Mengmeng Sun

The management of wounds with infection has consistently been an urgent problem due to bacterial infection and local inflammation. And owing to the overuse of antibiotics, drug-resistant superbugs have emerged, especially Methicillin-Resistant Staphylococcus aureus (MRSA). Hence, the treatment for MRSA-infected wounds is a critical problem. Here, a dissolvable microneedle patch that promotes wound healing with an inhibition effect on MRSA is reported. Specifically, it is represented by coupling the synthesized CuCoNCOs nanomaterials and tannic acid (TA) with hyaluronic acid (HA) to construct microneedle nanopatches. In view of the synergistic effect of copper (Cu) and cobalt (Co), the CuCoNCOs exhibit excellent antibacterial properties while maintaining great biological compatibility and persistence, ensuring low virulence to human cells. In addition, CuCoNCOs also present a high antioxidant and wound healing effect. The microneedle patches can quickly deliver CuCoNCOs antibacterial nanomaterials and TA to deep wound tissue. Therefore, CuCo-TA-MNs have shown good treatment effect in the treatment of MRSA infectious wounds. These results suggest that CuCo-TA-MNs have great promise in the treatment of clinically infectious wounds.

Selenium is an important trace element with certain antioxidant effects. Nano-selenium, as a novel selenium source, has the advantages of strong biological activity, high absorption efficiency, and low toxicity. The aim of the present study was to compare the protective effects of sodium selenite and nano-selenium on intestinal oxidative stress induced by hydrogen peroxide (H₂O₂) in mice. A total of 60 female mice were randomly divided into 6 groups with 10 replicates per group and 1 mouse per replicate (n = 10). The first three groups were as follows: the Control group (C), fed with basal diet; the sodium selenite group (SS), basal diet + 0.3 mg·kg⁻¹ sodium selenite; and the nano-selenium group (NS), basal diet + 0.3 mg·kg⁻¹ nano-selenium. The latter three groups (CH, SSH, NSH) were fed the same diet as the former three groups, but the last 10 days of the experiment were fed with drinking water containing 0.3% H₂O₂ to induce oxidative stress. The results showed that under normal conditions, the supplementation with sodium selenite or nano-selenium decreased the spleen index of mice; sodium selenate up-regulates GPX3 expression in the ileum, and increases T-SOD in the colon of mice; and nano-selenium up-regulated GPX1 expression but decreased T-AOC in the jejunum. After drinking water treated with H₂O₂, H₂O₂ increased the expression of intestinal inflammatory factors and selenium proteins, such as IL-1β and SOD in jejunum, IL-1β, NF-κB, IL-10, TXNRD1, TXNRD2, GPX1, GPX3, GPX4, and CAT in ileum, and IL-1β and SOD in colon. At the antioxidant level, H₂O₂ decreased T-AOC in the jejunum. In the H₂O₂ treatment, sodium selenite and nano-selenium increased the ratio of VH to CD (VH/CD) in jejunum; sodium selenite up-regulated the expression of TXNRD1 in jejunum, down-regulated the expression of GPX3 in ileum, at the antioxidant level, decreased the T-SOD and T-AOC in colon, and increased the content of MDA in ileum; and nano-selenium down-regulated the expression of TXNRD1 in colon. At the same time, the expression of IL-1β, NF-κB, IL-10, TXNRD1, TXNRD2, GPX1, GPX4, and CAT can be restored to normal levels by selenium supplementation. According to the results, drinking H₂O₂ induced intestinal oxidative stress in mice to a certain extent, and selenium supplementation mitigated the destructive effect of H₂O₂ on the intestinal morphology of mice jejunum and restored the level of related inflammatory factors, and had a positive effect on antioxidants.

