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•PVP and EC can be used to fabricate scaffolds by coaxial electrospinning.•The addition of gold nanoparticles improved the porosity and mechanical properties of PVP/EC scaffolds.•Gold ...nanoparticles-loadedPVP/EC coaxial electrospun nanofibers showed great osteogenic bioactivity both in vitro and in vivo.
Biomaterial-based scaffolds fabricated by electrospinning technique are promising platforms for bone tissue engineering. However, the current scaffolds have some limitations in terms of poor osteogenic bioactivities. In this study, citrate-stabilized gold-nanoparticles (GNPs) were encapsulated into polyvinylpyrrolidone/ethylcellulose scaffolds fabricated by coaxial electrospinning technique. Three types of GNPs-loaded electrospun scaffolds (P/E-0.5, P/E-1, and P/E-1.5) were prepared by changing the feeding GNPs. The morphological and physicochemical properties of these GNPs-incorporated electrospun scaffolds were comprehensively characterized. The results demonstrated that GNPs were successfully encapsulated into electrospun scaffolds, and their addition barely affected the morphology but improved the porosity and mechanical properties. In vitro studies revealed that GNPs-incorporated electrospun scaffolds showed excellent biocompatibility and osteogenic bioactivities, wherein the alkaline phosphatase activity, mineralized nodule formation, and the osteogenic-related genes expression were enhanced in GNPs-incorporated electrospun scaffolds compared to the neat P/E electrospun nanofibers. Then, the GNPs-incorporated electrospun scaffolds were surgically implanted into the defect area of the rat skull bone to test their in vivo bone repairing effect. It was observed that GNPs-incorporated scaffolds rapidly accelerated bone regeneration in vivo. Taken together, GNPs-incorporated coaxial electrospun nanofibers might be considered as promising scaffolds in the field of bone tissue regeneration.
Bacterial cellulose (BC) possesses the desirable properties of biocompatibility, high porosity, high surface area and noticeable mechanical strength as a scaffold in bone tissue engineering. However, ...the lack of osteogenic activity restricts its application. In this study, gold nanoparticles (GNPs) with excellent osteogenic differentiation ability were incorporated into the network of BC hydrogel (Au/BC hydrogels) by the in-situ fermentation. The effects of GNPs on physicochemical properties of BC hydrogel and subsequently in vitro osteogenic differentiation and in vivo bone regeneration of Au/BC hydrogels were comprehensively investigated. The results showed that the increased feeding amounts of GNPs could remarkablly enhance the Au/BC hydrogels with better mechanical properties, higher porosity, larger surface area, and biocompatibility. The sustainable release of GNPs endowed the hydrogels with an outstanding biological activity in facilitating osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Mechanism research showed that autophagy might be a potential pathway for Au/BC hydrogels-induced osteogenic differentiation of hBMSCs. In addition, Au/BC hydrogel exhibited an excellent in vivo bone repair performance in a rabbit model of femoral defect, which was evidenced by the significant newly bone formation. Overall, the multifunctional Au/BC hydrogels fabricated by in-situ fermentation could serve as a good scaffold for promoting bone tissue regeneration in clinic.
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•Gold nanoparticles (GNPs) with excellent osteogenic differentiation ability were incorporated into the network of BC hydrogelby the in-situ fermentation.•The developed hydrogels demonstrated desirable mechanical properties, sustainable release ability of GNPs, favorable biocompatibility and excellent osteogenic activities.•Mechanism research revealed that autophagy might play a vital role in osteogenic differentiation of hBMSCs treated with Au/BC hydrogels.•The incorporation of GNPs into hydrogels remarkably improved the bone regeneration performance in vivo.
Prehydrolyzate, which is from the prehydrolysis process in dissolving pulps industry, contains various sugar-derived and lignin compounds such as xylooligosaccharides (XOS), gluco-oligosaccharides, ...xylose, glucose, and soluble lignin (S-L). The XOS has several beneficial effects on human physiology. XOS and S-L in prehydrolyzate are difficult to efficiently fractionate due to their similar molecular weights and water solubility. In this work, we proposed a sustainable and green process using polystyrene divinylbenzene (PS-DVB) resin to simultaneously separate and recover XOS and S-L. Enzymatic hydrolysis with endo-1,4-β-xylanase and fermentation with
were sequentially applied to purify XOS to minimize xylose content as well as amplify contents of xylobiose and xylotriose. In addition, 2D-HSQC NMR was used to analyze the structural characteristics of XOS and S-L. Furthermore, the biological abilities of antioxidants and prebiotics of these fractions were investigated by scavenging radicals and cultivating intestinally beneficial bacterias, respectively.
