Chitosan-Modified Polyethyleneimine Nanoparticles for Enhancing the Carboxylation Reaction and Plants' CO2 Uptake

Increasing plants' photosynthetic efficienc y is a major challenge that must be addressed in order to cover the food demands of the growing population in the changing climate. Photosynthes i s is greatly limited at the initial carboxylation reaction, where CO2 is converted to the organic acid 3-PGA, catalyzed by the RuBisCO enzyme. RuBisCO has poor affinity for CO2, but also the CO2 concentration at the RuBisCO site is limited by the diffusion of atmospheric CO2 through the various leaf compartments to the reaction site. Beyond genetic engineer-ing, nanotechnology can offer a materials-based approach for enhancing photosynthesis, and yet, it has mostly been explored for the light-dependent reactions. In this work, we developed polyethyleneimine-based nanoparticl e s for enhancing the carbox-ylation reaction. We demonstrate that the nanoparticles can capture CO2 in the form of bicarbonate and increase the CO2 that reacts with the RuBisCO enzyme, enhancing the 3-PGA production in in vitro assays by 20%. The nanoparticles can be introduced to the plant via leaf infiltration and, because of the functionalization with chitosan oligomers, they do not induce any toxic effect to the plant. In the leaves, the nanoparticles localize in the apoplastic space but also spontaneously reach the chloroplasts where photosynthetic activity takes place. Their CO2 loading-dependent fluorescence verifies that, in vivo, they maintain their abi l i t y to capture CO2 and can be therefore reloaded with atmospheric CO2 while in planta. Our results contribute to the development of a nanomaterials-based CO2-concentrating mechanism in plants t h a t can potentially increase photosynthetic efficiency and overall plants' CO2 storage

Synthesis of Carboxyl-EDOT as a Versatile Addition and Additive to PEDOT:PSS

Two steps synthesis of EDOT (3,4-ethylenedioxythiophene) derivate bearing a carboxylic acid group (carboxyl-EDOT) is presented. This reactive monomer has been copolymerized with EDOT to afford PEDOT copolymers. Thanks to the most common additives usually added to the PEDOT:PSS dispersion, ethylene glycol and 4-Dodecylbenzenesulfonic acid (DBSA), the carboxylic acid has been used to crosslink the material via esterification reactions. This result offers the possibility to produce a polymer network without adding any crosslinking agent. Furthermore, the short synthetic pathway of carboxyl-EDOT offers the possibility to incorporate new functionality either in EDOT monomer or in PEDOT materials with a reasonable chemical effort and background

Thiophene-based aldehyde derivatives for functionalizable & adhesive semiconducting polymers

The pursuit for novelty in the field of (bio)electronics demands for new and better performing (semi)conductive materials. Since the discovery of poly(3,4-ethylenedioxythiophene) (PEDOT)-the ubiquitous golden standard-many studies have focused on its applications, but only few on its structural modification and/or functionalization. This lack of structural variety strongly limit

Design and Morphological Investigation of High-χ Catechol-Containing Styrenic Block Copolymers

We report the synthesis of multifunctional block copolymers (BCPs) showing a high Flory–Huggins interaction parameter (χ), which enable sub-10 nm line-space structures for a low degree of polymerization (N). The high χ BCPs are based on a poly(3,4-dihydroxystyrene)–block-poly(4-trimethylsilylstyrene) (PDHS-b-PTMSS) architecture. The controlled synthesis of the PDHS-b-PTMSS precursors was performed using user-friendly sequential nitroxide mediated polymerization (NMP) of poly(3,4-diacetoxystyrene) and block-poly(4-trimethylsilylstyrene) (PDAS-b-PTMSS). Thereafter, acid-catalyzed deprotection of the acetoxy moieties produced a library of PDHS-b-PTMSS BCPs with molecular weights ranging from 2.1 to 44.5 kg/mol. Bulk lamellar and cylindrical structures with periodicities as small as 8 nm were revealed by small-angle X-ray scattering. Moreover, PDHS-b-PTMSS thin films were assembled using solvent vapor annealing to define 10 nm line-space patterns in favorable conditions, i.e., at 20 °C for 20 min. In summary, our work brings further knowledge to the BCP toolbox for next-generation nanomanufacturing needs

