Fabrication of polydimethylsiloxane-attached solid slippery surface with high underwater transparency towards the antifouling of optical window for marine instruments.

Marine optical instruments are commonly suffering serious biofouling problem caused by the adhesion of marine microorganisms, which severely affects the instruments to monitor the marine environment. Herein, we developed a robust solid slippery surface (SSS) by fabricated a covalently attached polydimethylsiloxane (PDMS) layer on glass substrate to solve the biofouling problem of marine optical instrument windows. The SSS could effectively inhibit the settlements of marine microorganism (bacteria and alga) in various environmental conditions, resulting from the high flexibility of PDMS molecular chains, and thus could maintain its high underwater-transparency. The antifouling mechanism of SSS was results from the weak nonspecific electrostatic Lifshitz-van der Waals forces and less specific hydrogen bonds between SSS and microorganism, which was been confirmed via both single bacterial force spectroscopy measurement and molecular dynamics simulation. Compared with the traditional slippery lubricant-infused porous surface (SLIPS), the SSS exhibited a better robust mechanical stability than that of the SLIPS. In addition, our study provides a valuable method to fabricated the SSS with reliable underwater-transmittance and antifouling properties, which is promised for the applications for the antifouling of marine optical instruments.

Distribution and retention of microplastics in plantation mangrove forest sediments.

Microplastics (MPs) in ocean tides can be effectively intercepted by mangroves, especially sediments, which are considered to be effective sinks. However, the retention of plantation mangrove forests on MPs is still unclear. In this study, the spatial distribution and its implication factors of MPs in surface sediments of plantation mangrove forests were investigated for the first time. In plantation forests, MPs were detected with abundances ranging from 67 ± 21 to 203 ± 25 items/kg, and plantation forests were significantly lower than natural forests at the CJ sampling site (p < 0.05). Plantation forests had fewer fibrous MPs than natural forests (p < 0.05). Furthermore, the MPs abundance showed strong linear relationships with the sand content (p = 0.002, R2 = 0.86) and Aegiceras corniculata biomass (p = 0.001, R2 = 0.84). Partial least squares path modeling analysis (PLS-PM) indicated that these two factors influenced MPs abundance by retaining MPs with fibrous, fragmented, denser and larger-sized characteristics. Our results revealed the differences in MPs abundance and characteristics between plantation and natural mangrove forests, and it is necessary to monitor MPs pollution to provide significant guidance for the restoration of constructed wetlands.

The oral microbiome of pregnant women facilitates gestational diabetes discrimination.

The oral microbiota plays an important role in the development of various diseases, whereas its association with gestational diabetes mellitus (GDM) remains largely unclear. The aim of this study is to identify biomarkers from the oral microbiota of GDM patients by analyzing the microbiome of the saliva and dental plaque samples of 111 pregnant women. We find that the microbiota of both types of oral samples in GDM patients exhibits differences and significantly varies from that of patients with periodontitis or dental caries. Using bacterial biomarkers from the oral microbiota, GDM classification models based on support vector machine and random forest algorithms are constructed. The area under curve (AUC) value of the classification model constructed by combination of Lautropia and Neisseria in dental plaque and Streptococcus in saliva reaches 0.83, and the value achieves a maximum value of 0.89 by adding clinical features. These findings suggest that certain bacteria in either saliva or dental plaque can effectively distinguish women with GDM from healthy pregnant women, which provides evidence of oral microbiome as an informative source for developing noninvasive biomarkers of GDM.

Development of biodegradable polyesters based on a hydroxylated coumarin initiator towards fluorescent visible paclitaxel-loaded microspheres.

In this work, we developed a facile end-functionalization method using hydroxylated coumarin to initiate the ring-opening polymerization of cyclic esters to synthesize a series of fluorescent biodegradable aliphatic polyesters with tailorable properties. The resulting fluorescent functionalized poly(l-lactide) (PLLA-COU), poly(ε-caprolactone) (PCL-COU) poly(δ-valerolactone) (PVL-COU) and poly(trimethylene carbonate) (PTMC-COU) were investigated to evaluate the dependence of fluorescence on the chemical structure and molecular weight of the materials. The differences in the electron withdrawing ability and the density of ester groups are responsible for the changes in the fluorescence quantum yield. Then, two representative biodegradable materials, namely, PLLA-COU and PCL-COU, were used to prepare fluorescent paclitaxel-loaded microspheres. During in vitro drug release, the release rate of the PCL-COU microspheres is dramatically faster than that of the PLLA-COU microspheres due to the difference in the material nature and their surface morphologies, possibly achieving a tunable degradation and release rate for the drug carriers. Fluorescent functionalized polyester microspheres can retain their fluorescence properties and emit bright blue light for fluorescence tracing during the degradation process. Biological evaluations showed that both fluorescent polyesters are devoid of any significant toxicity and have good biocompatibility. The results demonstrated that the obtained fluorescent polyesters are promising for use in traceable and controlled drug delivery with tunable drug release.