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BACKGROUND: Due to the sudden release and the rapid removal by proteases, platelet-rich plasma hydrogel leads to shorter residence times of growth factors at the wound site. In recent years, researchers have focused on the use of hydrogels to encapsulate platelet-rich plasma in order to improve the deficiency of platelet-rich plasma hydrogels. OBJECTIVE: To prepare self-assembled polypeptide-platelet-rich plasma hydrogel and to explore its effects on the release of bioactive factors of platelet-rich plasma. METHODS: The self-assembled polypeptide was synthesized by the solid-phase synthesis method, and the solution was prepared by D-PBS. Hydrogels were prepared by mixing different volumes of polypeptide solutions with platelet-rich plasma and calcium chloride/thrombin solutions, so that the final mass fraction of polypeptides in the system was 0.1%, 0.3%, and 0.5%, respectively. The hydrogel state was observed, and the release of growth factors in platelet-rich plasma was detected in vitro. The polypeptide self-assembly was stimulated by mixing 1% polypeptide solution with 1% human serum albumin solution, so that the final mass fraction of the polypeptide was 0.1%, 0.3%, and 0.5%, respectively. The flow state of the liquid was observed, and the rheological mechanical properties of the self-assembled polypeptide were tested. The microstructure of polypeptide (mass fraction of 0.1% and 0.001%) -human serum albumin solution was observed by scanning electron microscope and transmission electron microscope. RESULTS AND CONCLUSION: (1) Hydrogels could be formed between different volumes of polypeptide solution and platelet-rich plasma. Compared with platelet-rich plasma hydrogels, 0.1% and 0.3% polypeptide-platelet-rich plasma hydrogels could alleviate the sudden release of epidermal growth factor and vascular endothelial growth factor, and extend the release time to 48 hours. (2) After the addition of human serum albumin, the 0.1% polypeptide group still exhibited a flowing liquid, the 0.3% polypeptide group was semi-liquid, and the 0.5% polypeptide group stimulated self-assembly to form hydrogel. It was determined that human serum albumin in platelet-rich plasma could stimulate the self-assembly of polypeptides. With the increase of the mass fraction of the polypeptide, the higher the storage modulus of the self-assembled polypeptide, the easier it was to form glue. (3) Transmission electron microscopy exhibited that the polypeptide nanofibers were short and disordered before the addition of human serum albumin. After the addition of human serum albumin, the polypeptide nanofibers became significantly longer and cross-linked into bundles, forming a dense fiber network structure. Under a scanning electron microscope, the polypeptides displayed a disordered lamellar structure before adding human serum albumin. After the addition of human serum albumin, the polypeptides self-assembled into cross-linked and densely arranged porous structures. (4) In conclusion, the novel polypeptide can self-assemble triggered by platelet-rich plasma and the self-assembly effect can be accurately adjusted according to the ratio of human serum albumin to polypeptide. This polypeptide has a sustained release effect on the growth factors of platelet-rich plasma, which can be used as a new biomaterial for tissue repair. [ABSTRACT FROM AUTHOR]

Purpose: Advances in the design and manufacturing of novel synthetic bioactive scaffolds as bone substitute in bone reconstruction are at the forefront of orthopedic study due to their excellent biological performances. However, fabricating bioactive scaffolds with similar osteogenic and mechanical properties of a natural bone still remains a challenge. Our aim was to produce functional bioactive scaffolds with biologically interactive ions, microstructure for cell proliferation and a suitable biodegradation rate in critical-size bone defect. Methods: A homogenous strontium-doped calcium silicate (Sr-CaSi) bioactive granule with interconnected porous network was fabricated. Critical-size bone defect (Ø ~6.5 × 8.5 mm) was created at the distal femur of New Zealand rabbit and the animals were divided into two groups (blank group and implanted/Sr-CaSi group). The blank had no granules while the implanted group was grafted with Sr-CaSi granules at the defect. Bone repair was assed using investigations of micro-CT, 3D argumentation and histological evaluations. Results: The Sr-CaSi group had complete bone healing and reconstruction. The granule showed physiochemical tolerance and was able to biodegrade enhancing the formation of new bone matrix and remodeling. However, the blank group had limited proliferation and osteogenic differentiation of new bone tissue, hence there was retarded ingrowth of new bone tissues. Conclusion: The Sr-CaSi group saw excellent bone mineralization due to biostimulation effect of the bioceramic granules. The extensive stimulation and osteogenic factors in bone healing by the novel Sr-CaSi shows it is indispensable in bone tissue engineering and regenerative medicine. [ABSTRACT FROM AUTHOR]

