Synthesis of Poly(L-lactide)-poly(ε-caprolactone)-poly(ethylene glycol) Terpolymer Grafted onto Partially Oxidized Carbon Nanotube Nanocomposites for Drug Delivery.

Nanocomposites prepared with a terpolymer of poly(L-lactide) (PLLA)-poly(ε-caprolactone) (PCL)-poly(ethylene glycol) (PEG) and partially oxidized carbon nanotubes (CNTs) were synthesized and characterized to evaluate their ability to act as an effective nanocarrier of the anticancer drug methotrexate. The homopolymers of PLLA and PCL were synthesized through ring-opening polymerization (ROP) and characterized through gel permeation chromatography (GPC). The PLLA-PCL-PEG terpolymers were synthesized through a four-step chemical route using oxalyl chloride as a linker agent and analyzed with H-NMR, C-NMR, and FTIR spectroscopies.

Synthesis of Novel Fluoro Phenyl Triazoles Click Chemistry with or without Microwave Irradiation and their Evaluation as Anti-proliferative Agents in SiHa Cells.

Aims: Perform the synthesis of novel fluoro phenyl triazoles click chemistry with or without microwave irradiation and their evaluation as anti-proliferative agents in SiHa cells.

Background: Triazoles are heterocyclic compounds containing a five-member ring with two carbon and three nitrogen atoms. They are of great importance since many of them have shown to have biological activity as antifungal, antiviral, antibacterial, anti-HIV, anti-tuberculosis, vasodilator, and anticancer agents.

Bio-Catalysis for the Functionalization of Cellulose Nanocrystals.

In this work, the chemical modification of cellulose nanocrystals (NCs) using an enzyme as a catalyst has been performed by a “grafting from” reaction, in order to covalently functionalize the external surface of NCs with both poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL) by ring-opening polymerization. Firstly, cellulose nanocrystals were prepared from commercial cellulose microcrystals by acid hydrolysis and then functionalized by using Yarrowia lipolytica lipase immobilized on Lewatit resin as a catalyst. To confirm the success of the grafting reactions, 1H-NMR has been performed as well as FT-IR and Raman spectroscopy.

Semi-Continuous Heterophase Polymerization to Synthesize Poly(methacrylic acid)-Based Nanocomposites for Drug Delivery.

The design of nanocomposites with the potential for drug delivery is a topic of great interest. In this work, the synthesis of nanocomposites of poly(methacrylic acid) (PMAA) grafted onto carbon nanotubes (CNTs) functionalized with poly(amidoamine) (PAMAM) dendrimer by semicontinuous heterophase polymerization , at three different methacrylic acid (MAA) dosing rates, is reported. is a polymerization technique poorly used to prepare nanocomposites containing CNTs and has the potential to produce more ordered alkyl methacrylic polymer chains, which could favor the obtaining of a homogenous nanocomposite.

High-Performance Polyurethane Nanocomposite Membranes Containing Cellulose Nanocrystals for Protein Separation.

With the aim of exploring new materials and properties, we report the synthesis of a thermoplastic chain extended polyurethane membrane, with superior strength and toughness, obtained by incorporating two different concentrations of reactive cellulose nanocrystals (CNC) for potential use in kidney dialysis. Membrane nanocomposites were prepared by the phase inversion method and their structure and properties were determined. These materials were prepared from a polyurethane (PU) yielded from poly(1,4 butylene adipate) as a soft segment diol, isophorone diisocyanate (IPDI) and hexamethylenediamine (HMDA) as isocyanate and chain extender, respectively (hard segment), filled with 1 or 2% / CNC.

Synthesis of Poly(methacrylic acid-co-butyl acrylate) Grafted onto Functionalized Carbon Nanotube Nanocomposites for Drug Delivery.

Design of a smart drug delivery system is a topic of current interest. Under this perspective, polymer nanocomposites (PNs) of butyl acrylate (BA), methacrylic acid (MAA), and functionalized carbon nanotubes (CNTs) were synthesized by in situ emulsion polymerization (IEP). Carbon nanotubes were synthesized by chemical vapor deposition (CVD) and purified with steam.

Ultrasound-assisted reaction of 1,4-naphthoquinone with anilines through an EDA complex.

Naphthoquinone amino derivatives exhibit interesting physicochemical properties and a wide range of biological activities with potential medicinal applications. A clean, fast and simple method for the preparation of phenylamino-1,4-naphthoquinones is presented by the reaction of naphthoquinone (NQ) and anilines under ultrasound irradiation (US). Anilino derivatives were synthesized in good yields and shorter reaction times in comparison with the conventional method.

Yarrowia lipolytica Extracellular Lipase Lip2 as Biocatalyst for the Ring-Opening Polymerization of ε-Caprolactone.

(YL) is a "non-conventional" yeast that is capable of producing important metabolites. One of the most important products that is secreted by this microorganism is lipase, a ubiquitous enzyme that has considerable industrial potential and can be used as a biocatalyst in the pharmaceutical, food, and environmental industries. In this work, lipase (YLL) was immobilized on Lewatit and Amberlite beads and is used in the enzymatic ring-opening polymerization (ROP) of cyclic esters in the presence of different organic solvents.

In Vitro Studies of Chromone-Tetrazoles against Pathogenic Protozoa, Bacteria, and Fungi.

In vitro studies to fourteen previously synthesized chromone-tetrazoles and four novel fluorine-containing analogs were conducted against pathogenic protozoan (Entamoeba histolytica), pathogenic bacteria (Pseudomonas aeruginosa, and Staphylococcus aureus), and human fungal pathogens (Sporothrix schenckii, Candida albicans, and Candida tropicalis), which have become in a serious health problem, mainly in tropical countries.

Synthesis of novel bis-1,5-disubstituted-1H-tetrazoles by an efficient catalyst-free Ugi-azide repetitive process.

A series of five novel bis-1,5-disubstituted-1H-tetrazoles (bis-1,5-DS-1H-T) were quickly prepared by a catalyst-free Ugi-azide repetitive process from easily accessible starting materials in excellent yields, either at room temperature (88%-95%) or using mild MW-heating conditions (80%-91%). These molecules may have a wide range of applications, such as chelating agents, organocatalysts and luminescent materials, and mainly as bioactive compounds.

Synthesis of biodegradable polymers using biocatalysis with Yarrowia lipolytica lipase.

Yarrowia lipolytica lipase (YLL) was used as catalyst in the enzymatic ring-opening polymerization (ROP) of ε-caprolactone. This low-cost solid-state lipase produces low-molecular-weight polyesters with unique multiphase morphology as determined by carbon-13 NMR. YLL attaches sugar head groups to polycaprolactone in a one-pot biocatalytic pathway.

Optofluidic variable focus lenses.

Here we propose optofluidic spherical microlenses that can change their focal distance by varying the refractive index of the liquid that composes them. These lenses are fabricated in the bulk of a polymeric mixture. Results of a characterization study of the profile of the lenses, the image forming capability, and the behavior of the focal distance as a function of the refractive index are presented.

Carbon-13 CP-MAS nuclear magnetic resonance studies of teas.

13C CP-MAS NMR spectra of green and black tea were obtained and assigned based on the solid-state NMR spectra of tropolone, (+)-catechin hydrate, gallic acid, caffeine and flavone derivatives. The peak shape and chemical shifts observed for carbonyl carbons in CP-MAS spectra of teas indicate the existence of different chemical species, mainly free phenollic acids and ester derivatives of flavonoids. The peak patterns allow to establish differences between both teas.