Effects of MgO nanoparticle addition on the mechanical properties, degradation properties, antibacterial properties and in vitro and in vivo biological properties of 3D-printed Zn scaffolds

Bone tissue engineering is the main method for repairing large segment bone defects. In this study, a layer of bioactive MgO nanoparticles was wrapped on the surface of spherical Zn powders, which allowed the MgO nanoparticles to be incorporated into 3D-printed Zn matrix and improved the biodegradation and biocompatibility of the Zn matrix. The results showed that porous pure Zn scaffolds and Zn/MgO scaffolds with skeletal-gyroid (G) model structure were successfully prepared by selective laser melting (SLM). The average porosity of two porous scaffolds was 59.3 and 60.0%, respectively. The pores were uniformly distributed with an average pore size of 558.6-569.3 μm. MgO nanoparticles regulated the corrosion rate of scaffolds, resulting in a more uniform corrosion degradation behavior of the Zn/MgO scaffolds in simulated body fluid solution. The degradation ratio of Zn/MgO composite scaffolds in vivo was increased compared to pure Zn scaffolds, reaching 15.6% at 12 weeks. The yield strength (10.8 ± 2.4 MPa) of the Zn/MgO composite scaffold was comparable to that of cancellous bone, and the antimicrobial rate were higher than 99%. The Zn/MgO composite scaffolds could better guide bone tissue regeneration in rat cranial bone repair experiments (completely filling the scaffolds at 12 weeks). Therefore, porous Zn/MgO scaffolds with G-model structure prepared with SLM are a promising biodegradable bone tissue engineering scaffold.

One-pot solvothermal preparation of the porous NiS2//MoS2 composite catalyst with enhanced low-temperature hydrodesulfurization activity

The simple preparation of mesoporous NiS2//MoS2 composite catalyst through a one-pot solvothermal method is presented. The improvement of the specific surface area (220 m2/g) and the construction of the porous structure are realized by this method in the case of no support. The organics acts as a microscopic binder contribute to uniform stacking of MoS2 with NiS2 clusters. The composite structure including NiS2 and MoS2 was obtained (proved by XRD, XPS, TEM, IR, UV-vis and RAMAN) and changed the microelectronic environment of the active metal surface (DFT calculation). The mesoporous NiS2//MoS2 catalyst (Ni1Mo1-200) showed an excellent hydrodesulfurization performance of dibenzothiophene (DBT conversion: 78 % at 260 °C) and a high ratio of direct desulfurization pathway (SDDS/HYD = 16.6) at a low reaction temperature. By combining the characterization and theoretical calculation results, the advantages of this NiS2//MoS2 composite structure in synergistic catalysis was further confirmed.

Amphoteric composite of ZrP and N-doped porous carbon: Synthesis, characterization, and potential use for cycloaddition of CO2

Composites of amorphous ZrP and N-doped carbon were prepared in a one-step pyrolysis process instead of general post-loading technique. Owing to their mesoporous structure (6-10 nm) and Zr content (up to 41 wt%), the amphoteric materials have potential use in the cycloaddition of CO2 to epoxides, which is an acid‒base tandem process including the ring opening of epoxides and the addition of CO2. Substantial work has been done on how starting materials impact the structure and performance of composite materials. The coordination between metal and melamine has been confirmed, and it can be implanted in the melamine-polymer initiation of formation of porous metal-carbon materials. The composite catalysts exhibit amphoteric properties, present broad-spectrum adsorption, and finally produce carbonates via cycloaddition of CO2 to epoxides. It is remarkable that the multiple characteristics of porous solids are stabilized, and no significant loss of catalytic performance is observed after four cycles.

Nonlinear frequency analysis of porous Bi directional functionally graded beams utilizing reddy shear deformation theory

The nonlinear frequency response of bi-directional functionally graded porous beams experienced range of various end conditions is investigated in this work. The end conditions which are simply supported, clamped-simply supported, clamped-clamped, and clamped-free are taken by using the Von Karman geometric nonlinearity, Green's tensor and Reddy third-order shear deformation theory. A generalized differential quadrature technique (GDQM) accompanied by direct numerical iterance approach is proposed to solve equations. The findings are presented to aid in future research into the effects of various gradient indices, vibration amplitude ratios, porosity coefficients, shear and elastic substrate parameters, boundary conditions, and vibration frequencies on the bi-directional functionally graded beams. The outcomes of this research have practical applications and can be utilized to enhance the design of bi-directional beams. The results are also highly useful in anticipating and identifying potential causes of failure in these beams.

Bottom-up Solution Synthesis of Graphene Nanoribbons with Precisely Engineered Nanopores

The incorporation of nanopores into graphene nanostructures has been demonstrated as an efficient tool in tuning their band gaps and electronic structures. However, precisely embedding the uniform nanopores into graphene nanoribbons (GNRs) at the atomic level remains underdeveloped especially for in-solution synthesis due to the lack of efficient synthetic strategies. Herein we report the first case of solution-synthesized porous GNR (pGNR) with a fully conjugated backbone via the efficient Scholl reaction of tailor-made polyphenylene precursor (P1) bearing pre-installed hexagonal nanopores. The resultant pGNR features periodic subnanometer pores with a uniform diameter of 0.6 nm and an adjacent-pores-distance of 1.7 nm. To solidify our design strategy, two porous model compounds (1 a, 1 b) containing the same pore size as the shortcuts of pGNR, are successfully synthesized. The chemical structure and photophysical properties of pGNR are investigated by various spectroscopic analyses. Notably, the embedded periodic nanopores largely reduce the π-conjugation degree and alleviate the inter-ribbon π-π interactions, compared to the nonporous GNRs with similar widths, affording pGNR with a notably enlarged band gap and enhanced liquid-phase processability.

Physico chemical characterisation of pectin incorporated gelatin sponge and its functional evaluation in modulating contact activation haemostasis

Even though it is a common occurrence in practice, maintaining haemostasis can sometimes become a challenging issue in case of trauma, perioperative period, coagulation disorders, cancers, etc. Hemostatic materials are extensively used to assist in the cessation of bleeding. However, the definition of efficiency of haemostasis varies between intended procedures. This paper explores the feasibility of incorporating agents to increase the efficiency of local haemostasis. Pectin or β -D galacto hexopyranuronic acid/β Gal A, a structural polysaccharide widely present in terrestrial plants having an intrinsic hemostatic potential, is blended with gelatin and is explored in modulating passive haemostasis. The sponges are physico chemically characterized, and their hemostatic efficiency is evaluated in vitro using various assays. Biocompatibility evaluation is done by in vitro cytotoxicity assay. The results suggest that this biopolymer combination is a promising candidate for hemostatic control.

Study on the ice crystals growth under pectin gels with different crosslinking strengths by modulating the degree of amidation in HG domain

The ice crystal morphology formed under a series of amidated pectin gels with various crosslink strengths were investigated. The results showed that as the degree of amidation (DA) increased, pectin chains exhibited shorter homogalacturonan (HG) regions. Highly amidated pectin exhibited a faster gelation rate and a stronger gel micro-network via hydrogen bonds. Based on cryogenic scanning electron microscopy (cryo-SEM), smaller ice crystals were formed in frozen gel with low DA, suggesting that a weaker cross-linked gel micro-network was more effective at inhibiting crystallization. After sublimation, lyophilized gel scaffolds with high crosslink strength displayed less number of pores, high porosity, lower specific surface area, and greater mechanical strength. This study is expected to confirm that the microstructure and mechanical properties of freeze-dried pectin porous materials could be regulated by changing the crosslink strength of pectin chains, which is achieved by increasing the degree of amidation in the HG domains.