Gels with excellent mechanical properties and antifatigue-fracture capability are attractive materials for load-bearing applications; however, at extreme temperatures, they still suffer from catastrophic failure caused by freezing- or dehydration-induced crack propagation. Here, we present a series of hierarchical anisotropic composite organogels that are strong yet tough and antifatigue-fracture over a wide temperature range (-30 to 60 °C) through the combination strategies of freezing-casting, annealing, and solvent exchange with polyols. Such a hybrid design endows the gels with anisotropic and hierarchical structures and excellent tolerance to extreme temperatures, thus guaranteeing efficient energy dissipation and crack propagation resistance under both ambient and harsh conditions. For instance, the organogel obtained via solvent exchange with glycerol exhibited high strength (22.6 MPa), toughness (198.0 MJ/m³), fatigue threshold (6.92 kJ/m²), and particularly, a superhigh fracture energy (665.7 kJ/m²), which is even higher than anhydrous elastomers, metals, and alloys. Importantly, these values were further boosted at extreme temperatures, such as fatigue thresholds of 8.01 and 9.77 kJ/m² at -30 and 60 °C, respectively. This work offers an attractive strategy for fabricating gel materials that are reliable for load-bearing applications under extreme conditions.

Low-protein (LP) diets have been proposed as a strategy for animal production to conserve protein resources and reduce environmental nitrogen pollution. The aim of this study was to investigate the effect of a LP diet during gestation on the reproductive performance, serum amino acid concentrations, and nitrogen excretion in sows. A total of 24 healthy Landrace × Yorkshire sows (4 to 5 parities) with similar body weight and back fat were fed with normal gestational diet (control group, crude protein = 13.65%, n = 12) or a LP gestational diet (LP group, crude protein = 11.30%, n = 12) from day 30 of gestation to the day before parturition. All sows received same diet during lactation. Results showed that LP diet during mid-to-late gestation reduced the gain of backfat thickness during days 30 to 60 of gestation (P < 0.05) compared with the control group, without changing the reproductive performance of the sows. The gene expression levels of amino acid transporters in the placenta, and the organ indices of neonatal and weaned piglets, were all unchanged by the LP diet. The digestion and metabolism experiment revealed that the LP diet decreased nitrogen excretion and net nitrogen deposition during late gestation (P < 0.05). Additionally, the LP diet reduced serum concentrations of valine, arginine, lysine, and methionine on day 110 of gestation, and arginine, lysine, and methionine on day 21 of lactation, while it tended to decrease serum concentration of the total essential amino acids and the level of threonine in the milk throughout lactation (P < 0.05). Gestational LP diet al.o significantly reduced concentrations of serine and the total non-essential amino acids in the serum of neonatal piglets (P < 0.05) and serum threonine in weaned piglets, but increased leucine (P < 0.05) in the serum of weaned piglets. In conclusion, an appropriate reduction of dietary protein during mid-to-late gestation in sows (11.30% vs. 13.65%) could reduce their nitrogen excretion while maintaining reproductive performance, and it is recommended to supplement arginine and valine in the LP diets in addition to lysine, methionine, tryptophan, and threonine. This study highlights the significance of low-protein diets in protein feed saving and environmental protection.

In this study, we present the design of a molecularly imprinted polymer (MIP) for the detection of the antibiotic sparfloxacin (SPFK), combined with a high-precision quartz crystal microbalance (QCM) sensor. Green-synthesized ZIF-67@PDA-MIP was directly immobilized on the gold electrode surface of the QCM. This configuration takes advantage of the selective recognition capabilities of the MIP and the high-sensitivity response characteristics of the QCM sensor. It overcomes the limitations of traditional SPFK detection methods, offering both accurate detection and rapid responses for practical applications. The MIP-QCM sensor demonstrated enhanced sensitivity and affinity, achieving a detection limit as low as 10.3 ng/mL. Additionally, the selectivity of the sensor for SPFK was superior to that of other non-template molecules. It effectively detected SPFK residues in milk with acceptable accuracy, as indicated by recoveries ranging from 96.16% to 104.64% and a relative standard deviation (RSD) of less than 4.64%. These results suggest that the proposed MIP-QCM sensor provides an accurate, sensitive, rapid, and cost-effective method for detecting SPFK residues in animal products, and this advancement is expected to promote the widespread adoption of high-precision sensors in food safety testing.