Reducing the Flocculation of Milk Tea Using Different Stabilizers to Regulate Tea Proteins.

The regulation of flocs derived from polyphenol-protein formation in milk tea has not been fully explored. In this study, the flocculation of milk tea was regulated by adding 10 kinds of stabilizers with different characteristics. The stability coefficient and centrifugal precipitation rate were used as indexes. The optimal concentration ratio of the complex stabilizer was identified using the response surface methodology (RSM), being 0.04% for Arabic gum, 0.02% for ß-cyclodextrin and 0.03% for Agar. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the characteristics of different stabilizers in milk tea, and our findings were as follows: (1) The relative strength of the peaks in different stable systems was different. The absorption peaks were mainly near the wave numbers 3376 cm-1, 2928 cm-1, 1655 cm-1, 1542 cm-1, 1408 cm-1, 1047 cm-1 and 925 cm-1. (2) The milk tea system was an amorphous structure. The diffraction peak of the composite system was observed to be about 20°. The crystallinity of the milk tea in the compound group was 33.16%, which was higher than that of the blank group (9.67%). (3) The compound stabilizer reduced flocculation, and the stabilizing agents improved the surface order of milk tea. These results indicate that the combination of polysaccharide stabilizers (Arabic gum and agar) and oligosaccharide stabilizers (ß-CD) in certain proportions can regulate the flocculation of milk tea and improve its stability. The potential research avenues involving polyphenol-protein complex instability systems and their applications in food development are expanded by this work.

Preparation, characterization, and antibacterial effect of bio-based modified starch films.

There are several problems with common starch films, including strong water absorption and poor mechanical properties. To create a better starch film, octenyl succinate cassava starch ester (OSCS) was first blended with chitosan and nano ZnO to prepare an OSCS/CS/ZnO film. Then, the film was supplemented with different concentrations of ε-PL as a bacteriostatic agent to prepare a film that would resist bacterial invasion. The mechanical properties, barrier properties, optical properties, and color of the modified starch antibacterial films were investigated, and finally the antibacterial properties and cytotoxicity were tested. The results demonstrated that the modified starch antibacterial film had good mechanical properties, improved surface hydrophobicity, and had a UV-blocking effect. The modified starch antibacterial film with ε-PL of 8% had stable and long-lasting antibacterial properties, stable release, and good cytocompatibility. An active packaging material was successfully prepared using ε-PL and had a strong preservative effect on food.

Metabolomic Characterization of a cf. Neolyngbya Cyanobacterium from the South China Sea Reveals Wenchangamide A, a Lipopeptide with In Vitro Apoptotic Potential in Colon Cancer Cells.

Metabolomics can be used to study complex mixtures of natural products, or secondary metabolites, for many different purposes. One productive application of metabolomics that has emerged in recent years is the guiding direction for isolating molecules with structural novelty through analysis of untargeted LC-MS/MS data. The metabolomics-driven investigation and bioassay-guided fractionation of a biomass assemblage from the South China Sea dominated by a marine filamentous cyanobacteria, cf. Neolyngbya sp., has led to the discovery of a natural product in this study, wenchangamide A (1). Wenchangamide A was found to concentration-dependently cause fast-onset apoptosis in HCT116 human colon cancer cells in vitro (24 h IC50 = 38 µM). Untargeted metabolomics, by way of MS/MS molecular networking, was used further to generate a structural proposal for a new natural product analogue of 1, here coined wenchangamide B, which was present in the organic extract and bioactive sub-fractions of the biomass examined. The wenchangamides are of interest for anticancer drug discovery, and the characterization of these molecules will facilitate the future discovery of related natural products and development of synthetic analogues.

Expanding Cyclic Topology-Based Biomedical Polymer Panel: Universal Synthesis of Hetero-"8"-Shaped Copolymers and Topological Modulation of Polymer Degradation.

8-Shaped copolymers with two macrocycles connected together represent an interesting cyclic topology-derived polymer species due to the simultaneous incorporation of two cyclic moieties and the reported unique physical and chemical properties. To provide a proof-of-concept for a broad readership on biomedical polymers, a well-defined hetero-8-shaped amphiphilic copolymer, cyclic-poly(oligo(ethylene glycol)monomethyl ether methacrylate)-b-cyclic PCL (cPOEGMA-b-cPCL) is synthesized by an elegant integration of intrachain click cyclization and interchain click coupling. The potential of the self-assembled micelles of cPOEGMA-b-cPCL for controlled drug release is evaluated by in vitro drug loading and drug release, cellular uptake, cytotoxicity, and degradation studies. Most importantly, the micelles based on cPOEGMA-b-cPCL show much slower degradation profiles than the previously reported linear counterpart, POEGMA-b-PCL and tadpole-shaped analog, PEG-b-cPCL because of the presence of cyclic hydrophilic POEGMA segment. Therefore, this study not only develops a robust strategy for a universal precise synthesis of well-defined hetero-8-shaped copolymers based on diverse vinyl and ring-structured monomers, but also reveals the first modulation of polymer degradation property by topological control of the nondegradable moiety in the polymer construct through advanced macromolecular engineering.

[Effect of siRNA targeting PML-RARa fusion gene on activity of the acute promyelocytic leukemia cell line NB4].

This study aims to investigate the effects of small interference RNA (siRNA) targeting PML-RARa mRNA on the activity of the acute promyelocytic leukemia cell line NB4. The proliferation inhibition was evaluated by MTT assay and colony-formation inhibiting test. Apoptosis was determined by flow cytometry after siRNA treatment. The results showed that the cell growth of siRNA treated group was inhibited, and the apoptosis of NB4 could be induced. The siRNA targeting PML-RARα mRNA might be a valid therapy of acute promyelocytic leukemia.