials was determined through raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction tests. The appearance of the materials was investigated via transmission electron microscopy and scanning electron microscopy methods. N2 adsorption–desorption isotherm was applied to test its pore size distribution and pore structure. Thermogravimetric analysis (TGA) was utilized to identify the mass ratio of sulfur. The NS-CAPC/S materials was employed as positive electrode material in Li-S batteries. Electrochemical performance revealed the prepared NS-CAPC/S composite possessed good specific capacity, exceptionally high cycle stability and excellent rate performance.

The intricate dynamic feedback mechanisms involved in bone homeostasis provide valuable inspiration for the design of smart biomaterial scaffolds to enhance in situ bone regeneration. In this work, we assembled a biomimetic hyaluronic acid nanocomposite hydrogel (HA-BP hydrogel) by coordination bonds with bisphosphonates (BPs), which are antiosteoclastic drugs. The HA-BP hydrogel exhibited expedited release of the loaded BP in response to an acidic environment. Our in vitro studies showed that the HA-BP hydrogel inhibits mature osteoclastic differentiation of macrophage-like RAW264.7 cells via the released BP. Furthermore, the HA-BP hydrogel can support the initial differentiation of primary macrophages to preosteoclasts, which are considered essential during bone regeneration, whereas further differentiation to mature osteoclasts is effectively inhibited by the HA-BP hydrogel via the released BP. The in vivo evaluation showed that the HA-BP hydrogel can enhance the in situ regeneration of bone. Our work demonstrates a promising strategy to design biomimetic biomaterial scaffolds capable of regulating bone homeostasis to promote bone regeneration.

The present work reports the results of the lignin molecule degradation studies using nitrogen-doped ZnO photocatalysts supported on graphene oxide. Three different nitrogen precursors were used to achieve the nitrogen doping in ZnO, namely urea, ethylenediamine, and thiourea, using a microwave-assisted hydrothermal method. Our purpose is to demonstrate that different nitrogen precursors give rise to different amounts of doping in ZnO, which in turn, favorably affects their photocatalytic behavior. The synthesized compounds were tested on the lignin degradation reaction, under visible (Vis) and ultraviolet (UV) energy irradiation. Structural and physicochemical properties of prepared samples were investigated to provide explanation of the photocatalytic behavior observed in samples. XPS analyses were developed to determine differences in nitrogen content, as well to determine the proportion of N-N or O-Z-N binding in samples. Remarkable structural and photocatalytic differences were found for every sample as effect of the nitrogen precursor. Photocatalytic activity tests revealed that the percentage of lignin degradation under UV irradiation was 80 %; while using Vis energy the degradation value was 61 %.

Bone tissue engineering has emerged as a significant research area that provides promising novel tools for the preparation of biomimetic hydrogels applied in bone-related diseases (e.g., bone defects, cartilage damage, osteoarthritis, etc.). Herein, thermal sensitive polymers (e.g., PNIPAAm, Soluplus, etc.) were introduced into main chains to fabricate biomimetic hydrogels with injectability and compatibility for those bone defect need minimally invasive surgery. Mineral ions (e.g., calcium, copper, zinc, and magnesium), as an indispensable role in maintaining the balance of the organism, were linked with polymer chains to form functional hydrogels for accelerating bone regeneration. In the chemically triggered hydrogel section, advanced hydrogels crosslinked by different molecular agents (e.g., genipin, dopamine, caffeic acid, and tannic acid) possess many advantages, including extensive selectivity, rapid gel-forming capacity and tunable mechanical property. Additionally, photo crosslinking hydrogel with rapid response and mild condition can be triggered by different photoinitiators (e.g., I2959, LAP, eosin Y, riboflavin, etc.) under specific wavelength of light. Moreover, enzyme triggered hydrogels were also utilized in the tissue regeneration due to its rapid gel-forming capacity and excellent biocompatibility. Particularly, some key factors that can determine the therapy effect for bone tissue engineering were also mentioned. Finally, brief summaries and remaining issues on how to properly design clinical-oriented hydrogels were provided in this review., Graphical abstract Biomimetic hydrogels based on different crosslinking conditions, possess three-dimensional (3D) network with high aqueous content and functional properties, enabling their wide applications in bone tissue engineering. Recent advances in the design, preparation and application of light trigger hydrogels, thermal response hydrogels, small molecule crosslinking hydrogels, ionic crosslinking hydrogels and enzyme triggered hydrogels in the field of bone tissue engineering are reviewed.Image 1, Highlights • Diverse fabrication methods of advanced hydrogels were overviewed. • The process, advantages and drawbacks of advanced hydrogels were discussed. • Some key points in design of hydrogels for clinical use were summarized in this review. • The challenges, future directions and transformation potentials of hydrogels in bone tissue engineering were mentioned.

