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Symmetrical and dissymmetrical bolaforms were prepared with good to high yields from unsaturated L-rhamnosides and phenolic esters (ferulic, phloretic, coumaric, sinapic and caffeic) using two eco-compatible synthetic strategies involving glycosylation, enzymatic synthesis and cross-metathesis under microwaves activation. Furthermore, some of these new compounds present good eliciting properties depending on the carbon chain length and on the nature of the hydrophilic head. Their respective antioxidant activities have been also evaluated as well as their cytotoxic properties on dermal cells for cosmetic uses.

For this study, new dendrimers were prepared from poly(propylene imine) (PPI) and polyamidoamine (PAMAM) dendrimers using an efficient acid-base reaction with various phenolic acids. The syntheses were also optimized in both microwave and microfluidic reactors. These ionic and hydrophilic dendrimers were fully characterized and showed excellent antioxidant properties. Their cytotoxic properties have been also determined in the case of fibroblast dermal cells.

For this study, new dendrimers were prepared from poly(propylene imine) (PPI) and polyamidoamine (PAMAM) dendrimers using an efficient acid-base reaction with various phenolic acids. The syntheses were also optimized in both microwave and microfluidic reactors. These ionic and hydrophilic dendrimers were fully characterized and showed excellent antioxidant properties. Their cytotoxic properties have been also determined in the case of fibroblast dermal cells.

Paramylon is a linear β-1,3-glucan, similar to curdlan, produced as intracellular granules by the microalga Euglena gracilis, a highly versatile and robust strain, able to grow under various trophic conditions, with valorization of CO

International audience; Emission of volatile organic compounds (VOCs) in the atmosphere is a major health concern for the World Health Organization (WHO). For instance, more than 4 million premature deaths are attributed yearly to outdoor air pollution, thus calling for advanced remediation techniques. Absorption systems using solvents are commonly used to remove air pollutants, yet efficiency is limited by a solvent property, which is either hydrophilic or hydrophobic. As a consequence, classical solvents are not able to capture both hydrophilic and hydrophobic contaminants. Therefore, we synthesized the following ionic liquids from choline chloride and fatty acids: hexylcholinium levulinate, octylcholinium levulinate, hexylcholinium lactate and octylcholinium lactate. Ionic liquids were then tested for absorption of toluene, dichloromethane (CH2Cl2) and methyl ethyl ketone. Ionic liquids were characterized by 1H and 13C NMR, infrared spectroscopy, differential scanning calorimetry and thermal gravimetric analysis, density, viscosity and polarity. Vapor–liquid partition coefficients of VOC were determined for ionic liquids. We found that solvents were able to solubilize both hydrophobic and hydrophilic VOC. Moreover, no saturation was detected up to an initial VOC concentration of 3000 g/m3, whereas classical absorption processes usually involve gas streams containing VOC concentrations up to 1000 g/m3. Moreover, the solvent can be successfully recycled with unchanged capacity during five absorption–desorption cycles. Overall, our solvents appear promising for the treatment of industrial gaseous effluents.

A new gold nanoparticle-based construct has been designed to hydrophobic drugs delivery into cancer cells. Cyclodextrin scaffolds adsorbed on polyethyleneimine-coated gold nanoparticles (AuNP@PEI@CD) have been used to encapsulate hydrophobic tetrapyrrolic compounds consisting of gold complexes of 5,10,15,20-tetraphenyl porphyrin (AuTPPCl) and 5-(4-acetoxyphenyl)-10,15,20-triphenyl porphyrin (AuTPPOAcCl). These two nanoparticles have been tested for their cytotoxic activities against the two colorectal cancer cell lines HT-29 and HCT-116 and have shown significant increases in toxicity when compared to the corresponding non-vectorized tetrapyrrolic macrocycles.

Two protoporphyrin IX (PpIX) adamantane derivatives were synthesized and then metallated with zinc. The Zn-PpIX derivatives, exhibiting a high singlet oxygen quantum yield, were tested for their photodynamic activity against the HT-29 cell line. In order to enhance their water-solubility and their cellular bioavailability, these photosensitizers were encapsulated into the hydrophobic cavity of cyclodextrins (CD) previously attached to cellulose nanocrystals (CNCs) via electrostatic interactions. Under illumination, the encapsulated adamantanyl-porphyrins exerted an enhanced in vitro cytotoxicity, as compared with the corresponding free photosensitizers.