This paper addresses the numerical characterization of microstructures by the concept of tortuosity. After a brief review of geometric tortuosities, some definitions are considered for a benchmarking analysis. The focus is on the M-tortuosity definition, which is revised by expliciting the link to percolation theory, among other things. This operator fits with the analysis of real samples of materials whatever their complexity. A contribution of this paper is a new formulation of the M-tortuosity, making it generic to many situations. Additionally, the comparison of the various tortuosimetric descriptors, state-of-the-art definitions and M-tortuosity, is proposed by considering several scenarios thanks to stochastic multi-scale models of complex materials. The relationships with porosity, morphological heterogeneity and structural anisotropy are investigated. The results highlight the similarities and differences between the descriptors while attesting that the M-tortuosity is equivalent to the state-of-the-art definitions, for a potential use in diffusion and conductivity analyses. Moreover, the M-tortuosity handles correctly situations where state-of the-art algorithms fail. The anisotropic case highlights some limitations of the state-of-the-art definitions behaving differently according to the given propagation direction. In the case of unknown propagation and irregular piece of materials, the M-tortuosity provides a unique tortuosity value representative of the whole microstructure while detecting the anisotropy. These operators are freely available within the plug im! platform.

[Display omitted] • Exploring the unique properties and potential of Metal-Organic Frameworks (MOFs) as oxygen delivery systems. • Combining simulation and experimental approaches to design and evaluate MOFs as delivery systems for oxygen gas. • Discuss the benefits, challenges, and future directions of MOFs as an oxygen carrier in the medical field. Oxygen delivery systems are crucial in critical care medicine, particularly for managing acute respiratory distress. This study presents a novel approach, exploring the potential of Metal-Organic Frameworks (MOFs) as oxygen delivery systems. We highlight their unique properties and potential for enhancing oxygenation in medical settings. Understanding their biocompatibility, oxygen-carrying capacity, and controlled release mechanisms is pivotal for successful implementation in clinical practice. Thanks to their exceptional porosity, structural diversity, lower crystal density, and tunability, MOFs offer a fresh perspective on developing innovative oxygen carriers. We propose that MOFs will demonstrate biocompatibility, stability, and the ability to deliver oxygen in a controlled and sustained manner when administered intravenously in living organisms. Gas adsorption and molecular simulation techniques will demonstrate reversible oxygen binding within MOFs and predict controlled release kinetics. The findings of the simulations and experiments should indicate the feasibility of utilising MOFs as intravenous oxygen carriers with controlled and reversible oxygen release behaviour. [ABSTRACT FROM AUTHOR]

The venation-finned porous network has been demonstrated as a promising method to maximize the thermal transport access. To improve the heat storage efficiency, an innovative venation-finned porous network is employed here to enhance the melting performance of phase change materials (PCMs). The venation-finned porous network is quantitatively described by Murray's law and Voronoi method, and a modified thermal lattice Boltzmann model of PCM melting processes in a square cavity is developed and numerically analyzed to optimize the venation-finned porous network. The melting performance of composite PCMs with three configurations (venation fin, porous network and venation-finned porous network) are compared and analyzed. Moreover, the effects of branching angle and Murray coefficient on melting performance are comprehensively studied. It indicates that venation-finned porous network is favorable to melting performance improvement due to venation's inherent efficient heat transfer paths. Compared to venation fins and porous networks, the melting duration time of venation-finned porous networks is reduced by 78.4% and 21.4%, respectively. Furthermore, the branching angle of 45 ∘ and Murray coefficient of 3 are suggested for maximizing the melting efficiency. Importantly, the melting mechanism is conduction and convective conjugated heat transfer in composite PCMs with venation fins, however, it is dominated by heat conduction for those with porous networks or venation-finned porous networks. [ABSTRACT FROM AUTHOR]

