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Oxygen evolution reaction (OER) plays a crucial role in developing energy conversion and adjusting electronic structure of the electrocatalysts can effectively improve the catalytic activity and stability. However, it is a challenge to adjust the electronic structure on two-dimensional iridium dioxide nanosheets (IrO2 NS), which have the advantages of high atom utilization. Here, we regulate the surface properties of IrO2 NS through sulfonated carbon dots (SCDs) to promote the OER catalytic process. The catalyst IrO2 NS/SCDs-2 exhibited excellent catalytic activity with a lower overpotential of 180 mV than IrO2 NS (230 mV) at the current density of 10 mA·cm−2 in a 0.5 M H2SO4 solution. And after 160 h of stability testing, the overpotential of IrO2 NS/SCDs-2 only decreased by 4 mV. Moreover, transient potential scanning test can visually demonstrate that the addition of SCDs improves the conductivity of the catalyst and increases the electron transfer rate. [ABSTRACT FROM AUTHOR]

Dendritic cell (DC) vaccines have shown promising effects in cancer management, while low cell activity and low migration rate to lymph nodes limit their clinical application. Here, this work reports a bioink DC vaccine, synthesized by 3D printing methacryloyl gelatin to encapsulate DCs and tumor cellular vesicles overexpressing programmed cell death protein 1 (PD1‐CVs), for cancer immunotherapy. Compared with a traditional hydrogel, the porous 3D scaffold significantly improves the viability of DCs from ∼16% to ∼70% after 7 days of cell culture and increases the proportion of released DCs from the scaffold into lymph nodes by about fourfold. The PD1‐CVs stimulate DC maturation and block PD ligand‐1 (PD‐L1) in mature DCs and tumor cells, synergistically boosting DC‐mediated antitumor immunity. In breast tumor mouse models, this personalized 3D DC vaccine developed for site‐specific filling after tumor resection significantly suppress tumor recurrence and extend median survival time to 45 days. This 3D printed vaccine offers a simple, safe, and robust strategy for enhanced cell‐based cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Three-dimensional bioprinting is a potent biofabrication technique in tissue engineering but is limited by inadequate bioink availability. Plant-derived proteins are increasingly recognized as highly promising yet underutilized materials for biomedical product development and hold potential for use in bioink formulations. Herein, we report the development of a biocompatible plant protein bioink from pea protein isolate. Through pH shifting, ethanol precipitation, and lyophilization, the pea protein isolate (PPI) transformed from an insoluble to a soluble form. Next, it was modified with glycidyl methacrylate to obtain methacrylate-modified PPI (PPIGMA), which is photocurable and was used as the precursor of bioink. The mechanical and microstructural studies of the hydrogel containing 16% PPIGMA revealed a suitable compress modulus and a porous network with a pore size over 100 μm, which can facilitate nutrient and waste transportation. The PPIGMA bioink exhibited good 3D bioprinting performance in creating complex patterns and good biocompatibility as plenty of viable cells were observed in the printed samples after 3 days of incubation in the cell culture medium. No immunogenicity of the PPIGMA bioink was identified as no inflammation was observed for 4 weeks after implantation in Sprague Dawley rats. Compared with methacrylate-modified gelatin, the PPIGMA bioink significantly enhanced cartilage regeneration in vitro and in vivo, suggesting that it can be used in tissue engineering applications. In summary, the PPIGMA bioink can be potentially used for tissue engineering applications. [ABSTRACT FROM AUTHOR]

(1) Background: A rise in intraocular pressure (IOP) and decreased retinal ganglion cells are frequent indicators of effective modeling of chronic ocular hypertension in mice. In this study, the sensitivity of the mouse model to pharmaceutical therapy to reduce intraocular tension was assessed, the model's safety was confirmed using a cytotoxicity test, and the success rate of the mouse model of ocular hypertension was assessed by assessing alterations in IOP and neurons in the ganglion cell layer. (2) Methods: A mouse model of chronic ocular hypertension was produced in this study by employing photocrosslinkable sericin hydrogel injection and LED lamp irradiation. The eyes of 25 C57BL/6 male mice were subjected to 405 nm UV light from the front for 2 min after being injected with 5 μL of sericin hydrogel in the anterior chamber of the left eye. IOP in the mice was measured daily, and IOP rises greater than 5 mmHg were considered intraocular hypertension. When the IOP was lowered, the intervention was repeated once, but the interval between treatments was at least 2 weeks. The right eyes were not treated with anything as a normal control group. Mice eyeballs were stained with HE, Ni-type, and immunofluorescence to assess the model's efficacy. Two common drugs (tafluprost eye drops and timolol eye drops) were provided for one week after four weeks of stable IOP, and IOP changes were assessed to determine the drug sensitivity of the mouse model of chronic ocular hypertension. Furthermore, CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS) was utilized to investigate the safety of the ocular hypertension model by evaluating the deleterious effects of photocrosslinkable sericin hydrogel on cells. (3) Results: Before injection, the basal IOP was (9.42 ± 1.28) mmHg (1 kPa = 7.5 mmHg) in the experimental group and (9.08 ± 1.21) in the control group. After injection, cataract occurred in one eye, corneal edema in one eye, endophthalmitis in one eye, iris incarceration in one eye, and eyeball atrophy in one eye. Five mice with complications were excluded from the experiment, and twenty mice were left. Four weeks after injection, the IOP of the experimental group was maintained at (19.7 ± 4.52) mmHg, and that of the control group was maintained at (9.92 ± 1.55) mmHg, and the difference between the two groups was statistically significant (p < 0.05). Before the intervention, the IOP in the experimental group was (21.7 ± 3.31) mmHg in the high IOP control group, (20.33 ± 2.00) mmHg in the tafluprost eye drops group, and (20.67 ± 3.12) mmHg in the timolol maleate eye drops group. The IOP after the intervention was (23.2 ± 1.03) mmHg, (12.7 ± 2.11) mmHg, and (10.4 ± 1.43) mmHg, respectively. Before and after the intervention, there were no significant differences in the high-IOP control group (p > 0.05), there were statistically significant differences in the timolol eye drops group (p < 0.05), and there were statistically significant differences in the tafluprost eye drops group (p < 0.05). One week after drug withdrawal, there was no significant difference in IOP among the three groups (p > 0.05). In the high-IOP group, the protein (sericin hydrogel) showed a short strips or fragmented structure in the anterior chamber, accompanied by a large number of macrophages and a small number of plasma cells. The shape of the chamber angle was normal in the blank control group. The number of retinal ganglion cells decreased significantly 8 weeks after injection of sericin hydrogel into the anterior chamber, and the difference was statistically significant compared with the blank control group (p < 0.05). After the cells were treated with photocrosslinkable sericin hydrogel, there was no significant difference in the data of the CellTiter 96® assay kit of MTS compared with the blank control group (p > 0.05). (4) Conclusions: A mouse model of chronic intraocular hypertension can be established successfully by injecting sericin in the anterior chamber and irradiating with ultraviolet light. The model can simulate the structural and functional changes of glaucoma and can effectively reduce IOP after the action of most antihypertensive drugs, and it is highly sensitive to drugs. Sericin has no obvious toxic effect on cells and has high safety. [ABSTRACT FROM AUTHOR]