Results showed that PS-DVB resin could simultaneously separate XOS and solubilized lignin with excellent yields of 93.2% and 85.3%, respectively. The obtained XOS after being purified by enzymatic hydrolysis and fermentation contained 57.7% of xylobiose and xylotriose. 10.4% amount of inherent xylan was found in the S-L fraction obtained by PS-DVB resin separation. 2D-HSQC NMR revealed that lignin carbohydrate complexes existed in both XOS and S-L as covalent linkages between lignin and 4-
-methylglucuronoarabinoxylan. The biological application results showed that the antioxidant capacity of S-L was stronger than XOS, while XOS was superior in promoting growth of intestinal
and stimulating production of short-chain fatty acids by
The proposed strategy of sequentially combining hydrophobic resin separation, enzymatic hydrolysis, and fermentation was successfully demonstrated and resulted in simultaneous production of high-quality XOS and solubilized lignin. These biomass-derived products in prehydrolyzate can be regarded as value-adding prebiotics and antioxidants.
Bacterial cellulose (BC) is an exopolysaccharide with unique properties that has been applied in various fields. However, the dense and intertwined nature of BC fibers limits its use in certain ...applications, including 3D printing scaffolds for bone regeneration. In this work, a controllable BC-based bio-ink for 3D printing was successfully prepared by modifying the neat BC through maleic acid (MA) treatment, aiming to promote bone tissue regeneration. To achieve homogeneous BC dispersions while preserving its crystalline and chemical properties, BC was modified by MA solution (60 %, w/V) with solid-liquid ratio from 1꞉5 to 1꞉50 (w/V) to obtain MA-BC dispersions. The analysis results from microstructure, chemical group, crystallinity, and wettability indicated that the BC/MA solution with ratio of 1꞉30 demonstrated the best pre-treatment performance to obtain MA-BC. Subsequently, by combining MA-BC with gelatin, we successfully formulated MA-BC-GEL gels with favorable rheological properties and compression modulus, which can be used as promising bio-inks for 3D bioprinting applications. In vitro tests demonstrated 1꞉30 MA-BC possessed excellent biocompatibility, a significant ability to express the alkaline phosphatase gene and osteogenic-related genes, and facilitated the formation of mineralized nodules. The utilization of this novel bio-ink in scaffold preparation for bone regeneration highlights the promising application of modified BC in bone tissue engineering field.
A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion resistance. However, there is limited investigation on tuning ...microstructures of TC4 ELI to improve explosion resistance. Moreover, the current challenge is quantifying microstructural changes’ effects on explosion resistance and incorporating microstructural changes into finite element models. This work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism, and find a suitable method to incorporate microstructural changes into finite element models. In this work, we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element modeling. The Johnson‒Cook (JC) constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element models. Because of the heat treatment, one plate has equiaxed microstructure and the other has bimodal microstructure. The convex of the plate after the explosion has a quadratic relationship with the charge mass, and the simulation results demonstrate high reliability, with the error less than 17.5%. Therefore, it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion resistance. The bimodal target exhibits excellent deformation resistance. The response of bimodal microstructure to the shock wave may be more intense under explosive loading. The well-coordinated structure of the bimodal target enhances its resistance to deformation.
Ceramic composite structures are important in developing lightweight protection applications. Designers primarily design for armor-piercing threats. However, it is difficult to avoid the threat of ...high explosives or improvised explosive devices on the battlefield. In this work, three ceramic composite structures with different type and thickness of the ceramic panel were assessed by explosion test and finite element modelling to study their damage and failure characteristics. The ceramic composite structures exhibit good wave weakening ability. The type of ceramic does not change the anti-explosion performance of the composite structure when the surface density is similar, but the two kinds of ceramics show different damage and fracture mechanisms. Specifically, intergranular fracture mainly occurs in the alumina ceramic, whereas transgranular fracture mainly occurs in the SiC ceramic. In all cases, the back plate made of high strength steel undergoes plastic deformation and the ceramic panel is fragmented in response to the explosive impact, and the size of ceramic fragments increases from the center to the boundary of the ceramic panel.
Osteoarthritis (OA) is the most common degenerative joint disease worldwide, with the main pathological manifestation of articular cartilage degeneration. It have been investigated that ...pharmacological activation of transient receptor potential vanilloid 1 (TRPV1) significantly alleviated cartilage degeneration by abolishing chondrocyte ferroptosis. In this work, in view of the thermal activated feature of TRPV1, Citrate‐stabilized gold nanorods (Cit‐AuNRs) is conjugated to TRPV1 monoclonal antibody (Cit‐AuNRs@Anti‐TRPV1) as a photothermal switch for TRPV1 activation in chondrocytes under near infrared (NIR) irradiation. The conjugation of TRPV1 monoclonal antibody barely affect the morphology and physicochemical properties of Cit‐AuNRs. Under NIR irradiation, Cit‐AuNRs@Anti‐TRPV1 exhibited good biocompatibility and flexible photothermal responsiveness. Intra‐articular injection of Cit‐AuNRs@Anti‐TRPV1 followed by NIR irradiation significantly activated TRPV1 and attenuated cartilage degradation by suppressing chondrocytes ferroptosis. The osteophyte formation and subchondral bone sclerosis are remarkably alleviated by NIR‐inspired Cit‐AuNRs@Anti‐TRPV1. Furthermore, the activation of TRPV1 by Cit‐AuNRs@Anti‐TRPV1 evidently improved physical activities and alleviated pain of destabilization of the medial meniscus (DMM)‐induced OA mice. The study reveals Cit‐AuNRs@Anti‐TRPV1 under NIR irradiation protects chondrocytes from ferroptosis and attenuates OA progression, providing a potential therapeutic strategy for the treatment of OA.
