Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

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Sustainable polymers from renewable resources

Chemical modification of lignins: Towards biobased polymers

Synthesis, properties, and applications of magnetic iron oxide nanoparticles

A review on pyrolysis of plastic wastes

Aim: To present the research results concerning enhanced antimicrobial and release properties of the chitosan derivative with sulfadiazine/hyaluronic acid polyelectrolyte complex (PEC) hydrogel. Material and methods: The PECs have been prepared from chitosan of different molecular weight, sulfadiazine chitosan derivative and sodium hyaluronate. The complex structure was assessed by FT-IR spectroscopic method and swelling capacity was followed by weighing measurements. Results: It has been establish that chitosan derivative influenced both PEC properties and swelling capacity. Conclusions: Incorporation in PEC of the sulfadiazine chitosan is a new way to combine bacteriostatic effect of chitosan with that of sulfadiazine, to control properties, antimicrobial activity in the treatment of the wound.

Sulfadiazine modified CS/HA PEC destined to wound dressing.

UNLABELLED The International Diabetes Federation reported that 246 million adults worldwide had diabetes mellitus and the prevalence of this syndrome was expected to increase continuously. AIM To design new compound with potential antidiabetic and antioxidant activity. MATERIAL AND METHODS New benzylidene-thiazolidine derivatives (BT2a-2e) were obtained by condensation of xanthine-thiazolidine-4-one (TZ-4-one) with aromatic aldehydes. The synthesized compounds were characterized by spectral method (IR, 1H-NMR, 13C-NMR) and their antioxidant potential has been also evaluated. RESULTS The synthesized compounds have important antioxidant effects as compared to xanthine-thiazolidine derivatives. The most active compounds were those obtained by condensation with 4-dimethylaminobenzaldehyde (BT2c) and 4-nitro-benzaldehyde (BT2e). CONCLUSIONS The chemical modulations performed on the structure of TZD-4-one have a good influence on their antioxidant potential.

Synthesis and evaluation of antioxidant activity of some new benzylidene-thiazolidine-xanthine derivatives

In this paper, the behavior of modified/unmodified organosolv lignin (Alcell) solutions has been studied. Organosolv lignin was modified with different carboxylic acids, such as oleic, butyric, lactic acids and butyrolactone under cold plasma discharge. The modified lignins were characterized by particle size analysis and zeta potential measurements in water and alkaline solutions. It has been established that modification with different carboxylic acids, such as oleic, butyric, lactic acids, and butyrolactone under cold plasma discharge leads to structural and morphology changes of the solution properties for each kind of modified lignin. By cold plasma functionalization, solubility is changed, particle size and conductivity of aqueous solutions decrease, homogeneity decreases and zeta potential takes values close to the stability limit for dispersions. All these characteristics vary with the pH of solutions. In alkaline medium, the sizes of the lignin particles had a bimodal distribution, comparatively with the case of weak alkaline and acidic media. In acidic medium, the lignin associates had the greatest hydrodynamic values.

Solution properties of some modified lignins

On a etudie la decomposition photooxidative des mixtures temaires IPP/LER/PP-g-GMA. On a etablie que pour de concentrations relativement hauts de LER/PP-g-GMA on peut obtenir de melanges IPP/Lignine epoxidisee photodegradable. La conclusion est soutenue par les resultats de microscopie optique et electronique, proprietes superficielles et thermiques, spectroscopies IR et UV.

Polyolefins/lignosulfonates blends. III. Photooxidation of isotactic polypropylene epoxidized lignosulfonates blends

Gene therapy has exacerbated an impressive interest of researchers from different fields and has gained special attention in the last 20 years mainly because it promises a huge potential to cure or prevent various diseases, being a completely new discipline, both conceptually and technically. This chapter overviews the advances in the design and testing polymeric nanoparticles for gene therapies and is focused on the aim of using nanotechnology to increase the effectiveness of gene delivery and to decrease cellular toxicity. The different strategies to obtain nucleic acids–based nanotherapeutics are described, accompanied by various relevant examples of efficient polymeric nanoparticles employed in nucleic acids delivery. Polymeric nanoparticles are used as nonviral gene carriers and they are engineered to avoid the risks that viruses imply. Nanotechnology is used in gene therapy to design polymeric materials that can overcome extra- and intracellular barriers and to present efficient transfection.

Cornelia Vasile

Papers

Sulfadiazine modified CS/HA PEC destined to wound dressing.

Synthesis and evaluation of antioxidant activity of some new benzylidene-thiazolidine-xanthine derivatives

Solution properties of some modified lignins

Polyolefins/lignosulfonates blends. III. Photooxidation of isotactic polypropylene epoxidized lignosulfonates blends

Nucleic Acids–based Bionanomaterials for Drug and Gene Therapy