The thermal protection system (TPS) represents one of the most critical subsystems for vehicle re-entry. However, due to uncertainties in thermal loads, material properties, and manufacturing deviations, the thermal response of the TPS exhibits significant randomness, posing considerable challenges in engineering design and reliability assessment. Given that uncertain aerodynamic heating loads manifest as a stochastic field over time, conventional surrogate models, typically accepting scalar random variables as inputs, face limitations in modeling them. Consequently, this paper introduces an effective characterization approach utilizing proper orthogonal decomposition (POD) to represent the uncertainties of aerodynamic heating. The augmented snapshots matrix is used to reduce the dimension of the random field by the decoupling method of independently spatial and temporal bases. The random variables describing material properties and geometric thickness are also employed as inputs for probabilistic analyses. An uncoupled POD Gaussian process regression (UPOD-GPR) model is then established to achieve highly accurate solutions for transient heat conduction. The model takes random heat flux fields as inputs and thermal response fields as outputs. Using a typical multi-layer TPS and thermal structure as two examples, probabilistic analyses are conducted. The mean square relative error of a typical multi-layer TPS is less than 4%. For the thermal structure, the averaged absolute error of the radiation and insulation layer is less than 25 °C and 6 °C when the maximum reaches 1200 °C and 150 °C, respectively. This approach can provide accurate and rapid predictions of thermal responses for TPS and thermal structures throughout their entire operating time when furnished with input heat flux fields and structural parameters. [ABSTRACT FROM AUTHOR]

The utilization of two-dimensional (2D) nanosheets as catalysts is promising due to their atomic-scale thickness and extensive surfaces. The development of a high-quality, flexible Pt-based nanosheet with an efficient synthesis method is imperative. In this study, we present a 2D Pt2Pd porous alloy nanosheet synthesized through a novel process involving molten-alkali mechanochemical and borane morpholine complex reduction methods. This nanosheet exhibits a pristine 2D active surface, serving as an efficient catalyst for the oxygen reduction reaction (ORR). The Pt2Pd porous alloy nanosheet catalyst displays a high half-wave potential of 0.956 V versus the reversible hydrogen electrode (RHE), along with remarkable mass and specific activities of 1.38 A mg−1Pt and 3.70 mA cm−2 (at 0.9 V versus the RHE). When applied as the cathode in a zinc–air battery, it achieves a power density of 0.31 W cm−2 and demonstrates outstanding durability. This research introduces an innovative strategy for advancing high-quality, flexible 2D Pt-based materials. [ABSTRACT FROM AUTHOR]

Since chondrocytes are highly vulnerable to oxidative stress, an anti-oxidative bioink combined with 3D bioprinting may facilitate its applications in cartilage tissue engineering. We developed an anti-oxidative bioink with methacrylate-modified rutin (RTMA) as an additional bioactive component and glycidyl methacrylate silk fibroin as a biomaterial component. Bioink containing 0% RTMA was used as the control sample. Compared with hydrogel samples produced with the control bioink, solidified anti-oxidative bioinks displayed a similar porous microstructure, which is suitable for cell adhesion and migration, and the transportation of nutrients and wastes. Among photo-cured samples prepared with anti-oxidative bioinks and the control bioink, the sample containing 1 mg/mL of RTMA (RTMA-1) showed good degradation, promising mechanical properties, and the best cytocompatibility, and it was selected for further investigation. Based on the results of 3D bioprinting tests, the RTMA-1 bioink exhibited good printability and high shape fidelity. The results demonstrated that RTMA-1 reduced intracellular oxidative stress in encapsulated chondrocytes under H2O2 stimulation, which results from upregulation of COLII and AGG and downregulation of MMP13 and MMP1. By using in vitro and in vivo tests, our data suggest that the RTMA-1 bioink significantly enhanced the regeneration and maturation of cartilage tissue compared to the control bioink, indicating that this anti-oxidative bioink can be used for 3D bioprinting and cartilage tissue engineering applications in the future. [ABSTRACT FROM AUTHOR]