Background: Synthetic polymers present disadvantages such as high cost, limited availability, safety concerns, environmental hazards and overtime accumulation in body. Lignin, an aromatic biopolymer, is highly abundant and offers various advantages including cost effectiveness, biocompatibility and biodegradability. It also possesses various pharmacological activities including antioxidant, antibacterial, anticancer and UV protection, thus lignin has become a popular biopolymer in recent years and is no more considered as bio-waste rather an extensive research is been carried out on developing it as drug carrier. Lignin also has non-biomedical applications including dispersing agents, surfactants, detergent/cleaning agents, energy storage, etc. Methods: This review compiles patents granted on production of technical lignin, different lignin therapeutic carriers and its biomedical and non-biomedical applications. The literature is collected from recent years including both articles as well as patents and is carefully analyzed and compiled in an easy to comprehend pattern for guiding future research. Results: The reviewed patents and articles highlighted the advancement made in lignin isolation and valorization. Numerous lignin nanoformulations as drug delivery agents or as standalone entities with various pharmacological actions like antibacterial, antioxidant or UV protectant have been reported. As well as industrial applications of lignin as adhesives, insulators or supercapacitors have also made lignin a biopolymer of choice. Conclusion: Lignin being a bio-inspired polymer has huge potential in commercial applications. New methods of lignin isolation from lignocellulosic biomass including physical pretreatments, solvent fraction, and chemical and biological pretreatment have been widely patented. Several micro/nano lignin formulations with improved and controllable reactivity like nanocontainers, nanocapsules, nanoparticles have also been reported recently. Also various pharmacological properties of lignin have also been explored, thus valorization of lignin is a hot topic of hour.

Fabrication of selective adsorption coatings plays a crucial role in solid-phase microextraction (SPME). Herein, new strategies were developed for the in-situ fabrication of novel cobalt-based carbonaceous coatings on the nickel-titanium alloy (NiTi) fiber substrate using ZIF-67 as a precursor and template through the chemical reaction of ZIF-67 with glucose, dopamine (DA) and melamine, respectively. The adsorption performance of the resulting coatings was evaluated using representative aromatic compounds coupled to high-performance liquid chromatography (HPLC) with ultraviolet detection (HPLC-UV). The results clearly demonstrated that the adsorption selectivity was subject to the surface elemental composition of the fiber coatings. The cobalt and nitrogen co-doped carbonaceous coating showed better adsorption selectivity for ultraviolet filters. In contrast, the cobalt-doped carbonaceous coating exhibited higher adsorption selectivity for polycyclic aromatic hydrocarbons. The fabricated fibers present higher mechanical stability and higher adsorption capability for model analytes than the commercial polydimethylsiloxane and polyacrylate fibers. These new strategies will continue to expand the NiTi fibers as versatile fiber substrates for metal-organic frameworks (MOFs)-derived coating materials with controllable nanostructures and tunable properties.

