A New Strategy for Nucleic Acid Delivery and Protein Expression Using Biocompatible Nanohydrogels of Predefined Sizes.

We have developed new formulations of nanohydrogels (NHGs) complexed with DNA devoid of cell toxicity, which, together with their tuned sizes, makes them of great interest for delivering DNA/RNA for foreign protein expression. Transfection results demonstrate that, unlike classical lipo/polyplexes, the new NHGs can be incubated indefinitely with cells without apparent cellular toxicity, resulting in the high expression of foreign proteins for long periods of time. Although protein expression starts with a delay as compared to classical systems, it is sustained for a long period of time, even after passing cells without observation of toxicity.

New Biocompatible Nanohydrogels of Predefined Sizes for Complexing Nucleic Acids.

The advent of protein expression using m-RNA applied lately for treating the COVID pandemic, and gene editing using CRISPR/Cas9 technology for introducing DNA sequences at a specific site in the genome, are milestones for the urgent need of developing new nucleic acid delivery systems with improved delivery properties especially for in vivo applications. We have designed, synthesized, and characterized novel cross-linked monodispersed nanohydrogels (NHG's) with well-defined sizes ranging between 50-400 nm. The synthesis exploits the formation of self-assemblies generated upon heating a thermo-responsive mixture of monomers.

Solid-Phase Multicomponent Synthesis of 3-Substituted Isoindolinones Generates New Cell-Penetrating Probes as Drug Carriers.

A modular solid-phase multicomponent reaction for the synthesis of 3-substituted isoindolinone derivatives has been carried out. A mixture of a chiral β-keto lactam, an aldehyde, an isocyanide and a dienophile react to produce chiral 3-substituted isoindolinones in one pot. Modularity was accomplished by using solid supported aldehydes and dienophiles.

A peptide from Testudo horsfieldii tortoise spleen as a potential helper for reducing acute radiation syndrome.

The Middle Asian tortoise Testudo horsfieldii is one of the most radioresistant animals, with Lethal Dose (LD) 50/30 around 500 Gy. Extracts were prepared from different organs of the tortoise, and their biological activity was evaluated. Crude extract from the spleen was found to significantly increase survival of mice treated with lethal doses of radiation.

Matrix-assisted peptide synthesis on nanoparticles.

We report a new method for multistep peptide synthesis on polymeric nanoparticles of differing sizes. Polymeric nanoparticles were functionalized via their temporary embedment into a magnetic inorganic matrix that allows multistep peptide synthesis. The matrix is removed at the end of the process for obtaining nanoparticles functionalized with peptides.

Computational identification of antigen-binding antibody fragments.

Determining which parts of the Ab are essential for Ag recognition and binding is crucial for understanding B cell-mediated immunity. Identification of fragments of Abs that maintain specificity to the Ag will also allow for the development of improved Ab-based therapy and diagnostics. In this article, we show that structural analysis of Ab-Ag complexes reveals which fragments of the Ab may bind the Ag on their own.

Improved methods for thermal rearrangement of alicyclic α-hydroxyimines to α-aminoketones: synthesis of ketamine analogues as antisepsis candidates.

Ketamine is an analgesic/anesthetic drug, which, in combination with other drugs, has been used as anesthetic for over 40 years. Ketamine induces its analgesic activities by blocking the N-methyl-D-aspartate (NMDA) receptor in the central nervous system (CNS). We have reported that low doses of ketamine administrated to patients before incision significantly reduced post-operative inflammation as reflected by reduced interleukin-6 (IL-6) sera-levels.

Synthesis and functionalization of persistent luminescence nanoparticles with small molecules and evaluation of their targeting ability.

We have recently reported the design and use of inorganic nanoparticles with persistent luminescence properties. Such nanoparticles can be excited with a UV lamp for 2min and emit light in the near-infrared area for dozen of minutes without any further excitation. This property is of particular interest for small animal optical imaging, since it avoids the autofluorescence of endogenous fluorophores which is one major problem encountered when using fluorescent probes.