Manipulation of porous poly(l-lactide-co-ε-caprolactone) microcarriers via microfluidics for C2C12 expansion

The growth and repair of skeletal muscle are due in part to activation of muscle precursor cells, commonly known as satellite cells or myoblasts. In order to acquire enough cells for neoskeletal muscle regeneration, it is urgent to develop microcarriers for skeletal myoblasts proliferation with a considerable efficiency. The current study was thus proposed to develop a microfluidic technology to manufacture porous poly(l-lactide-co-ε-caprolactone) (PLCL) microcarriers of high uniformity, and porosity was manipulated via camphene to suit the proliferation of C2C12 cells. A co-flow capillary microfluidic device was first designed to obtain PLCL microcarriers with different porosity. The attachment and proliferation of C2C12 cells on these microcarriers were evaluated and the differentiation potential of expanded cells were verified. The obtained porous microcarriers were all uniform in size with a high mono-dispersity (CV < 5 %). The content of camphene rendered effects on the size, porosity, and pore size of microcarriers, and porous structure addition produced a softening of their mechanical properties. The one of 10 % camphene (PM-10) exhibited the superior expansion for C2C12 cells with the number of cells after 5 days of culture reached 9.53 times of the adherent cells on the first day. The expanded cells from PM-10 still retained excellent myogenic differentiation performance as the expressions of MYOD, Desmin and MYH2 were intensively enhanced. Hence, the current developed porous PLCL microcarriers could offer as a promising type of substrates not only for in vitro muscular precursor cells expansion without compromising any multipotency but also have the potential as injectable constructs to mediate muscle regeneration.

A novel synthesis of Porous Fe4N/carbon hollow microspheres for thin and efficient electromagnetic wave absorbers

Modulating the structure and morphology is essential in fabricating high-performance electromagnetic absorbing materials. Herein, we obtained porous Fe₃O₄/carbon hollow microspheres and porous Fe₄N/carbon hollow microspheres derived from Fe-glycerol hollow microspheres. Through structure and morphology analysis, we proved the existence of porous and hollow features. By comparison, it can be found that the porous Fe₄N/carbon hollow microspheres have electromagnetic wave absorption performance superior to that of porous Fe₃O₄/carbon hollow microspheres. The reflection loss value of porous Fe₄N/carbon hollow microspheres reaches -42.2 dB at a matching thickness of merely 1.4 mm, and its effective absorbing bandwidth approaches 4.5 GHz, whereas the reflection loss of porous Fe₃O₄/carbon hollow microspheres in the 2-18 GHz range is over -10 dB. Reasons for the better electromagnetic wave absorption performance are revealed to be that the magnetic Fe₄N has higher complex permittivity and complex permeability, and the porous hollow microspherical structure increases the multiple scattering and reflection of electromagnetic waves. Meanwhile, the impedance matching and attenuation constant are optimized together through the synergy of dielectric and magnetic loss. This research can provide instructive findings for thin-thickness electromagnetic wave absorbing materials based on Fe₄N with an appropriate microstructure.

A lumped model for long bone behavior based on poroelastic deformation and Darcy flow

The present paper provides a simplified model for compact bone behavior by accounting for bone fluid flow coupled to the elasticity of the porous structure. The lumped model considers the bone material as a layered poroelastic structure and predicts normal pressure versus displacement, i.e, a stress-strain curve. There is a parametric dependency on porosity and permeability but, in addition, on pressure history. Specifically, the pressure impulse (the integral of pressure versus time) plays a key role. This factor is alluded to in several past studies, but not highlighted in a simplified fashion. Based on a global flow balance, bone displacement depends on the fluid flow in a channel according to the classical Darcy model of 1856, and on the rate of change of fluid within the porous solid according to the 1941 classical model of Biot. The present results agree with those of Perrin et al. which, in turn, agree with results of a detailed numerical simulation.

Super-enhanced evaporation of droplets from porous coatings

HYPOTHESIS

The addition of a thin, hydrophilic, porous, coating to an impermeable solid will lead to more rapid evaporation of liquid droplets that impinge on the solid. The droplet will imbibe quickly, but the progress normal to the interface will be limited to the thickness of the coating, and therefore the liquid will spread laterally into a broad disk to expose a large liquid-vapor interface for evaporation.

EXPERIMENTS

Liquid droplets of volume 2.5-25 µL were placed on solids and then both the mass and area of each droplet were monitored over time. We compared data for smooth, impermeable hydrophilic glass to the same glass that was coated in thin (35-109 µm) porous, hydrophilic-glass layer fabricated from glass beads.

FINDINGS

The droplet was imbibed (wicked) into the coating within seconds, and the liquid spread laterally to form a thin, broad, disk. Critically, evaporation of a droplet was enhanced by a factor of 7-8 on the thin coating. The evaporation rate was not proportional to the reciprocal thickness of the coating. The ability to enhance evaporation of small droplets on a solid may have practical applications, for example, in speeding the death of microbes.

Metal Ion-Induced Porous MXene for All-Solid-State Flexible Supercapacitors

MXenes are normally used for energy storage applications. However, large nanosheets and restacking are detrimental to the ion diffusion and thus limit its rate capability. Here, a strategy to prepare flexible and porous MXene-M supercapacitor electrodes can simultaneously enlarge the interlayer spacing between layers and create holes in the layers. As a result, Ti₃C₂T_x-Mn presents an excellent lifespan, with still 248 F g^-1 after 100 000 cycles at a current density of 100 A g^-1. Moreover, Ti₃C₂T_x-Mn-based symmetric all-solid-state supercapacitor exhibits outstanding volumetric energy up to 52.4 mWh cm^-3 and retains 38.4 mWh cm^-3 at an ultrahigh volumetric power density of 55.3 W cm^-3. We believe this work provides an idea for the later regulation of MXene layer spacing and the design of porous structures, and can be widely used in the next-generation high-energy density and power density practical applications.

Visible-light-induced photocatalytic response of easily recoverable Mn2O3/SiO2 monolith in centimeter-scale towards degradation of ofloxacin: Performance evaluation and product analysis

Monolithic-photocatalysts being easily recoverable are a suitable alternative to powdered materials for pollutant treatment. This study was conducted to prepare Mn₂O₃/SiO₂ monoliths by wet-impregnating Mn(NO₃)₂^․4H₂O in SiO₂ monoliths. The crystallinity of oxide was affirmed via XRD analyses, whereas EDS and elemental-mapping, and XPS studies revealed the constituent elements and their oxidation states. FESEM images confirmed porous morphology, while BET-analysis confirmed its mesoporous nature (∼8.44 nm) and enormous surface area (∼241 m²/g). The DRS and PL studies disclosed that Mn₂O₃/SiO₂ monoliths consisted of narrow band-gap of ∼2.14 eV and had suitable electron/hole separation. The photocatalytic effectiveness of the monolith had been checked by degrading model dye methylene blue (MB) and antibiotic ofloxacin (OF). The influence of various reaction parameters for degradation, i.e., monolith dose, solution-pH, illumination-area, scavengers, etc., was noted. At optimal reaction conditions, outstanding competence was achieved for MB (95.23%; 0.0225 min^-1) and decent results were obtained for OF-degradation (73.2%; 0.0096 min^-1). The recyclable nature of the catalyst (∼12.7%-reduction in effectiveness after 10 successive cycles) was vindicated by several characterization studies after reusability. The O₂^•-radicals participated majorly in the degradation reaction. The reaction intermediates plus products, generated after the degradation of had been identified via LC/MS study. The mineralization extent of the OF and MB was also gauged through TOC analyses. The photocatalytic treatment of raw textile wastewater manifested ∼57.8% COD and 53% TOC-removal. This study emphasizes the competence of Mn₂O₃/SiO₂ monoliths for the photocatalytic abatement of refractory organic contaminants.

Biomechanical comparison of subsidence performance among three modern porous lateral cage designs

BACKGROUND

Cage subsidence remains a major complication after spinal surgery. The goal of this study was to compare the subsidence performance of three modern porous cage designs.

METHODS

Three porous cages were evaluated: a porous titanium cage, a porous polyetheretherketone cage and a truss titanium cage. Mechanical testing was performed for each cage per the American Society for Testing and Materials F2077 and F2267 standards to evaluate cage stiffness and block stiffness, and per a novel clinically relevant dynamic subsidence testing method simulating cyclic spine loading during 3-months postoperatively to evaluate the subsidence displacement.

FINDINGS

The porous polyetheretherketone cage demonstrated the lowest cage stiffness (21.0 ± 1.1 kN/mm), less than half of both titanium cages (truss titanium cage, 49.1 kN/mm; porous titanium cage, 43.6 kN/mm). The block stiffness was greatest for the porous titanium cage (2867.7 ± 105.3 N/mm), followed by the porous polyetheretherketone (2563.4 ± 72.9 N/mm) and truss titanium cages (2213.7 ± 21.8 N/mm). The dynamic subsidence displacement was greatest for the truss titanium cage, which was 1.5 and 2.5 times the subsidence displacement as the porous polyetheretherketone and porous titanium cages respectively.