Poly (ethylene glycol)-poly (n-butyl cyanoacrylate) (PEG-PBCA) is a remarkable drug delivery carrier for permeating blood-brain barrier. In this work, a novel high-gravity procedure was reported to intensify Knoevenagel condensation-Michael addition polymerization of PEG-PBCA. A series of PEG-PBCA containing different block ratios were synthesized with narrow molecular weight distribution of polydispersity indexes less than 1.1. Furthermore, the reaction time reduced 60% compared to conventional stirred tank reactor process. Chemical structures of as-prepared polymers were characterized. In vitro drug delivery performance was evaluated. The cytotoxicity of PEG-PBCA to brain microvessel endothelial cells (BMVEC) decreases with the extension of the PEG chain and the shortening of the PBCA chain. The polymer cellular uptake to BMVECs was better after improving hydrophilicity by PEG block. Results of blood-brain barrier permeability demonstrated that medium length of PBCA chain and short PEG chain are favorable for hydrophobic Nile red permeation, while long PEG chain and short PBCA chain are beneficial to delivery water-soluble doxorubicin hydrochloride (Dox). The average apparent permeability coefficient increased 1.7 and 0.25 times than that of raw Nile red and Dox, respectively. High-gravity intensified condensation polymerization should have great potential in brain drug delivery system.

Sustainable conversion of waste plastics into valuable carbon materials for diverse applications provides a promising strategy to dispose the municipal and industrial waste plastics. However, it remains a challenge to precisely control the crosslinking reaction for transforming waste polyesters into N-doped porous carbon (NPC) with well-defined microstructures. Herein, we put forwards a strategy of stepwise crosslinking using melamine and ZnCl2/NaCl eutectic salts to convert poly (ethylene terephthalate) (PET) into NPC at 550 °C. We prove that firstly melamine reacts with PET degradation products to form a crosslinking structure, and subsequently ZnCl2/NaCl promote the dehydration and decarboxylation of the crosslinking structure to generate a more thermally stable crosslinking structure. The coordination of two tandem crosslinking reactions is critical to control the microstructure of NPC. Without activations, NPC shows large specific surface area of 1173 m2 g−1, abundant N dopants, and rich oxygen-containing groups. These combined features endure NPC with excellent performance in CO2 capture and solar steam generation, e.g., high CO2 adsorption capacity of 6.47 mmol g−1 and evaporation rate of 1.62 kg m−2 h−1. More importantly, NPC is compared to or prevails over previous carbon-based CO2 adsorbents or photothermal materials. This work will advance the research on “green” reutilization of low-cost polyester wastes to prepare sustainable carbon for solar energy conversion, environmental protection, etc.

Statement of problem A vinegar-hydrogen peroxide mixture has been reported to be effective in eliminating Candida albicans and Staphylococcus aureus from acrylic resin, and its action has been reported to be comparable with that of sodium hypochlorite or peracetic acid. However, the effects of this mixture on cobalt-chromium alloys remain unknown. Purpose The purpose of this in vitro study was to evaluate the surface roughness, Knoop microhardness, surface free energy, and wettability of a cobalt-chromium alloy when exposed to a vinegar-hydrogen peroxide mixture. Material and methods Fifty specimens of cobalt-chromium alloy were fabricated and immersed for 900 minutes, simulating 3 months of a daily 10-minute immersion in the following chemical agents (n=10): distilled water (W); 0.5% sodium hypochlorite (H); 3% hydrogen peroxide and water dilution in 1:1 ratio (HP); white-wine vinegar and water dilution in 1:1 ratio (V); and vinegar and hydrogen peroxide mixture in 1:1 ratio (VHP). Surface roughness, Knoop microhardness, surface free energy, and wettability were measured with single blinding before and after immersions. Data were statistically analyzed by using 2-way repeated measures ANOVA (α=.05). Results The vinegar-hydrogen peroxide mixture did not affect the surface roughness or Knoop microhardness. However, 0.5% sodium hypochlorite significantly increased the roughness and decreased microhardness. Surface free energy and wettability increased after immersions, regardless of the types of solution. Conclusions Immersion in a vinegar-hydrogen peroxide mixture did not affect the surface characteristics of a cobalt-chromium alloy.