Fully synthetic phage-like system for screening mixtures of small molecules in live cells.

A synthetic "phage-like" system was designed for screening mixtures of small molecules in live cells. The core of the system consists of 2 mum diameter cross-linked monodispersed microspheres bearing a panel of fluorescent tags and peptides or small molecules either directly synthesized or covalently conjugated to the microspheres. The microsphere mixtures were screened for affinity to cell line PC-3 (prostate cancer model) by incubation with live cells, and as was with phage-display peptide methods, unbound microspheres were removed by repeated washings followed by total lysis of cells and analysis of the bound microspheres by flow-cytometry.

Fast and versatile microwave-assisted intramolecular Heck reaction in peptide macrocyclization using microwave energy.

We have revisited the intramolecular Heck reaction and investigated the microwave-assisted macrocyclization on preformed peptides using a model series of ring-varying peptides acryloyl-Gly-[Gly](n)-Phe(4-I)NHR; n = 0-4. The method was applied to both solution and solid supported cyclizations. We demonstrate that the intramolecular Heck reaction can be performed in peptides both in solution and solid support using a modified domestic microwave within 1 to 30 minutes in DMF under reflux with moderate yields ranging from 15 to 25% for a scale between 2-45 mg of linear precursors.

Involvement of adenosine in the antiinflammatory action of ketamine.

Background: Ketamine is an anesthetic drug. Subanesthetic doses of ketamine have been shown to reduce interleukin-6 concentrations after surgery and to reduce mortality and the production of tumor necrosis factor alpha and interleukin 6 in septic animals. Similarly, adenosine was shown to reduce tumor necrosis factor alpha and mortality of septic animals.

Approaches for introducing high molecular diversity in scaffolds: fast parallel synthesis of highly substituted 1H-quinolin-4-one libraries.

We have developed a two steps strategy for the parallel synthesis of highly diversified quinolin-ones. In the first step we have combined and improved different synthetic methods for generating quinolin-4-ones bearing four different substitutions at specific positions using round bottomed flasks. The synthesis was assessed for a large number of substituted quinolin-4-ones.

Anomalous regioselective four-member multicomponent Biginelli reaction II: one-pot parallel synthesis of spiro heterobicyclic aliphatic rings.

In a previous preliminary study, we found that a cyclic five-member ring beta-keto ester (lactone) reacts with one molecule of urea and two of aldehyde to give a new family of spiro heterobicyclic aliphatic rings in good yields with no traces of the expected dihydropyrimidine (Biginelli) products. The reaction is driven by a regiospecific condensation of two molecules of aldehyde with urea and beta-keto-gamma-lactone to afford only products harboring substitutions exclusively in a syn configuration (Byk, G.; Gottlieb, H.

Correction of anemia in uremic mice by genetically modified peritoneal mesothelial cells.

Background: During peritoneal dialysis, mesothelial cells become detached from the peritoneum and accumulate in the dialysate. Our aim was to evaluate the potential of peritoneal effluent (PF)-derived human peritoneal mesothelial cells (HPMC) as target for gene therapy. We used erythropoietin (EPO) as our target gene.

Optimization of cationic lipid mediated gene transfer: structure-function, physico-chemical, and cellular studies.

The rationale design aimed at the enhancement of cationic lipid mediated gene transfer is discussed. These improvements are based on the straight evaluation of the structure-activity relationship and on the introduction of new structures. Much attention have been given to the supramolecular structures of the lipid/DNA complexes, to the effect of serum on gene transfer and to the intracellular trafficking of the lipoplexes.

Design, synthesis, and evaluation of gadolinium cationic lipids as tools for biodistribution studies of gene delivery complexes.

Gadolinium-chelating cationic lipids have been synthesized to obtain lipoplexes with MRI contrast properties. These compounds were designed to follow the biodistribution of synthetic DNA for gene delivery by nuclear magnetic resonance imaging. The lipid MCO-I-68 was synthesized, and chelate complexes with gadolinium were formed and characterized in terms of physicochemical and DNA binding properties.