INTERPRETATIONS

Specific porous cage design plays a crucial role in the cage subsidence performance, to a greater degree than the selection of cage materials. A porous titanium cage with body lattice and microporous endplates significantly outperformed a truss titanium cage with a similar cage stiffness in subsidence performance, and a porous polyetheretherketone cage with half of its stiffness.

Explorations on efficient extraction of uranium with porous coal fly ash aerogels

In order to explore a suitable uranium adsorbent with the advantages of low-cost, recyclability and high efficiency, porous coal fly ash aerogels with different size of coal fly ash were synthesized. Among them, PCFAA-1250 (prepared with 1250 mesh coal fly ash (CFA)) showed better adsorption performance and the maximum adsorption efficiency even approached 96.5% (C₀ = 10 mg L^-1, m/V = 1.0 g L^-1, T = 298 K, t = 24 h and pH = 3.0), which was higher than most of previous adsorbents. Langmuir and pseudo-second-order models were more likely to be used to determine the removal behavior of uranium on PCFAA, illustrating that the adsorption reaction was uniform chemisorption. Meanwhile, the adsorption process on PCFAA was spontaneous. Notably, the desorption efficiencies of all of PCFAA were more than 80% after five cycles, which suggested that PCFAA possessed good recyclability, especially PCFAA-1250. Besides, the adsorption mechanism was further revealed via XPS and the uranium ions were immobilized on the surface of adsorbents through complexation. Based on above conclusions, it could be concluded that PCFAA-1250 had the potential to be a candidate for the extraction of uranium from wastewater.

Increasing N active sites by in-situ growing conformal C3N4 layer in hierarchical porous carbon-based networks for fast Li+ transfer and polysulfide anchoring in lithium-sulfur batteries

Various challenges remain to be overcome in lithium-sulfur (Li-S) batteries, including the volume expansion and low conductivity of sulfur, the shuttle effect of lithium polysulfides and the sluggish redox reaction in the cell. Herein, we propose a multilayered conductive framework by the in situ growth of a conformal graphene-like C₃N₄ (GCN) coating on porous CNT@NC networks with carbon nanotubes (CNTs) as the core and N-doped carbon (NC) as the crosslinking shell. The abundant N in the GCN coating increased the surface N concentration of the framework from 14.38% to 18.77%, which enriched the active sites in the frameworks for the adsorption and catalysis conversion of LiPSs and Li₂S with a low energy barrier. Furthermore, the scalable frameworks can provide an 85% porosity for a sufficient reaction interface and accommodate the volume expansion of sulfur. The synergistic effect between GCN and the highly conductive hierarchical structure can accelerate the transport of Li⁺ and electrons as well as the diffusion of electrolyte. Benefitting from the above advantages, the Al-free CNT@NC@GCN electrode exhibits a reversible capacity of 647.6 mAh g^-1 after cycling for 450 cycles at 1C with a low capacity fading rate of 0.09% per cycle. This proposed facile strategy creates inspiring insights into the design of novel cathode materials for Li-S batteries.

Preparation, characterization and formation mechanism of size-controlled lignin nanoparticles

Lignin is a renewable raw material with excellent adsorption, biodegradability, and non-toxicity. As a new, green nanomaterial, lignin nanoparticles (LNPs) have been explored as high-value renewable materials for applications in many fields. Herein, we provide a simple, rapid approach for the fabrication of size-controlled LNPs using a titrimetric nanoprecipitation method. The prepared LNPs were formed through a layer-by-layer self-assembly approach from inside to outside based on π-π interactions and had spherical shapes with porous surfaces and particle sizes from 272.0 to 915.4 nm. The average particle size of LNPs varied with stirring speed and decreased as the volume of deionized water increased. Compared with those of the original lignin, the chemical structural characteristics of LNPs did not change significantly. The proposed scheme for the preparation of LNPs is simple, inexpensive, and possesses the properties of both lignin and nanomaterials. The sizes of LNPs were controlled. Therefore, this is a good scheme for high-value applications of lignin.

Evolution of polyetheretherketone (PEEK) and titanium interbody devices for spinal procedures: a comprehensive review of the literature

INTRODUCTION

Interbody fusion is commonly utilized for arthrodesis and stability among patients undergoing spine surgery. Over the last few decades, interbody device materials, such as titanium and polyetheretherketone (PEEK), have been replacing traditional autografts and allografts for interbody fusion. As such, with the exponential growth of bioengineering, a large variety cage surface technologies exist. Different combinations of cage component materials and surface modifications have been created to optimize interbody constructs for surgical use. This review aims to provide a comprehensive overview of common surface technologies, their performance in the clinical setting, and recent modifications and material combinations.

MATERIALS AND METHODS

We performed a comprehensive review of the literature on titanium and PEEK as medical devices between 1964 and 2021. We searched five major databases, resulting in 4974 records. Articles were screened for inclusion manually by two independent reviewers, resulting in 237 articles included for review.

CONCLUSION

Interbody devices have rapidly evolved over the last few decades. Biomaterial and biomechanical modifications have allowed for continued design optimization. While titanium has a high osseointegrative capacity, it also has a high elastic modulus and is radio-opaque. PEEK, on the other hand, has a lower elastic modulus and is radiolucent, though PEEK has poor osseointegrative capacity. Surface modifications, material development advancements, and hybrid material devices have been utilized in search of an optimal spinal implant which maximizes the advantages and minimizes the disadvantages of each interbody material.

Choice of Spinal Interbody Fusion Cage Material and Design Influences Subsidence and Osseointegration Performance

OBJECTIVE

The objective of the study was to quantify the effect of cage material (titanium-alloy vs. polyetheretherketone or PEEK) and design (porous vs. solid) on subsidence and osseointegration.

METHODS

Three lateral cages (solid PEEK, solid titanium, and 3-dimension-printed porous titanium cages) were evaluated for cage stiffness, subsidence compression stiffness, and dynamic subsidence displacement under simulated postoperative spine loading. Dowel-shaped implants made of grit-blasted solid titanium alloy (solid titanium) and porous titanium were fabricated using commercially available processes. Samples were processed for mechanical push-out testing and polymethylmethacrylate histology following an established ovine bone implantation model.

RESULTS

The solid titanium cage exhibited the greatest stiffness (57.1 ± 0.6 kN/mm), followed by the porous titanium cage (40.4 ± 0.3 kN/mm) and the solid PEEK cage (37.1 ± 1.2 kN/mm). In the clinically relevant dynamic subsidence, the porous titanium cage showed the least amount of subsidence displacement (0.195 ± 0.012 mm), significantly less than that of the solid PEEK cage (0.328 ± 0.020 mm) and the solid titanium cage (0.538 ± 0.027 mm). Bony on-growth was noted histologically on all implant materials; however, only the porous titanium supported bony ingrowth with marked quantities of bone formed within the interconnected pores through 12 weeks. Functional differences in osseointegration were noted between groups during push-out testing. The porous titanium showed the highest maximum shear stress at 12 weeks and was the only group that demonstrated significant improvement (4-12 weeks).

CONCLUSIONS

The choice of material and design is critical to cage mechanical and biological performances. A porous titanium cage can reduce subsidence risk and generate biological stability through bone on-growth and ingrowth.

Solar-driven enhanced chemical adsorption and interfacial evaporation using porous graphene-based spherical composites

Solar-energy-driven water purification is a promising technology for obtaining clean water during the current global climate crisis. Solar absorbers with high light absorption capacity and efficient energy conversion are critical components of solar-driven water evaporation and purification systems. Herein, we demonstrate that porous reduced graphene oxide (rGO)-based composite spheres facilitate efficient water evaporation and effective organic pollutant adsorption from water. Most solar light (>99% for 1 mm thick composites) is absorbed by the porous rGO-based composite spheres floating on water and is subsequently converted into heat, which is efficiently transferred to water at the air-water interface. Evaporation efficiency via energy conversion by the floating sphere composites reaches ∼74%. The increase in surface temperature of water also contributes to improving the adsorption capacity of the rGO-based composite spheres for organic pollutants. Furthermore, the composites can effectively block ultraviolet radiation, preventing the chemical reaction of water pollutants into harmful components.

