Current status of development and biomedical applications of peptide-based antimicrobial hydrogels.

Microbial contamination poses a serious threat to human life and health. Through the intersection of material science and modern medicine, advanced bionic hydrogels have shown great potential for biomedical applications due to their unique bioactivity and ability to mimic the extracellular matrix environment. In particular, as a promising antimicrobial material, the synthesis and practical biomedical applications of peptide-based antimicrobial hydrogels have drawn increasing research interest. The synergistic effect of peptides and hydrogels facilitate the controlled release of antimicrobial agents and mitigation of their biotoxicity while achieving antimicrobial effects and protecting the active agents from degradation. This review reports on the progress and trends of researches in the last five years and provides a brief outlook, aiming to provide theoretical background on peptide-based antimicrobial hydrogels and make suggestions for future related work.

[Establishment of indices for soybean low temperature damages in key growth stage in high cold region]. / é«˜å¯’åŒºå¤§è±†å ³é”®ç”Ÿè‚²æœŸä½Žæ¸©å†·å®³æŒ‡æ ‡æž„å»º.

Establishment of indices for low temperature damage of soybeans is important for systematically analyzing the adaptation strategies to climate change and collaborative adaptation technology for disaster prevention and mitigation and other stresses in high cold region. Based on historical data of low temperature damage and phenophase of soybean from 1980 to 2020 and daily temperature data from 78 meteorological stations in Heilongjiang Province, we used GIS to match the phenophase and meteorological data, by considering the accumulated temperature anomaly in different growth stages, and constructed a comprehensive soybean low temperature damages index (CSCDI) in high cold region. Using K-S distribution fitting test and the lower limit value of confidence intervals, we constructed the level index of soybean low temperature damage. The results showed that the CSCDI lower limits of mild, moderate and severe low temperature damage were 0.061, 0.115 and 0.237 from sowing to emergence stage, were 0.072, 0.152 and 0.312 from emergence to flowering, and 0.133, 0.245 and 0.412 from flowering to maturity, respectively. The time distribution of soybean low temperature damage inversed by CSCDI in Heilongjiang Province was consistent with the historical disaster records. The spatial distribution showed obvious latitude characteristics, with the frequency of low temperature damage increasing gradually from south to north.

Cow dung-derived biochars engineered as antibacterial agents for bacterial decontamination.

Disposal of the pollutants arising from farming cattle and other livestock threatens the environment and public safety in diverse ways. Herein, we report on the synthesis of engineered biochars using cow dung as raw material, and investigating these biochars as antibacterial agents for water decontamination. By coating the biochars with N-halamine polymer and loading them with active chlorine (i.e., Cl+), we were able to regulate them on demand by tuning the polymer coating and bleaching conditions. The obtained N-halamine-modified biochars were found to be extremely potent against Escherichia coli and Staphylococcus aureus. We also investigated the possibility of using these N-halamine-modified biochars for bacterial decontamination in real-world applications. Our findings indicated that a homemade filter column packed with N-halamine-modified biochars removed pathogenic bacteria from mining sewage, dairy sewage, domestic sewage, and artificial seawater. This proposed strategy could indicate a new way for utilizing livestock pollutants to create on-demand decontaminants.

Antibacterial Povidone-Iodine-Conjugated Cross-Linked Polystyrene Resin for Water Bacterial Decontamination.

Bacterial contamination in water purification systems is generating significant concern as a global health issue. In this paper, we describe fabricating antibacterial povidone-iodine-conjugated cross-linked polystyrene resins (i.e., P(St-DVB-NVP)-I2) and investigating them as antimicrobial agents for water decontamination. Comprehensive antibacterial tests showed that the addition of povidone-iodine to polystyrene resins resulted in strong antibacterial activity against pathogenic bacteria. In addition, the as-synthesized P(St-DVB-NVP)-I2 was confirmed to have hydrophobicity and favorable biocompatibility. We then examined the possibility of using P(St-DVB-NVP)-I2 as an antibacterial filter for water treatment and found that it could efficiently remove bacteria from water. An analog experiment demonstrated that the capability of P(St-DVB-NVP)-I2 for water bacterial decontamination was not influenced by the presence of mineral ions in the water. Most significantly, we confirmed the potential reusability of P(St-DVB-NVP)-I2 through a recycling test. This method of creating an antibacterial resin by building a conjugation of cross-linked polystyrene with povidone-iodine is safe, cost-effective, and environmentally friendly, and the resin shows promise for use in water purification filters.