Generating of induced pluripotent stem cells (iPSCs) can be achieved by ectopic expression of defined transcription factor sets. However, most instances of iPSC induction have been achieved using viral vectors, which carry the risk of unpredictable genetic dysfunction. Here, for the first time, a non‐viral vector based on calcium phosphate nanoparticles for the generation of virus‐free iPSCs from human umbilical cord mesenchymal stem cells (HUMSCs) via co‐delivery of the four plasmids (Oct4, Sox2, Klf4, and c‐Myc) is reported. As a result, a total of 98 colonies from 200 000 cells have been obtained, with a reprogramming efficiency of 0.049%. The iPSCs shows positive expression of pluripotency markers, including OCT4, SSEA‐3, SSEA‐4, NANOG, and TRA‐1‐81. Moreover, the iPSCs are able to differentiate into all three germ layers in vitro. Subcutaneous injection of the iPSCs into immunocompromised mice results in the formation of teratomas containing a variety of tissues from all three germ layers. These findings indicate that co‐delivery of the four Yamanaka factors via plasmid‐encapsulated calcium phosphate nanoparticles can provide a simple, safe, and efficient method for the generation of virus‐free iPSCs, which is crucial for their future clinical applications in the field of regenerative medicine.

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Pleurotus eryngii is a medicinal/edible mushroom with great nutritional value and bioactivity. Its polysaccharide has recently been developed into an effective gene vector via cationic modification. In the present study, cationized P. eryngii polysaccharide (CPS), hybridized with calcium phosphate (CP), was used to codeliver plasmids (Oct4, Sox2, Klf4, c-Myc) for generating induced pluripotent stem cells (iPSCs). The results revealed that the hybrid nanoparticles could significantly enhance the process and efficiency of reprogramming (1.6-fold increase) compared with the CP nanoparticles. The hybrid CPS also facilitated epigenetic modification during the reprogramming. Moreover, these hybrid nanoparticles exhibited multiple pathways (both caveolae- and clathrin-mediated endocytosis) in their cellular internalization, which accounted for the improved iPSCs generation. These findings therefore present a novel application of P. eryngii polysaccharide in pluripotent reprogramming via active epigenetic modification.

Polyketides are a large group of natural biomolecules that are normally produced by bacteria, fungi and plants. These molecules have clinical importance due to their anti-cancer, anti-microbial, anti-oxidant and antiinflammatory properties. Polyketides are biosynthesized from units of acyl-CoA by different polyketide synthases (PKSs), which display wide diversity of functional domains and mechanisms of action between fungi and bacteria. Coculture of different microorganisms can produce novel products distinctive from those produced during single cultures. This study compared the new polyketides produced in such co-culture systems and discusses aspects of the cultivation systems, product structures and identification techniques. Current results indicate that the formation of new polyketides may be the result of activation of previously silent PKSs genes induced during co-culture. This review indicated a potential way to produce pure therapeutic polyketides by microbial fermentation and a potential way to develop functional foods and agricultural products using co-co-culture of different microorganisms. It also pointed out a new perspective for studies on the process of functional foods, especially those involving multiple microorganisms .

Lactobacillus rhamnosus can convert DON to 3-epi-DON in vitro and reduce DON toxicity in vivo.

Small heat shock proteins (sHSPs) are heat shock proteins sized 12-43 kDa that can protect proteins from denaturation, particularly under high temperature; sHSPs thus increase the heat tolerance capability of an organisms enabling survival in adverse climates. sHSP20 is overexpressed in Oenococcus oeni in response to low temperatures. However, we found that overexpression of sHSP20 in Escherichia coli BL21 increased the microbial survival ratio at 50 °C by almost 2 h. Adding sHSP20 to the glutamate dehydrogenase solution significantly increased the stability of the enzyme at high temperature (especially at 60-70 °C), low pH values (especially below 6.0), and high concentration of metal ions of Ga, Zn, Mn, and Fe. Notably, the coexpression of sHSP20 significantly enhanced soluble expression of laccase from Phomopsis sp. XP-8 (CCTCCM209291) in E. coli without codon optimization, as well as the activity and heat stability of the expressed enzyme. In addition to the chaperone activity of sHSP20 in the gene containing host in vivo and the enzyme heat stability in vitro, our study indicated the capability of coexpression of sHSP20 to increase the efficiency of prokaryotic expression of fungal genes and the activity of expressed enzymes. Graphical abstract ᅟ.

The main purpose of this article is to investigate the qualitative effects of different factors on the response of forced vibration of shape memory alloy spring oscillator. Specially, the introduction of dry friction factor causes the governing equations to change from a smooth system to a (Filippov-type) non-smooth system in which the sliding phenomenon was observed. The mechanism, geometric structure, and analytic conditions of sliding bifurcations in a general ndimensional piecewise smooth system were discussed in detail. The theoretical results obtained are verified by numerical analysis, and the feasibility of involved theories is estimated by calculation of sliding time.