Micro- and Nano-Fibrillated Cellulose (MNFCs) have gained an increasing attention due to their remarkable properties but their production usually requires an intensive multi-step process. This study proposes to find a novel approach involving steam explosion for the production of lignin-containing micro- and nano-fibrillated cellulose (L-MNFCs) using Eucalyptus globulus bark as a new lignocellulosic feedstock. Eucalyptus globulus bark was first pre-treated in alkali conditions by steam explosion in alkaline conditions (200°C, 8 min) or by conventional alkaline cooking in a rotating autoclave (170°C, 60 min), refined and then grinded until the formation of gels. The chemical composition (Ionic chromatography, FTIR-ATR) of the pulps and morphology of the products (Morfi Neo, Optical and Atomic Force Microscopies (AFM), suspension turbidity) have been studied. Nanopapers were produced from lignin-containing microfibrils to investigate the mechanical properties. Results obtained showed that steam explosion produced pulps with slightly higher lignin content (≈ 9 %), containing shorter fibers (≈ 400 µm) and higher amounts of fine elements (≈ 86 %) compared to conventional alkali cooking (≈ 5 %, ≈ 560 µm and 66 %, respectively). AFM images of SteamEx L-MNFC gels showed a web-like structure containing lignin nanoparticles.

This work produced a MgAl-layered double hydroxide by hydrothermal treatment of a plasma electrolytic oxidation (PEO) coating on magnesium alloy AZ31 in an phosphate electrolyte, followed by an ion-exchange reaction in 0.1 M phosphate solution. The coated specimens were scratched. Characterization, including utilization of the localized technique SIET, measured the pH and pMg distributions and optical morphologies around the artificial defects during immersion in 0.05 M NaCl solution. In contrast with phosphate loaded PEO/LDHs, a stronger alkalinization area (with pH 11.4∼12.3) appeared in the passive PEO specimens. Due to formation of insoluble Mg(OH)2 products, the pMg map showed depletion of Mg2+ in this high pH area. Combined with optical morphologies and SEM images, the better self-healing ability toward defects for phosphate loaded PEO/LDHs was confirmed.

Lung cancer is the most common malignancy in the world, with high mortality rate. Nevertheless, therapies to act effectively against lung cancer remain elusive. So far, chemotherapy is still the frontline treatment of lung cancer. Doxorubicin (DOX) is a broad-spectrum anti-tumor drug. However, DOX often has serious side effects and causes multi-drug resistance, which greatly limits its clinical application. In this work, biodegradable methoxy poly(ethylene glycol)-block-poly(lactic acid) (MPEG-PLA) nanomicelles modified by Cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) polypeptide was used for the co-delivery of curcumin (CUR) and DOX (CUR-DOX/cRGD-M). The particle size of the self-assembled drug-loaded nano-micelle approximately was 27.4 nm and the zeta potential was −2.7 mV. Interestingly, CUR can enhance the uptake of DOX by Lewis lung carcinoma (LL/2) cells. The experimental results in vivo and in vitro showed that CUR-DOX/cRGD-M combination therapy could promote apoptosis of lung cancer cells, and conspicuously inhibit the tumor growth. Our data indicate that CUR-DOX/cRGD-M will be biodegradable and sustainable, which may have potential clinical application value in the treatment of lung cancer.

Finding a sustainable, inexpensive way for Ag-NPs synthesis is considered as one of the most important requirements for industrial application. Oxidized starch was prepared using sodium periodate. Oxidized starch (DAS) was characterized by measuring aldehyde content and using FTIR spectroscopy. DAS was used as reducing and stabilizing agent for the preparation of Ag nanoparticles (Ag-NPs). Factors that may affect the preparation of Ag-NPs include pH, AgNO3/DAS molar ratio, temperature and time were studied. UV-Vis. spectroscopy and particle size analysis showed that DAS can act as reducing and stabilizing agent for the preparation of Ag-NPs and the mean particle size was 19 nm. The so prepared AgNPs were used as antibacterial agent for cotton fabric using the pad dry cure method. The results of antibacterial test showed that the presence of Ag-NPs enhanced the antibacterial properties of the treated cotton fabrics.

In this work, we investigated leaching of lanthanide and yttrium (REY) from a Central Appalachian coal and its ashes obtained at 550–950 °C with the main purpose of understanding the impact of ashing temperature on REY leachability in water, ammonium sulfate, and hydrochloric acid. It is found that the coal contains a negligible amount of water-soluble REY, less than 1% ion-exchangeable REY, and about 28% of HCl-soluble REY. Ashing leads to dramatic changes in REY leachability in both ammonium sulfate and hydrochloric acid solutions, which is believed to be related to transformation and redistribution of organically-associated REY in coal during the ashing process. Ashing temperature significantly affects REY leaching from coal ashes; higher ashing temperature results in lower REY leachability in both solutions. Clay minerals may play a significant role in changing the leachability of REY after ashing. In addition, the results also suggest that the organic matter in the coal is relatively enriched in heavy REY.