Multicolor photoluminescence from non-conjugated poly(3,4-dihydropyran) nanoparticles

In recent years, non-conjugated organic luminophores are receiving considerable interest from the scientific community, offering new conceptual basis for the development of alternative photoluminescence-based technologies. In this work, the polymerization of 3,4dihydropyran was exploited for the preparation of non-conjugated photoluminescent polymer nanoparticles. Remarkably, excitation-dependent multicolor emission ranging from blue to yellow 2 was observed both in solid and in solution. In contrast with similar materials, this behavior was not attributed to aggregation-induced emission, but rather to the presence of independent, noninteracting chromophores located on the polymer structure. Structural and optical characterization along with further chemical modifications suggest that the emission is related to the presence of acetal groups formed by ring-opening polymerization. In addition, it was shown that the removal of unsaturated structures could enhance the photoluminescence quantum yield of the polymer (QY) up to 0.20 (λex = 355 nm). This work provides a new type of non-conjugated organic luminophore with both high QY and multicolor emission

Radiothérapie à visée Curative dans les adénocarcinomes de prostate localisés survenant après 80 ans. Une étude du Rare Cancer Network

info:eu-repo/semantics/publishe

Thiophene-Based Trimers for In Vivo Electronic Functionalization of Tissues

Electronic materials that can self-organize in vivo and form functional components along the tissue of interest can result in a seamless integration of the bioelectronic interface. Previously, we presented in vivo polymerization of the conjugated oligomer ETE-S in plants, forming conductors along the plant structure. The EDOT-thiophene-EDOT trimer with a sulfonate side group polymerized due to the native enzymatic activity of the plant and integrated within the plant cell wall. Here, we present the synthesis of three different conjugated trimers based on thiophene and EDOT or purely EDOT trimers that are able to polymerize enzymatically in physiological pH in vitro as well as in vivo along the roots of living plants. We show that by modulating the backbone and the side chain, we can tune the electronic properties of the resulting polymers as well as their localization and penetration within the root. Our work paves the way for the rational design of electronic materials that can self-organize in vivo for spatially controlled electronic functionalization of living tissue.Funding Agencies|European UnionEuropean Union (EU) [800926]; MSCA-IF-2018 [838171]</p

Curative external beam radiotherapy in patients over 80 years of age with localized prostate cancer: A retrospective rare cancer network study

Purpose: To analyse tolerance and outcome of patients over 80 years of age who choose external beam radiation therapy to the prostate as a curative treatment. Methods and material: We evaluated acute and late side effects, biological DFS (bDFS) and actuarial survival as well as causes of death in relation to the clinical status including co-morbidity, PSA value, Gleason score and modalities of external radiotherapy in patients with localised prostate cancer >80 years of age. Results: From January 1990 to December 2000, 65 eligible cases (median age: 81) were treated by 12 different participating institutions in the Rare Cancer Network. Tumour stage was T1N0M0, T2N0M0 and T3N0M0 for 10, 40, and 15 patients, respectively. Median follow-up was 65 months (range 22-177). Five-year overall survival rate was 77% with a 5-year bDFS rate of 73%. The incidence of grade 3 early toxicity was 12% and 9% for urinary and digestive tract, respectively. Conclusions: Radiation therapy given with curative intent is well tolerated in this selected group of patients aged over 80 years with localised prostate cancer. Results in terms of survival do not suggest a deleterious impact of this treatment. Therefore the authors recommend that radiation therapy with curative intent should not be withheld in selected elderly patients with localised prostate cancer. © 2009 Elsevier Ireland Ltd. All rights reserved.SCOPUS: re.jinfo:eu-repo/semantics/publishe