Porous multifunctional phenylcarbamoylated-β-cyclodextrin polymers for rapid removal of aromatic organic pollutants

In this work, polymers containing a large number of benzene rings and multiple functional groups were designed to remove aromatic organic pollutants. Using tetrafluoroterephthalonitrile (TFTPN) as a rigid crosslinking agent to crosslink different functionalized phenylcarbamoylated-β-cyclodextrin derivatives to prepare a series of porous multifunctional cyclodextrin (CD) polymerizations, including three preliminary polymerized adsorption materials and a mix β-cyclodextrin polymer (X-CDP) prepared via a secondary crosslinking procedure of the above three materials. The X-CDP preparation process connects the pre-formed nanoparticles and increases the presence of linkers inside the particles. At the same time, X-CDP exhibited porous structure with various functional groups such as nitro, chlorine, fluorine, and hydroxyl. Those special characteristics render this material with good adsorption ability towards various aromatic organic pollutants in water, including tetracycline, ibuprofen, dichlorophenol, norfloxacin, bisphenol A, and naphthol. Especially, the maximum adsorption capacity for tetracycline at equilibrium reached 110.56 mg·g^-1, which is competitive with the adsorption capacities of other polysaccharide adsorbents. X-CDP removed organic contaminants much more quickly than other adsorbents, reaching almost ~95% of its equilibrium in only 30 s, and the rate constant reaches 2.32 g·mg^-1·min^-1. The main adsorption process of the pollutants by X-CDP fitted the pseudo-second-order kinetic and Langmuir isotherm well, indicating that the adsorption process is monolayer adsorption. Moreover, X-CDP possessed the good reusability where the pollutant removal rate was only reduced 8.3% after five cycles. Such advantages render the polymer great potential in the rapid treatment of organic pollutants in water bodies.

Unprecedented Duel Role of Polyaniline for Enhanced Pseudocapacitance of Cobalt-iron Layered Double Hydroxide

Creating nanosized pores in layered materials can increase the abundant active surface area and boost potential applications of energy storage devices. Herein, a unique synthetic strategy based on the polyaniline (PANI) doped two-dimensional (2D) cobalt-iron layered double hydroxide (CoFe-LDH/P) nanomaterials are being designed, and the formation of pores at low temperature (80 °C) is developed. It is found that the optimized concentration of PANI creates the nanopores on the CoFe-LDH nanosheets among all other polymers. The well-ordered pores of CoFe-LDH/P allow the high accessibility of the redox-active sites and promote effective ion diffusion. The optimized CoFe-LDH/P2 cathode reveals a specific capacitance 1686 (1096 Cg^-1 ) and 1200 Fg^-1 (720 Cg^-1 ) at 1 and 30 Ag^-1 respectively, a high rate capability (71.2%), and a long cycle life (98% over 10000 cycles) for supercapcitor applications. Charge storage analysis suggested that the CoFe-LDH/P2 electrode displays like a capacitive-type storage mechanism (69% capacitive at 1 mVs^-1 ). Moreover, an asymmetric aqueous supercapacitor (CoFe-LDH/P2//AC) was fabricated, delivering the excellent energy density (75.9 Wh kg^-1 at 1124 W kg^-1 ) with outstanding stability (97.5%) over 10000 cycles. This work opens a new avenue for designing porous 2D materials at low temperature for aqueous energy storage devices. This article is protected by copyright. All rights reserved.

Fabrication of porous TiO2 foams by powder metallurgy technique and study of bulk crushing strength for biomedical application

Despite the importance of porous titanium oxide (PA-TiO2) in diverse functional applications, very little information is available on the compatible mechanical properties for potential biomedical applications. In this study, PA-TiO2 foam was synthesized using space-holding powder metallurgy and sintering methods to produce interconnected opened-cell structure with surface morphology of mountain-like features associated with the extensive rift valley system. Three different types of PA-TiO2 foams with porosities of 35-52% and mean pore diameter of 190-210 μm were fabricated for evaluating the effect of porosity on mechanical properties of bulk PA-TiO2. The modulus of elasticity of PA-TiO2 foams exhibited in the range of 45-262 MPa which was within the range of modulus of elasticity of human cancellous bone. Cytotoxicity test is performed in vitro analysis to observe the effect of cell toxicity to produce osteointegration when used as implantable materials. There was no cytotoxicity effect found and remarkable cell growth was observed for human cancerous (HeLa) cell line. However, there was no cytotoxicity effect found and cell growth was not observed for Vero cell line. This study suggested that PA-TiO2 facilitates cell growth without spreading toxicity and has mechanical properties of cancellous bone. Hence, it has potential application as implant and medical devices in biomedical applications.

Porous electrospun microfibers for low flow-resistant solid phase extraction of fluoroquinolones in tap water, egg and milk samples

In this work, porous electrospun microfibers (PEMFs) were prepared using a polyimide/polyvinylpyrrolidone/polyethylene glycol (PI/PVP/PEG) solution mixture with coaxial ultrasonic water vapor spraying. After removing PVP and PEG by ultrasonic water washing, the PEMFs were successfully demonstrated as adsorbents for solid phase extraction (SPE). Most non-porous electrospun nanofibers are hundreds of nanometers in diameter, with a specific surface area of dozens of square meters per gram. In contrast, the diameter of the as-prepared PEMFs was tuned between 3 and 8 μm, the specific surface area was 76 m²g^-1 and the pore size was ca 25 nm. Therefore, the flow resistance of the PEMF-SPE cartridges was similar to those of conventional commercial SPE cartridges, and much lower than those of SPE cartridges packed with electrospun nanofibers. Using the PEMF-SPE cartridges with ultra-performance liquid chromatography-fluorescence detector (UPLC-FLD), five fluoroquinolones (FQs) in tap water, egg and milk samples were extracted and quantified successfully. After optimizing the extraction conditions, FQs in water samples were extracted and eluted with high recoveries of 84.8-114.8%. The inter-batch and intra-batch relative standard deviation (RSD) values for the FQs were in the range of 1.9-9.5% (n=3), and the limits of detection were between 0.0024-0.014 μg L^-1. The method was linear in the concentration range of 0.005-10 μg L^-1. The reliability of the developed method was validated by analyzing tap water, egg and milk samples, and the recovery values were found to be in the range of 74.8-116.6% under the optimized conditions.

Hydrophilic and underwater superoleophobic porous graphitic carbon nitride (g-C3N4) membranes with photo-Fenton self-cleaning ability for efficient oil/water separation

Due to the great fouling resistance property, (super)hydrophilic/underwater superoleophobic membranes are prevalent candidates for oil-polluted wastewater treatment. Even so, membrane fouling inevitably occurs during long-term operation. Therefore, it is of great significance to construct anti-fouling membranes with robust flux recovery. Herein, a polyvinyl pyrrolidone (PVP) coated porous potassium-doped g-C₃N₄ (PKCN) membrane was fabricated for the first time by vacuum filtration. The as-prepared membrane displays enhanced hydrophilicity and underwater superoleophobicity. The permeability of the membrane increased significantly after sonication treatment, which is attributed to the increased pore volume and small nanosheets size that shorten the transport pathway of water molecules. Importantly, owing to the high photo-Fenton activity, the PKCN membrane exhibits fast (within 15 min) and excellent flux recovery (96.5%) after the photo-Fenton cleaning process. Furthermore, after 10 repeated usages, the PKCN membrane still keeps stable permeability and excellent purification efficiency. This work opens a door for developing self-cleaning membranes with the superior anti-fouling ability for effective oil/water separation.