This study tested whether osseous integration into poly (ε-caprolactone) (PCL) bioplastic scaffolds with fully-interconnecting 155 ± 8 μm pores is enhanced by an adhesive, non-inflammatory 99% degree of deacetylation (DDA) chitosan coating (99-PCL), or further incorporation of pro-inflammatory 83% DDA chitosan microparticles (83-99-PCL) to accelerate angiogenesis. New Zealand White rabbit osteochondral knee defects were press-fit with PCL, 99-PCL, 83-99-PCL, or allowed to bleed (drill-only). Between day 1 and 6 weeks of repair, drill-only defects repaired by endochondral ossification, with an 8-fold higher bone volume fraction (BVF) versus initial defects, compared to a 2-fold (99-PCL), 1.1-fold (PCL), or 0.4-fold (83-99-PCL) change in BVF. Hematoma innate immune cells swarmed to 83-99-PCL, elicited angiogenesis throughout the pores and induced slight bone resorption. PCL and 99-PCL pores were variably filled with cartilage or avascular mesenchyme near the bone plate, or angiogenic mesenchyme into which repairing trabecular bone infiltrated up to 1 mm deep. More repair cartilage covered the 99-PCL scaffold (65%) than PCL (18%) or 83-99-PCL (0%) (p < 0.005). We report the novel finding that non-inflammatory chitosan coatings promoted cartilage infiltration into and over a bioplastic scaffold, and were compatible with trabecular bone integration. This study also revealed that in vitro osteogenesis assays have limited ability to predict osseous integration into porous scaffolds, because (1) in vivo, woven bone integrates from the leading edge of regenerating trabecular bone and not from mesenchymal cells adhering to scaffold surfaces, and (2) bioactive coatings that attract inflammatory cells induce bone resorption., Graphical abstract Image 1, Highlights • Porous polycaprolactone scaffolds elicited drawn-out osteochondral wound repair. • Regenerating trabecular bone only infiltrated angiogenic mesenchyme free of inflammatory cells. • 83% DDA chitosan stimulated sterile inflammatory angiogenesis and trabecular bone resorption. • 99% DDA chitosan coatings promoted chondrogenesis inside and over the PCL articular surface.

Conductive hydrogels have attracted considerable attention owing to their potential for use as electronic skin and sensors. However, the loss of the inherent elasticity or conductivity in cold environments severely limits their working conditions. Generally, organic solvents or inorganic salts can be incorporated into hydrogels as cryoprotectants. However, their toxicity and/or corrosive nature as well as the significant water loss during the solvent exchange present serious difficulties. Herein, a liquid-like yet non-toxic polymer-polyethylene glycol (PEG) was attempted as one of the components of solvent for hydrogels. In the premixed PEG-water hybrid solvent, polyacrylamide (PAAm) was in situ polymerized, overcoming the inevitable water loss induced by the high osmotic pressure of the PEG solution and achieving tailored water capacity. Interestingly, the mechanical strength (“soft-to-rigid” transition) and anti-freezing properties of organohydrogels can be simultaneously tuned over a very wide range through adjusting PEG content. This was due to that with increasing PEG in solvent, the PAAm chains transformed from stretching to curling conformation, while PEG bonded with water molecules via hydrogen bonds, weakening the crystallization of water at subzero temperature. Additionally, a highly conductive Ti3C2Tx-MXene was further introduced into the organohydrogels, achieving a uniform distribution triggered by the attractive interaction between the rich functional groups of the nanofillers and the polymer chains. The nanocomposite hydrogels demonstrate high electrical conductivity and strain sensitivity, along with a wide working temperature window. Such a material can be used for monitoring human joint movement even at low temperature and has potential applications in wearable strain sensors.