By introducing functional groups such as quaternary amine groups, sulfonic acid groups, triazine groups, and other mespore nanomaterials into the hydrogel, better separation effect of some organic framework materials has been obtained. Due to a reasonable design and preparation strategy, the hydrogel composite-modified silica can be used in the selective separation of various analytes such as pesticides, alkylbenzenes, polycyclic aromatic hydrocarbons, nucleosides/bases, benzoic acids, antibiotics, and carbohydrates. Through the exploration of chromatographic retention behavior, it is proved that the column can be used in mixed-mode liquid chromatography. The intra-day relative standard deviation for retention time of this new stationary phase is 0.12–0.16% (n = 10), and the inter-day relative standard deviation is less than 0.39% (n = 5). This new stationary phase can also be used for separation in complex samples. The limit of detection (LOD) for chlorotoluron in farm irrigation water is 0.21 µg/L and the linear range is 2–250 µg/L. After optimizing the chromatographic conditions, the highest efficiency of the hydrogel column in RPLC and HILIC modes has reached 32,400 plates/m (chlorobenzuron) and 41,300 plates/m (galactose). This new type of hydrogel composite is a porous network material with flexible functional design and simple preparation method and its application has been expanded in liquid chromatography separation successfully. The hydrogel composed of triallyl cyanate cross-linking agent and 3-(2-(methacryloyloxy) ethyl) dimethylamine) propane-1-sulfonate (SBMA) monomer which were co-modified on the surface of mesoporous silica with MOF-919 for separation in mixed-mode liquid chromatography. [ABSTRACT FROM AUTHOR]

• Slower stress drop during faulting in granite rock specimen at higher temperature. • Healing of fractures due to sintered submicrometer feldspar fragments. • Healing in feldspars suppresses dynamic rock failures. • Healing in feldspars and porosity in quartz constructs the porous media framework. Earthquakes induced during the construction of fracture reservoirs in granitoids are an important issue for the development of ultra-high-enthalpy geothermal systems. We performed axial compression experiments on granite specimens under hydrothermal conditions to evaluate this potential, simulating Quaternary granitoids at approximately 4 km depth. Our experiments were primarily conducted under a confining pressure, pore pressure, and loading velocity of 104 MPa, 39 MPa, and 0.1 μm/s, respectively, and we varied the temperature from 400 °C to 750 °C. Although failures occurred in all specimens, we observed several temperature-dependent deformation parameters. Both the apparent Young's modulus in the elastic deformation stage and the peak stress decreased with increasing temperature. Furthermore, the stress drop during failure after attaining the peak stress was slower at higher temperatures, taking almost 5 times longer at 650 °C and 750 °C than at 400 °C. We found that the fracture patterns evolved from localized to distributed and then to dissipated with increasing temperature. Well-developed fractures in quartz grains were observed at the thin-section scale, whereas fractures in feldspar grains seemed to be inconspicuous. However, SEM observations revealed that feldspar grains had actually been more fragmented, and that submicrometer feldspar particles formed within the fault gouge zone. Additionally, those feldspar fragments were sintered at temperatures above 550 °C. Sintering enhanced fracture healing during faulting, explaining the slower observed stress drop at higher temperatures and possible leading to the suppression of dynamic rupture propagations (induced earthquakes). In contrast, sintering of quartz particles in the gouge did not occur at temperatures below 750 °C, allowing for the preservation of the porous network necessary for geothermal reservoirs. [ABSTRACT FROM AUTHOR]

