Fabrication of self-healing hydrogel from quaternized N-[3(dimethylamino)propyl]methacrylamide copolymer for antimicrobial and drug release applications.

Self-healing hydrogels have attracted great attention in recent years because of their wide application in bioscience and biotechnology. In this study, P(DMAPMA-stat-DAA) were synthesized by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization and quaternized to import antimicrobial properties. Then quaternized P(DMAPMA-stat-DAA) was used to prepare hydrogel containing acylhydrazone groups with Polyethylene oxide (PEO) diacylhydrazide as a cross-linking agent. The acylhydrazone groups imparted a variety of properties, including group responsiveness and self-healing properties to the hydrogel. At the same time, the quaternary ammonium endowed the hydrogel with the antimicrobial property. The mechanical property, self-healing properties, and antimicrobial property of hydrogels were investigated intensively. Results showed hydrogels formed in neutral conditions, and the luminescent property was introduced with PEO23 dinaphthhydrazide (DNH) cross-linking. The hydrogels showed a controlled pH-sensitive DOX·HC l and Ovalbumin (OVA) release profile. In addition, the hydrogel showed the antimicrobial property and may have important applications in the biomedical field in the near future.

Exosomes derived from adipose tissue, bone marrow, and umbilical cord blood for cardioprotection after myocardial infarction.

Human mesenchymal stem cells (MSCs) have the potential for improving cardiac function following myocardial infarction (MI). This study was performed to explore the cardioprotection of bone marrow mesenchymal stem cells (BMMSCs), adipose tissue-derived mesenchymal stem cells (ADMSCs), and umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) for myocardium in rats after MI. MI models were established in rats, which were injected with PBS, BMMSCs, ADMSCs, and UCMSCs. Cardiac function was detected by ultrasonic cardiogram. TTC staining, TUNEL staining, and immunohistochemistry were adopted to determine infarction area, cardiomyocyte apoptosis, and microvascular density (MVD), respectively. Exosomes were derived from BMMSCs, ADMSCs, and UCBMSCs, and identified by morphological observation and CD63 expression detection. Neonatal rat cardiomyocytes (NRCMs) were isolated and cultured with hypoxia, subjected to PBS and exosomes derived from BMMSCs, ADMSCs, and UCMSCs. Flow cytometry and enzyme-linked immunosorbent assay were used to determine NRCM apoptosis and the levels of angiogenesis-related markers (VEGF, bFGF, and HGF). According to ultrasonic cardiogram, BMMSCs, ADMSCs, and UCMSCs facilitated the cardiac function of MI rats. Furthermore, three kinds of MSCs inhibited cardiomyocyte apoptosis, infarction area, and increased MVD. NRCMs treated with exosomes derived from BMMSCs, ADMSCs, and UCMSCs reduced the NRCM apoptosis and promoted angiogenesis by increasing levels of VEGF, bFGF, and HGF. Notably, exosomes from ADMSCs had the most significant effect. On the basis of the results obtained from this study, exosomes derived from BMMSCs, ADMSCs, and UCBMSCs inhibited the cardiomyocyte apoptosis and promoted angiogenesis, thereby improving cardiac function and protecting myocardium. Notably, exosomes from ADMSCs stimulated most of the cardioprotection factors.

Linc01230, transcriptionally regulated by PPARγ, is identified as a novel modifier in endothelial function.

Evidence is growing that PPARγ could improve the bioavailability of NO in pathological conditions to maintain endothelial function by activating Akt/eNOS pathway. LincRNAs participate in regulating development of cardiovascular diseases. Although investigations have been made to delineate the function of PPARγ and lincRNAs, little is known about the regulation relationship between them, especially in endothelial cells. In this study, we not only verified that PPARγ could antagonize the adverse effects brought from ox-LDL, but also found a novel factor related to PPARγ, named linc01230. According to our study, PPARγ transcriptionally regulated linc01230 by specifically combining with two binding regions, which have superposition effect, in the upstream of linc01230 promoter. In addition, linc01230 reduced ox-LDL induced endothelial dysfunction and affected the phosphorylation of Akt. These results conclude linc01230 as a novel modifier in PPARγ-mediated activation of Akt in endothelial function.

[Heavy metals distribution characteristics and ecological risk evaluation in surface sediments of dammed Jinshan lake].

In order to reveal the pollution loading of heavy metals in Dammed Jinshan lake, six heavy metals (As, Cu, Pb, Cd, Zn, Cr) from 18 sediment samples were analyzed using ICP, and the distribution characteristics of heavy metals in the sediment were comprehensively evaluated through concentration coefficient, geo-acumulation indexes, potential ecological risk evaluation and traceability analysis. The results showed that (1) the average contents of As, Pb, Cu, Zn, Cr, Cd were 23.22, 26.20, 24.42, 143.12, 245.30 and 0.67 mg x kg(-1), respectively, in the surface sediments of dammed Jinshan Lake. The average contents of Pb and Cu were lower than the primary standard and secondary standards of soil environmental quality standards. The average contents of Zn and Cr were lower than the primary standard and higher than the secondary standards of soil environmental quality standards. The average contents of As and Cd were higher than the primary and secondary standards of soil environmental quality standards. From the spatial distribution, the contents of Pb and Zn were the highest at sampling site No. 1, which was located at the Beigushan Square. The contents of As,Cu, Cr, Cd were the highest at sampling sites Nos. 12, 3, 14, and 7, respectively; (2) The order of concentration coefficient was As > Cr > Cd > Pb > Zn > Cu, which indicated that the enrichment amount of As was the highest and that of Cu was the lowest; (3) Based on the geo-acumulation indexes, the Cu is clean and Pb, Zn, Cd is the light pollution and As, Cr moderate pollution; (4) The order of Potential ecological risk coefficient was Cd > As > Cr > Pb > Cu > Zn, Cr, Pb, Cu, Zn were of light ecological risk and As, Cd were of medium ecological risk. From the spatial distribution, the sampling sites Nos. 1, 6, 7 and 12 had medium potential ecological risk, and the rest sample points had slight potential ecological risk; (5) The principal component analysis (PCA) revealed that the main reason for the differences of heavy metals in surface sediments of Jinshan lake was the different sediment environmental background value at the 18 samples sites. Besides, the pollution sources in each sampling sites also contributed to the differences in heavy metals; (6) the influence of the dam on the heavy metals distribution was not clear, and requires long-term study.