High-voltage and low-cost manganese-based P2-type oxides show real promise as promising cathode for sodium-ion batteries (SIBs). But the P2−O2 phase transformation and Na+/vacancy ordering results in the inferior structural stability and Na+ diffusion coefficient, which further leads to rapid decay of capacity and poor rate capability. Herein, in consideration of the synergetic effects of dual cationic doping, electrochemically inactive Li+ and active Co3+ co-doping are proposed to solve the above issues. The novel two-step doping strategy, Co doping during synthesis of precursors via co-precipitation reaction followed by Li doping during solid-state reaction, are rationally developed. As anticipated, the Li, Co co-doped P2-type oxide exhibits the absence of P2−O2 phase transformation and Na+/vacancy disordering, which gives rise to an outstanding cycling stability (86.7% capacity retention within 100 cycles at 0.1C) and high-rate capability (reversible capacity of 109 mAh g−1 even at 10C). In addition, the full-cells composed of the co-doped P2-type positive and hard carbon negative show high energy-density, good lifespan and high-rate property. This proposed cationic co-doping provides an effective and scalable tactics for modulating the structural properties of high-voltage P2-type cathodes for advanced SIBs.

The performance of lignin depolymerization is basically determined by the interunit C–O and C–C bonds. Numerous C–O bond cleavage strategies have been developed, while the cleavage of C–C bond between the primary aromatic units remains a challenging task due to the high dissociation energy of C–C bond. Herein, a multifunctional RuRe alloy catalyst was designed, which exhibited exceptional catalytic activity for the cleavage of both C–O and C–C linkages in a broad range of lignin model compounds (β-1, α-5, 5-5, β-O-4, 4-O-5) and two stubborn lignins (kraft lignin and alkaline lignin), affording 97.5% overall yield of monocyclic compounds from model compounds and up to 129% of the maximum theoretical yield of monocyclic products based on C–O bonds cleavage from realistic lignin. Scanning transmission electron microscopy (STEM) characterization showed that RuRe (1:1) alloy particles with hexagonal close-packed structure were homogeneously dispersed on the support. Quasi-in situ X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS) indicate that Ru species were predominantly metallic state, whereas Re species were partially oxidized; meanwhile, there was a strong interaction between Ru and Re, where the electron transfer from Re to Ru was occurred, resulting in great improvement on the capability of C–O and C–C bonds cleavage in lignin conversion.

Nowadays, there are still many challenges to skin regeneration. As a new type of skin substitute, hydrogel has emerging gradually with its excellent properties. However, it is still a challenge to combine with biological active agents to facilitate skin regeneration. Under the circumstance, we synthesized arginine-based poly(ester amide) (Arg-PEA) and hyaluronic acid (HA-MA), and combined them into new hybrid hydrogels via photo-crosslinking. We found that the internal structure and physicochemical properties of hybrid hydrogels were greatly improved with the increase of content of Arg-PEA. Therefore, we designed hybrid hydrogels with 5 wt% and 10 wt% of Arg-PEA content, respectively. Besides, we selected the corresponding anti-inflammatory (CRP, TNF-α) indicators to detect the anti-inflammatory properties of the hybrid hydrogels at the protein level, and the corresponding antioxidant indicators (SOD, GSH/GSSG, MDA) were selected to investigate the antioxidant properties of hybrid hydrogels at the cellular level in vitro. In addition, we also selected relevant genes to test the effect of hybrid hydrogels on fibrosis and vascularization in the process of skin wound healing in vitro and verified them in vivo with a mouse dorsum wound model. The results confirmed that Arg-PEA/HA-MA (AH) hybrid hydrogel was a prospective scaffold material for skin regeneration.

In the present study, composites of Polyaniline and some fruit peels were synthesized in various conditions and used for lead removal from aqueous solutions. Adsorption tests were conducted in batch mode using the most efficient adsorbent, and the effects of medium pH, initial lead concentration, contact time, adsorbent dosage, and adsorption isotherms were investigated. The results showed that all composites were more efficient in lead removal compared to the fruit peels alone. The highest removal percentage was related to the composite of banana peel and Polyaniline that synthesized in the aqueous solution in the presence of 2 g·L−1 Poly ethylene glycol. This composite showed 95.96% lead adsorption at pH=6, the contact time of 90 min, the initial lead concentration of 25 mg·L−1, and an adsorbent concentration of 8 g·L−1. Adsorption isotherm study showed that adsorption of lead by synthesized composite could be fitted by both Langmuir and Freundlich models, but the Langmuir model was more fitted than Freundlich. Besides, some characteristics of the composites, such as chemical composition (XRD analysis), structure, and morphology (SEM analysis) and functional groups (FTIR analysis), were studied.

