News

New article: Fabrication of hydrogel scaffolds via photocrosslinking of methacrylated silk fibroin.

Bessonov I1, Rochev Y2, Arkhipova A3, Kopitsyna M4, Bagrov D1, Karpushkin E5, Bibikova T1, Moysenovich A6, Soldatenko A1, Nikishin I1, Kotliarova M1, Bogush V7, Shaitan K1, Moisenovich M3.

Silk fibroin is a promising biomaterial for tissue engineering due to its valuable mechanical and biological properties. However, being a natural product and a protein, it lacks the processability and uniform quality of an advanced synthetic material. Here we propose a way to overcome this contradiction using novel fibroin photocrosslinkable derivative (FBMA).
 FBMA was synthesized by methacrylation of native fibroin nucleophilic side groups. It was dissolved in either formic acid (FA) or hexafluoroisopropanol (HFIP), and the obtained solutions were photocrosslinked into hydrogel scaffolds of various structural forms including films, micropatterns, pads, and macroporous sponges. UV-exposition of dry FBMA films through a photomask created complex microscaled patterns of the polymer. The nature of the solvent affected the properties of resulting hydrogels. When HFIP was used as the solvent, the resulting hydrogels had a storage modulus ~4 times higher than that of hydrogels fabricated using FA and ~20 times higher compared to the reference hydrogel obtained from pristine fibroin. Both FBMA-based hydrogels were biocompatible and supported fibroblast adhesion and growth in vitro. Cells cultivated on FBMA scaffolds produced with HFIP exhibited more spread phenotype at 4 and 24 hours of cultivation, consistent with increased stiffness of the hydrogel. 
 Hence, FBMA is an attractive material for fabrication of micropatterned scaffolds of centimeter-scale size with minutely tunable physico-chemical properties via convenient and reproducible technological processes, applicable for rapid prototyping.

New article: Spectrophotometric determination of lactic acid

August 2016 Journal of Analytical Chemistry 71(8):755-758

DOI: 10.1134/S1061934816080037

L. N. BorshchevskayaL. N. Borshchevskaya Tatiana GordeevaTatiana Gordeeva A. N. Kalinina Sergey Pavlovich. SineokySergey Pavlovich. Sineoky

New article in Cell by Alex Mironov: Bacterial Nitric Oxide Extends the Lifespan of C. elegans.

Ivan Gusarov, Laurent Gautier, Olga Smolentseva, Ilya Shamovsky, Svetlana Eremina, Alexander Mironov, Evgeny Nudler

Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA.

Cell (impact factor: 32.4). 02/2013; 152(4):818-30. DOI:10.1016/j.cell.2012.12.043

ABSTRACT Nitric oxide (NO) is an important signaling molecule in multicellular organisms. Most animals produce NO from L-arginine via a family of dedicated enzymes known as NO synthases (NOSes). A rare exception is the roundworm Caenorhabditis elegans, which lacks its own NOS. However, in its natural environment, C. elegans feeds on Bacilli that possess functional NOS. Here, we demonstrate that bacterially derived NO enhances C. elegans longevity and stress resistance via a defined group of genes that function under the dual control of HSF-1 and DAF-16 transcription factors. Our work provides an example of interspecies signaling by a small molecule and illustrates the lifelong value of commensal bacteria to their host.

Another article in Science: "H2S: A Universal Defense Against Antibiotics in Bacteria"

H2S: A Universal Defense Against Antibiotics in Bacteria

Science 334, 986 (2011); DOI: 10.1126/science.1209855

Konstantin Shatalin,1 Elena Shatalina,1 Alexander Mironov,2 Evgeny Nudler1*

Many prokaryotic species generate hydrogen sulfide (H2S) in their natural environments. However, the biochemistry and physiological role of this gas in nonsulfur bacteria remain largely unknown. Here we demonstrate that inactivation of putative cystathionine b-synthase, cystathionine g-lyase, or 3-mercaptopyruvate sulfurtransferase in Bacillus anthracis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli suppresses H2S production, rendering these pathogens highly sensitive to a multitude of antibiotics. Exogenous H2S suppresses this effect. Moreover, in bacteria that normally produce H2S and nitric oxide, these two gases act synergistically to sustain growth. The mechanism of gas-mediated antibiotic resistance relies on mitigation of oxidative stress imposed by antibiotics.

Bioengineering: Study results from GosNiigenetika, State Research Institute of Genetics and Selection of Industrial Microorganisms provide new insights into bioengineering

New Article: A novel model system for design of biomaterials based on recombinant analogs of spider silk proteins

Spider dragline silk possesses impressive mechanical and biochemical properties. It is synthesized by a couple of major ampullate glands in spiders and comprises of two major structural proteins--spidroins 1 and 2. The relationship between structure and mechanical properties of spider silk is not well understood. Here, we modeled the complete process of the spider silk assembly using two new recombinant analogs of spidroins 1 and 2.

The Ministry of Education and Science of the Russian Federation