Polyoxometalates (POM) have a wide range of applications in electrochemistry, catalysis, and energy storage due to their variable structure and nature. Here, we designed a novel 3D porous network of ultrathin V 6 O 13 -POM nanosheets on carbon cloth (V 6 O 13 -POM//CC) for the first time by one-pot hydrothermal method with the help of phosphotungstic acid. Serving as inorganic ligands, the anions of phosphotungstic acid coordinate with V cations, facilitating the assembly of nanoclusters and guiding to control of the morphology of V 6 O 13 -POM composites, which increases the specific surface area and multiple active sites for the reaction of lithium ions batteries (LIBs). Furthermore, the synergistic effect of V 6 O 13 and POM improves the stability of the structure and increases the capacity of the electrode in LIBs. V 6 O 13 -POM//CC as an anode material exhibited a high reversible capacity of 2.03 mAh cm-2 at a high current density of 2 mA cm-2 after 120 cycles. To illustrate the generality of the synthesis strategy, we also obtained MoO 3 -POM//CC via a similar method. By using V 6 O 13 -POM//CC and MoO 3 -POM//CC as the anode materials, LIBs exhibited high reversible areal specific capacity and excellent cycling stability which are expected to achieve commercial applications. • Porous network of ultrathin V 6 O 13 -POM nanosheets were synthesized on CC in one step. • The anions of H 3 O 40 PW 12 ·xH 2 O coordinated with the V cations control the morphology. • The synergistic effect of V 6 O 13 and POM improves the stability and capacity of LIBs. • TMO-POM//CC is expected to be the electrode material for future ultra-flexible LIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • We developed a highly efficient oil absorbent with open dodecahedral high porous connectivity in PU hierarchical structure. • Presence of 2D nanoflakes on the pore wall of pristine sponge creates a rough surface and interface contact area that enhances capillary suction of oil into the system, allowing it to absorb oil more than 37 times of its original mass. • The system can be used multiple times without deteriorating its inherent properties. • The system has been implemented in a device for large-scale technological applications. Development of absorbent material for oil and organic solvents is critical for removing contaminants from the water surface. Advancement of an oil absorber with a significant contribution for structural parameters of porous configuration of materials is highly coveted in order to ensure crude oil supply for future generations. In this study, we demonstrate structural parameters of the pores of surface modified two-dimensional (2D) CuSe nanoflakes engineered polyurethane (PU) sponge, with combination of synergistic low surface energy and surface roughness, playing an important role in the efficient removal of oil from water. Due to large surface of porous sponge and two dimensional nanoflakes along with their interface, the system showed an efficient crude oil uptake capacity of more than 37 times of its original mass. Furthermore, the developed system can be recycled and reused 50 times while maintaining high crude oil absorption efficiency, and even after 50 cycles, the system has retained good recycling absorption capacity, indicating the brilliance of the system. In addition, the system has promising implications as a favorable absorbent for crude oil–water separation due to its quick absorption (1.5 s) and high separation efficiency (96%). The selective absorption efficiency, quick oil-absorption rate, large amount of oil separation with high efficiency under one platform, has been implemented in a device for technological application in large scale. [ABSTRACT FROM AUTHOR]

This paper addresses the descriptors-based characterization of dense 3D microstructures using the unifying concept of accessibility, mixing local shape features with global topology. Underlying percolation and constrictivity features are jointly considered by probing the connected components of the microstructure with structuring elements with increasing sizes. Adapted morphological operations are combined to provide a scalable protocol embedding suitable descriptors applied on accessible volumes, yielding a sharp discrimination power. The suggested framework named A-protocol can efficiently analyze complex microstructures by applying a stratified sampling for the selection of paths' endpoints, when connected. It stops when percolation ends, at a critical radius value. The A-protocol is tested on Cox multi-scale Boolean models using the Euler number as an arbitrarily chosen embedded descriptor. This computational protocol is available in the open access software environment plug im!. [Display omitted] • A-protocol framework based on a dynamical vision of accessibility. • Enhancing any numerical descriptor by hindrance consideration. • Stochastic point percolation handling any complex microstructures. • Stochastic point accessibility mixing constrictivity and stochastic point percolation. [ABSTRACT FROM AUTHOR]