Theranostic visualization of dextran at the nanoscale is beneficial for understanding the bioregulatory mechanisms of this molecule. In this study, we applied structured illumination microscopy (SIM) to capture the distribution of Cy5-Dextran at different incubation periods in living cells. The results showed that Cy5-Dextran could be absorbed by HeLa cells. In addition, we clarified that Cy5-Dextran exhibited differential organelle distribution (lysosomal or mitochondrial) in a time-dependent manner. Moreover, lysosomal Cy5-Dextran localization was found to be independent of the autophagy process, while Cy5-Dextran localized to the mitochondria triggered a pro-apoptotic event, upregulating the levels of reactive oxygen species (ROS) to accelerate mitochondrial fragmentation. This work uses a visualized strategy to reveal the anti-tumor bioactivity of dextran, which was achieved by regulating apoptosis and autophagy.

The modification and functionalization of peptides is of great significance in modern biotechnology and drug development. Here we report a highly reactive Michael-type warhead for the covalently modification of cysteine on peptide and protein. By installing a vinyl group onto a methionine residue of peptide, the produced vinyl sulfonium can be efficiently nucleophilic added by appropriate cysteine residue of this peptide, and thus yield a cyclized peptide. This peptide cyclization strategy was proven to exhibit improved cell penetration and good stability. Moreover, a peptide ligand bearing vinyl sulfonium could covalently bind to the cysteine in the target protein, indicating the potential of vinyl sulfonium as a novel warhead for developing covalent peptide inhibitor.

This paper presents a method of the formation of composite polymer-containing coatings on a Mg–Mn–Ce magnesium alloy by forming a ceramic-like layer using plasma electrolytic oxidation (PEO) and subsequent spraying superdispersed polytetrafluoroethylene suspension. The coating composition and their morphological features were studied by SEM, EDS, GDOES, and XRD. The presented data confirm the embedding of fluoropolymer in the PEO coating. The evaluation of the corrosion properties of the formed composite polymer-containing coatings indicates a decrease in the corrosion current density by more than 3 orders of magnitude in comparison with the base PEO coating. The incorporation of a fluoropolymer in a PEO layer by more than 32% increases the load value at which abrasion of the coating to the substrate occurs and reduces the wear of the coating by more than 27 fold in comparison with the PEO layer. It has been established that composite coatings possess hydrophobic properties: the value of the contact angle attains 152 °.

Novel bioactive injectable composites based on biopolymeric hydrogels reinforced with insulin-functionalized silica particles were synthesized. The insulin (INS) was immobilized on the surface of amine-modified silica particles employing covalent attachment by EDC/NHS chemistry and via electrostatic interaction. The resulting formulations were examined for the morphology (SEM), chemical composition (FTIR, XPS) as well as protein content. To facilitate the injectability and support the bone regeneration, developed particles were dispersed in biopolymeric sol composed of collagen, chitosan and lysine-modified hyaluronic acid and crosslinked with genipin. By means of rheological study, the sol-gel in situ transition of obtained systems was verified. It was found in vitro study that MG-63 cells cultured on the developed composites exhibit significantly higher alkaline phosphatase (ALP) activity, compared to the pristine hydrogel. Furthermore, the biomineralization ability in the simulated body fluid (SBF) model was also demonstrated. Our findings suggest that proposed herein novel hydrogel-based composites might be the promising formulation for regeneration of bone defects, especially as a less-cost effective support/alternative for BMP-2 systems.

Nanocomposites of polyvinyl acetate and silica are prepared by sol-gel method. Samples are characterized using Infrared Spectroscopy, Thermal Analysis (TGA-DTGA) and X-ray photoelectron spectroscopy. In the hybrids with higher content of silica, it is evidenced the presence of hydrogen bonding between the residual silanols on the silicate network and the carbonyl of PVAc, this is determined by FTIR and XPS. It was also found that the hybrid containing 75% of silica suspension and 25% of polyvinyl acetate was the most thermally stable by TGA-DTGA.

