Occurrence and distribution of microplastics in the adjacent environment of Yellow River Delta, China.

In the precent study, the microplastics (MPs) pollution level was evaluated in diverse environmental samples from the Yellow River Delta. The results indicated that the abundance of MPs in water, sediment and soil samples ranged from 0.50 to 7.83 items·L-1, 200 to 4200 items·kg-1, and 100 to 1400 items·kg-1, respectively. Film form of MPs was dominant in water, while fiber MPs were dominant in both sediment and soil samples. In all samples, most MPs were < 1 mm in size. White was the main color in water, black was the main color in sediment and soil samples. The most common MPs type was polyethylene (33 %) in water, while rayon accounted for the majority of MPs in sediment (42 %) and soil (70 %) samples. The redundancy analysis results showed that MPs in water and sediment were more affected by water quality, while soil MPs were easily affected by landscape pattern.

Natural polyelectrolyte self-assembled multilayers based on collagen and alginate: stability and cytocompatibility.

Scientific interest in the self-assembly of collagen composite films has been increasing for their potential application in constructing bioactive materials. Here we report a highly stable and cytocompatible collagen/alginate (COL/ALG) ultrathin film, which was linearly fabricated via a layer-by-layer self-assembled technique. The variation in morphology and thickness of the films in air and in solutions with different pH and ion values were tested by atomic force microscopy. Results showed that the solutions with high pH values or solutions that contained electrolytes would disintegrate the film, while films with that were cross-linked for a long time prevented the dissolution and contributed to stability maintenance of the films. Interestingly, the COL/ALG coating not only improved the adhesion and proliferation of the human periodontal ligament cells, but also modified the morphology and migration of cells on the surface of glass and poly-L-lactic acid (PLA) electrospun scaffolds. In conclusion, the COL/ALG ultrathin films were highly stable and cytocompatible and could be easily fabricated by the cost-effective self-assembled technique presented. The findings of this study have the potential to play an important role in the surface modification of biomaterials.

Facile synthesis of chitosan-based nanogels through photo-crosslinking for doxorubicin delivery.

Chitosan-based nanogels are effective carriers for drug delivery due to their biocompatibility and biodegradability. However, the chemically cross-linked nanogels usually require complicated procedures or tough conditions. Herein, we report a simple approach to generate chitosan-based nanogels by photo-crosslinking of poor solvent-induced nanoaggregates without requiring any emulsifying agent, catalyst, or external crosslinker. O-nitrobenzyl alcohol-modified carboxymethyl chitosan was synthesized and self-crosslinked into the nanogels in a mixed solution of ethanol and water under 365 nm light irradiation due to UV-induced primary amine and o-nitrobenzyl alcohol cyclization. The nanogels (CMC-NBA NPs) and lactobionic acid-decorated nanogels (LACMC-NBA NPs) displayed a uniform diameter (~200 nm) and excellent stability under physiological conditions. Notably, the nanogels exhibited a high loading content (~28 %) due to π-π stacking and electrostatic interactions between doxorubicin (DOX) and the carriers. These DOX-loaded nanogels showed rapid drug release under slightly acidic conditions. The cell and animal experiments confirmed that LACMC-NBA NPs increased cellular uptake, improved cytotoxicity in tumor cells, and enhanced growth inhibition in vivo than CMC-NBA NPs. Thus, these photo-crosslinked nanogels possess great potential for DOX delivery.

The composite sandwich structure of dNCPs polyelectrolyte multilayers induced the osteogenic differentiation of PDLSCs in vitro.

This study reported about the fabrication of dentin non-collagenous proteins (dNCPs) polyelectrolyte multilayers and evaluated its osteogenic potential. The composite sandwich structure of dNCPs polyelectrolyte multilayers was generated on the surface of polycaprolactone electrospinning membranes by the Layer-by-Layer self-assembly technique. The dNCPs-coated membranes comprised the experimental group and the non-coated membranes acted as the control. Nanofiber morphologies of both membranes were observed under scanning electron microscope. The release of dNCPs was evaluated by ELISA kit. Periodontal ligament stem cells (PDLSCs) were seeded on both membranes. The morphology changes and proliferation of cells were tested. The expressions of osteogenic-related genes and proteins were evaluated by RT-PCR, alkaline phosphatase (ALP) activity assay, and immunofluorescence staining. dNCPs-coated membranes displayed significantly different fiber morphology than the non-coated membranes. A stable release of dentin phosphoprotein was maintained from day 4 to day 15 in the experimental group. Cells on dNCPs-coated membranes were found to have cuboidal or polygonal shapes. The proliferative rate of cells was significantly lower in the experimental group from day 4 to day 9 (p<0.05). However, cells on the dNCPs-coated membranes demonstrated a significantly higher ALP content and expression levels of osteogenic gene and proteins than the controls (p<0.05). These results indicated that dNCPs polyelectrolyte multilayers could induce the osteogenic differentiation of PDLSCs in vitro.

Comprehensive tissue-specific gene set enrichment analysis and transcription factor analysis of breast cancer by integrating 14 gene expression datasets.

Breast cancer is the most commonly diagnosed malignancy in women. Several key genes and pathways have been proven to correlate with breast cancer pathology. This study sought to explore the differences in key transcription factors (TFs), transcriptional regulation networks and dysregulated pathways in different tissues in breast cancer. We employed 14 breast cancer datasets from NCBI-GEO and performed an integrated analysis in three different tissues including breast, blood and saliva. The results showed that there were eight genes (CEBPD, EGR1, EGR2, EGR3, FOS, FOSB, ID1 and NFIL3) down-regulated in breast tissue but up-regulated in blood tissue. Furthermore, we identified several unreported tissue-specific TFs that may contribute to breast cancer, including ATOH8, DMRT2, TBX15 and ZNF367. The dysregulation of these TFs damaged lipid metabolism, development, cell adhesion, proliferation, differentiation and metastasis processes. Among these pathways, the breast tissue showed the most serious impairment and the blood tissue showed a relatively moderate damage, whereas the saliva tissue was almost unaffected. This study could be helpful for future biomarker discovery, drug design, and therapeutic and predictive applications in breast cancers.