Precision-porous polyurethane elastomers engineered for application in pro-healing vascular grafts: Synthesis, fabrication and detailed biocompatibility assessment

Unmet needs for small diameter, non-biologic vascular grafts and the less-than-ideal performance of medium diameter grafts suggest opportunities for major improvements. Biomaterials that are mechanically matched to native blood vessels, reduce the foreign body capsule (FBC) and demonstrate improved integration and healing are expected to improve graft performance. In this study, we developed biostable, crosslinked polyurethane formulations and used them to fabricate scaffolds with precision-engineered 40 μm pores. We matched the scaffold mechanical properties with those of native blood vessels by optimizing the polyurethane compositions. We hypothesized that such scaffolds promote healing and mitigate the FBC. To test our hypothesis, polyurethanes with 40 μm pores, 100 μm pores, and non-porous slabs were implanted subcutaneously in mice for 3 weeks, and then were examined histologically. Our results show that 40 μm porous scaffolds elicit the highest level of angiogenesis, cellularization, and the least severe foreign body capsule (based on a refined assessment method). This study presents the first biomaterial with tuned mechanical properties and a precision engineered porous structure optimized for healing, thus can be ideal for pro-healing vascular grafts and in situ vascular engineering. In addition, these scaffolds may have wide applications in tissue engineering, drug delivery, and implantable device.

Nylon lattice design parameter effects on additively manufactured structural performance

Lattice structures are used in a multitude of applications from medical to aerospace, and their adoption in these applications has been further enabled by additive manufacturing. Lattice performance is governed by a multitude of variables and estimating this performance may be needed during various phases of the design and validation process. Numerical modeling and constitutive relationships are common methodologies to assess performance, address risks, lower costs, and accelerate time to market for innovative and potentially life altering products. These methods are usually accompanied by engineering rationales to justify the methods appropriateness. However, engineering analyses and numerical models should be validated using experimental data when possible to quantify the accuracy of their predictions under conditions relevant to their planned use. In this work, a set of lattice design parameters are evaluated using numerical modeling and experimental methods under quasi-static tensile, compressive, and shear modalities. Regular body centered cubic (BCC) and stochastic Voronoi Tessellation Method (VTM) lattices are constructed with three different cell lengths (2.5 mm, 4.0 mm, 5.0 mm) and various strut diameter thicknesses (ranging from 0.536 mm-1.3506 mm) while maintaining the lattice's relative density (0.2 and 0.3). Some strut diameters were selected to challenge the AM process limits. Specimens were fabricated in nylon 12 on a laser powder bed fusion system. Optical microscopy showed up to a 28.6% difference between as-designed and fabricated strut diameters. Simulated reaction loads revealed up to a 4.6% difference in BCC lattices within a constant relative density at a 1.4 mm displacement boundary condition while the VTM samples had up to a 19.5% difference. Errors between the experimental and simulated lattice reaction loads were as high as 97.0%. This error magnitude appears to strongly correlate with lattice strut diameter. These results showcase that a computational estimation, even one with reasonable assumptions, may erroneously characterize the performance of these lattice structures, and that these assumptions should be challenged by experimentally evaluating and validating critical quantities of interest.

Stalagmites in karst cave inspired construction: lotus root-type adsorbent with porous surface derived from CO2-in-water Pickering emulsion for selective and ultrafast uranium extraction

Simultaneous construction of porous and hollow adsorbent, especially from gas-in-water Pickering emulsion (PE) reactor, is vital for improving mass transfer kinetics and uptake amount. Inspired by the formation process of stalagmites in karst cave, amino and amidoxime bifunctionalized lotus root-type microsphere with porous surface (NH₂@AO-PLRMS) is prepared by the silica nanoparticles (SPs)-stabilized CO₂-in-water Pickering emulsion reactor and subsequent two-step grafting polymerization. The important roles of SPs acting as Pickering emulsifier, surface pore-forming agent, and adjusting internal lotus root structure are confirmed. Lotus root-type pores are dependent on the interface intensity and the permeability for compressed CO₂ bubbles in PE droplets. Benefitting from the lotus root-type structure and abundant affinity sites, the maximum uranium adsorption capacity of NH₂@AO-PLRMS is 1214.5 mg·g^-1 at 298 k, and an ultrafast uptake process can be achieved in the first 30 min. Both thermodynamic and kinetic studies indicate a spontaneous, entropy increased, and exothermic chemisorption process, and the synergies of amidoxime and amino groups can enhance the adsorption selectivity. Remarkably, NH₂@AO-PLRMS displays a high uranium adsorption capacity and desorption efficiency after seven cycles. These findings provide a way to obtain adsorbents with enhanced uranium extraction performance from gas-in-water PE reactor.

Adsorptive reduction of water hardness by a highly porous and regenerative geopolymer fabricated from coal fly ash waste with low-temperature calcination

In this research paper, potassium-activated geopolymer cubes (GeoC) fabricated from waste coal fly ash with low-temperature calcination were investigated as a water softening agent. The GeoC reduced water hardness contents by adsorbing calcium (Ca²⁺) and magnesium (Mg²⁺) ions from aqueous solutions. Batch experiments were conducted to investigate the adsorption performance for Ca²⁺ and Mg²⁺, including contact time, initial concentration of cations, and interference with competitive cations. The best performance for water hardness adsorption was found on GeoC-35, fabricated with the highest silicate ratio to hydroxide. The adsorption process reached equilibrium after a contact time of 6 h for Ca²⁺ and 24 h for Mg²⁺. The maximum adsorption capacity for Ca²⁺ and Mg²⁺ was 52.0 and 17.3 mg/g, respectively. Langmuir and pseudo-second-order models fitted the experimental data well, indicating that chemical reactions occurred on a homogeneous surface. The GeoC can also be reused for removing hardness. Furthermore, the increase in potassium and silicon concentration in solution varied directly with removal efficiency, suggesting that the aluminosilicate framework played a role in reducing water hardness via cationic exchange. The presence of competitive cations decreased adsorption ability, albeit it still exhibited an appreciable removal performance.

Porous loofah-sponge-like ternary heterojunction g-C3N4/Bi2WO6/MoS2 for highly efficient photocatalytic degradation of sulfamethoxazole under visible-light irradiation

A novel porous loofah-sponge-like ternary heterojunction g-C₃N₄/Bi₂WO₆/MoS₂ (CN-BM) was prepared via a facile method. The introduction of binary Bi₂WO₆/MoS₂ into g-C₃N₄ could be qualified for constructing reasonable heterostructure while regulating photocatalysts morphology. Benefiting from the unique structure, the ternary heterojunction composites not only inhibited the agglomeration but also exhibited the prominent visible-light harvest capacity and abundant active sites, which could accelerate the photogenerated carriers separation and preserve the robust redox ability. The results showed that the optimized sample (CN-BM2) displayed the excellent degradation efficiency of sulfamethoxazole (SMX) under visible-light irradiation (over 99% within 60 min), and the fitted pseudo-first-order kinetic rate constant reached to 0.089 min^-1, where it was 3.17 times than that of pure CN. Additionally, the radical scavenger experiments and electron spin resonance experiments indicated that the active species super-oxide radical and hole played a major role in the degradation experiment. The charge transfer mechanism was proposed and the main intermediates indicated that the active radicals attacked on the benzene ring and isoxazole ring in SMX, and further mineralized to inorganic molecules eventually.

Aptamer-decorated porous microneedles arrays for extraction and detection of skin interstitial fluid biomarkers

The detection of biomarkers in body fluids plays a great role in the diagnosis, treatment, and prognosis of diseases. Here, we present novel aptamer-decorated porous microneedles (MNs) arrays to realize the extraction and detection of biomarkers in skin interstitial fluid (ISF) in situ. The porous MNs arrays are fabricated by replicating the negative molds comprising glass microspheres with a UV-curable ethoxylated trimethylolpropane triacrylate (ETPTA). As the MNs arrays combine the superiorities of porous structure and aptamers, their specific surface area increased significantly to 6.694 m²/g, thus vast of stable aptamer probes with a concentration of 0.9459 μM could be immobilized. In addition, the MNs arrays could extract skin ISF into their porous structure on the basis of the capillarity principle, and subsequently capture and detect skin ISF biomarkers without sample post-process. Taking advantage of these features, we further demonstrated a highly sensitive and rapid detection of ISF endotoxin in the concentration ranges of 0.0342 EU/mL to 8.2082 EU/mL from rats model injected with endotoxin via tail vein by using such aptamer-decorated porous MNs arrays, with the limit of detection (LOD) of 0.0064 EU/mL. These results indicated that the aptamer-decorated porous MNs arrays possess great potential for non-invasive extraction and detection of biomarkers in clinical applications.