International audience; Two pentamethylcyclopentadienyl (Cp*) rhodium(III) and iridium(III) metalla-prisms of the general formula [(Cp*M)6(tpt)2(dhnq)3]6+ (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine, dhnq = 5,8-dihydroxy-1,4-naphthoquinonato; M = Rh, [1]6+; M = Ir, [2]6+) have been synthesized by mixing in methanol the neutral dinuclear complexes (Cp*M)2(dhnq)Cl2 (M = Rh, Ir), AgCF3SO3 and tpt. In a similar fashion, the addition of porphin during the formation of [1]6+ and [2]6+ leads to the carceplex systems [porphin⊂1]6+ and [porphin⊂2]6+. All complexes were isolated as their triflate salts and characterized by different analytical techniques including for the carceplex [porphin⊂1][CF3SO3]6 by a single-crystal X-ray structure analysis. The hosts were evaluated as drug delivery vectors on the HT-29 cancer cell line, and after internalization, porphin was photo-activated to generate phototoxicity. Interestingly, the IC50 values of the empty and filled metalla-cages are around 1 μM, while upon irradiation (20 J/cm2) only lower nanomolar concentrations of the [porphin⊂cage][CF3SO3]6 systems are necessary to inhibit cell growth by 50%, showing an excellent ratio between cytotoxicity and phototoxicity.

International audience; Glycerol-based ionic liquids were prepared by alkylation of solketal amines. These ones were easily obtained from tosyl solketal compound through a microwaves assisted amination without using solvent. This crucial step allowed the formation of various solketal amines in 50 min at 85 °C with high yields. The alkylation with Me3OBF4 led next to ionic liquids with BF4− as anion presenting a good thermal stability.

International audience; This Letter reports the synthesis and the characterization of two new water-stable and soluble photosensitizer-conjugated magnetic nanoparticles (PS-MNPs) composed of an iron oxide magnetic core coated with a biocompatible dextran shell bearing polyaminated chlorin p6. Designed to improve cancer cell targeting, these photosensitizers were assayed for their antitumour activity against two variants of B16 mouse melanoma cell line (B16F10 and B16G4F, with or without melanin, respectively). Cell viability measurements demonstrated that PS-MNPs were more phototoxic than PEI-chlorin p6 making these photosensitizers promising for further in vitro and in vivo investigations.

International audience; Porphyrin-polyamine conjugates bearing two (cis or trans position) or four spermidine or spermine units were synthesized. We studied the photostability, the hydrophilic/lipophilic balance of porphyrin-polyamine derivatives and the production of singlet oxygen. All these compounds possess physicochemical features required for their use in PDT. Then, we investigated the photocytotoxic efficacy of these porphyrin-polyamine derivatives and the cell death pathway implicated. All compounds appear to be more efficient than Photofrin® to induce HaCat and MCF7 cell death, essentially by apoptosis. Collectively, these data show that porphyrin-polyamine conjugates could be promising phototherapeutic agents.

A new anti-cancer drug delivery system, based on gold nanoparticles, has been designed for hydrophobic active compounds. The system is a conjugate of gold/polyethyleneimine (AuNPs/PEI) nanoparticles and sulphated β-cyclodextrin (CD). Anionic cyclodextrin was attached to the positively charged AuNPs/PEI nanoparticles by ionic bonds. Tanshinone IIA and α-mangostin were extracted, purified and encapsulated into the AuNPs/PEI/CD nanoparticles. In vitro preliminary cell viability assays against prostate cancer cell lines PC-3 and DU145 showed that encapsulation resulted in increased cytotoxicity.

International audience; The synthesis of curcumin-cyclodextrin/cellulose nanocrystals (CNCx) nano complexes was performed. CNCx were functionalized by ionic association with cationic β-cyclodextrin (CD) and CD/CNCx complexes were used to encapsulate curcumin. Preliminary in vitro results showed that the resulting curcumin-CD/CNCx complexes exerted antiproliferative effect on colorectal and prostatic cancer cell lines, with IC50s lower than that of curcumin alone.

International audience; We report on the synthesis of cellulose paper bearing a cationic porphyrin, designed for antimicrobial applications. Tricationic porphyrin has been covalently grafted on paper, without previous chemical modification of the cellulosic support, using 1,3,5-triazine derivative as linker. The obtained porphyrin-grafted paper was characterized by infrared (ATR-FTIR), UV-visible and diffuse reflectance UV-vis (DRUV) spectroscopies to confirm the triazine linkage. Thermogravimetric analysis (TGA) was used to investigate thermal properties of grafted paper. Antimicrobial activity of porphyrin-cellulose material was tested under visible light irradiation against Staphylococcus aureus and Escherichia coli. The two bacterial strains deposited on the resulting photosensitizing filter paper are efficiently killed after illumination.