Li et al develop a Cit‐AuNRs@Anti‐TRPV1 switch for photothermal activation of TRPV1 signaling for the treatment of osteoarthritis. Cit‐AuNRs@Anti‐TRPV1 has good photothermal responsiveness, and it can rapidly warm up under near‐infrared (NIR) irradiation. By controlling the NIR power and action time, it can realize effective, controllable and targeted activation of TRPV1, thereby suppressing the ferroptosis of chondrocytes to attenuate OA.
In this paper, a new flexible stab-resistant composite material was prepared by growing ZnO nanowires on aramid plain fabric by the hydrothermal method. Through SEM, FTIR, and XRD characterization, ...it is proved that ZnO nanowires have been grown on aramid fabric and the surfaces of aramid filaments become much rougher. Moreover, the inter-filament friction and breaking strength of aramid fabric with nanowires are increased significantly, especially the inter-filament friction, which has been increased by more than 4 times after ZnO nanowires growth. Stab tests were conducted on the bare aramid fabric sample and aramid fabric sample with ZnO nanowires based on the test standard of GA 68–2019. Both of the two samples are 43 layers and are subject to 5 stabs of D1 knife, 3 stabs of D2 knife and 3 stabs of D3 knife. The stab resistance of aramid fabric grown with nanowires is significantly enhanced, and the average penetration depth under the D1 knife impact is decreased by 49.7%. The reason may be that the inter-filament friction increases dramatically with the nanowires and thus the friction energy consumption increases. The flexibility test results show that the softness characteristics of the single aramid fabric and the 43-layer fabric with the nanowires are still maintained. In addition, although the growth of nanowires will lead to smaller voids and a decrease of air permeability of the fabric, the moisture permeability has been slightly improved because ZnO nanowires have the ability to bind with water.
Transient receptor potential vanilloid family member 1 (TRPV1) has been revealed as a therapeutic target of osteoarthritis (OA), the most common deteriorating whole joint disease, by impeding ...macrophagic inflammation and chondrocytes ferroptosis. However, the clinical application for capsaicin as the TRPV1 agonist is largely limited by its chronic toxicity. To address this issue, we developed a bifunctional controllable magnetothermal switch targeting TRPV1 for the alleviation of OA progression by coupling of magnetic nanoparticles (MNPs) to TRPV1 monoclonal antibodies (MNPs-TRPV1). Under the alternating magnetic field (AMF) stimulation, MNPs-TRPV1 locally dissipated heat, which was sufficient to trigger the opening and activation of TRPV1, and effectively impeded macrophagic inflammation and chondrocyte ferroptosis. This magnetothermal modulation of TRPV1 simultaneously attenuated synovitis and cartilage degeneration in mice incurred by destabilization of medial meniscus surgery, indicating the delayed OA progression. Furthermore, MNPs-TRPV1 with AMF exposure remarkably reduced knee pain sensitivity, alleviated the crippled gait, and improved spontaneous ambulatory activity performance in the mice OA model. Overall, this work provides a potential pathogenesis-based precise OA therapy with temporally and spatially magnetothermal modulation of TRPV1 in a controllable manner.
The naturally tight entanglement of fibers in bacterial cellulose (BC) results in low printability when BC is used as a bioink for printing scaffolds. In this study, neat BC was treated by ...TEMPO-mediated oxidation (TO-BC) and maleic acid (MA-BC) to prepare homogeneous BC dispersions to fabricate scaffolds for bone regeneration. Results showed that the treatments released individual fibrils in the corresponding uniform dispersions without impairing inherent crystalline properties. Compared with TO-BC, MA-BC hybridized with gelatin could endow the gel with improved rheological properties and compression modulus for 3D printing. Both TO-BC and MA-BC dispersions showed good osteoblast viability. However, MA-BC possessed more pronounced ability to express osteogenic marker genes and formation of mineralized nodules in vitro. Compared with TO-BC-based gelatin scaffolds, MA-BC-based gelatin scaffolds showed a better ability to stimulate the regeneration of rat calvaria, demonstrating a higher bone mineral density of newly formed bone and trabecular thickness in vivo.
•TEMPO and MA treatments can liberate individual fibrils in BC dispersion.•MA treated BC endows gelatin with better compression modulus for 3D printing.•MA treated BC shows best performance for bone regeneration in vitro and in vivo.
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