Make it clean, make it safe: A review on virus elimination via adsorption

Recently, the potential dangers of viral infection transmission through water and air have become the focus of worldwide attention, via the spread of COVID-19 pandemic. The occurrence of large-scale outbreaks of dangerous infections caused by unknown pathogens and the isolation of new pandemic strains require the development of improved methods of viruses' inactivation. Viruses are not stable self-sustaining living organisms and are rapidly inactivated on isolated surfaces. However, water resources and air can participate in the pathogens' diffusion, stabilization, and transmission. Viruses inactivation and elimination by adsorption are relevant since they can represent an effective and low-cost method to treat fluids, and hence limit the spread of pathogen agents. This review analyzed the interaction between viruses and carbon-based, oxide-based, porous materials and biological materials (e.g., sulfated polysaccharides and cyclodextrins). It will be shown that these adsorbents can play a relevant role in the viruses removal where water and air purification mostly occurring via electrostatic interactions. However, a clear systematic vision of the correlation between the surface potential and the adsorption capacity of the different filters is still lacking and should be provided to achieve a better comprehension of the global phenomenon. The rationalization of the adsorption capacity may be achieved through a proper physico-chemical characterization of new adsorbents, including molecular modeling and simulations, also considering the adsorption of virus-like particles on their surface. As a most timely perspective, the results on this review present potential solutions to investigate coronaviruses and specifically SARS-CoV-2, responsible of the COVID-19 pandemic, whose spread can be limited by the efficient disinfection and purification of closed-spaces air and urban waters.

Chemically assembling chromium vanadate into an urchin-like porous rich matrix with ultrathin nanosheets for rapid Zn2+ storage

Aqueous zinc ion battery (AZIB) is a promising battery system developed in recent years, which has the advantages of safety, environmental protection and low price. However, it is still a puzzle to develop and improve cathode materials with satisfactory performance. In this paper, the chromium vanadate (CrVO₃) electrode material was reported for the first time. The obtained CrVO₃ have mesoporous structure (the mesopore sizes: 2-50 nm), excellent conductivity, high surface area (129.3 m² g^-1) and uniform thickness of 2 nm, which provides a short path for rapid transfer of zinc ions, a large surface area for high pseudocapacitance, and sufficient voids to mitigate volume expansion. Given these structural advantages, the CrVO₃ cathode delivers high capacities of 188.8 and 112.8 mAh g^-1 at 0.5 and 4 A g^-1 and excellent long cycle stability, respectively. More importantly, the Zn//CrVO₃ battery provided an energy density of 231.9 Wh kg^-1 at a power density of 100.4 W kg^-1. Meanwhile, insight into the formation mechanism and Zn²⁺ storage mechanism by ex situ methods. The results show that the porous CrVO₃ is a promising cathode material for AZIBs, which provide a valuable idea for the design of porous vanadate with significantly enhanced performances in electrochemical energy storage.

Evaporation and in-situ gelation induced porous hybrid film without template enhancing the performance of lithium ion battery separator

The current commercialized polyethylene (PE) separator has poor wettability and thermal stability which will seriously restrict the electrochemical performance and affect the safety of lithium ion battery. Herein, a porous hybrid layer coated separator with high thermal stability, good electrochemical performance and improved wettability was prepared by a template-free method via the synergistic effect between tetraethoxysilane (TEOS) and aramid nano fibers (ANFs) during the evaporation of solvent and the in-situ gelation of TEOS. The results show that the porous hybrid coating layers can enhance the thermal stability, wettability and electrolyte uptake of the separators. Moreover, the lithium ion transference number is also increased. As a result, the battery assembled with the composite separator exhibits enhanced electrochemical performance in terms of cycle stability and rate performance. When coupled with LiCoO₂cathode, the capacity retention rate is as high as 96.0% after 100 cycles at 0.2C.

Current interpretations on the in vivo response of bone to additively manufactured metallic porous scaffolds: A review

Recent advances in the field of metallic additive manufacturing have expanded production capabilities for bone implants to include porous lattice structures. While traditional models of de novo bone formation can be applied to fully dense implant materials, their applicability to the interior of porous materials has not been well-characterized. Unlike other reviews that focus on materials and mechanical properties of lattice structures, this review compiles biological performance from in vivo studies in pre-clinical models only. First, we introduce the most common lattice geometry designs employed in vivo and discuss some of their fabrication advantages and limitations. Then lattice geometry is correlated to quantitative (histomorphometric) and qualitative (histological) assessments of osseointegration. We group studies according to two common implant variables: pore size and percent porosity, and explore the extent of osseointegration using common measures, including bone-implant contact (BIC), bone area (BA), bone volume/total volume (BV/TV) and biomechanical stability, for various animal models and implantation times. Based on this, trends related to in vivo bone formation on the interior of lattice structures are presented. Common challenges with lattice structures are highlighted, including nonuniformity of bone growth through the entirety of the lattice structure due to occlusion effects and avascularity. This review paper identifies a lack of systematic in vivo studies on porous AM implants to target optimum geometric design, including pore shape, size, and percent porosity in controlled animal models and critical-sized defects. Further work focusing on surface modification strategies and systematic geometric studies to homogenize in vivo bone growth through the scaffold interior are recommended to increase implant stability in the early stages of osseointegration.

3D Taraxacum-like porous Pd nanocages with Bi doping: High-performance non-Pt electrocatalysts for ethanol oxidation reaction

Modifying the electronic structure and optimizing the geometric structure can expeditiously tune the electrocatalytic properties of catalysts, resulting in considerably enhanced electrocatalytic performance towards electrocatalytic oxidation of liquid fuels. We herein report a simple synthetic strategy to prepare Bi-doped 3D taraxacum-like Pd nanocages (NCs) composed of porous nanosheets, which possess high surface areas and strong synergistic effects. Notably, a trace of Bi diffuses into the lattice of Pd and increases the electronic effects of the surface of Pd, endowing PdBi-0.5 NCs/C with superior electrocatalytic performance towards ethanol oxidation reaction (EOR). The mass activity and specific activity of PdBi-0.5 NCs/C were 3494.8 mA mg_Pd^-1 and 10.37 mA cm^-2, being 4.08- and 4.82- fold enhancements as compared with commercial Pd/C, respectively. Moreover, the highly open porous 3D nanocages structure with rich active sites and defects can also facilitate the mass/electron transfer to favor the EOR kinetics.

Photocatalytic degradation of methyl orange using pullulan-mediated porous zinc oxide microflowers

One of mankind's biggest concerns is water pollution. Textile industry emerged as one of the main contributors with dyes as the main pollutant. Presence of dyes in water is very dangerous due to their toxicity; thus, it is important to remove them from water. In these recent years, heterogeneous advance oxidation process surfaced as a possible dyes' removal technique. This process utilizes semiconductor as photocatalyst to degrade the dyes in presence of light and zinc oxide (ZnO) appears to be a promising photocatalyst for this process. In this study, pullulan, a biopolymer, was used to produce porous ZnO microflowers (ZnO-MFs) through green synthesis via precipitation method. The effects of pullulan's amount on the properties of ZnO-MFs were investigated. The ZnO-MF particle size decreased with the increased of pullulan amount. Interestingly, formation of pores occurred in presence of pullulan. The synthesized ZnO-MFs have the surface area ranging from 6.22 to 25.65 m² g^-1 and pore volume up to 0.1123 cm³ g^-1. The ZnO-MF with the highest surface area was chosen for photocatalytic degradation of methyl orange (MO). The highest degradation occurred in 300 min with 150 mg catalyst dosage, 10 ppm initial dye concentration, and pH 7 experimental conditions. However, through comparison of photodegradation of MO with all synthesized ZnO-MFs, 25PZ exhibited the highest degradation rate. This shows that photocatalytic activity is not dependent on surface area alone. Based on these results, ZnO-MF has the potential to be applied in wastewater treatment. However, further improvement is needed to increase its photocatalytic activity.