Carbon dots (CDs) have attracted more interest in tumor theranostics, but they suffer from the rapid renal clearance due to small size and high hydrophilicity. To solve such problems, hydrophobic pH-triggered carbon dot-drug conjugate (CDs-Hy-DOX) with high doxorubicin (DOX) content of 48.23% were designed by covalent conjugation of DOX onto the CDs via acid-labile linkage with hydrazine (Hy) as bridge. Then the fluorescent traceable hybrid prodrug nanoparticles were fabricated via co-self-assembly with the CDs-Hy-DOX as pH-sensitive prodrug and a pH/reduction dual-triggered degradable hyperbranched polymer PEG-PO-Cy as polyethylene glycol (PEG)-based surfactant, as well as gatekeeper for pH/reduction dual-triggered DOX release. The hybrid prodrug nanoparticles with hydrodynamic diameter of 220 nm and DOX content of 22.99% were obtained with the optimized co-self-assembling condition. They could release 68.98% of DOX in the simulated tumor microenvironment within 3 days in a sustained release mode, with a premature drug leakage of 7.58%. After the acid-triggered DOX release from the CDs-Hy-DOX, which was accelerated by the pH/reduction dual-triggered degradation of the hyperbranched polymer, the strong fluorescence of CDs-Hy was recovered, demonstrating the promising potential in future tumor nanotheranostics.

Soil aggregation plays an important role in agricultural production activities. However, the structure of soil aggregation is destroyed by the natural environment and unreasonable farming management, resulting in the loss of water, fertilizers and pesticides in soil. At present, hydrogels have been widely reported to promote the formation of soil aggregation. In this paper, amphiphilic calcium alginate (ASA/Ca2+) was applied to promote the formation of soil aggregation and enhance pesticide retention. Initially, an ASA was obtained through the one-pot Ugi condensation (a four-component green chemical reaction). Then, ASA/Ca2+ hydrogel is prepared by Ca2+ cross-linking. The formation of soil aggregation was determined through the Turbiscan Lab Expert stability analyzer, Confocal Laser Scanning Microscope (CLSM), and Transmission Electron Microscope (TEM). And the effect of soil aggregation on acetamiprid environmental behavior was investigated by adsorption kinetics, adsorption isotherms, and leaching. The results shown that the three-dimensional network structure of ASA/Ca2+ hydrogel can promote the formation of soil aggregation. Aggregate durability index (ADI) was 0.55 in the presence of ASA/Ca2+ hydrogel, indicating that amphiphilic hydrogel can enhance the stability of soil aggregation. The adsorbing capacity of acetamiprid was 1.58 times higher than pure soil, and the release of acetamiprid only about 20% in the presence of ASA/Ca2+ hydrogel. These results would be helpful for the formation of soil aggregation and pesticides adsorption on soil aggregation. Thus, ASA/Ca2+ hydrogel is likely to improve soil quality, simultaneously it can minimize the mobility of pesticides in the agricultural system.

PURPOSE To assess the shear bond strength of composite resin to polyether ether ketone (PEEK) after mechanical and chemical surface treatments. MATERIALS AND METHODS A total of 48 PEEK discs were fabricated and divided equally into four surface treatment groups (n = 12 each): (1) airborne particle abrasion with 50-μm alumina particles at 2 MPa pressure for 10 seconds; (2) 98% sulfuric acid etching for 1 minute; (3) airborne particle abrasion and sulfuric acid etching; and (4) no surface treatment. Specimens were conditioned, then Gradia composite veneer (GC) was applied to the PEEK surfaces and polymerized. Bond strength was measured with shear bond test using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were applied for statistical analysis. RESULTS The mean shear bond strength values of the sulfuric acid-etched group were higher than that of the airborne particle abrasion + acid etching, airborne particle abrasion, and control groups (P < .05). Mean shear bond strength values for the airborne particle abrasion + acid etching samples were higher than for the control and airborne particle abrasion groups (P < .05). CONCLUSION There was no significant difference between the samples treated with airborne particle abrasion and the control group.