Pseudocapacitance multiporous vanadyl phosphate/graphene thin film electrode for high performance electrochemical capacitors

Supercapacitors are being considered as promising electricity storage devices with green sustainable energy conversion. To efficiently develop and optimize pseudocapacitive material of vanadyl phosphate, herein, multiporous vanadyl phosphate/graphene (denoted as MP-VOPO₄@rGO) is fabricated for the first time with phytic acid as a phosphorus source by extremely simple sol-gel and drop coating methods, and used as the free binder thin film electrode of supercapacitors. The smart combination of honeycomb-like architecture and graphene incorporation results in more active sites and low internal resistance, significantly improving energy storage performance. The effect of introducting polystyrene (denoted as PS) template and rGO on the performance of the nanocomposite is systematically analyzed by comparing the performance of the corresponding thin film electrodes. The MP-VOPO₄@rGO thin film electrode delivers superior pseudocapacitive performance of 672 F g^-1 at 1 A g^-1 as well as a remarkable rate capability of 552 F g^-1 at 5 A g^-1, and it presents a remarkable longterm cycling stability, with a capacitance retention of 83.5% after 5000 cycles. Very interestingly, the results of surface capacitance contribution dominance clearly demonstrates its rapid capacitive response. In addition, based on MP-VOPO₄@rGO thin film as positive and negative electrodes, the corresponding assembled symmetric supercapacitors exihibits outstanding energy density of 26.3 Wh kg^-1 at power density of 249.9 W kg^-1. This investigation can not only provide a versatile strategy to design other thin film electrode materials but also open up a new insight into the development of polyanion phosphate composites for next-generation high performance energy storage systems.

Pulmonary toxicity of synthetic amorphous silica - effects of porosity and copper oxide doping

Materials can be modified for improved functionality. Our aim was to test whether pulmonary toxicity of silica nanomaterials is increased by the introduction of: a) porosity; and b) surface doping with CuO; and whether c) these modifications act synergistically. Mice were exposed by intratracheal instillation and for some doses also oropharyngeal aspiration to: 1) solid silica 100 nm; 2) porous silica 100 nm; 3) porous silica 100 nm with CuO doping; 4) solid silica 300 nm; 5) porous silica 300 nm; 6) solid silica 300 nm with CuO doping; 7) porous silica 300 nm with CuO doping; 8) CuO nanoparticles 9.8 nm; or 9) carbon black Printex 90 as benchmark. Based on a pilot study, dose levels were between 0.5 and 162 µg/mouse (0.2 and 8.1 mg/kg bw). Endpoints included pulmonary inflammation (neutrophil numbers in bronchoalveolar fluid), acute phase response, histopathology, and genotoxicity assessed by the comet assay, micronucleus test, and the gamma-H2AX assay. The porous silica materials induced greater pulmonary inflammation than their solid counterparts. A similar pattern was seen for acute phase response induction and histologic changes. This could be explained by a higher specific surface area per mass unit for the most toxic particles. CuO doping further increased the acute phase response normalized according to the deposited surface area. We identified no consistent evidence of synergism between surface area and CuO doping. In conclusion, porosity and CuO doping each increased the toxicity of silica nanomaterials and there was no indication of synergy when the modifications co-occurred.

Fabrication of polylactic acid (PLA)-based porous scaffold through the combination of traditional bio-fabrication and 3D printing technology for bone regeneration

Artificial bone grafts possess the advantages of good biodegradability, customizable dimensions, and sufficient mechanical properties, which can promote cell proliferation and differentiation in bone tissue regeneration. 3D printing is a delicate approach that endows the scaffolds with excellent controllability and repeatability when compared with conventional bio-fabrication methods. However, the limitation of printing resolution somehow makes it difficult to prepare bone defect substitution with high porosity and hierarchical construct. In this study, we utilized polylactic acid (PLA) as printing materials and developed a smart strategy to combine 3D printing technology with bio-fabrication methods. A porous planar scaffold was printed and then rolled up into a spiral structure with adjustable pore size and porosity. The topographic features and morphology of the artificial scaffolds were examined through stereomicroscope and SEM, respectively. The porous spiral scaffold presented good mechanical properties in a set of mechanical testing. Later, the human fetal osteoblasts (hFOB) were cultured on the porous spiral scaffold and its control groups for a total of 28 days. The MTS analysis, alkaline phosphatase (ALP) assay, and alizarin red S (ARS) staining were used to analyze the cell proliferation, osteogenic differentiation, and mineral deposition after a certain period of time. The results indicated that compared with the other two scaffolds, the porous spiral scaffold with larger surface area and better interconnections between internal porous networks could significantly improve the spatial cell compartment and promote cell growth and differentiation. The porous spiral scaffold may see versatile applications in large-volume bone defects regeneration.

An open-source handheld extruder loaded with pore-forming bioink for in situ wound dressing

The increasing demand in rapid wound dressing and healing has promoted the development of intraoperative strategies, such as intraoperative bioprinting, which allows deposition of bioinks directly at the injury sites to conform to their specific shapes and structures. Although successes have been achieved to varying degrees, either the instrumentation remains complex and high-cost or the bioink is insufficient for desired cellular activities. Here, we report the development of a cost-effective, open-source handheld bioprinter featuring an ergonomic design, which was entirely portable powered by a battery pack. We further integrated an aqueous two-phase emulsion bioink based on gelatin methacryloyl with the handheld system, enabling convenient shape-controlled in situ bioprinting. The unique pore-forming property of the emulsion bioink facilitated liquid and oxygen transport as well as cellular proliferation and spreading, with an additional ability of good elasticity to withstand repeated mechanical compressions. These advantages of our pore-forming bioink-loaded handheld bioprinter are believed to pave a new avenue for effective wound dressing potentially in a personalized manner down the future.

Short-term outcomes and complications of 65 cases of porous TTA with flange: a prospective clinical study in dogs

Background

Cranial cruciate ligament rupture (CrCLR) is the most common orthopaedic cause of lameness in the hind limb in dogs. Many surgical treatments have been described, but tibial tuberosity advancement (TTA) is one of the most commonly used today. Since it was first described, TTA has evolved to reduce major complications and to arrest the progression of osteoarthrosis. The aim of this study was to assess a surgical technique called Porous TTA with flange prospectively. This study was performed in 61 dogs that underwent 65 Porous TTA with flange procedures, to validate it as an alternative CrCLR treatment. Complications and clinical outcomes (pain, lameness, weight bearing, flexion, extension, crepitation and atrophy) were reported over 3 months, i.e. at 3, 6 and 12 weeks postoperatively.

Results

The results showed a positive clinical outcome, a minor complication rate of 47.69% at the first review 3 weeks postoperatively, 10.77% at the second one (6 weeks after the surgery) and 4% at the third one (at 12 weeks). Major complications were observed only at the last review, with one case that had an infection requiring implant removal; this represented 1.5% of cases. Variables evaluated for a relationship with complication scores and improvement were body condition score, sex, age, breed, body weight, breed size, side of the affected limb, traumatic anamnesis and time of lameness before surgery. No relationship was detected.

Conclusions

Clinical outcomes and complications show that Porous TTA with flange is an efficient alternative for surgical treatment of CrCLR in dogs.

Functionalised calcium carbonate as a coformer to stabilize amorphous drugs by mechanochemical activation

The aim of this study was to investigate the amorphization, physical stability and drug release of a model drug, carvedilol (CAR), when loaded onto functionalised calcium carbonate (FCC) using mechanochemical activation (vibrational ball milling). The solid-state characteristics and physical stability of CAR-FCC samples, prepared at different weight ratios and for different milling times, were determined using differential scanning calorimetry and X-ray powder diffraction. Upon milling CAR-FCC samples containing 50% CAR, amorphization of CAR was observed after 10 min. For CAR-FCC samples milled for either 30 or 90 min, it was found that CAR was amorphised at all ratios (10-90% CAR), but FCC remained crystalline. The glass transition temperature (T_gα) of the various CAR-FCC samples milled for 90 min was found to be similar (38 °C) for all ratios containing 20% CAR and above. The similar T_gαs for the different drug ratios indicate deposition of amorphous CAR onto the surface of FCC. For CAR-FCC samples containing 10% CAR, a T_gα of 49 °C was found, which is 11 °C higher compared with other CAR-FCC samples. This may indicate restricted molecular mobility resulting from CAR molecules that are in close contact with the FCC surface. The physical stability, under both stress (100 °C) and non-stress conditions (25 °C at dry conditions), showed that drug concentrations up to 30% CAR can be stabilized in the amorphous form for at least 19 weeks under non-stress conditions when deposited onto FCC, compared to less than a week physical stability of neat amorphous CAR. In vitro drug release showed that CAR-FCC samples containing 60% CAR and below can improve the drug release and generate supersaturated systems compared to neat amorphous and crystalline CAR. Samples with lower drug concentrations (40% CAR and below) can maintain supersaturation during 360 min of dissolution testing. This study indicates that the crystalline inorganic material, FCC, can facilitate amorphization of drugs, provide stabilization against drug crystallization, and improve dissolution properties of amorphous drugs upon mechanochemical activation.

Application of FTIR-ATR spectroscopy to confirm the microwave assisted synthesis and curing of Cashew nut shell liquid derived nanostructured materials

The present work reports the development of nanostructured material from Cashew nut shell liquid (CNSL, an agro byproduct of cashew industry, 87% cardanol) to evaluate their potential in antibacterial applications as a substitute of petroleum feedstock via an energy-efficient method. The nanostructured material was synthesized by coordination polymerization reaction of cardanol and divalent Mn(II) salt with the aid of microwave irradiations. FTIR spectroscopy was used to confirm the proposed structure of the synthesized materials. FTIR-ATR spectroscopy was employed to verify the curing of material by comparing the spectra of the cured samples with the frequencies of uncured samples. Magnetic moment and UV-visible spectroscopy were used to confirm the proposed structure of the material further. Morphology of the synthesized material was investigated by XRD, optical microscopy, SEM and TEM and thermal behaviour by TGA/DTG/DSC technique. Agar diffusion method was utilized to investigate the antibacterial activity of the synthesized material against bacterial strains E. coli, K. pneumoniae, B. subtilis and S. aureus. N₂ adsorption-desorption was investigated to check BET specific surface area and BJH pore size distribution of the same. The results revealed that the synthesized materials were obtained as semicrystalline, porous, thermally stable and nanostructured film forming materials with moderate to good antibacterial activity against different nosocomial bacteria. They can be used as thermally stable antibacterial agents in the field of films/coatings for health care applications.

Interfacial separation of concentrated dye mixtures from solution with environmentally compatible nitrogenous-silane nanoparticles modified with Helianthus annuus husk extract

The capacity of an adsorbent to bind and remove dye from solution greatly depends on the type of functionalization present on the nanoparticles surface, and its interaction with the dye molecules. Within this study, nitrogenous silane nanoparticles were hydrothermally synthesized resulting in the formation of rapid and highly efficient adsorbents for concentrated mixed dyes. The amorphous silane nanoparticles exhibited a monolayer based mechanism of mixed dye adsorption with removal capacities between 416.67 and 714.29 mg/g of adsorbent. Dye removal was predominantly due to the electrostatic attraction between the positively charged silane nanoparticles (13.22-8.20 mV) and the negatively charged dye molecules (-54.23 mV). Addition of H. annuus extract during synthesis resulted in three times the surface area and 10 times increased pore volume compared to the positive control. XPS analysis showed that silane treatments had various nitrogen containing functionalities at their surface responsible for binding dye. The weak colloidal stability of silane particles (13.22-8.20 mV) was disrupted following dye binding, resulting in their rapid coagulation and flocculation which facilitated the separation of bound dye molecules from solution. The suitability for environmental applications using these treatments was supported by a bacterial viability assay showing >90% cell viability in treated dye supernatants.

Porous antimicrobial starch particles containing N-halamine functional groups

The porous antimicrobial starch particles containing N-Halamine functional groups (PST-MBA-Cl particles) were synthesized by a crosslinking polymerization between starch (ST) and N, N'-methylenebisacrylamide (MBA), and then a chlorination of amide groups of MBA. The synthetic process used only water as the solvent and was environmentally friendly. The results showed that under the optimal preparation conditions, the as-synthesized PST-MBA-Cl particles could have a Cl⁺% of 8.60 %. Antimicrobial tests showed that PST-MBA-Cl particles had very powerful antimicrobial efficacy against both Staphylococcus aureus and Escherichia coli and could completely kill Staphylococcus aureus with a concentration of 2.1 × 10⁶ CFU/mL and Escherichia coli with a concentration of 5.6 × 10⁶ CFU/mL within a contact time of one minute. Furthermore, the N-Halamine functional groups of PST-MBA-Cl particles also showed excellent stability under storage and reproducibility. Therefore, the as-synthesized PST-MBA-Cl particles will have potential applications in water disinfection.

Hierarchical Porous RGO/PEDOT/PANI Hybrid for Planar/Linear Supercapacitor with Outstanding Flexibility and Stability

Many hybrid electrodes for supercapacitors (SCs) are a reckless combination without proper structural design that keeps them from fulfilling their potential. Herein, we design a reduced graphene oxide/poly(3,4-ethylenedioxythiophene)/polyaniline (RGO/PEDOT/PANI) hybrid with hierarchical and porous structure for high-performance SCs, where components fully harness their advantages, forming an interconnected and conductive framework with substantial reactive sites.Thus, this hybrid achieves a high capacitance of 535 F g-1 along with good rate capability and cyclability. The planar SC based on this hybrid deliver an energy density of 26.89 Wh kg-1 at a power density of 800 W kg-1. The linear SC developed via modifying a cotton yarn with the hybrid exhibits good flexibility and structural stability, which operates normally after arbitrary deformations. This work provides a beneficial reference for developing SCs.

Porous β-Mo2C nanoparticle clusters supported on walnut shell powders derived carbon matrix for hydrogen evolution reaction

Herein, we choose the waste walnut shell as the carbon source, and ammonium heptamolybdate as the molybdenum source to prepare the β-Mo₂C catalyst supported on carbon matrix (Mo₂C@C) by the calcination method for hydrogen evolution reaction (HER). The open pores in the porous Mo₂C nanoparticle clusters can facilitate electrolyte permeation and hydrogen molecules release as well as the carbon matrix can enhance the conductivity. As a result, the optimal Mo₂C exhibits an efficient HER performance, with an overpotential of 140 mV at 10 mA cm^-2 and a Tafel slope of 63 mV dec^-1 as well as excellent electrochemical stability. The strategy changing waste walnut shell into the effective catalysts sets an example for the searching and designing rational energy materials.

Self-standing hollow porous AuPt nanospheres and their enhanced electrocatalytic performance

In this paper, we present a template method to fabricate AuPt hollow nanospheres by depositing Au inner layer and dendritic Pt outer layer onto PS template. The as-prepared AuPt hollow nanospheres can form self-standing hollow nanostructures under thermal treatment which is confirmed by small-angle X-ray scattering results. We believe that the self-standing structural features of them result from different thermal stability of Au and Pt elements. The small-angle X-ray diffraction measurements and X-ray photoelectron spectroscopy of binding energies certify the existing interaction between Au and Pt. It is suggested that Pt mole contents of AuPt hollow nanospheres can be varied by changing H₂PtCl₄ concentration during chemical deposition process. The methanol electrochemical oxidation reaction indicates these as-prepared AuPt hollow nanospheres possessing excellent potential applications on catalysts. Moreover, synthesis of multilayer hollow porous nanospheres such as Pt@Au@Pt proves that our method greatly enriches the species of the self-standing, hollow and porous functional nanomaterials.

Preparation and Characterization of AMT/Co(acac)3-Loaded PAN/PS Micro-Nanofibers with Large through-Pores

This study focused on the fabrication and characterization of ammonium metatungstate hydrate (AMT) combined with cobalt(III) acetylacetonate (Co(acac)₃)-loaded electrospun micro-nanofibers. The morphologies, structures, element distribution, through-pore size, and through-pore size distribution of AMT/Co(acac)₃-loaded PAN/PS micro-nanofibers were investigated by a combination of field emission scanning electron microscopy (FESEM), flourier transformation infrared (FTIR) spectroscopy, energy disperse spectroscopy (EDS), through-pore size analyzer, and so on. These micro-nanofibers have many advantages in their potential application as electro-catalysts. The porous and large thorough-pore will benefit for effective electrolyte penetration, in addition to promoting gas bubbles evolving and releasing from catalyst surface timely.